phases of soil erosion derived colluviation in the loess hills of south germany in south germany soil erosion is as old as farming and dates back to early neolithic times its sedimentary products form thick colluvial and alluvial sediment bodies in all drainage basins numerous local studies exist but the extrapolation of findings from local case studies to a regional scale has been problematic here a graphical approach is used for frequency analysis of existing data a frequency distribution for optical dates on colluvial sediments from the beginning of agriculture until 1200 ad was constructed by 1 representing the optical ages by gaussian distributions and 2 summing all the single curves the resulting graph clearly shows phases of increased colluviation during periods of stronger human impact a first significant increase occurred during the bronze age during the iron age roman period and at around 800 ad distinct maxima appear in the distribution and highest frequencies are present towards the end of the analysed period at around 1100 ad conclusions that can be drawn from such an approach are limited by sampling bias and other factors but for the analysed period and on a regional and long term scale colluviation seems to have been mainly triggered by intensity of land use climatic fluctuations are of only secondary importance rainfall events that were sufficiently erosive to produce colluvial sediments occurred throughout the agricultural periods the limiting factor for colluvium production was sensitivity of the landscape to erosion and this is a result of land use d 2002 elsevier science b v all rights reserved

a grassed waterway and earthen dams to control muddy floods from a cultivated catchment of the belgian loess belt muddy floods i e runoff from cultivated areas carrying large quantities of soil are frequent and widespread in the european loess belt they are mainly generated in dry zero order valleys and are nowadays considered as the most likely process transferring material eroded from cultivated hillslopes during the holocene to the flood plain the huge costs of muddy flood damages justify the urgent installation of control measures in the framework of the soil erosion decree of the belgian flemish region a 12 ha grassed waterway and three earthen dams have been installed between 2002 2004 in the thalweg of a 300 ha cultivated dry valley in the belgian loess belt the measures served their purpose by preventing any muddy flood in the downstream village despite the occurrence of several extreme rainfall events with a maximum return period of 150 years the catchment has been intensively monitored from 2005 2007 and 39 runoff events were recorded in that period peak discharge per ha was reduced by 69 between the upstream and the downstream extremities of the grassed waterway gww furthermore runoff was buffered for 5 12 h behind the dams and the lag time at the outlet of the catchment was thereby increased by 75 reinfiltration was also observed within the waterway runoff coefficients decreasing by a mean of 50 between both extremities of the gww sediment discharge was also reduced by 93 between the gww s inflow and the outlet before the installation of the control measures specific sediment yield ssy of the catchment reached 3 5 t ha 1 yr 1 and an ephemeral gully was observed nearly each year in the catchment since the control measures have been installed no ephemeral gully has developed and the ssy of the catchment dropped to a mean of 0 5 t ha 1 yr 1 hence sediment transfer from the cultivated dry valley to the alluvial plain should dramatically decrease total cost of the control measures that are built fora 20 year period is very low 126 sic ha 1 compared to the mean damage cost associated with muddy floods in the study area 54 sic ha 1 yr 1 similar measures should therefore be installed to protect other flooded villages of the belgian loess belt and comparable environments c 2008 elsevier b v all rights reserved

modelling differential catchment response to environmental change the caesar cellular automaton evolutionary slope and river model is used to demonstrate significant differences in coarse sediment transfer and alluviation in medium sized catchments when responding to identical holocene environmental changes simulations for four u k basins the rivers swale ure nidd and wharfe shows that catchment response driven by climate and conditioned by land cover changes is synchronous but varies in magnitude there are bursts of sediment transfer activity generally of rapid removal but with some sediment accumulation dspikest with longer periods of slow removal or accumulation of sediment in different valley reaches within catchments reach sensitivity to environmental change varies considerably some periods are only recorded in some reaches whilst higher potential sensitivity typically occurs in the piedmont areas of the catchments modelled here these differential responses appear to be highly non linear and may relate to the passage of sediment waves by variable local sediment storage and availability and by large and small scale thresholds for sediment transfer within each catchment differential response has major implications for modelling fluvial systems and the interpretation of field data model results are compared with the record of dated alluvial deposits in the modelled catchments d 2005 elsevier b v all rights reserved

holocene alluvial sediment storage in a small river catchment in the loess area of central belgium abstract soil erosion and sediment deposition widely affect landscape development particularly in erosion prone areas with loess derived soils nevertheless until now few attempts were made to quantify soil losses and sediment storage over long centennial or millennial timescales in this study the holocene alluvial sediment storage in a small river catchment 52 km2 of the belgian loess belt is estimated and a preliminary sediment budget for the catchment is presented in the valley of the nethen river c 13 km long a detailed survey of the alluvial sediment archive was conducted hand augerings and percussion drillings were made along cross valley transects at 12 locations in the catchment ams 14c dating of peat samples provided a temporal framework for the interpretation of the cores results show that the thickness of holocene sediment deposits in the nethen valley is 4 to 6 m which corresponds to a total clastic sediment mass of 14 106 t stored in the valley bottom three alluvial units could be distinguished and associated with deposition phases from 9600 to 2900 b c 2900 b c to a d 1000 and a d 1000 to present in contrast to the older sediments units 1 and 2 deposits from the last 1000 year unit 3 contain little organic matter they are seldom intercalated with peat layers and devoid of tufa unit 3 reaches a thickness of c 2 m thereby representing 50 of the holocene sediment mass stored in the alluvial plain the mean sedimentation rate in the alluvial plain for this last phase is 26 t ha 1 a 1 which is about tenfold larger than the sedimentation rates calculated for the older holocene sediment units sediment supply towards the alluvial plain has therefore increased tremendously since medieval times these results are in contrast to dating results obtained for colluvial sediments in a nearby dry valley within the catchment of the nethen where soil erosion and sediment deposition started in the early iron age and was already substantial during the roman age this means that there is a time lag of about one millennium between the onset of high sedimentation rates in the upstream area and high deposition rates in the alluvial plain this is probably caused by a change in coupling sediment connectivity between the plateau slopes and rivers as soil erosion proceeds first the dry zero order valleys in the catchment act as sediment traps and only after these are filled sediment reaches the floodplains the preliminary sediment budget for the nethen catchment illustrates that 50 of the sediment that was eroded during the holocene was stored in colluvial deposits which are mainly located on footslopes and in dry valley bottoms another 29 of the sediment mass is stored in the alluvial plain

