bed material transport estimated from the virtual velocity of sediment this study evaluates the possibility of determining bed material transport using the virtual rate of travel of individual particles dimensions of the active layer of the streambed and porosity and density of streambed material magnetically tagged stones and scour indicators were employed in carnation creek british columbia to quantify transport rates observations cover flows up to 36 m3 s 1 0 081 transport rates ranging from 0 090 to 9 7 kg s 1 0 12 13 2 m3 h 1 display a relatively sensitive trend with maximum stream power as expected error analysis indicates that uncertainty in virtual velocity covers the majority of sample variance an evaluation of the two measurement techniques used to delineate active layer dimensions magnetically tagged stones and scour indicators indicates that they yield comparable depths widths and transport rates over the range of flows observed issues for further study are discussed 1998 john wiley sons ltd

transience and persistence in the depositional record of continental margins 1 continental shelves and coastal plains are large persistent depositional landforms which are stationary nonmigrating at their proximal ends and characterized by relatively steady long term growth in detail however their surface form and stratigraphic record is built of transient freely migrating landscape elements we derive the timescales of crossover from transient to persistent topographic forms using empirical scaling relations for mean sediment accumulation as a function of averaging time based upon tens of thousands of empirical measurements a stochastic noisy diffusion model with drift predicts all the gross features of the empirical data it satisfies first order goals of describing both the surface morphology and stratigraphic completeness of depositional systems the model crossover from noise dominated to drift dominated behavior corresponds to the empirical crossover from transport dominated autogenic transient behavior to accommodation dominated subsidence persistent behavior which begins at timescales of 102 103 years and is complete by scales of 104 105 years because the same long term scaling behavior emerges for off shelf environments it is not entirely explicable by steady subsidence fluctuations in sediment supply and routing probably have significant influence at short term transient scales the exponents of the scaling relations vary with environment particularly the prevalence of channeled sediment transport at very small scales modeling sediment transport as a diffusive process is inappropriate our results indicate that some of the timescales of interest for climate interpretation may fall within the transitional interval where neither accommodation nor transport processes are negligible and deconvolution is most challenging

postglacial topographic evolution of glaciated valleys a stochastic landscape evolution model the retreat of valley glaciers has a dramatic effect on the stability of glaciated valleys and exerts a prolonged influence on the subsequent fluvial sediment transport regime we have studied the evolution of an idealized glaciated valley during the period following retreat of ice using a numerical model the model incorporates a stochastic process to represent deepseated landsliding non linear diffusion to represent shallow landsliding and an approximation of the bagnold relation to represent fluvial sediment transport it was calibrated using field data from several recent surveys within british columbia canada we present ensemble model results and compare them with results from a deterministic linear diffusion model to show that explicit representation of large landslides is necessary to reproduce the morphology and channel network structure of a typical postglacial valley our model predicts a rapid rate of fluvial sediment transport following deglaciation with a subsequent gradual decline similar to that inferred for holocene time we also describe how changes in the model parameters affect the estimated magnitude and duration of the paraglacial sediment pulse

glacially induced organization of channel reach morphology in mountain streams 1 we examine the spatial distribution of channel reach morphologies in formerly glaciated mountain drainage basins of coastal british columbia canada using field and geographic information systems derived data we show that the local channel slope and the degree of colluvial alluvial coupling imposed by the glacial valley morphology dictate the spatial organization of channel types in particular the complex glacially induced channel long profile produces characteristic sequences of channel reaches that depart from the downstream succession colluvial boulder cascade step pool rapids riffle pool distinctive of simple unglaciated mountain streams typically the presence of one hanging valley in the river long profile produces and separates two full successions of channel types a headmost one characterized by an ephemeral seasonal hydrologic regime and a downstream one where water runoff is perennial we document that channel types are well separated in plots of slope versus shear stress area versus shear stress and slope versus relative roughness in agreement with these outcomes multivariate discriminant analyses coupled with principal component analysis of 98 study reaches yield a highly successful channel type classification when slope shear stress and relative roughness are considered success rates depending on whether or not boulder cascade reaches are pooled together with step pools are 88 and 75 respectively previous work in unglaciated settings has suggested that mountain channels have distinct bed morphology states that vary primarily with slope our study reveals that even in formerly glaciated valleys where slope is largely inherited from glacial times these distinct bed states exist and vary mostly with slope adding considerable strength to this empirical knowledge

geomorphometric assessment of spatial sediment connectivity in small alpine catchments abstract complex and rugged topography induces large variations in erosion and sediment delivery in the headwaters of alpine catchments an effective connection of hillslopes with the channel network results in highly efficient sediment transfer processes such as debris flows in contrast morphological conditions producing decoupling of hillslopes from channels e g glacial cirques may exclude large areas of the catchment from sediment delivery to its lower parts moreover an efficient connection between hillslopes and channel network does not always ensure an effective downstream transfer of sediment low slope channel reaches e g in hanging valleys cause sediment deposition which often results in changes of the sediment transport processes typically from debris flow to streamflow with low bedload and suspended load rates the availability of high resolution digital terrain models such as those derived from aerial lidar improves our capability to quantify the topographic controls on sediment connectivity a geomorphometric index based on the approach by borselli et al 2008 was developed and applied to assess spatial sediment connectivity in two small catchments of the italian alps featuring contrasting morphological characteristics the results of the geomorphometric analysis were checked against field evidences showing good performance and thus potential usefulness of the index

spatial distribution of sediment storage types and quantification of valley fill deposits in an alpine basin reintal bavarian alps germany spatial patterns of sediment storage types and associated volumes using a novel approach for quantifying valley fill deposits are presented for a small alpine catchment 17 km 2 in the bavarian alps the different sediment storage types were analysed with respect to geomorphic coupling and sediment flux activity the dominant landforms in the valley in terms of surface area were found to be talus slopes sheets and cones followed by rockfall deposits and alluvial fans and plains more than two thirds of the talus slopes are relict landforms completely decoupled from the geomorphic system notable sediment transport is limited to avalanche tracks debris flows and along floodplains sediment volumes were calculated using a combination of polynomial functions of cross sections seismic refraction and gis modelling a total of 66 seismic refraction profiles were carried out throughout the valley for a more precise determination of sediment thicknesses and to check the bedrock data generated from geomorphometric analysis we calculated the overall sediment volume of the valley fill deposits to be 0 07 km 3 this corresponds to a mean sediment thickness of 23 3 m the seismic refraction data showed that large floodplains and sedimentation areas which have been developed through damming effects from large rockfalls are in general characterised by shallow sediment thicknesses 20 m by contrast the thickness of several talus slopes is more than twice as much for some locations e g narrow sections of valley the polynomial generated cross sections resulted in overestimations of up to one order of magnitude whereas in sections with a moderate valley shape the modelled cross sections are in good accordance with the obtained seismic data for the quantification of valley fill deposits a combined application of bedrock data derived from polynomials and geophysical prospecting is highly recommended d 2003 elsevier b v all rights reserved

trends and controls of holocene floodplain sedimentation in the rhine catchment article i nfo holocene floodplain sedimentation in the rhine catchment is controlled by human and climate impacts intricate river behaviour modifies the fluvial response to the external impacts making cause effect analysis difficult especially on large spatial scales to better understand the relative importance and interdependencies of external and internal controls temporally resolved floodplain sedimentation rates are established using three different methods i floodplain storage studies on the trunk stream ii depth age analysis of overbank deposits from different parts of the catchment and iii cumulative frequency distributions of 14 c ages from floodplain deposits from various parts of the catchment the applied methodology strongly differs with the available temporal resolution and the size of the corresponding catchment all three methods show a strong increase in sedimentation rate for more recent periods that can be linked to increasing human impact evidences for climate impacts and intricate river behaviour are less clear and hindered by insufficient temporal resolution of the currently available data

changing hillslope and fluvial holocene sediment dynamics in a belgian loess catchment floodplain deposition is an essential part of the holocene sediment dynamics of many catchments and a thorough dating control of these floodplain deposits is therefore essential to understand the driving forces of these sediment dynamics in this paper we date floodplain and colluvial deposition in the belgian dijle catchment using accelerator mass spectrometric radiocarbon and optical stimulated luminescence dating relative mass accumulation curves for the holocene were constructed for three colluvial sites and 12 alluvial sites a database was constructed of all available radiocarbon ages of the catchment and this database was analysed using relative sediment mass accumulation rates and cumulative probability functions of ages and site specific sedimen tation curves cumulative probability functions of ages were split into different depositional environments representing stable phases and phases of accelerated clastic deposition the results indicate that there is an important variation between the different dated sites after an initial stable early and middle holocene phase with mainly peat growth in the floodplains clastic sedimentation rates increased from 4000 bc on this first phase was more pronounced and started somewhat earlier for colluvial deposits then for alluvial deposits the main part of the holocene deposits both in colluvial and alluvial valleys was deposited during the last 1 ka the sedimentation pattern of the individual dated sites and the catchment wide pattern indicate that land use changes are responsible for the main variations in the holocene sediment dynamics of this catchment while the field data do not provide indications for a climatological influence on the sediment dynamics copyright 2011 john wiley sons ltd

quantifying postglacial sediment storage at the mountain belt scale sediment storage is an often neglected term in sediment budgets despite being the crucial link between rates of erosion and sediment yield mountain belts in particular host large valley fills that modulate fluxes of water and sediment buffer the geomorphic coupling between hillslopes and river channels reduce local valley relief and protect bedrock from fluvial incision here we propose a region growing algorithm based on a slope gradient criterion to automatically extract areas of postglacial fluvial and lacustrine valley fills from digital topography at the mountain belt scale applying this method to the european alps we find that the size frequency relationship of 17 766 individual sediment storage units expressed by either area or volume follows a power law over four and five orders of magnitude with scaling exponents 1 77 and 1 71 respectively we show that 90 of the area covered by sediment storage is in the lower quartile of the mountain belt9s elevation and below the median local relief on average low gradient valley fill occupies 6 of the studied drainage basins this fraction increases with basin size likely reflecting the larger accommodation space of trunk valleys generated by multiple glacial interglacial cycles comparison with sediment storage mapped in the southern alps new zealand indicates that rates of uplift and precipitation control the extent and spatial distribution of sediment storage at the mountain belt scale

buffers barriers and blankets the dis connectivity of catchment scale sediment cascades abstract catchment configuration and the nature of connectivity within and between landscape compartments affect the operation of sediment cascades and geomorphic responses to disturbance events of differing magnitude and frequency this paper introduces the concept of landform impediments termed buffers barriers and blankets that impede sediment conveyance by limiting the connectivity between landscape compartments buffers restrict sediment delivery to channels barriers inhibit sediment movement along channels and blankets drape channel or floodplain surfaces affecting the accessibility of sediment to entrainment these features operate as a series of switches which turn on off processes of sediment delivery determining the effective catchment area at any given time using previously documented examples the role of these features in affecting the operation of sediment cascades in a low relief passive landscape setting such as the australian landmass is contrasted to examples from high relief uplifting settings in new zealand the australian examples are further explored by examining how changes to landscape connectivity brought about by human disturbance since european settlement have impacted upon landscape sensitivity and prospects for river recovery this approach to analysis of impediments to sediment conveyance is generic and can be applied in any environmental setting