s type asteroids ordinary chondrites and space weathering the evidence from galileo s fly bys of gaspra and ida new observations of the s type asteroids gaspra and ida especially by the galileo spacecraft demonstrate that a space weathering process operates which modifies the reflectance spectra of fresh material to be redder straighter and have shallower absorption bands the weathering process appears similar to but less potent than that observed on the moon it operates in the sense that it would tend to convert spectra of ordinary chondrites oc to having the spectral traits of s type asteroids these results appear to resolve the major obstacles of the long standing s type conundrum about the provenance of ordinary chondrite meteorites a wide body of recent research which is reviewed here builds on previous meteoritical evidence to support a new developing consensus that the larger s type asteroids are a diverse assortment of silicaceous assemblages which includes the ordinary chrondite parent bodies recent fairly realistic laboratory simulations of space weathering processes have changed oc spectra to resemble s type spectra j f bell s highly regarded earlier paradigm that oc parent bodies would be found only among sub 10 km main belt asteroids has been tested by an extensive observational survey by r binzel and his proteges the result is that no small main belt analog for the ocs has been found not even the somewhat oc like object boznemcova this article reviews the history of the s type conundrum which set the stage for galileo s historic flybys i review the findings about gaspra and ida including results about their geology their geophysical structure and probable origins and about ida s small moonlet dactyl density constraints on ida set by dactyl s orbit rule out for ida at least the classic view of s types as metallic stripped cores of differentiated precursor asteroids new analysis of the galileo spectral images of ida is presented that provides strong evidence that space weathering occurs on ida and that ida and the koronis family asteroids in general are plausibly oc like in composition after reviewing 1990s developments on the s type conundrum i advocate a new perspective that the ordinary chondrite parent bodies are among the s type asteroids a diverse grouping that also contains other silicaceous and silicate metal assemblages presumably including various stony irons and primitive achondrites represented in meteorite collections gaspra may be such a metal rich assemblage

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

the processes and timing of sediment delivery from headwaters to the trunk stream of a central european mountain gully catchment abstract gully systems determine downstream water quality and sediment loads since they are located where streams begin they are often only considered as a sediment source and the degree to which gully systems also store sediment and the timescales of this storage have received less attention gully sediment storage is important because many sedimentary archives such as floodplains and lakes have recorded increases in sedimentation rates particularly in medieval times which are interpreted as the result of increased slope erosion and gully activity at present there is insufficient evidence directly linking such other sedimentary archives and gully systems there is also a lack of long term records which may indicate how the major external controls climatic or anthropogenic might determine gully responses to address this we analysed sediment sources and sinks within a small 43 ha gully catchment in the spessart mountains germany we found five main phases of erosion and deposition since 13 ka which revealed catchment vegetation significantly controlled geomorphic responses a loss of vegetation due to climate deterioration e g younger dryas or deforestation e g medieval period caused widespread slope instability and the aggradation of the gully thalweg in contrast well forested conditions before the medieval period and again in recent years re stabilised the slopes leading to gully incision with knickpoint retreat this result differs from previous interpretations of gully activity in central europe that gully erosion mostly occurred in medieval times our results also demonstrate that only the initial phase of knickpoint retreat is significant for supplying sediment to the gully fan and trunk stream then knickpoint retreat leads to a relative increase in the thalweg storage capacity downstream which limits further sediment export this has important implications for the interpretation of floodplain ages since the initial supply of gully sediment to trunk streams may not coincide with human impact instead there will be a lagged response between catchment reforestation and the onset of gully incision which in this study is up to 150 years therefore the assumption of a direct causal link between increases in floodplain sedimentation and slope erosion may not always be valid

factors controlling sediment yield from small intensively cultivated catchments in a temperate humid climate abstract data on sediment yield from 26 small cultivated catchments 10 10 000 ha in central belgium were collected based on sedimentation rates in small flood retention ponds area specific sediment yield varies from 0 4 to 20 6 t ha 1 year 1 for catchments ranging from 7 to 4873 ha various catchment properties were analysed in order to understand this large variation in sediment yield catchment area alone explains 64 of the observed variance in area specific sediment yield although no other parameter could explain more it is concluded that catchment area is not a valid parameter to link with sediment yield overall catchment geomorphology e g presented by the hypsometric integral is much more important in controlling sediment yield the lack of data however made this not very clear a multiple regression model including three morphological catchment properties is a valuable tool to predict total sediment yield t year 1 from catchments in central belgium this model has an efficiency of 0 81 furthermore it was concluded that the within catchment spatial distribution of parameters for instance slope steepness is very important but difficult to obtain one single representative value the use of spatially distributed erosion and sediment delivery models is therefore necessary accurate sediment yield data like the one presented in this study however are needed to validate these models

size and density sorting of metal and silicate grains under microgravity conditions and the origin of chondrites 1 we report here experiments on nasa s kc 135 microgravity facility aimed at investigating metal silicate fractionation in chondrites metal and sand particle mixtures with sizes and relative proportions approximating chondritic values were allowed to undergo density and aerodynamic sorting as air was passed through 310 ten centimeter long 2 54 cm diameter columns under microgravity conditions metal and silicate fractionation was found to occur when gases passed through the mixtures and when the particle diameter ratio was large 3 0 with sand being enriched near the surface of the beds this is contrary to experiments performed under terrestrial gravity and the semi empirical ergun equation while the reason for this discrepancy is not well understood the present results do suggest that separation of metal and silicates will readily occur under microgravity conditions on the surface of asteroids

fluvial sediment budgets in the north carolina piedmont phillips j d 1991 fluvial sediment budgets in the north carolina piedmont geomorphology 4 231 241 sediment budgets for four large 1000 km 2 drainage basins in the piedmont physiographic province of north carolina were estimated from data compiled during erosion and sedimentation surveys budgets for the upper tar upper neuse haw and deep river basins showed broadly similar trends in allocation of eroded sediment among yield and storage sediment yield as a percentage of mean annual gross erosion within the basins averaged 10 this was less than the rate of alluvial storage which averaged 14 of annual gross erosion about 76 of the mean annual erosion was stored as colluvium on hillslopes there are relatively small differences in sediment delivery and storage ratios among the study basins this suggests that the relative order of magnitude of the allocation of eroded sediment for southern piedmont rivers is colluvial storage alluvial storage and yield of the sediment that does reach the streams more than half is stored as alluvium on an average annual basis aggrading channels and floodplains siltation of benthic habitats and sediment pollution problems are thus likely to persist unless dramatic reductions in upland erosion or in sediment delivery to streams are realized with respect to longer term basin evolution results point to the need for an improved understanding of the temporal scales of colluvial and alluvial sediment storage