the application of computational fluid dynamics to natural river channels three dimensional versus two dimensional approaches this paper addresses the recent trend in fluvial geomorphology towards using computational fluid dynamics to explore the adjustment between flow processes sediment transport and river channel morphology it aims to evaluate the extent to which three dimensional 3d models improve predictive ability and prediction utility compared to two dimensional 2d applications this is achieved through comparing the predictions of both 3d and 2d models with high quality field data identical boundary conditions obtained from a confluence within a gravel bed river system with high relative roughness are defined for each model evaluation of the 3d model suggests that there is a fundamental limitation upon model predictive ability due to problems of specifying topographic complexity however comparison with the 2d model shows that the 3d model has a higher predictive ability particularly if the 2d model is not corrected for the effects on flow structure of secondary circulation further the 3d model provides more reliable estimates of bed shear stress and other more useful information such as the three dimensional flow field important for mixing processes this suggests that there is significant merit in the move towards 3d models but that research is required to incorporate methods developed in other fields for dealing with boundary condition uncertainties

quantifying sediment storage in a high alpine valley turtmanntal switzerland the determination of sediment storage is a critical parameter in sediment budget analyses but in many sediment budget studies the quantification of magnitude and time scale of sediment storage is still the weakest part and often relies on crude estimations only especially in large drainage basins 100 km2 we present a new approach to storage quantification in a meso scale alpine catchment of the swiss alps turtmann valley 110 km2 the quantification of depositional volumes was performed by combining geophysical surveys and geographic information system gis modelling techniques mean thickness values of each landform type calculated from these data was used to estimate the sediment volume in the hanging valleys and the trough slopes sediment volume of the remaining subsystems was determined by modelling an assumed parabolic bedrock surface using digital elevation model dem data a total sediment volume of 781 3 106 1005 7 106 m3 is deposited in the turtmann valley over 60 of this volume is stored in the 13 hanging valleys moraine landforms contain over 60 of the deposits in the hanging valleys followed by sediment stored on slopes 20 and rock glaciers 15 for the first time a detailed quantification of different storage types was achieved in a catchment of this size sediment volumes have been used to calculate mean denudation rates for the different processes ranging from 0 1 to 2 6 mm a based on a time span of 10 ka as the quantification approach includes a number of assumptions and various sources of error the values given represent the order of magnitude of sediment storage that has to be expected in a catchment of this size copyright 2009 john wiley sons ltd

timing and significance of talus slope reworking trotternish skye northwest scotland exposures through the upper rectilinear or near rectilinear segment of vegetated relict talus slopes at the foot of the trotternish escarpment northern skye exhibit stacked debris flow diamictons intercalated with surface wash horizons and occasional buried organic palaeosols thus indicating a long history of reworking at this site radiocarbon dates for the tops of buried palaeosols indicate that reworking of sediment locally predates 5 9 5 6 cal ka bp and has been intermittently active throughout the late holocene broad coincidences of timing are evident for the onset of reworking of different sectors of the talus slope at c 5 9 5 6 cal ka bp c 2 3 1 7 cal ka bp and c 0 7 0 5 cal ka bp that may represent more widespread reworking analysis of subfossil palynomorphs within some buried palaeosols suggests that most reworking postdates the main period of local anthropogenic woodland clearance dated to the mid holocene buried palaeosols examined contain no evidence of local burning of veg

a temporarily changing holocene sediment budget for a loess covered catchment central belgium abstract this study presents a holocene sediment budget for the nethen catchment a typical river catchment 55 km 2 in the belgian loess belt soil erosion and hillslope sediment storage are quantified by extrapolating detailed data obtained from soil profile truncation studies in three representative zero order sub catchments floodplain sediment storage is estimated by augerings along several transects across the main river and some of its tributaries the sediment budget shows that ca 38 of the soil eroded during the holocene is redeposited as colluvium on hillslopes and in dry valley bottoms another 23 of the eroded sediment is now stored as alluvium in the floodplain the remaining 39 or 21 10 6 mg is exported from the catchment dating of both colluvial and alluvial sediment deposits reveals that sediment dynamics between the hillslopes the dry valley bottoms and the floodplain behave highly non linearly before 500 bc sediment delivery from the hillslopes to the river channels was near maximum however since the onset of significant agriculture in the late bronze age early iron age increased rates of soil erosion are only reflected in the colluvium but not in the floodplain resulting in very low hillslope sediment delivery ratios from the medieval period onwards soil erosion increased even further mainly as a result of a further increase in agricultural land use but now also accelerated floodplain sedimentation took place due to an improved slope channel coupling and the management of floodplains

changes in sediment flux and storage within a fluvial system some examples from the rhine catchment the rhine river system can look back on a long history of human impact whereas significant anthropogenic changes to the river channel started only 200 years ago the impacts of land use have been felt for more than 7500 years here we review results from several case studies and show how land use change and climate impacts have transformed the fluvial system we focus on changes in sediment delivery pathways and slope channel coupling and show that these vary in time and depend on the magnitude of a rainfall event these changes must be accounted for when trying to use sediments as archives of land use change and climatic impacts on fluvial systems for example human impact is recorded in slope deposits only as long as rainfall intensity and runoff generation do not exceed the threshold for gullying similarly climatic impacts are only recorded in alluvium when both the landscape is rendered sensitive by human activities e g deforestation and rainfall thresholds for gullying are exceeded copyright 2003 john wiley sons ltd

coarse sediment connectivity in river channel systems a conceptual framework and methodology identification of coarse sediment connectivity down river channel systems is important for understanding the linkages between river reaches the influence of sediment sources on channel morphology and the mechanisms and liability to propagation of morphological change a conceptual framework is developed in which several types and degrees of connectivity are proposed it is hypothesised that sediment connectivity varies with sediment sources and with stream competence to transport the coarse fractions a method of identifying the status of reaches is developed based on field mapping of morphology and sedimentology the analysis is exemplified by two channels one an ephemeral channel in se spain the other a perennial channel in nw england questions arise over whether reaches that lack channel stores transfer coarse sediment three scenarios are suggested 1 lack of flux due to lack of competence of the reach 2 flushing through of sediment due to high competence and 3 potential transport of coarse sediment but exhaustion or lack of availability changes in connectivity will take place over different time scales depending on the nature of exchange and time scales of storage short term variations in connectivity can be identified by repeated mapping

using sediment travel distance to estimate medium term erosion rates a 16 year record fine grained 80 m magnetite was introduced onto a semi arid grassland hillslope in 1992 as part of a set of rainfall simulation experiments using measurements of magnetic susceptibility the median distance travelled by these magnetite grains during subsequent natural runoff events in the 16 year period up to 2008 was estimated coupling this estimate to direct measurements of sediment flux obtained during the rainfall simulation experiments has enabled estimation of the erosion rate over this period the estimated average erosion rate of between 2 61 10 2 and 4 36 10 2 kg m 1 year 1 is equivalent to a rate of ground lowering between 0 020 and 0 033 mm year 1 this estimate is consistent with in the sense of being less than an estimate of total sediment detachment over the same period the rate of erosion measured using this travel distance approach is an order of magnitude less that obtained from a study based on 137cs in a nearby catchment and compatible with the longevity of continents copyright 2010 john wiley sons ltd

exhaustion and steady state models for predicting landslide hazards in the canadian rocky mountains abstract the temporal distribution of landslides can be evaluated by steady state and exhaustion models the probability of landsliding remains constant through time in the steady state model but the probability decreases in the exhaustion model as more slopes fail rock sliding down bedding surfaces on overdip slopes exhausts hazardous sites to leave stable dipslope landforms in kananaskis country in the canadian rocky mountains the distribution of rock slides in this area can be better explained by the exhaustion model than by the steady state model

fluvial clastic sediment yield in canada scaled analysis this report presents a set of maps of regional fluvial sediment yield in canada based mainly on the water survey of canada archive of riverine suspended sediment observations regional scaling rel

geomorphic coupling and sediment connectivity in an alpine catchment exploring sediment cascades using graph theory through their relevance for sediment budgets and the sensitivity of geomorphic systems geomorphic coupling and sediment connectivity represent important topics in geomorphology since the introduction of the systems perspective to physical geography by chorley and kennedy 1971 a catchment has been perceived as consisting of landscape elements e g landforms subcatchments that are coupled by geomorphic processes through sediment transport in this study we present a novel application of mathematical graph theory to explore the network structure of coarse sediment pathways in a central alpine catchment numerical simulation models for rockfall debris flows and hillslope and channel fluvial processes are used to establish a spatially explicit graph model of sediment sources pathways and sinks the raster cells of a digital elevation model form the nodes of this graph and simulated sediment trajectories represent the corresponding edges model results are validated by visual comparison with the field situation and aerial photos the interaction of sediment pathways i e where the deposits of a geomorphic process form the sources of another process forms sediment cascades represented by paths a succession of edges in the graph model we show how this graph can be used to explore upslope contributing area and downslope source to sink functional connectivity by analysing its nodes edges and paths the analysis of the spatial distribution composition and frequency of sediment cascades yields information on the relative importance of geomorphic processes and their interaction however regardless of their transport capacity in the study area the analysis stresses the importance of mass movements and their interaction e g the linkage of large rockfall source areas to debris flows that potentially enter the channel network moreover it is shown that only a small percentage of the study area is coupled to the channel network which itself is longitudinally disconnected by natural and anthropogenic barriers besides the case study we discuss the methodological framework and alternatives for node and edge representations of graph models in geomorphology we conclude that graph theory provides an excellent methodological framework for the analysis of geomorphic systems especially for the exploration of quantitative approaches towards sediment connectivity

catchment scale dis connectivity in sediment flux in the upper hunter catchment new south wales australia abstract dis connectivity within and between landscape compartments affects the extent and rate of transfer of energy and matter through catchments various landforms may impede sediment conveyance in a river system whether laterally to the channel termed buffers or longitudinally along the channel itself termed barriers a generic approach to analysis of landscape dis connectivity using slope threshold analysis in gis tied to air photograph interpretation and field mapping of buffers and barriers is tested in the upper hunter catchment australia under simulated conditions effective catchment area which is a measure of the proportion of a catchment that has the potential to contribute sediment to the channel network varies from 73 to just 3 of the total catchment area for differing subcatchments in the upper hunter this variability can be explained by the spatial distribution and assemblage of buffers and barriers in each subcatchment multiple forms of disconnectivity are evident in some subcatchments such that when one buffer or barrier is breached other features still impede sediment transfer within the system the importance of the position of buffers and barriers within any given subcatchment is emphasised spatial variability in valley width exerts a critical control on catchment connectivity with more efficient sediment conveyance in narrow valleys relative to wider valleys characterised by piedmonts terraces fans and extensive floodplains in which conveyance is impeded this variability reflects the landscape history and geological setting of each subcatchment the framework developed in this paper can be used to assess the impact of natural or human induced buffers and barriers on catchment scale sediment flux in any landscape setting providing a physical template atop which other biogeochemical fluxes could be examined

some methodological developments in the analysis of sediment transport processes using age distribution of floodplain deposits abstract floodplain areas are primary storage sites for river sediment in the saru river ages of floodplain surfaces were examined by tree ring analysis and vertical and horizontal configurations of floodplain deposits were measured by field and aerial photo surveying a flood in 1992 provided a good opportunity to examine depositional and erosional processes of floodplain sediment before and after the flood predominant disturbances were observed in the unconstrained wide reaches where floodplains develop this event indicated that eroded areas of floodplain deposits in each age class linearly increased with sediment volume and that the proportion of the total area eroded decreased exponentially with increase in the age of sediment we constructed basic equations expressing continuity of age distribution in order to analyze river sedimentation in a time series according to the results of the 1992 flood the floodplain disturbance rates determined by this analysis showed similar temporal changes with sediment transport rates monitored at the iwachishi reservoir a sharp increase in sediment discharge was seen after 1962 associated with the historical maximum rainfall in the temporal analysis of floodplain sediment the time series approach presented here is useful for evaluating the speed of sediment waves and the cumulative impact of sedimentation in a river basin

the sediment delivery problem abstract the linking of on site rates of erosion and soil loss within a drainage basin to the sediment yield at the basin outlet and improved knowledge and representation of the associated processes of sediment delivery represent a major research need within the field of erosion and sedimentation and also an important scale problem in drainage basin studies this paper reviews the limitations of the sediment delivery ratio concept by considering the problems of temporal and spatial lumping and its blackbox nature some recent advances in our understanding of the sediment delivery system and its modelling are described and the lack of detailed empirical investigations is highlighted the significance of recent concern for the role of sediments in the transport of nutrients and contaminants to sediment delivery studies is introduced and the need for further work in this field is emphasised

the recent history of erosion and sedimentation on the southern tablelands of southeastern australia sediment flux dominated by channel incision abstract as in other regions colonised from europe within the last few centuries australia s vegetation and soils have been dramatically changed by clearing cropping and grazing in southeastern australia particularly on the southern tablelands the impacts of european settlement are clearly manifested by channel incision by using stratigraphic and documentary evidence in conjunction with aerial photographs sediment budgets for the post settlement period have been constructed to define the fluxes and stores of sediment for each of the major geomorphic components of the 136 km2 catchment of jerrabomberra creek near canberra using these budgets and some plausible assumptions it has been possible to approximate the history of both the sediment delivery ratio and sediment yield for this catchment while the quantities estimated in this analysis are approximations the trends through time are credible sediment yield increased rapidly to a peak after european settlement and has returned to a level between the peak and the pre european value the delivery ratio has followed a similar trend the most general conclusion to emerge is that in this landscape both the total sediment flux and the sediment yield of the catchment have been dominated by channel erosion this result is contrary to the findings in many parts of the world where sheet and rill erosion dominates the fluxes the soil conservation implication of these results is clear to control off site effects of erosion the focus must be on the channels

establishing a holocene sediment budget for the river dijle abstract a holocene sediment budget was constructed for the 758 km 2 dijle catchment in the belgian loess belt in order to understand long term sediment dynamics hillslope sediment redistribution was calculated using soil profile information from 809 soil augerings which was extrapolated to the entire catchment using morphometric classes as large parts of the forests within the catchment prove to have undergone little or no erosion since medieval times a correction was applied for the presence of forests total holocene erosion amounts 817 66 mt for the catchment of which 327 34 mt was deposited as colluvium this corresponds with a net holocene soil erosion rate of 10 8 0 8 10 3 mg ha 1 for the entire dijle catchment alluvial deposits were studied through 187 augerings spread over 17 cross valley transects the total alluvial sediment deposition equals 352 11 mt or 42 of total eroded sediment mass results indicate that at the scale of a medium sized catchment the colluvial sediment sink is as important as the alluvial sediment sink and should not be neglected as a result the estimation of erosion through alluvial storage and sediment export would yield large errors dating of sediment units show an important increase in alluvial deposition from medieval times onwards indicating the important influence of agricultural activities that developed from that period mean sediment export rates from the catchment for the last 1000 1200 years range between 0 8 and 1 3 mg ha 1 a 1 and are consistent with present suspended sediment measurements in the dijle erosion for agricultural land for this period is 9 2 2 2 mg ha 1 a 1 sediment budgets for the various tributary catchments provide an insight in the sources and sinks of sediment at different scales within the catchment

from gullies to mountain belts a review of sediment budgets at various scales this paper reviews the state of the art in the concept as well as in the application of sediment budgets in sedimentary research sediments are a product of mass dispersal at the earth surface and take part in global cycles sediment budgets aim at quantifying this mass transfer based on the principle of mass conservation and are the key to determine ancient fluxes of solid matter at the earth surface this involves fundamental questions about the interplay of uplift climate and denudation in mountain belts and transfer of sediments from the continents to the oceans as well as applied issues such as soil and gully erosion reservoir siltation and coastal protection first after introducing basic concepts relevant scales and methodologies the different components of quaternary routing systems from erosion in headwaters river systems glacial and paraglacial systems lakes deltas estuaries coasts shelves epicontinental seas and deep sea fans are discussed in terms of their sediment budget most suitable are sedimentologically closed or semi closed depositional environments e g alluvial fans lakes deltas and deep sea fans in a second step the dynamics of passive active and collisional tectonic settings and sediment budgets in related sedimentary basins are explored and new concepts of sediment portioning at large geodynamic scales are introduced ancient routing systems are more or less incomplete and may be intensively fragmented or destroyed in active tectonic settings in terms of sedimentary basin types rifts intracontinental and epicontinental settings are preferred objects of sediment budgets because of their persistence and relatively simple overall sedimentary architecture however closing basins such as foreland forearc retroarc piggy back and wedge top basins may provide excellent snapshots of orogenic sediment fluxes in a third step the large long lived routing systems of the amazon the ganges brahmaputra and the rhine are reviewed for each system estimates of either sediment volumes mass or sediment fluxes of continental and marine subsystems have been compiled in order to receive a complete routing in terms of mass conservation for specific time periods since the late glacial maximum as well as the cenozoic following lessons can be taken from these case studies i depositional centers and fluxes show strong shifts in space and time and call for caution when simply looking at subsystems ii the response times of these large systems are within the milankovich time interval thus lower than predicted from diffusion models iii cyclic routing of sediments in continental basins is much more dominated by climate human control than by eustacy and iv at long time scales ultimate sinks win over intermittent storage it is concluded from this review that the quantitative understanding of global sediment cycling over historic and geologic time and its response to allogenic forcing is still in its infancy and further research is needed towards a holistic view of sediment routing systems at various temporal and spatial scales and their coupling with global biogeochemical cycles this includes i to better determine response times of large routing systems by linking quaternary with cenozoic sediment budgets and continental with marine sub systems ii to combine advanced provenance techniques with sediment budgets in order to reconstruct ancient systems iii to study sediment partitioning at the basin scale iv to reconcile continental supply dominated sequence stratigraphy with the eustatic dominated marine concept and iv to account for non actualism of ancient systems with respect to their erosion and transport mode in particular during glaciations and pronounced arid intervals glacial and eolian sediment routing may cross over hydrologic boundaries of drainage basins thus challenging the principle of mass conservation

holocene floodplain sediment storage and hillslope erosion within the rhine catchment the response of fluvial systems to land use and climate change varies depending on catchment size while forcing response mechanisms of small catchments are reasonably well understood the response of larger drainage basins is less clear in particular the impact of land use and climate change on the rhine system is poorly understood because of the catchment size 185 000 km 2 and the long history of human cultivation which started approximately 7500 years ago a sediment budget is calculated to specify the amount of alluvial sediment that was deposited during the holocene and to estimate long term soil erosion rates the results suggest that 599 14 10 9 t of holocene alluvial sediment is stored in the non alpine part of the rhine catchment south and central germany eastern france the netherlands about 50 of holocene alluvial sediment is deposited along the trunk valley and the delta upper rhine lower rhine coastal plain while the rest is stored along the tributary valleys the floodplain sediment storage corresponds to a mean erosion rate of 0 559 0 16 t ha per yr 38 59 10 7 mm kyr across the rhine catchment outside the alps this holocene averaged estimate amounts for sediments that were delivered to the channel network and is at the lower limit of erosion rates from other studies of different methodology

sediment budget for five millennia of tillage in the rockenberg catchment wetterau loess basin germany abstract the long cultivated loess landscapes of central europe provide the opportunity to explore the long term perspective on the evolution human natural sediment systems that are driven by human caused soil erosion processes a balance of spatially non uniform sediment production sedimentation and delivery was developed to highlight the quantitative dimensions and functioning of anthropogenic sediment redistribution in an undulating loess catchment of temperate europe the presented long term perspective relies on analysing pedostratigraphic and lithostratigraphic field data from 728 corings across 10 km 2 gis based data processing and the analysis of data uncertainty for a period of 5000 years of tillage anthropogenic sediment production equals 9425 t ha 1 of which 62 still reside as colluvial sediment on the catchment s hillsides the valley floors fulfil a sediment conveyor function through transporting 77 of the sediment received from the hillsides whole catchment yield to the contiguous higher order valley is 29 of the amount of anthropogenic sediment production the average catchment scale depth of soil truncation is 0 64 m while the remaining anthropogenic sediment cover has an average thickness of 0 46 m effective surface denudation 0 18 m the long term integral net erosion rate is 0 5 t ha 1 a 1 because of extensive sediment retention on hillsides the inherited human imprint on the soilscape eventually can be judged as beneficial rather than detrimental the ubiquitous cover of humic colluvia generally is more suitable for intense cultivation than pristine pedostratigraphies the sediment budget although build from a historic perspective also provides a plausible reference for realistic objectives of managing the soil erosion problem in human natural sediment systems

cosmogenic nuclide budgeting of floodplain sediment transfer abstract cosmogenic nuclides produced in quartz may either decay or accumulate while sediment is moved through a river basin a change in nuclide concentration resulting from storage in a floodplain is potentially important in large drainage basins in which sediment is prone to repeated burial and remobilization as a river migrates through its floodplain we have modeled depth and time dependent cosmogenic nuclide concentration changes for 10 be 26 al and 14 c during sediment storage and mixing in various active floodplain settings ranging from confined shallow rivers with small floodplains to foreland basin scale floodplains traversed by deep rivers floodplain storage time estimated from channel migration rates ranges from 0 4 kyr for the beni river basin bolivia to 7 kyr for the amazon river basin while floodplain storage depth estimated from channel depth ranges from 1 to 25 m for all modeled active floodplain settings the long lived nuclides 10 be and 26 al show neither significant increase in nuclide concentration from irradiation nor decrease from decay we predict a hypothetical response time after which changes in 10 be or 26 al concentrations become analytically resolvable this interval ranges from 0 07 to 2 myr and exceeds in all cases the typical residence time of sediment in a floodplain due to the much shorter half life of 14 c nuclide concentrations modeled for the in situ produced variety of this nuclide are however sensitive to floodplain storage on residence times of the cosmogenic nuclide composition of old deposits in currently inactive floodplains that have been isolated for periods of millions of years from the river that once deposited them is predicted to either increase or decrease in 10 be and 26 al concentration depending on the depositional depth these conditions can be evaluated using the 26 al 10 be ratio that readily discloses the depth and duration of storage we illustrate these models with examples from the amazon basin as predicted modern bedload collected from an amazon tributary the bolivian beni river shows no systematic change in nuclide concentration as sediment is moved through 500 km of floodplain by river meandering in contrast in the central amazon floodplain currently untouched by the modern river system low 26 al 10 be ratios account for minimum burial depths of 5 to 10 m for a duration of 5 myr the important result of this analysis is that in all likely cases of active floodplains cosmogenic 10 be and 26 al concentrations remain virtually unchanged over the interval sediment usually spends in the basin thus spatially averaged denudation rates of the sediment producing area can be inferred throughout the entire basin provided that nuclide production rates are scaled for the altitudes of the sediment producing area only because floodplain storage does not modify nuclide concentrations introduced from the sediment source area