time integrated 3d approach of late quaternary sediment depocenter migration in the tagus depositional system from river valley to abyssal plain quantification of sediment volumes in continental to deep ocean basins is key to understanding processes of sediment distribution in source to sink depositional systems using our own and published data we present the first quantification of sediment volume changes in basins along the course of a major southwest european river during the deglaciation the salient points of this quantitative record in the tagus and equivalent north atlantic basins show crucial roles for sea level climate and land use in the distribution of sediments the bypass of sediments starved the tagus basins and subsequently sedimentation mainly occurred on the tagus abyssal plain during the sea level lowstand of the last glacial maximum the main sediment depocenter rapidly shifted via the continental shelf to the lower tagus valley during sea level rise in the deglaciation period finally the main sediment depocenter shifted further landward into the lower tagus valley during sea level high stand in the holocene during the high stand phase last 7 ky sediment flux increased up to 2 5 times due to climate and land use changes the average catchment denudation rate during the last 12 ky 0 04 0 1 mm y is in agreement with those of other european catchments our study clearly demonstrates the added value of detailed knowledge of 3d depocenter distribution size and chronology this allowed us to identify an increased sediment flux during the last 7 ky which was not identified using local observations from boreholes alone the uniqueness of the tagus depositional system lies in the combination of a large accommodation space in the bedrock confined lower tagus valley the steep lowstand surface gradient and the narrow continental shelf with canyons indenting the shelf break

morphological control on sedimentation rates and patterns of delta floodplains in the swiss alps abstract glacially overdeepened alpine valleys and their perialpine lakes are very effective sedimentary sinks that include landforms as alluvial fans fan deltas and deltas the sedimentary archives of these landforms can provide long sedimentary records of erosion and aggradation processes in a catchment focusing on longer time series is vital to improve the conventional instrument based models of sediment transfer as longer time series record the effective low frequency sediment discharges triggered by high magnitude floods the research reported here combines statigraphical analysis of the sedimentary records of two lake deltas in the bernese alps with geostatistical modeling of the sedimentation storage of delta plain deposits from the three dimensional sediment storage model the sedimentary environments and aggradation dynamics of the aare and the lutschine rivers were reconstructed in 500 year time slices over the last 2500 years the spatial distributions of the aggradation rates of the two deltas show similar trends with decreasing downstream rates from delta apex to the delta front at lake brienz which is related to the adaption of the river s longitudinal profile to the pleistocene overdeepened valley morphology local modification of this trend was detected at narrowing of the valley floor caused by landslides the quantification of delta plain sediment volumes provides evidence that aggradation processes have decreased aare or remained nearly stable lutschine in the delta plains during the last 1500 years despite the strong human impact in the form of land use this decrease and the possible compensation of major human induced catchment erosion may be attributed to a more or less efficient regulation of the river channels during the last millennium which transferred the sediment load into lake brienz the sediment volumes obtained and the historical progradation of delta lobes support the previous hypothesis of the connectivity from source headwater catchments to sink perialpine lakes in the main valleys of the bernese alps the results of our study provide new insight into the quantitative estimation of sediment storage for geomorphic process modeling and into the evolution of alpine deltas during the late holocene

soil erosion in small catchments of the quercy region southwester france during the holocene erosion rates in two small catchments of the quercy region southwestern france calculated from colluvial deposits trapped in karstic depressions show a progressive increase during the holocene rates lower than 0 2 t ha 1 yr 1 have been found for the period that covers the beginning of the holocene to the early iron age the soils buried in the depressions testify to the permanence of a forest cover until the late neolithic and to its replacement by a herbaceous vegetation during protohistorical times probably as a consequence of forest clearance and increased grazing by cattle after the early iron age erosion increased significantly and the mean rate reached 0 8 t ha 1 yr 1 before mediaeval times the associated coarse grained crudely stratified colluvium is thought to reflect ploughing of the surrounding fields erosion rate increased up to c 1 3t ha 1 yr 1 during mediaeval and modem times

characterization and quantification of holocene colluvial and alluvial sediments in the valdaine region southern france this study presents a holocene sediment budget for the valdaine region located at the edge of the southern french pre alps holocene colluvial and alluvial deposition are quantified based on existing and new field data average sediment thickness values were calculated for different landscape units and available chronological data were used to make a time differentiated sediment budget total holocene colluvial deposition in the valdaine 334 km2 amounts 167 106 m3 while alluvial deposition in the roubion and jabron catchments in total 610 km2 including their catchment upstream the valdaine amounts 177 106 m3 especially colluvial deposition is high 0 75 106 g m2 compared with other catchments three major deposition periods 8500 2000 bc 700 bc ad 800 and ad 1200 2000 and two periods of relative hillslope stability with local fluvial incision 2000 700 bc and ad 800 1200 set the framework for a time differentiated sediment budget results show that depositional phases relate to intense

development of organic porosity in the woodford shale with increasing thermal maturity abstract using a combination of focused ion beam milling and scanning electron microscopy we describe the evolution of secondary organic porosity in eight woodford shale late devonian early mississippian samples with mean random vitrinite reflectance values ranging from 0 51 ro to 6 36 ro organic porosity was observed to be absent in samples with vitrinite reflectance values of up to 0 90 ro with the first appearance of secondary pores starting with the 1 23 ro sample porosity in the organic matter was unexpectedly absent in a sample with a vitrinite reflectance of 2 00 ro however organic pores were again found in samples with higher thermal maturities porosity when present did not appear to be uniformly distributed among the organic matter that was within less than a micron of each other suggesting important differences in composition of the organic matter thin regions of organic matter were observed between grains raising the possibility that small amounts of the deposited organic matter were compacted between grains to form thin layers and or the structures are part of the secondary organic matter interpreted to be post oil bitumen which was left behind as a residue during oil migration through the shale some regions of porous organic matter appeared to be grain protected whereas others did not which indicates that these non protected porous organic regions may be stress supporting with porosity intact under in situ reservoir conditions these observations suggest that thermal maturity alone is insufficient to predict porosity development in organic shales and other factors such as organic matter composition complicate porosity development