sensitivity of west and central european river systems to environmental changes during the holocene a review abstract sediment deposition in floodplains is an essential part of the sediment dynamics of a catchment these sediment dynamics can vary largely on a holocene time scale under the influence of driving forces such as land use and climatic variations in this paper we review the holocene floodplain sediment deposition history of rivers in west and central europe with special attention to the influence of climate and land use variability during the early holocene preboreal to atlantic period most floodplains were rather stable with limited floodplain aggradation after this initial phase of relative stability sedimentation rates increase during the middle and late holocene with often the most important deposition phase during the last 1000 to 2000 a the start of the increase in sedimentation varies spatially with an earlier start in the west france germany then in the east poland belarus ukraine while there are also local differences between regions which are settled early e g loess regions compared to later settled regions the sedimentation history of most floodplains can be linked to the local land use history while influence of climatic variations on floodplain aggradation is often reported to be of minor importance processes related to bedload are often reported to be more influenced by climatic events relationships between the driving forces and the sediment history are mainly based on synchronicity and there is seldom proof for a direct causal relationship future research should focus on a system based approach integrating the floodplain deposition in the entire sediment dynamics which includes also erosion colluvial deposition and export main research questions that need further attention include integration of system based concepts like landscape connectivity and buffering effects and also the assessment of the individual contribution of land use changes and climatologic variations on the sediment dynamics detailed sediment budget studies combined with modeling studies can make an important contribution to the understanding of floodplain sediment dynamics

sediment residence time and connectivity in non equilibrium and transient geomorphic systems abstract growing empirical evidence shows that many geomorphic systems are in transient state or out of equilibrium with respect to the external driving forces the transient state is often related to the dis connectivity of the many constituent parts of geomorphic systems as a result of sediment storage along the sediment flow path from its source to the final sink the response time of geomorphic systems to external changes is thus dependent on the residence time of sediment in various storage compartments here i present a mathematical concept based on reservoir theory to model residence time of sediment using millennial scale sediment budgets the framework sheds light on the limitation of the sediment delivery ratio which is often used as a measure of sediment connectivity in geomorphic systems and provides analytical information on process type pace of sediment flux and connectivity of storage compartments along the sediment cascade the application of the reservoir theory to geomorphic systems under agricultural land use shows that sediment delivery ratios are linked to the virtual velocity of the eroded sediment the time since the onset of agricultural land use and the size of the studied basins with respect to the temporal evolution of sediment storages that temporarily remove sediment from the conveyor belt the framework aims to estimate the sediment residence time in storages which is linked to the effective time scale of disconnectivity reanalysis of a long term empirical sediment budget from central europe reveals that the response to agricultural land use which started 5000 years bp is mainly buffered by the long residence time of sediment on hillslopes in the order of 10 3 years which results in a delayed floodplain aggradation furthermore the framework was applied to paraglacial mountain systems that inherit striking evidences of pleistocene glacial erosion and still recover from the change from glacial to interglacial conditions as a consequence of the reduced lateral and longitudinal connectivity i show that paraglacial response times of sediment flux in mountain headwater in the canadian rocky mountains range in the order of 100 400 ka the results indicate that response times at the transition from glacial to interglacial conditions are much longer than the return interval of the major glaciations causing a transient behavior of mountain headwater basins during interglacial periods the presented reanalysis of millennial scale sediment budgets of agricultural and mountain geosystems provides an integrative framework to link paleo environmental reconstructions and the connectivity of transient geomorphic system to external changes

post collisional sediment budget history of the alps tectonic versus climatic control based on the sediment budget of the eastern swiss and western alps since the oligocene the regional tectonic evolution has been identified as the dominant factor it is superimposed on the influence of both regional and global climate change and global sea level change during late pliocene and pleistocene times climate became the dominant factor because of cyclic glaciations the early post collisional history of the alps is characterized by a doubling of sediment discharge rates around the rupelian chattian boundary this increase is attributed to isostatic re adjustment either after large scale thermal reorganization of the lithosphere related to slab break off or to crustal thickening as continental crust became subducted from middle oligocene to late miocene times the overall trend of sediment discharge rates in the entire alps was modified only during relatively short lived phases these are characterized by an increase in aquitanian ca 23 21 ma and late burdigalian times ca 18 16 4 ma and a decrease in early to middle burdigalian 21 19 ma and langhian to serravalian times 16 4 12 ma an important still ongoing period of uplift reflected by rapidly increasing sediment discharge rates started in latest miocene times in the swiss and western alps and affected the eastern alps some 2 million years later the reason for this uplift is not clear but deep seated lithospheric processes appear to be likely

soil erosion and sediment deposition in the belgian oess belt during the holocene establishing a sediment budget for a small agricultural catchment a method to establish a holocene sediment budget for a 103 ha agricultural catchment representative for the belgian loess belt is presented soil erosion and sediment deposition were determined based on 185 coring locations and a large excavation in the valley bottom results were integrated in a gis and interpolation techniques applied to derive spatial patterns of erosion and sedimentation total soil erosion sediment deposition and sediment export were calculated and the results show that volumes are highly dependent on the interpolation technique used sediment delivery ratios between 20 and 42 are derived and are consistent with data reported in previous studies this clearly shows that the majority of the sediments produced during the holocene have been stored near their source area and have not been delivered to the downstream rivers the spatial distribution of soil erosion and sediment deposition within the catchment is strongly dependent on slope gradient and position within the catchment which suggests that since human impact began topography has been the main factor determining long term soil erosion and sedimentation

scale linkage and contingency effects of field scale and hillslope scale controls of long term soil erosion anthropogeomorphic sediment flux in agricultural loess watersheds of southern germany abstract agricultural landscapes with a millennial scale history of cultivation are common in many loess areas of central europe over time patterns of erosion and sedimentation have been continually modified via the variable imposition of anthropogenic discontinuities and linkages on fragmented hillslope sediment cascades which eventually caused the complicated soilscape pattern these field records challenge topographically oriented models of hillslope erosion and simple predictions of longer term change of spatial soilscape by cultivation activities a thorough understanding how soilscape patterns form in the long term however is essential to develop spatial concepts of the sediment budget particularly for the spatial modeling of anthropogenic hillslope sediment flux using gis in this study i used extensive datasets of anthropogenic soil truncation and burial in a typical undulating loess watershed in southern germany 10 km2 wetterau basin n of frankfurt a m spatial soilscape properties and historic sediment flux as caused by cultivation over seven millennia were evaluated by these data the soilscape pattern on the low gradient hillslopes of the study area was found to be marked by a statistical near random pattern of varying depth thickness of truncation and overthickened burial moreover it was shown that truncation and burial had developed independently from each other and did not correlate with either hillslope gradient or downslope curvature hence in the field any combination of few nearly preserved severely truncated or completely removed soil profiles with either no some or a thick sediment cover is present thereby lacking an obvious spatial pattern here i suggest putting long term change of the soilscape into a contextual anthropogeomorphic systems perspective that accommodates components of human induced soil erosion operating at different spatial scales to interpret the longer term spatial consequences at the hillslope system level in the study area system scale linkages are marked by the spatial intersection of a finer scaled managed field system with a broader hillslope scale framework of natural erosion controls in the low gradient study area field borders exert control over the spatial reference of soil erosion and sedimentation sites over time this brought about a growing historical and spatial contingency change to the soilscape because of arbitrary spatial changes of the field system which are inherent in its socio agricultural maintenance thus the very low gradient and low erosivity setting of the study area have singled out the agency of human induced spatial and connectivity controls and contingency for long term spatial hillslope sediment flux although these findings may be less true for different settings they allow for deriving a generic conceptual model of the linkages between natural and anthropogenic subsystems to interpret the effects of long term human induced sediment flux accordingly the resulting balance between on hillslope net storage and net delivery to streams is scaling with basic physiographic properties of erosivity and sedimentation as well as the degree of anthropogenic hillslope fragmentation for loess areas in europe variable fields are fundamental anthropogeomorphic units that determine appropriate system scaling for historic sediment flux analysis and constrain retrodiction and prediction of changing fluxes at a point and a time at watershed scales methodical implications address adequate sampling strategies to record soilscape change as a result of which a critical review of the applicability of the catena concept to long cultivated hillslopes in central europe was included finally the suggested refined generic model of long term human controlled sediment flux involves a number of research opportunities particularly for linking modeling approaches to long term field records of cultivation related change in the soilscape

from sedimentary records to sediment budgets multiple approaches to catchment sediment flux this paper reviews the traditional approach to sediment budget studies in geomorphology new approaches and more specifically the potential impact of new methodological advances each component of the budget is discussed including the spatial and volumetric estimations of erosion deposition and storage and the precision and accuracy of flux rate estimation examples are used from recent work in germany the netherlands and the uk and include the pedogenic approach to erosion estimation remote sensing lidar geophysics and sediment based dating techniques for flux rate estimation the precision and accuracy of catchment sediment flux estimates based upon sediment storage is not only dependant upon volumetric accuracy but also on the precision and accuracy of sediment dating in this area there has been a revolution with direct sediment dating techniques tl osl esr freeing budget studies from the constraints and biases of radiocarbon of particular importance is the use of cosmogenic nuclides for dating but which can also be used to derive long term erosion rates but only using a steady state assumption finally a tentative initial application of the sediment budget approach to pleistocene terrace staircase in unglaciated basins is discussed it is argued that only now do we have the techniques available to be able to produce accurate sediment budget estimations at spatial scales greater than that of zero order basins and over time periods greater than that covered by direct observations

establishing sediment budgets for two small lowland agricultural catchments in the uk sediment budgets have been established for two small 4 km2 lowland agricultural catchments by using 137cs measurements sediment source fingerprinting and more traditional monitoring techniques to quantify the individual components of the budget the gross and net erosion rates for the fields on the catchment slopes were estimated using 137cs measurements within selected fields which encompassed a representative range of slope angles slope lengths and land use these estimates were extrapolated over the entire catchment using a simple topographically driven soil erosion model terrain based gis tbgis superimposed on a dem to derive catchment average gross and net erosion rates suspended sediment yields were measured at the catchment outlets and sediment source fingerprinting techniques were used to establish the relative contributions from the catchment surface subsurface tile drains and eroding channel banks to the sediment yields in channel and wetland storage were quantified using both direct measurements and 137cs measurements the sediment budgets established for the catchments highlighted the importance of subsurface tile drains as a pathway for sediment transfer accounting for ca 60 and 30 of the sediment output from the two catchments erosion from channel banks contributed ca 10 and 6 of the sediment output from the two catchments although the suspended sediment yields from these catchments were considered high by uk standards ca 90 t km 2 year 1 the sediment delivery ratios ranged between 14 and 27 indicating that a major proportion of the mobilised sediment was stored within the catchments in field and field to channel storage were shown to be of similar magnitude but storage of sediment in the channel system and associated wetlands was relatively small representing 5 of the annual suspended sediment yield

carbon burial in soil sediments from holocene agricultural erosion central europe 1 natural and human induced erosion supplies high amounts of soil organic carbon oc to terrestrial drainage networks yet oc fluxes in rivers were considered in global budgets only recently modern estimates of annual carbon burial in inland river sediments of 0 6 gt c or 22 of c transferred from terrestrial ecosystems to river channels consider only lakes and reservoirs and disregard any long term carbon burial in hillslope or floodplain sediments here we present the first assessment of sediment bound oc storage in central europe from a synthesis of 1500 holocene hillslope and floodplain sedimentary archives we show that sediment storage increases with drainage basin size due to more extensive floodplains in larger river basins however hillslopes retain hitherto unrecognized high amounts of eroded soils at the scale of large river basins such that average agricultural erosion rates during the holocene would have been at least twice as high as reported previously this anthropogenic hillslope sediment storage exceeds floodplain storage in drainage basins 105 km2 challenging the notion that floodplains are the dominant sedimentary sinks in terms of carbon burial oc concentrations in floodplains exceed those on hillslopes and net oc accumulation rates in floodplains 0 7 0 2 g c m 2a 1 surpass those on hillslopes 0 4 0 1 g c m 2a 1 over the last 7500 years we conclude that carbon burial in floodplains and on hillslopes in central europe exceeds terrestrial carbon storage in lakes and reservoirs by at least 2 orders of magnitude and should thus be considered in continental carbon budgets

channel reach morphology in mountain drainage basins a classification of channel reach morphology in mountain drainage basins synthesizes stream morphologies into seven distinct reach types colluvial bedrock and five alluvial channel types cascade step pool plane bed pool rime and dune ripple coupling reach level channel processes with the spatial arrangement of reach morphologies their links to hillslope processes and external forcing by confinement ripar ian vegetation and woody debris defines a process based framework within which to assess channel condition and response potential in mountain drainage basins field investigations demonstrate character istic slope grain size shear stress and roughness ranges for different reach types observations consistent with our hypothesis that alluvial channel morphologies reflect specific roughness configurations ad justed to the relative magnitudes of sediment supply and transport ca pacity steep alluvial channels cascade and step pool have high ratios of transport capacity to sediment supply and are resilient to changes in discharge and sediment supply whereas low gradient alluvial channels pool rime and dune ripple have lower transport capacity to supply ra tios and thus exhibit significant and prolonged response to changes in sediment supply and discharge general differences in the ratio of transport capacity to supply between channel types allow aggregation of reaches into source transport and response segments the spatial distribution of which provides a watershed level conceptual model linking reach morphology and channel processes these two scales of channel network classification define a framework within which to in vestigate spatial and temporal patterns of channel response in moun tain drainage basins

holocene and modern sediment budgets for the ganges brahmaputra river system evidence for highstand dispersal to flood plain shelf and deep sea depocenters the partitioning of fluvial sediment load across continental margins is an important control on strata formation and sequence development however few quantitative sediment budgets that encompass entire dispersal systems exist for the ganges brahmaputra river system sediment discharge is estimated to be 10 9 t yr at gauging stations 300 km inland of the coast but little has been known of the downstream fate of this material geochronological geophysical and stratigraphic investigations of the lowland flood plain delta plain and shelf help to delineate the extent of holocene fill and allow calculation of a first order sediment budget results reveal that 1500 10 9 m 3 of sediment fill has been sequestered within the flood plain and delta plain since ca 7000 yr b p or about one third of the annual discharge the remaining load appears to be apportioned between the prograding subaqueous delta 1970 10 9 m 3 and transport to the deep sea bengal fan via a nearshore canyon modern 100 yr budget estimates based on short term accretion rates indicate a similar dispersal pattern and show that contemporaneous deposition continues within these disparate depocenters the roughly equal partitioning of sediment among flood plain shelf and deep sea settings reflects the respective influence of an inland tectonic basin a wide shelf and a deeply incised canyon system the findings also support new sequence stratigraphic models for these settings and indicate the important insight that modern river deltas can provide for ancient margin systems furthermore results affirm that values of riverine sediment flux to the oceans may be considerably overestimated by not accounting for loss to the flood plains downstream of the gauging stations

development and response of a coupled catchment fan system under changing tectonic and climatic forcing sediment fans are a potentially useful and underexploited recorder of earth s climatic and tectonic history but historical observations have led to conflicting views on the importance of tectonic climatic and lithologic variables in controlling fan morphology and deposition a one dimensional model of a sediment fan and its associated catchment is used to explore the sensitivity of such simple sediment routing systems to perturbations in fault slip and precipitation rates a transport limited catchment is coupled to a fan whose surface slope is set by the balance between catchment sediment efflux and the available tectonically generated basin accommodation rock uplift rate is spatially variable across the model space increasing the fault slip rate or decreasing the precipitation rate leads to an increase in fan slope temporary back stepping of the fan toe and a pronounced angular unconformity conversely a decrease in slip rate or an increase in precipitation rate results in a decrease in fan slope and progradation and eventual stabilization of the fan toe once perturbed the system evolves toward a new equilibrium state with time constants of 0 5 to 2 myr these response times are insensitive to slip rate but are strongly dependent on precipitation rate variations in fan slope are well described by a dimensionless parameter that expresses equilibrium slope as a function of slip rate precipitation rate system size and catchment lithology this parameter holds promise as a predictive tool in inverting the morphology of natural fans for environmental variables

quantitative models of sedimentary basin filling summary quantitative modelling of the filling of sedimentary basins was begun in earnest in the 1960s dozens of themes and variations have been proposed since then and have yielded an abundance of idealized stratigraphic patterns as functions of both imposed changes and basin properties post plate tectonic modelling began with rigid lid models which show the stratigraphic signature of subsidence variation this work introduced the connection between stratigraphy and the rheology of the lithosphere rigid lid models are the simplest type of geometric model in which the sediment surface is assigned prescribed geometries usually corresponding to different depositional environments these can reproduce many aspects of overall stratal geometry but are formally restricted to relatively long timescales for which quasi steady surface topography can be assumed so called dynamic models attempt to represent the morphodynamics of the sediment surface by abstracting and averaging short term transport processes most of the dynamic models proposed to date can be seen as special cases of a single general morpho dynamic equation the most important result of the first wave of quantitative basin filling models is that even relatively simple models can produce reasonable stratal patterns we now have a wide array of tools for exploring scenarios searching for general behaviours and effects and making initial quantitative predictions we have also learned that basin response to external forcing as recorded in stratigraphy can be as sensitive to the characteristics of the basin as to the forcing the main brake on the development of basin modelling is not computing power but lack of methods and data for testing the models we have already developed physical experiments which are only just beginning are one means of doing this experimental stratigraphy is a bridge to quantitative field tests which will require collaboration among academic researchers from a wide range of areas and between academia and industry on projects of greater scale and degree of integration than we have seen so far the advancement of quantitative sedimentary geology will also require significant changes in the way the subject is taught at all levels

sediment source and storage in small watersheds on the keuper marls in luxembourg as indicated by soil profile truncation and the deposition of colluvium abstract soil survey reports and soil maps of 11 second order watersheds on the keuper marls in luxembourg were used to establish the extent to which soils were modified by accelerated erosion and colluviation and to calculate the volume of colluvium the amount of truncation of the soil profiles in the eroded area is on average 55 cm of which the equivalent of 36 cm remains in the watersheds as colluvium the 34 of the eroded soil material that has left the watersheds represents the longterm sediment delivery ratio landuse exerted a more powerful control on the production of colluvium than geomorphology the area occupied by colluvial soils c ha which offer good quality land can be predicted from the area under agriculture l ha with the equation c 74 l 56 comparison with palynologically dated colluvium produced figures for sediment yield of the source areas in the range between 700 and 1800 kg ha year

modeling the sensitivity of sediment and water runoff dynamics to holocene climate and land use changes at the catchment scale abstract an increasing number of studies have indicated that soil erosion sediment redistribution and water discharge during the holocene have varied greatly under influence of environmental changes in this paper we have used a modeling approach to study the driving forces for soil erosion and sediment redistribution on the one hand and water discharge on the other hand during the holocene for the belgian dijle catchment soil erosion and sediment redistribution was modeled using the spatially distributed watem sedem model several scenarios of past land use and climate were used to model soil erosion colluvial sedimentation and sediment export to the fluvial system and those scenarios were combined with a sensitivity analysis modeling results are validated based on an available time differentiated field based sediment budget water discharge was modeled using the spatially distributed stream model with a daily time step the model was calibrated based on contemporary discharge data the results indicate that soil erosion has increased between the early holocene and the current situation by ca 9 due to climatic variations and by ca 6000 due to changes in land use the average discharge has increased by ca 7 mainly due to land use changes and the discharge also shows more peaks the decrease in cropland area and increase in built up area since 1775 ce has resulted in a decrease in soil erosion and in a further increase in discharge showing the difference in sensitivity of both processes to land use changes

testing a cellular modelling approach to simulating late holocene sediment and water transfer from catchment to lake in the french alps since 1826 this paper describes the application of a hydrogeomorphological numerical model caesar to simulate at hourly time steps changes in the hydrological and sediment regime of the petit lac d annecy catch ment the outputs of the model were validated in three ways in the short term 5 years water discharge out puts were compared against observed instrumental data over the longer term modelled sediment discharge ad 1825 2005 was compared with proxies for detrital sediment influx environmental magnetism and accumu lation rates discerned from a 210 pb chronology for the lake sediments finally spatial validation of the modelled erosion and deposition of sediment was undertaken by comparison with a field and remotely sensed survey of catchment geomorphology the results suggest that while minor perturbations in forest cover during the last 180 years have partially conditioned the response of the sediment system the bulk of modelled sediment discharge and particularly the peaks in sediment discharge were controlled by flood duration and magnitude which in turn is driven by precipitation storms floods and snowmelt basin geometry and geomorphology of each sub catchment ire and tamie were also important in producing differences in the modelled sediment discharge in essence these differences were a function of sediment accommodation space and the ability of each system to store and release sediments modelled sediment discharge and para lake sediments display similar histories and thus are both interpreted as reflecting variations in detrital sediment supply intriguingly the style of mod elled sediment discharge from the ire a confined mountain torrent displays a greater similarity to and perhaps dominates the lake sediment record these results provide partial validation of the caesar model and indi cate that perhaps in the future it may be used as an exploratory and predictive tool in determining the impact of changes in climate meteorology and land use on lake catchment systems