space weathering on airless bodies resolving a mystery with lunar samples using new techniques to examine the products of space weathering of lunar soils we demonstrate that nanophase reduced iron npfe0 is produced on the surface of grains by a combination of vapor deposition and irradiation effects the optical properties of soils both measured and modeled are shown to be highly dependent on the cumulative amount of npfe0 which varies with different starting materials and the energetics of different parts of the solar system the measured properties of intermediate albedo asteroids the abundant s type asteroids in particular are shown to directly mimic the effects predicted for small amounts of npfe0 on grains of an ordinary chondrite regolith this measurement and characterization of space weathering products seems to remove a final obstacle hindering a link between the abundant ordinary chondrite meteorites and common asteroids

gully catchments as a sediment sink not just a source results from a long term 12 500 year sediment budget sediment delivery from hillslopes to trunk streams represents a significant pathway of mass transfer in the landscape with a large fraction facilitated by gully systems the internal gully geomorphic dynamics represent a considerable gap in many landscape and empirical erosion models therefore a better understanding of these processes over longer timescales 10 10 years is needed this study analyses the sediment mass balance and storage dynamics within a headwater gully catchment in central europe over the last 12 500 years human induced erosion resulted in hillslope erosion rates 2 3 times higher than under naturally de vegetated conditions during the younger dryas however the total sediment inputs to the gully system and therefore gully aggradation were similar net gully storage has consistently increased to become the second largest term in the sediment budget after hillslope erosion storage is 45 and 73 of inputs during two separate erosion and aggradation cycles in terms of the depletion of gully sediment storage the sediment mass balance shows that export beyond the gully fan was not significant until the last 500 years due to reduced gully fan accommodation space the significance of storage effects on the gully sediment mass balance particularly the export terms means that it would be difficult to determine the influences of human impact and or climatic changes from floodplain or lake sedimentary archives alone and that the sediment budgets of the headwater catchments from which they drain are more likely to provide these mechanistic links

prehistoric and roman gullying in the european oess belt a case study from central belgium in contrast with the understanding of present day soil erosion processes knowledge on past soil erosion phenomena is still rather limited although some studies report on severe gully erosion phases during the fourteenth and eighteenth centuries almost no evidence is available that documents earlier gully erosion phases this study investigates the development and age of two old permanent gullies that are conserved in the ancient meerdaal forest in central belgium the development history of both gullies is very similar in the first gully archaeological evidence was found indicating an erosion phase during roman times followed by a partial infilling of the gully in the second gully radiocarbon dating provided evidence of the same roman activity phase cal yr 46 bc ad 78 but also of an earlier incision phase during the middle bronze age cal yr 1743 1602 1568 1533 bc also here the erosion phase was followed by a partial infilling this limited infilling indicates that the catchment of the gullies was reforested quite rapidly hereby cutting off all runoff and sediment production this has led to a unique situation in the meerdaal forest with the conservation of about 43 similar large gullies in an area of about 17 km 2 this area has a high geovalue as the studied gullies are among the oldest and best conserved gullies in northwestern europe

modeling impacts of erosion and deposition on soil organic carbon in the big creek basin of southern illinois abstract land use land cover lulc plays an important role in influencing the spatial intensity of water erosion which is the primary governor of horizontal translocation of soil organic carbon soc the fate of redistributed soc through erosion remains debatable and the mineralization rate of exposed soc protected in soil aggregates is the major focus of this argument cohesive spatially explicit modeling of soc and erosion can potentially reduce some of the controversy to this end we simulated erosion deposition and photosynthetic in situ flux of soc in a small watershed of 28 42 ha located in the big creek basin of southern illinois the main objectives of this research were a to study erosion and deposition dynamics under different lulc b to examine the extent of carbon dislocation and deposition possible in the study area and c to determine the net soc accretion and reduction possible by accounting for gains through annual photosynthesis and deposition and losses from erosion under different lulc scenarios to fulfill our objectives we combined geowepp an erosion deposition process model with century 4 0 an ecosystem model used for simulating soc our results show that between 11 and 31 of the eroded soil gets deposited in the same basin depending on the lulc type leaving the remainder to be transported downstream additionally as expected soc flux due to erosion and deposition varies with the type of management practices in the case of conservation management practices the flux associated with erosion and deposition remains below 10 in comparison to in situ soc transformations due to annual photosynthesis however in the case of non conservation management practices this proportion rises above 50

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

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

comparison of pore systems of clay rich and silica rich gas shales in the lower silurian longmaxi formation from the jiaoshiba area in the eastern sichuan basin china abstract the jiaoshiba area in the eastern sichuan basin hosts the largest commercial shale gas field in china with an annual production of 1 7 bcf the gases are primarily produced from the clay rich siliceous marine shales in the wufeng and longmaxi formations in this paper sixteen organic rich shale samples from a variety of lithofacies from the longmaxi formation in the jiaoshiba area were studied to evaluate the pore systems of clay rich shales by comparison with the silica rich gas shales the investigation includes the assessment of porosity and pore size distribution by means of shale bulk and skeletal density measurements low pressure n2 co2 gas adsorption and mercury intrusion the shale samples with different lithofacies have porosity values ranging from 3 25 to 5 65 and display similar fractional volumes of micropores mesopores and macropores and corresponding specific surface areas all three pore fractions contribute to the shales total pore volumes while the total specific surface areas are mainly contributed to by micropores and mesopores there is a positive correlation between pore volumes and toc contents indicating that the porosities in the shales are dominated by organic matter pores with toc content being the main parameter controlling pore development toc normalized pore volumes decrease with a further increase in the toc content from 1 6 to 4 2 this may be related to the fact that the toc rich shales are more susceptive to mechanical compaction clay mineral content appears to have little effect on the pore volume or specific surface area development in the shales shale samples with clay rich siliceous shale lithofacies display similar toc contents porosities and fractional volumes of all pore sizes and specific surface areas with those of the silica rich argillaceous and argillaceous siliceous mixed lithofacies this suggests that the marine shales with silica rich argillaceous and argillaceous siliceous mixed lithofacies from the longmaxi formation in the jiaoshiba area are capable of generating significant amount of pore spaces for shale gas storage