the temporal and spatial quantification of holocene sediment dynamics in a meso scale catchment in northern bavaria germany the aufsess river catchment 97 km2 in northern bavaria germany is studied to establish a holocene sediment budget and to investigate the sediment dynamics since the early times of farming in the third millennium bce the temporal characterization of the sediment dynamics is based on an intensive dating program with 73 osl and 14 14c ages to estimate soil erosion and deposition colluvial and alluvial archives are investigated in the field by piling and trenching supported by laboratory analyses the sediment budget shows that 58 of these sediments are stored as colluvium in on and foot slope positions 9 are stored as alluvium in the floodplains and 33 are exported from the aufsess river catchment colluviation starts in the end neolithic c 3100 bce while first indicators of soil erosion derived alluviation is recorded c 2 3 ka later the pattern of sedimentation rates also displays differences between the colluvial and alluvial system with a distinct increase in the middle ages c 1000 c

cirque development in a steadily uplifting range rates of erosion and long term morphometric change in alpine cirques in the ben ohau range new zealand the intractable obstacle to understanding cirque evolution has been the lack of an independent timescale against which to measure morphometric change by using known rates of transport and uplift of the southern alps combined with the oxygen isotope record contained in marine sediments it is possible to estimate the duration of glacial occupancy of cirques in the ben ohau range the pattern is one of very limited glaciation of the southern range with glacial occupancy increasing northwards map based measurement of 18 morphometric properties in each of 92 cirques reveals systematic northward trends in cirque size form and altitude which are explained as reflections of increasing cirque age i e length of glacial occupancy thus the validity of space time substitution is demonstrated rather than assumed and morphometric trends define evolutionary stages of cirque development for cirques with up to c 750 ka occupancy rates of downcutting average 0 29 mma 1 and headwall retreat 0 44 mm a 1 there is no indication of attainment of an equilibrium form within this time both cirque size and form continue to evolve throughout with few parameters showing a convergence of value with cirque age some morphometric parameters perform much better than others the k coefficient of the long profile descriptor is the most powerful predictor of cirque age and simple measures correlate better than derived measures e g ratios of dimensions the trends identified concur with some previously published ideas but for the first time provide empirically quantified rates of change at an appropriate timescale copyright 2006 john wiley sons ltd

colluvial sediment dynamics in mountain drainage basins abstract colluvial sediment dynamics are examined using a 70 year landslide inventory in formerly glaciated mountain drainage basins of coastal british columbia canada landslide sediment transfer is documented by identifying landslide types and by characterizing preferential sites of landslide initiation delivery and storage across spatial scales data analysis reveals that open slope landslides delivering material to seasonal or perennial channels and fluvial terraces are the dominant mechanisms of sediment transfer this finding suggests high instability of the low order channel network and its ongoing re organization degradation after generalized sediment recharge occurred in the last glacial maximum in the study period landslide activity across the landscape has generated net degradation on planar slopes and first order colluvial channels whereas unchannelled valleys higher order colluvial channels and alluvial channels have accumulated material the scaling relation of the landslide sediment yield appears to be controlled by the spatial arrangement of the relict glacial macro forms landslide yield is highest in unchannelled topography decreases at the scale of channel initiation ad 0 002 km2 and remains constant for drainage areas where length scales of cirque valley walls and hanging valley floors overlap 0 002

transformation of tectonic and climatic signals from source to sedimentary archive sedimentary rocks reflect past tectonic and climatic events numerical simulations suggest that changes in precipitation and in the rate of tectonic uplift affect the grain size and the distribution of sediments deposited downstream

hypsometry of glaciated landscapes hypsometry frequency distribution of elevations is often used to characterize landscape morphology traditionally in the context of the degree of uvial dissection recently the hypsometry of glaciated regions has been used to infer how rates of glacial erosion compare with tectonic uplift rates however many factors other than tectonics can also exert a major in uence on the hypsometry of a glaciated landscape resulting in a wide variety of hypsometries using examples from the eastern sierra nevada california the western sangre de cristo range colorado and the ben ohau range new zealand we demonstrate that all else being equal the hypsometries of neighbouring basins can indicate the relative degree of glacial modi cation in each a selection of drainage basins from the rocky mountains shows that the position of the equilibrium line altitude ela within the drainage basin relief is a dominant variable in determining the hypsometry of a glaciated basin this is a non linear effect once the ela falls to some critical level the glaciers scour deeply below the ela causing a noticeably different hypsometry the hypsometry of an arbitrary region encompassing many drainage basins can disguise the variation present in the hypsometries and thus landforms of the individual basins unique local circumstances such as the presence of a mountain ice eld waiho basin southern alps substantial hanging valleys avalanche creek glacier national park a narrow outlet canyon sawmill creek sierra nevada and isolated geologic structures baker creek sierra nevada can have a major impact on the hypsometry of an individual basin copyright 2004 john wiley sons ltd

coupling relationships hillslope fluvial linkages in the hodder catchment nw england abstract variations in the coupling of sediment transfer between different parts of a fluvial catchment e g hillslope to axial stream can hamper understanding but are an integral part of the geomorphological record depositional environments respond to a combination of land use climate storms floods and autogenic conditioning the distribution of sediment in the upland landscapes of nw england is out of equilibrium with contemporary climate and geomorphological processes more a function of peri and paraglacial mobilisation of glacigenic deposits soil and vegetation development after deglaciation have interrupted any progression toward sediment exhaustion with sediment release controlled largely by extrinsic perturbation with late holocene anthropogenic activity climate and extreme hydrological events the likely candidates this paper presents a new radiocarbon dated holocene geomorphological succession for the river hodder nw england alongside evaluating new palaeoecological and geoarchaeological data to discern the impacts of human activity these data show a late holocene expansion in human occupation and use of the landscape since the iron age 700 0 cal b c with more substantial changes in the character and intensity of upland land use in the last 1300 years the geomorphological responses in the uplands were the onset of considerable and widespread hillslope erosion gullying and associated alluvial fan development interpretation of the regional radiocarbon chronology limits gullying to four more extensive and aggressive phases after 500 cal b c the downstream alluvial system has responded with considerable valley floor deposition and lateral channel migration that augmented sediment supply by remobilising the existing floodplain terraces and led to the aggradation of a series of inset alluvial terraces the timing of these changes between states of aggradation and incision in alluvial reaches reflects the increased connectivity between the hillslope and alluvial systems aspects of both the regional climate and land use histories are conducive to increasing discharge and sediment flux but the region wide lowering of erosion thresholds appears a key driver conditioning these sediment rich conditions and producing a landscape that was more susceptible to erosion under lower magnitude flows

self organized criticality in river basins challenging sedimentary records of environmental change for many years researchers have linked increases in sediment and bedload from drainage basins to external factors such as increased rainfall however natural systems have always shown a high degree of scatter or nonlinearity in this response which has made prediction of sediment yields difficult we identify and describe a mechanism for self organized criticality in the bedload sediment output from a simple drainage basin evolution model this implies that identical floods will give considerably different sediment yields which effectively renders the system unpredictable therefore existing empirical methods for estimating sediment yields may need to be radically reevaluated furthermore sedimentary records used to infer past climate or environmental conditions could simply reflect the internal system dynamics instead of external drivers

a general model of paraglacial landscape response a unifying attribute of all forms of paraglacial response is that deglaciation results in the exposure of unstable or metastable sediment sources that are subsequently tapped by a wide variety of processes over a wide range of timescales the paraglacial period in different geomorphological contexts is therefore con ditioned by two variables glacially conditioned sediment release and rate of sediment reworking under steady state conditions the latter may be approximated by an exhaustion model in which sediment yield is related to the amount of remaining available sediment by a negative exponential function this model offers an approximation for the behaviour of primary paraglacial systems in which glacigenic sediment sources are not replenished the long term behaviour of secondary primarily uvial paraglacial systems in which sediment inputs include both in situ and reworked glacigenic sediment appears intrinsically more complex but consistent with an exhaustion model if initial sediment avai

nested temporal suspended sediment yields green lake basin british columbia canada suspended sediment yield was determined for a mountain watershed by calculating the volume of sediment stored in the watershed s outlet lake basin and monitoring sediment transport for the lake s primary inflow lake based yields for the 1931 2001 period 0 21 0 03 mg km 2 day 1 are 10 higher than estimates for the last 3000 years 0 19 0 05 mg km 2 day 1 fluvial 0 24 0 08 mg km 2 day 1 and lake based yields ca 0 21 0 07 mg km 2 day 1 are comparable over the period of overlap 1999 2001 persistence in the long term yield record is dominated by low frequency century to decadal periodicity this periodicity is shown to inflate the standard error of the sediment yield estimate for the basin elevated transport of suspended sediments following years of extreme yield is uncommon in the green lake record and indicates a sediment transport regime that is supply limited for this watershed approximately 50 years of suspended sediment monitoring would be required to reduce the uncertainty of the yield estimate to 37 of its average value a summer rainstorm in 1991 delivered more suspended sediment to the green lake basin than any other event in the last 3000 years

postglacial adjustment of steep low order drainage basins canadian rocky mountains 1 it is generally argued that pleistocene glaciation results in increased sediment flux in mountain systems an important but not well constrained aspect of pleistocene glacial erosion is the geomorphic decoupling of cirque basins from main river systems this study provides a quantitative link between glacier induced basin morphology postglacial erosion and sediment delivery for mountain headwaters with basin area 28 respectively and ii larger fan sizes at outlets of noncirque basins compared to cirques although small headwater basins represent the steepest part of mountain environments and erode significant postglacial sediment the majority of sediment remains in storage under interglacial climatic conditions and does not affect large scale mountain river systems

residence time of alluvium in an aggrading fluvial system relationships between the surface area and age of alluvial deposits were used to estimate the residence time of alluvium in the 2205 km2 waipaoa river basin new zealand the contemporary waipaoa river is an efficient transporter of sediment to the continental shelf but the basin has been characterized by rapid channel and valley aggradation in the historic period and by extensive mid to late holocene alluvial storage in the lower reaches the area weighted mean age of alluvial deposits in the lower part of the river basin is 4400 yr these deposits comprise terrace remnants isolated by downcutting and holocene to recent sediments that are potentially remobilizable by the modern river even though the amount of storage is small relative to downstream transport the majority of the potentially remobilizable alluvium is likely to remain in storage for 100 yr and its half life time for 50 per cent removal is 2000 yr within the confines of the flfloodplain the apparent loss of older deposits is due primarily to burial but losses of the most recent deposits are due almost entirely to remobilization 30 40 per cent with the remainder preserved in the alluvial record for at least 104 yr most of this sediment is likely to remain in storage until there is a shift to a degradational state copyright 2006 john wiley sons ltd

equilibrium scale and inheritance in geomorphology abstract of the many equilibrium terms that have been proposed only two are needed dynamic equilibrium in the original sense of g k gilbert 1877 and steady state the former refers to the relationship between the process components of a system the latter to the system as a whole the tendency towards establishing a dynamic equilibrium is inherent in all natural systems that contain negative feedbacks between processes capable of compensating each other in geomorphology equilibrium tendencies of the mass budget are more relevant than those of the energy budget the validity of the equilibrium concept is discussed at several scales from a slope point to entire slopes drainage basins and mountain ranges the effects of eksystemic changes vary depending upon the length of the intervals between such changes in comparison to the length of the required relaxation times this relationship also applies to the influence of inherited forms patterns and materials that have become components of present day systems