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

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

the origin of chondrites metal silicate separation experiments under microgravity conditions ii 1 in order to understand mechanical processes likely to be occurring on the surfaces of asteroids we have performed experiments with mineral mixtures on nasa s kc 135 microgravity facility the behavior of sand and iron filing mixtures the sand and metal being in the proportions and with grain sizes of ordinary chondrite meteorites was observed with digital cameras as gas was flowed upward through the mixtures and the plane went through cycles of positive zero negative and normal gravity partial separation of gas and sand occurred readily under gas flow and microgravity conditions and sometimes survived subsequent turbulence this behavior is consistent with predictions of the ergun equation derived from terrestrial experiments the data have implications for understanding chondrite genesis for understanding the spectra of asteroid surfaces and for the design of equipment to function on asteroid surfaces

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

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

rapid development and infilling of a buried gully under cropland central belgium abstract analysis of contemporary and past gully erosion and infilling processes allowed to reconstruct the long term evolution of a permanent gully system under cropland an active and a buried gully under cropland were investigated the recent sediment deposits within the active gully adjacent to the buried gully showed that the recent gully was filling in at a mean rate of 6 4 cm a 1 in the buried gully several erosion and deposition phases could be identified and the type of deposited sediments revealed a complex infilling history charcoal pottery and brick fragments of different sizes were found at all depths of the gully infilling their age indicates that the first gully incised after the midst of the 17th century most probably in the second half of the 18th century or the early 19th century gully morphology and analogy with the processes in the recent gully indicate that the buried gully filled in rapidly overall five cycles of cut and fill occurred in 350 years or less and four cycles even within little less than a few decades indicating that gully development and infilling under cropland can be very rapid processes

applying terzaghi s method of slope characterization to the recognition of holocene land slippage abstract during site investigations engineering geologists are expected to recognize landslides both active and dormant those without substantial experience evaluating the evolution of geomorphic features associated with localized mass wasting often mischaracterize site conditions karl terzaghi suggested seven steps in characterizing natural hillslopes including 1 a literature review 2 site reconnaissance 3 a program of subsurface exploration 4 preparation of sketches and diagrams illustrating the essential features 5 preparation of a preliminary geology report 6 observation and mapping of geologic structures exposed during excavation for construction and 7 development of contingency plans for anticipated variations in old landslide features based on our interpretation of terzaghi s original principles we review some of the most common interpretive problems with nomenclature of landslide features describe common mistakes in characterizing old landslides and present technical approaches that often aid in the recognition of old landslide features a wide variance in geological terms exists for describing landslides and various terms have been applied to the same features by workers in different areas which often leads to confusion some of these terms include nomenclature such as slip surfaces alluvial fans colluvium and slope creep active surficial landslides are relatively easy to recognize when they are well exposed although these features tend to become obscured with time anomalous hummocky topography often provide key recognition features of a slope s geomorphic evolution deeper seated bedrock landslides can be more difficult to recognize because their features become increasingly mollified with time these features can often be identified by anomalous geomorphic features such as isolated saddles or anomalous discontinuous benches these features are some of the best locations to excavate borings or exploratory trenches well placed trenches across headscarp grabens can provide more detailed structure of old landslides and are usually a cost effective approach additional subsurface exploration can often be employed to characterize landslides small diameter borings are usually employed for geotechnical investigations but can easily be applied to landslides depending on the mean particle size diameter d50 downhole logging of large diameter holes is the best method to evaluate complex subsurface conditions such as dormant bedrock landslides

age and source of colluvial sediments at vaihingen enz germany abstract colluvial sediments accumulated on the lower slopes of a ridge as a result of past and present soil erosion were dated by optical 14 c and archaeological methods this allowed us to reconstruct the depositional history of the colluvium and also to identify temporary sedimentary sinks in its transportational pathway a cascade model of colluvium formation is developed colluvial sediments resulting from early soil erosion in the neolithic to iron age periods were mainly deposited on the upper slopes significant deposition on the lower slope occurred for the first time during the iron age and roman period since then deposition rates have increased because of more intensive land use

the nature of small scale flooding muddy floods and retention pond sedimentation in central belgium abstract this study investigates the spatial variation of small scale flooding and muddy floods in rural areas in a medium sized study area 5516 km2 and the linkage with controlling factors a questionnaire set up in central belgium indicates that 43 of the municipalities have to deal from time to time with muddy floods generated from direct runoff from arable land and 36 with flooding of permanent streams a strong relation exists between the nature of the problem and the site in relation to topography and landuse areas suffering from muddy floods have significantly steeper cultivated slopes compared to areas suffering only from small scale flooding the high spatial and temporal frequency of small scale flooding and muddy floods results in emotional and significant economic damage to private households as a control measure more than 100 retention ponds have been constructed with 50 more to be built in the near future the mean cost for the construction of a retention pond amounts to 380 000 euro these retention ponds store large quantities of sediment from runoff events and must thus be dredged regularly with costs of the order of 1 5 million euro yearly the dredged sediment volumes can be used to assess and predict sediment yield for these drainage basins values vary between 0 19 and 6 m3 ha 1 year 1 for basins ranging from 25 to 5000 ha

establishing fine grained sediment budgets for the pang and lambourn locar catchments uk summary an integrated approach to data collection combining the use of 137cs measurements sediment source fingerprinting bed sediment surveys and conventional river monitoring has been successfully employed to establish the fine grained sediment budgets of two lowland groundwater fed catchments in the uk gross surface erosion is higher on cultivated land pang 55 263 t yr 1 or 507 t km 2 yr 1 lambourn 79 997 t yr 1 or 437 t km 2 yr 1 than on pasture pang 1960 t yr 1 or 140 t km 2 yr 1 lambourn 1425 t yr 1 or 95 t km 2 yr 1 in both study areas and a substantial proportion of the mobilized sediment is sequestered within the fields pang 28 058 t yr 1 or 228 t km 2 yr 1 lambourn 55 575 t yr 1 or 281 t km 2 yr 1 and between the individual fields and the river channel network pang 28 672 t yr 1 or 233 t km 2 yr 1 lambourn 24 782 t yr 1 or 125 t km 2 yr 1 the sediment contribution from banks and subsurface sources is relatively low and typically ca 5 t yr 1 in the pang and ca 11 t yr 1 in the lambourn representing only about 1 of the suspended sediment output from each study catchment the mean level of fine grained sediment storage in the main channel system is equivalent to 38 pang and 21 lambourn of the respective mean annual suspended sediment yields of the two catchments the estimated sediment delivery ratio for both study catchments is ca 1