the onset of an eruption selective assimilation of hydrothermal minerals during pre eruptive magma ascent of the 2010 summit eruption of eyjafjallajokull volcano iceland abstract the complex processes occurring in the initial phases of an eruption are often recorded in the products of its opening stage which are usually characterized by small volume and limited dispersal and thus generally poorly studied the 2010 eruption of eyjafjallajokull iceland represents a unique opportunity for these investigations thanks to the good preservation of tephra deposits within the ice snow pack a detailed geochemical investigation on the glassy groundmass of single ash clasts disclosed a population of fragments with unusual high 87 sr 86 sr up to 0 70668 for icelandic magmatism and anomalous elemental composition with respect to most of the juvenile material of the eruption this suggests that during its rise before intruding into the ice cover magma at a dyke tip selectively assimilated hydrothermal minerals with seawater related high sr isotopic ratios zeolites silica phases anhydrite hosted in altered volcanic epiclastic rocks according to the observed precursory seismicity only restricted to few hours before the onset of the eruption this process could have accompanied subcritical aseismic fracture opening during the days before the eruption possibly related to stress corrosion cracking processes which enhanced the partial dissolution melting and subsequent selective assimilation of the host rocks

the history of soil erosion and fluvial deposits in small catchments of central europe deciphering the long term interaction between humans and the environment a review abstract during the last few decades many case studies focused on the dynamics of fluvial systems in response to hillslope erosion land use impact and climate changes this paper will review the current state of knowledge of the dynamics of past soil erosion and gullying in small catchments

comparing landscape evolution models with quantitative field data at the millennial time scale in the belgian loess belt this study compares three landscape evolution models and their ability to correctly simulate measured 2500 year landscape evolution in two small catchments in the belgian loess belt watem lt and lapsus both model tillage and water erosion and deposition and have detachment limited descriptions for water erosion and deposition equations in lapsus are more mechanistic than those in watem lt watem ltt resembles watem lt but is a transport limited model all three models are dem based calibration and validation simulations were performed forward in time on 1d transects for four spatial resolutions and backward in time for 2d catchments at 20 m resolution for transects model outputs were compared with discretized observations of transect shape for catchments outputs were compared with point observations of palaeo altitude averaged over landscape element classes for transects the three models performed well resulting in model efficiency factors of 0 92 to 0 99 for calibration and 0 62 to 0 96 for validation however for catchments simulations showed that the transport limited watem ltt model could not realistically simulate long term landscape evolution performance of watem lt and lapsus at catchment scale was similar to that on transects although lapsus has problems with backward calculation tests demonstrate that a transport limited approach cannot be used to model long term landscape evolution in the belgian loess belt which is in agreement with theoretical and empirical understanding of soil erosion processes in this environment the difference in performance between transport limited and detachment limited models is clear only when the models are evaluated in a 2d catchment the lack of such distinction when models were applied in a 1d transect highlights the importance of evaluating landscape evolution models in a 2d setting so that effects of flow convergence divergence can be accounted for copyright 2011 john wiley sons ltd

reconnaissance sediment budgets for lynn valley british columbia holocene and contemporary time scales volumes of erosional and depositional landforms were estimated by reconnaissance methods in a steep forested drainage basin in the coast mountains british columbia to examine what insight might be gained into the sediment budget in the absence of direct measurements of sediment transfer processes sediment transfers in postglacial and contemporary time were inferred on hillslopes from hillslopes to stream channels and within stream channels data were collected by aerial photographic analysis and field observation postglacial sediment sources are major gullies created by debris slides and flows failures in glaciolacustrine terraces and stream channel degradation depositional landforms consist of talus slopes and colluvial and alluvial fans contemporary sediment sources include debris slides and flows in established gullies and minor processes on hillslopes debris slide and debris flow volumes were calculated and other processes were estimated from regional values erosion rate averaged over postglacial time is 276 t km 2 a 1 0 15 mm a 1 surface lowering with gullies and stream channel degradation contributing 170 and 82 t km 2 a 1 respectively a terminal alluvial fan provides an independent check of the results in contemporary time erosion rates are calculated to be 350 t km 2 a 1 with debris flows and slides contributing nearly all of this sediment the contemporary rate is probably perturbed by recent land use history mass movement processes appear to be the dominant mechanism of sediment transfer and contributions from pleistocene valley deposits have declined significantly during holocene time resume les volumes de terrain erodes et deposes ont ete estimes par des methodes de reconnaissance dans un bassin de drainage boise a pentes abruptes des montagnes cotieres de la colombie britannique afin d etudier quelles connaissances sur le budget sedimentaire pourraient etre acquises en l absence de mesures directes du processus de transfert de sediments les transferts de sediments a l epoque post glaciaire et contemporaine ont ete inferes sur les flancs des cotes des flancs des cotes vers les chenaux des rivieres et dans les chenaux des rivieres les donnees proviennent de l analyse de photographies aeriennes et d observations sur le terrain les sources de sediments post glaciaires sont des ravines creees par des glissements et des coulees de debris des effondrements de terrasses glacio lacustres et la degradation de chenaux les formes de terrain creees par deposition comprennent des tabliers d eboulis et des deltas colluviaux et alluvionnaires les sources contemporaines de sediments comprennent des glissements et des coulees de debris dans des ravines etablies et des processus mineurs sur des pentes les volumes des glissements et des coulees de debris ont ete calcules et d autres processus ont ete evalues a partir de valeurs regionales la moyenne du taux d erosion pour la periode post glaciaire est de 276 tonnes km 2 a 1 abaissement de la surface de 0 15 mm a les ravines et la degradation des chenaux des ruisseaux contribuant respectivement 170 et 82 tonnes km 2 a 1 un delta alluvionnaire terminal permet une verification independante des resultats a l epoque contemporaine les taux d erosion sont calcules comme etant 350 tonnes km 2 a 1 et les glissements et des coulees de debris y contribueraient pour la presque totalite le taux contemporain est probablement perturbe par l utilisation recente du terrain les processus de mouvements de masse semblent etre le mecanisme dominant de transfert de sediments et les contributions provenant des depositions dans les vallees au pleistocene ont diminue de facon significative durant l holocene traduit par la redaction campbell and church 713

sediment connectivity in the high alpine valley of val muschauns swiss national park linking geomorphic field mapping with geomorphometric modelling abstract the efficiency of sediment routing through mountain sediment cascades is controlled by the connectivity of hillslopes to the main river system a lack of connectivity may cause long term sediment storage and exclude large fractions of a basin from the sediment routing for several thousand years here we studied sediment dynamics in a small formerly glaciated valley in the swiss alps to characterise the sediment connectivity to the stream we calculated a morphometric index using a gis algorithm the modelling results were tested against a field based geomorphic mapping of sediment storages which were evaluated with respect to their state of de coupling in accordance to the field diagnostics the modelling results indicate very well that the present day sediment flux is conditioned by the glacial valley morphometry inherited through pleistocene glaciation especially in the upper hanging valleys the connectivity index is reduced noticeably due to the glacial cirque morphology based on the field mapping 30 of the hillslope sediment cascades are interrupted and 20 of the storage boundaries are currently affected by a lack of material transfer as a consequence 29 of the basin surface is currently disconnected from the main river nevertheless the gis algorithm overestimates the connectivity within the basin because it fails to calculate decoupling between neighbouring pixels in digital terrain models dtms around 35 of the basin surface which has been mapped in the field as being decoupled is related to relative high connectivity our study highlights the potential of morphometric gis modelling for studying sediment connectivity but additionally emphasises the indispensability of geomorphic field mapping for a holistic understanding of mountain cascading systems

effective timescales of coupling within fluvial systems this paper presents a review of the coupling concept in fluvial geomorphology based mainly on previously published work coupling mechanisms link the components of the fluvial system controlling sediment transport down the system and the propagation of the effects of base level change up the system they can be viewed at several scales at the local scale involving within hillslope coupling hillslope to channel coupling and within channels tributary junction and reach to reach coupling at larger scales coupling can be considered as zonal coupling between major zones of the system or as regional coupling relating to complete drainage basins these trends are illustrated particularly by the examples of hillslope to channel coupling in the howgill fells northwest england badland systems in southeast spain alluvial fans in spain usa and uae and base level induced dissection of neogene sedimentary basins in southeast spain as the spatial scales increase so do the timescales involved effective temporal scales relate to magnitude and frequency characteristics recovery time and propagation time the relative importance changing with the spatial scale for downsystem coupling at the local scale the first two are important with propagation time increasing in importance in larger systems especially in those involving upsystem coupling related to base level change the effective timescales range from the individual event with a return period of decades through decadal to century timescales for downsystem coupling to tens to hundreds of thousands of years for the basinwide response to base level change the effective timescales influence the relative importance of factors controlling landform development

meso scale catchment sediment budgets combining field surveys and modeling in the dragonja catchment southwest slovenia in this paper we present a methodology to construct a sediment budget for meso scale catchments we combine extensive field surveys and expert knowledge of the catchment with a sediment delivery model the meso scale mediterranean drainage basin of the dragonja 91 km2 southwest slovenia was chosen as case study area during the field surveys sheet wash was observed on sloping agricultural fields during numerous rainfall events which was found to be the main source of sediment with the sediment yield model watem sedem the estimated net erosion on the hillslopes 4 1 t ha 1 y 1 91 of inputs the second source bank erosion 4 2 0 25 t ha 1 y 1 was monitored during several years with erosion pins and photogrammetric techniques the last source channel incision was derived from geomorphological mapping and lichenomery and provided 3 8 0 17 t ha 1 y 1 of the sediment input the river transports its suspended sediment mainly during high flow events sampled with automated water samplers about 27 1 2 t ha 1 y 1 of the sediment delivered to the channel is deposited on floodplains and low terraces downstream estimated with geomorphological mapping coring and cesium 137 measurements the sediment transported as bedload disintegrates during transport to the outlet due to the softness of the bedrock material as a result the river carries no bedload when it reaches the sea the results imply a build up of sediment in the valleys catchment however extreme flood events may flush large amounts of sediment stored in the lower parts of the system geomorphological evidence exists in the catchment that such high magnitude low frequency events have happened in the past

meteoric cosmogenic beryllium 10 adsorbed to river sediment and soil applications for earth surface dynamics abstract rainfall scavenges meteoric cosmogenic 10be from the atmosphere 10be falls to the earth s surface where it binds tightly to sediment particles in non acidic soils over the life span of those soils as such meteoric 10be has the potential to be an excellent geochemical tracer of erosion and stability of surfaces in a diverse range of natural settings meteoric 10be has great potential as a recorder of first order erosion rates and soil residence times even though this tracer was first developed in the late 1980s and showed great promise as a geomorphic tool it was sidelined in the past two decades with the rise of the sister nuclide in situ 10be which is produced at a known rate inside quartz minerals since these early days substantial progress has been made in several areas that now shed new light on the applicability of the meteoric variety of this cosmogenic nuclide here we revisit the potential of this tracer and we summarize the progress 1 the atmospheric production and fallout is now described by numeric models and agrees with present day measurements and paleo archives such as from rain and ice cores 2 short term fluctuations in solar modulation of cosmic rays or in the delivery of 10be are averaged out over the time scale soils accumulate 3 in many cases the delivery of 10be is not dependent on the amount of precipitation 4 we explore where 10be is retained in soils and sediment 5 we suggest a law to account for the strong grain size dependence that controls adsorption and the measured nuclide concentrations and 6 we present a set of algebraic expressions that allows calculation of both soil or sediment ages and erosion rates from the inventory of meteoric 10be distributed through a vertical soil column the mathematical description is greatly simplified if the accumulation of 10be is at a steady state with its export through erosion in this case a surface sample allows for the calculation of an erosion rate explored further this approach allows calculation of catchment wide erosion rates from river sediment similar to the approach using 10be produced in situ in contrast to the in situ 10be approach however these analyses can be performed on any sample of fine grained material even where no quartz minerals are present therefore this technique may serve as a tool to date sediment where no other chronometer is available to track particle sources and to measure earth surface process rates in soil suspended river sediment and fine grained sedimentary deposits