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

holocene sediment budgets for upland catchments the problem of soilscape model and data availability abstract this study presents a holocene sediment budget for the upland catchment of the speyerbach in the palatinate forest southwestern germany the influences of both data availability and the choice of an appropriate soilscape model on the sediment budget calculations are investigated for budget calculations the spatial distribution of soils was derived from the soil map 1 50 000 thickness values of soil truncation and colluvial burial were extracted from two soil data sets with varying information content data processing contained a disaggregation of the soil map with the help of land use data in order to model the sediment budget a reference soil thickness a so called soilscape model which represents the initial conditions is necessary as upland soils are developed in periglacial solifluction sheets the main solifluction sheet mss hauptlage showing a constant thickness and being affected by soil forming processes was chosen determining the initial thickness of the mss is a crucial point as a comparison of reference values shows the literature values are actual thicknesses and differ significantly between 30 and 100 cm among various studies therefore a statistical model using the local profile descriptions of the soil database for the speyerbach catchment was set up we found that the 95 percentile worked best to extract the depths of pristine soils hence a pristine soil profile depth of 60 or 70 cm could be extracted for the speyerbach catchment calculating the sediment budget for 60 cm returns a sediment delivery rate sdr of 64 8 with a soilscape model of 70 cm a catchment sdr of 83 2 can be derived which is 18 4 higher than the first one the computed sdr is twice as high as the sdr determined by houben et al houben p burggraaf p hoffmann t kleefeld k zimmermann a dikau r 2007 reconstructing holocene land use change and sediment budgets in the rhine system pages news 15 1 17 18 and rommens et al rommens t verstraeten g poesen j govers g van rompaey a j j peeters i lang a 2005 soil erosion and sediment deposition in the belgian loess belt during the holocene establishing a sediment budget for a small agricultural catchment the holocene 15 7 1032 1043 this may reflect differences in physio geographical settings and settlement history between a loess covered basin catchment and a deeply furrowed upland catchment since no datings or proxy data are available the classification to individual settlement periods and furthermore an estimation of human impact is not possible yet future work will address the estimation of human impact by the analysis of historical data and datings of colluvial layers as well as a field validation of the computed sediment budgets

alluvial fans as an effect of long term man landscape interactions and moist climatic conditions a case study from the glubczyce plateau sw poland abstract at the mouth of periodically drained valleys in the loess glubczyce plateau sw poland favorable conditions for deposition of alluvial fan sediments occur so these forms are very common in the investigated area the origin of the forms analyzed is related to long term human landscape interactions because deforestation and land use changes started in the neolithic ca 5 5 ka bc causing intensification of soil erosion processes willful and continuous interference by man into natural environment began at that time thus human impact is responsible for acceleration of runoff and mobilization of sediment which formed alluvial fans at the mouths of episodically drained valleys the objectives of this study are 1 to measure the morphological and topographical characteristics of the fans 2 to describe and analyze the inner structures of the alluvial fans analyzed and 3 to date the alluvial fan deposition the alluvial fans are mainly formed of silty clayey massive sediments the gravel sand layers occurring in two exposures indicate the incision of the valleys in the older pleistocene sediments underlying the loess upland deposits and intensive phases of erosion in the course of which coarser material could have been transported radiocarbon dating of the peat filling the bottoms of the valleys and underlying the mineral deposits of the fans indicates that sediment transfer from cultivated valley slopes and its deposition at the mouth of the valleys was recorded in alluvial fan sediments by the neolithic 6895 140 bp during this period erosion was probably intensified by a moister climate radiocarbon dating of organic layers which were discovered inside the sediments of two fans show that the youngest dated stage of intensified erosion took place in early medieval times when the glubczyce plateau was colonized again by slavs after the settlement depression during the migration period

historical analysis indicates seepage control on initiation of meandering in analytical and numerical models of river meandering initiation of meandering typically occurs uniformly along the streamwise coordinate in the channel based on a historical analysis of the nierskanaal here we show how and under which circumstances meandering has initiated in isolated sections of a channel the nierskanaal was constructed by the end of the 18th century as a straight channel between the river niers and the river meuse the purpose of this measure was to reduce flood risk in the downstream reaches of the river niers the banks on the dutch part of the channel were left unprotected and developed into a morphodynamically active channel featuring a meandering planform and valley incision the planform development and incision process is analysed using topographic maps and airborne lidar data meandering initiated in three sections of the channel where the channel sinuosity developed asynchronously sedimentary successions in the study area show layers of iron oxide indicating groundwater seepage from aeolian river dunes and river deposits located nearby only at the spots where meandering has initiated iron oxide is found close to the surface level this provides a clue that seepage triggered bank erosion by increasing moisture content of the banks the isolated meandering sections expanded in the longitudinal direction valley incision has developed in the first decades after the construction of the channel and diminished after a gravel layer was reached gravel was deposited in the downstream half of the channel bed acting as an armouring layer the spatial variation in meandering behaviour as observed in the nierskanaal justifies efforts to implement the influence of floodplain heterogeneity and the effect of seepage on bank erosion in meander models

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

heavy metal contamination in overbank sediments of the geul river east belgium its relation to former pb zn mining activities overbank sediments of the geul river east belgium are highly contaminated by the heavy metals pb zn and cd due to former pb zn mining activities in the drainage basin geochemical variations in vertical overbank sediment profiles sampled 1 km north of the mine tailings of plombieres allow metal fluxes back to the 17th century to be reconstructed the vertical profiles are subdivided into three major units corresponding to different industrial periods based on sedimentological criteria as well as on the distribution of contaminants alluvial sediments with the highest heavy metal concentrations correspond to the major period of mining activity of the 19th century the fact that zn mining at the la calamine open mine started before large scale mining of the pbs zns subsurface exploitations is reflected in the vertical profiles by an increase in zn content before a marked increase in pb and cu the regional extent of contamination in the alluvial deposits was evaluated on the basis of the geochemical analysis of sediments at depths of the 0 20 cm and 80 100 cm most of the upper samples are extremely contaminated significant local variations in heavy metal concentration in the lower samples are interpreted in terms of which overbank sediment horizon has been sampled at a depth of 80 100 cm this indicates that blind sampling of overbank sediments to characterize the degree of contamination in shallow boreholes can give very erratic results

spatial delineation of organic carbon rich colluvial soils in chernozem regions by terrain analysis and fuzzy classification abstract colluvial soils are considered to be the direct result of accelerated soil erosion resulting in accumulation of humus rich soil material in terrain depressions and base parts of slopes the organic carbon concentration in these soils and their depth make them an important organic carbon storage mapping the colluvial soils therefore represents an important contribution in total carbon stock estimation a method of delineating colluvial soils is proposed by applying a combination of high resolution digital elevation model analysis and detailed field survey two models based on fuzzy classification of soil units were created using different topographic derivatives as the only input parameters to predict the colluvial soil area on a morphologically diverse study site in the southern moravia czech republic the model that considers only the derivatives with a strong relationship to colluvial soil occurrence reached 71 accuracy in colluvial area delineation while the model combining six commonly used derivatives showed less favorable results the main advantage of the method lies in a low demand of input soil data and its relatively high accuracy

a cellular model of holocene upland river basin and alluvial fan evolution coulthard t j macklin m g kirkby m j 2002 a cellular model of holocene upland river basin and alluvial fan evolution earth surface processes and landforms 27 3 269 288

alluvial and colluvial sediment storage in the geul river catchment the netherlands combining field and modelling data to construct a late holocene sediment budget abstract we used a combined approach of a two dimensional erosion and hillslope sediment delivery model watem sedem and detailed geomorphological reconstructions to quantify the different components in a sediment budget for the geul river catchment southern netherlands since the high middle ages hillslope erosion and colluvium deposition were calculated using the model while floodplain storage was estimated using field data our results show that more than 80 of the total sediment production in the catchment has been stored as colluvium mostly generated by hillslope erosion while almost 13 is stored in the floodplain since the high middle ages this situation resembles a capacity limited system model results for the period prior to the high middle ages with a nearly completely forested catchment show that far less sediment was generated and that most of the sediments were directly transported to the main river valleys or out of the catchment a supply limited system geomorphological analysis of a large alluvial fan shows the sensitivity of the study area to changes in the percentage of arable land our combined field data modeling study presents an elegant method to calculate a catchment sediment budget for a longer period and is able to identify and quantify the most important sediment storage elements furthermore it provides a valuable tool to calculate a sediment budget while only limited dated fluvial sediment sequences are available

budgeting soil erosion from floodplain sediments of the central rhenish slate mountains westerwald germany the distribution thickness and composition of the floodplain sediments in the valleys of the gelbach lower westerwald and grose nister upper westerwald depend on the occurrence of loessic periglacial cover beds in their catchments as well as on historical land use the budget of floodplain sedimentation was derived from a study of the floodloams underlying the monastery garden of marienstatt a village in the grose nister valley from the study of two occupation levels pottery shards and radiocarbon dating 55 of the floodloam can be attributed to the modern period younger than c ad 1450 from the radiocarbon age of a charcoal fragment extracted from the base of the floodloam at another site in the nister valley it can be concluded that the floodloams were almost exclusively deposited by human impact since the time of high medieval expansion of settlement into the uplands the fine grained loamy sediments blanket a rather irregular floodplain of channels and gravel bars similar results as to t

the geology of 433 eros the global high resolution imaging of asteroid 433 eros by the near earth asteroid rendezvous near shoemaker spacecraft has made it possible to develop the first comprehensive picture of the geology of a small s type asteroid eros displays a variety of surface features and evidence of a substantial regolith large scale facets grooves and ridges indicate the presence of at least one global planar structure directional and superposition relations of smaller structural features suggest that fracturing has occurred throughout the object as with other small objects impact craters dominate the overall shape as well as the small scale topography of eros depth diameter ratios of craters on eros average 0 13 but the freshest craters approach lunar values of 0 2 ejecta block production from craters is highly variable the majority of large blocks appear to have originated from one 7 6 km crater shoemaker the interior morphology of craters does not reveal the influence of discrete mechanical boundaries at depth in the manner of craters formed on lunar mare regolith and on some parts of phobos this lack of mechanical boundaries and the abundant evidence of regolith in nearly every high resolution image suggests a gradation in the porosity and fracturing with depth the density of small craters is deficient at sizes below 200 m relative to predicted slopes of empirical saturation this characteristic which is also found on parts of phobos and lunar highland areas probably results from the efficient obliteration of small craters on a body with significant topographic slopes and a thick regolith eros displays a variety of regolith features such as debris aprons fine grained ponded deposits talus cones and bright and dark streamers on steep slopes indicative of efficient downslope movement of regolith these processes serve to mix materials in the upper loose fragmental portion of the asteroid regolith in the instance of ponded materials and crater wall deposits there is evidence of processes that segregate finer materials into discrete deposits the near observations have shown us that surface processes on small asteroids can be very complex and result in a wide variety of morphologic features and landforms that today seem exotic future missions to comets and asteroids will surely reveal still as yet unseen processes as well as give context to those discovered by the near shoemaker spacecraft

land use and climatic impacts on the rhine system rheinlucifs quantifying sediment fluxes and human impact with available data abstract the rheinlucif project investigates the effects of land use and climatic impacts on sediment fluxes in the river rhine catchment among the world s large rivers the rhine system has been particularly affected by land use changes for 7500 years resulting in its transformation to an entirely man controlled environment geomorphologically this transformation is performed by largely man induced sediment fluxes since the mid holocene as the large scale of the rhine catchment inhibits a renewed recording of stratigraphic records the main goal is to synthesize quantitative data on sediment flux climatic and human impacts from already available data from various fields of earth surface and social sciences particularly history and archaeology this paper presents the first steps and results of methodological groundwork exploring how to derive sediment budgets from available spatially distributed data soil maps geological maps dems furthermore a new basically statistical approach utilising archaeological data is outlined this approach provides time series of quantified human impact i e information on population densities and open land woodland ratios the first results derived from four different sediment budget approaches are helpful in order to assess the quality of available data for budget calculation purposes although some estimates on erosion and alluvial deposition seem to broadly agree a considerable disparity of holocene erosion and colluviation values occurs when these values are compared to the outcome of an independently recorded soil mapping campaign in a pilot area however in general the results suggest that all applied approaches chiefly require an improved estimation of sediment storage on the one hand this accounts for the need of more precise information on holocene floodplain deposits on the other hand as the larger portion of man induced sediments still resides in the sloping parts of catchments realistic estimates on man induced colluvial deposition on slopes are essential apart from budgeting issues all data on holocene erosion and sedimentation in the rhine catchment lacked a sufficient dating control therefore further investigations on fluxes between budget components necessitate additional datings quantified data on human impact is indispensable to the modelling of sediment fluxes because human impact is deemed to be the major driving force of sediment production and re distribution although the archaeological approach was developed and tested by utilising well documented data about the neolithic era the promising statistical evaluation suggests that this method can be applied to even less well documented proto prehistoric and historic periods