sediment connectivity a framework for understanding sediment transfer at multiple scales a major challenge for geomorphologists is to scale up small magnitude processes to produce landscape form yet existing approaches have been found to be severely limited new ways to scale erosion and transfer of sediment are thus needed this paper evaluates the concept of sediment connectivity as a framework for understanding processes involved in sediment transfer across multiple scales we propose that the concept of sediment connectivity can be used to explain the connected transfer of sediment from a source to a sink in a catchment and movement of sediment between different zones within a catchment over hillslopes between hillslopes and channels and within channels using fluvial systems as an example we explore four scenarios of sediment connectivity which represent end members of behaviour from fully linked to fully unlinked hydrological and sediment connectivity sediment travel distance when combined with an entrainment parameter reflecting the frequency magnitude response of the system maps onto these end members providing a coherent conceptual model for the upscaling of erosion predictions this conceptual model could be readily expanded to other process domains to provide a more comprehensive underpinning of landscape evolution models thus further research on the controls and dynamics of travel distances under different modes of transport is fundamental copyright 2014 john wiley sons ltd

cumulative probability functions and their role in evaluating the chronology of geomorphological events during the holocene cumulative probability functions cpfs for large numbers of radiocarbon age determinations are increasingly being used by scientists as a methodology to discern environmental histories while the recent compilation of regional databases of the radiocarbon dating control for fluvial sediment sequences has been beneficial for identifying gaps in knowledge and stimulating new research there are a number of problems that critically undermine the use of these cpfs as sensitive hydroclimatic proxies i the cpf method is underpinned by the assumption that each radiocarbon measurement is a true age estimate for a point in time whereas each measured age in fact forms a scatter around the true age of the sample ii calibration of radiocarbon ages is responsible for much of the structure in cpfs and compounds the problem of scatter and smears the chronological control iii the databases incorporate multiple types of environmental changes differing chronological relationships between the 14c measurements and the dated events with pre dating dating or post dating chronological control each displaying variable length temporal lags all mixed together in the same analysis and iv the radiocarbon ages from individual case studies need to be more robustly tested before being incorporated into regional databases all these factors negate the value of cpfs as sensitive proxies of environmental change because peaks in probability for individual radiocarbon measurements are likely to be an incorrect estimate for the age of a geomorphological event and this problem is compounded by combining probabilities for multiple unrelated events in this paper we present a critical analysis of cpfs and their interpretation before suggesting alternative approaches to analysing radiocarbon geochronologies of geomorphic events which include i bayesian age modelling of river terrace development ii developing regional databases that test specific geomorphic hypotheses iii bayesian age modelling of palaeoflood records and iv analysis of sedimentation rates copyright 2011 john wiley sons ltd

sediment delivery ratios a misaligned approach to determining sediment delivery from hillslopes correspondence to p i a kinnell school of resource environmental and heritage sciences university of canberra canberra act 2601 australia e mail peter kinnell canberra edu au considerable interest exists in the impact of land management on water quality throughout the world a large number of non point source nps pollution or water quality models exist in many cases these models use the universal soil loss equation usle wischmeier and smith 1978 or the revised version of the usle rusle renard et al 1997 to model erosion on hillslopes in conjunction with sediment delivery ratios sdrs to determine the sediment delivered from the hillslope to water bodies the sdr can be defined as the ratio of the erosion upslope of a point in the landscape to the sediment delivered from that point erosion involves detachment transport and deposition processes that operate all the time the net loss or gain of soil material depends on the balance between the rates of particle uplift and deposition in the context of modelling sediment delivery on hillslopes with respect to water quality erosion refers to the situation where there is a net loss of soil material from the soil surface and deposition to the situation where there is a net gain the use of sdrs owes its origin to the observation that using erosion predicted by the usle overestimates the amount of sediment delivered from hillslopes because sediment deposition often occurs on hillslopes and the usle does not account for deposition the usle was developed on planar surfaces and was not designed to apply to situations where there is a net gain of soil material on the area being considered however sdrs are essentially performance factors that simply relate observed or modelled amounts at the plot scale to observed amounts at a larger scale using them to predict sediment delivery from hillslopes can produce erroneous results one of the features of the usle rusle sdr approach is that the predicted amount of sediment delivered from the hillslopes varies directly with the predicted erosion for any given hillslope profile halving the erosion results in a halving of the amount of sediment delivered from the hillslope however the deposition effect results from sediment in or entering the flow exceeding the transport capacity of that flow at a point on the hillslope as a result sediment delivery is directly related to erosion if the transport capacity of the flow is not exceeded i e sdr 1 0 but it is limited by the transport capacity if erosion exceeds the capacity of the flow to transport the eroded material i e sdr 1 0 this concept is encapsulated in figure 1 and in so called process based erosion models like wepp

scale variation of post glacial sediment yield in chilliwack valley british columbia the holocene volumetric sediment budget is estimated for coarse textured sediments sand and gravel in a large formerly glaciated valley in southwest british columbia erosion is estimated by compiling volumetric loss estimated in digital elevation models dems of gullied topography and by applying a non linear diffusion model on planar undissected hillslopes estimates of steepland yield are based on estimates of post glacial deposition volumes in fans cones and deltas at the outlets of low order tributary catchments erosion of post glacial fans and tributary valley fills is estimated by reconstructing formerly continuous surfaces results are classed by catchment order and compared across scales of contributing area revealing declining specific sediment yield in m3 km 2 a 1 with catchment area for the smaller tributaries 10 km2 and increasing specific sediment yield for larger tributaries and chilliwack valley itself approximately 60 of mobilized sediment is redeposited in first to third order catchments with lesser proportions stored at the outlets of higher order catchments a simple network routing model emphasizes the significant sediment flux contributions from colluvium drift blankets and gullies in steeper terrain as this material is deposited at junctions within the lower drainage network an increasing proportion of material is derived from remnant valley fills and para glacial fans in the major valleys yield from lower order steepland catchments tends to remain in storage indefinitely sequestered on footslopes these observations have implications for modelling the post glacial sediment balance amongst catchments of varying size after 104 years the system remains in disequilibrium the critical linkage lies between low order hillslope catchments fourth order and the larger valleys with more complex fluvial systems copyright 2010 john wiley sons ltd

linking environmental regimes space and time interpretations of structural and functional connectivity connectivity as a concept has been increasingly part of discussions or explanations in hydrology geomorphology and ecology we address recent critiques of this approach by demonstrating how a refinement which distinguishes structural connectivity from functional connectivity can be used to explain patterns observed in very different environmental systems these systems are found in linkages between surface and subsurface flowpaths and the hyporheos in the river don a temperate river channel in yorkshire uk in surface and subsurface fluxes in agricultural land in the uk and in vegetation and surface conditions in a degrading environment at the sevilleta lter site in the semi arid southwest usa first we demonstrate long term geological and structural controls mediated by in channel processes second human organization of landscape elements is a significant control on runoff and erosion so that similar events can produce very different responses and vice versa third linkages between the removal of grass vegetation and runoff and erosion produce non linear and path dependent feedbacks which control the subsequent degradation of the landscape making the process difficult to reverse as a result of these studies we argue that even in cases where connectivity cannot be directly quantified at least at present this limitation does not prevent the concept from being a useful heuristic device for exploring responses of complex systems furthermore this result implies that an increasing need exists for disciplinary connectivity to investigate such systems

conceptual assessment of dis connectivity and its application to the ganga river dispersal system abstract connectivity in river dispersal systems is an important evolving concept and helps in understanding their dynamics in this study the types of connectivity have been defined on the basis of two components namely physical contact and transfer of material based on this four types of connectivity are recognized these are a active connected system b inactive connected system c partially active connected system and d disconnected system connectivity indices have been proposed based on the process understanding of different types of connectivity this conceptual understanding of connectivity has been applied to the ganga dispersal system a large river system results of the connectivity analysis on the ganga dispersal system reveal that different sets of data such as sediment budgets geochemical isotopic data and radiogenic 238 u 234 u 230 th data are noncoherent therefore developing rigorous and well constrained quantitative multidisciplinary data sets is needed to have a better understanding of connectivity at multiple spatio temporal scales in large river dispersal systems this would ultimately help model the dynamics of such systems

disequilibrium of holocene sediment yield in glaciated british columbia it is generally supposed that specific sediment yield the quantity of sediment passing a monitored river cross section per unit area drained upstream of that section declines as the area drained increases1 3 part of the sediment mobilized from the land surface is supposed to go back into storage at field edges and on footslopes and floodplains in contrast we show here that data from british columbian rivers reveal a pattern of increasing specific sediment yield at all spatial scales up to 3 104 km2 this results from the dominance of secondary remobilization of quaternary sediments along river valleys over primary denudation of the land surface the result controverts the conventional model which has been derived from studies of small highly disturbed agricultural catch ments the rivers are still responding to the last glaciation giving a landscape relaxation time greater than 10 kyr this holds pro found implications for geomorphological theory and for studies of erosion

millennial lag times in the himalayan sediment routing system abstract any understanding of sediment routing from mountain belts to their forelands and offshore sinks remains incomplete without estimates of intermediate storage that decisively buffers sediment yields from erosion rates attenuates water and sediment fluxes and protects underlying bedrock from incision we quantify for the first time the sediment stored in 38 000 mainly postglacial himalayan valley fills based on an empirical volume area scaling of valley fill outlines automatically extracted from digital topographic data the estimated total volume of 690 242 452 km 3 is mostly contained in few large valley fills 1 km 3 while catastrophic mass wasting adds another 177 31 km 3 sediment storage volumes are highly disparate along the strike of the orogen much of the himalaya s stock of sediment is sequestered in glacially scoured valleys that provide accommodation space for 44 of the total volume upstream of the rapidly exhuming and incising syntaxes conversely the step like long wave topography of the central himalayas limits glacier extent and thus any significant glacier derived storage of sediment away from tectonic basins we show that exclusive removal of himalayan valley fills could nourish contemporary sediment flux from the indus and brahmaputra basins for 1 kyr though individual fills may attain residence times of 100 kyr these millennial lag times in the himalayan sediment routing system may sufficiently buffer signals of short term seismic as well as climatic disturbances thus complicating simple correlation and interpretation of sedimentary archives from the himalayan orogen its foreland and its submarine fan systems