ponded deposits on asteroid 433 eros in late january 2001 the near shoemaker spacecraft performed low altitude passes over the surface of 433 eros coordinated observations of the asteroid surface were obtained at submeter resolution by the near laser rangefinder and the multispectral imager this paper presents three independent coordinated observations of a 90 m pond adjacent to a granular debris flow including the highest resolution altimetric measurements of ponded deposits on eros the ponded deposits appear to have been emplaced by fluid like motion of dry asteroidal regolith a simple model of seismic agitation from impacts is developed to account for pond formation on eros the model predicts that ponds should form readily on eros but not on the moon where ponds are not observed the model also suggests that the absence of observable ponds in the largest craters of eros as well as on phobos and deimos may be related to regolith depth

on the effects of petrographic composition on coalbed methane sorption abstract the effect of petrographic composition on the methane sorption capacity has been determined for a suite of coals and organic rich shales subbituminous and bituminous coals were separated into bright and dull lithotypes by hand picking the methane sorption capacities range between 0 5 and 23 9 cm 3 g at a pressure of 6 mpa the low volatile bituminous canmore coal and the anthracite sample have the highest capacities with the natural coke having the lowest for low rank coals there is no significant difference between bright and dull samples except for one coal with the dull sample having a greater sorption capacity than its bright equivalent for higher rank coals the bright samples have a greater methane capacity than the dull samples and the difference between sample pairs increases with rank the boghead coal samples have the highest sorption capacities in the liptinite rich coals suite and are higher than subbituminous to medium volatile bituminous samples pore size distribution indicates that methane is held as solution gas in liptinite rich coals and by physical sorption in micropores in liptinite poor coals these contrasting processes illustrate that liptinite rich samples need to be independently assessed the positive relationship between reactive inertinite content and methane sorption capacity occurs within the subbituminous to medium volatile bituminous coals because the reactive inertinite is structurally similar to vitrinite and have a higher microporosity than non reactive inertinite reactivity of inertinite should be assessed in cbm studies of dull coals to provide a better understanding of petrographic composition effects on methane capacity

development of a holocene glacier fed composite alluvial fan based on surface exposure age dating techniques the illae fan jotunheimen norway abstract holocene development of a composite alpine alluvial fan is reconstructed and dated based on its geomorphology and schmidt hammer exposure age dating shd supplemented by terrestrial cosmogenic nuclide dating tcnd lichenometry radiocarbon dating soil development and palaeohydrological analysis shd ages of 7080 450 to 8220 440 years and a tcnd age of 6075 1220 years from the fan surface indicate that fan aggradation occurred in the early holocene through episodic debris floods phase 1 in response to paraglacial processes following deglaciation of the catchment 9 7 ka stabilisation during the holocene thermal maximum phase 2 was followed by re activation of the fan involving entrenchment and terrace formation phase 3 which occurred in response to neoglaciation after 5 5 ka and culminated in the little ice age the main control on fan development was the effect of the changing extent of glaciers in the catchment on sediment supply initially evinced in high magnitude debris floods hyperconcentrated flows and later in water floods typical fluvial processes aggradation switched to stabilisation as paraglacial activity waned while later entrenchment was associated with relatively low bedload results provide the basis of a conceptual model of alluvial fan evolution for glacierized catchments related to holocene environmental change

sediment yield and storage variations in the negron river catchment south western parisian basin france during the holocene period in the negron river catchment area 162 km2 surface sediment stores are composed of periglacial calcareous greze 5 106 t and loess 21 106 t and holocene alluvium 12 6 106 t peat 0 6 106 t and colluvium 18 5 106 t seventy five per cent of the holocene sediments is stored along the thalwegs present net sediment yield calculated from solid discharge at the negron outlet is low 0 6 t km 2 a 1 due to the dominance of carbonate rocks in the catchment mean sediment yield during the holocene period is 7 0 t km 2 a 1 from alluvium stores and 7 6 t km 2 a 1 from colluvium stores thus the gross sediment yield during the holocene period is about 18 7 t km 2 a 1 and the sediment delivery ratio 3 per cent the yield considerably varies from one sub basin to another 3 9 to 24 5 t km 2 a 1 according to lithology about 25 per cent and 50 per cent of initial stores of periglacial greze and loess respectively were reworked during the holocene period sediment yield has increased by a factor of 6 in the last 1000 years due to the development of agriculture the very high rate of sediment storage on the slope during that period 88 per cent of the yield can be accounted for by the formation of cultivation steps rideaux it is predicted that the current destruction of these steps will result in a sediment wave reaching the valley floors in the coming decades subboreal and subatlantic sediments and pollen assemblages in the taligny marsh where one third of the alluvium is stored show the predominant influence of human activity during these periods in the negron catchment copyright 2002 john wiley sons ltd

relating soil erosion and sediment yield to geomorphic features and erosion processes at the catchment scale in the spanish pre pyrenees erosion and sediment redistribution are important processes in landscape changes in the short and long term in this study the rmmf model of soil erosion and the sedd model of sediment delivery were used to estimate annual soil loss and sediment yield in an ungauged catchment of the spanish pre pyrenees and results were interpreted in the context of the geomorphic features the estana catchment is divided into 15 endorheic sub catchments and there are 17 dolines gullies and slopes were the main erosive geomorphic elements whereas the colluvial alluvial valley floor and doline deposits were depositional elements spatially distributed maps of gross soil erosion sediment delivery ratio sdr and sediment yield sy were generated in a gis severe erosion rates 100 mg ha 1 year 1 were found in gullies whereas mean and maximum erosion rates were very high on slopes developed on keuper facies and high in soils on muschelkalk facies where crops are grown the depositional type geoforms were predicted by the models to have an erosive dynamic those results were consistent with the rates of erosion quantified by 137cs which reflects the significant role of human activities in triggering soil erosion catchment area was positively correlated with erosion rate but negatively correlated with sdr and sy the latter were negatively correlated with the proportion of the surface catchment covered with forests and scrublands the topography of the area influenced the high sdr and sy in the dolines and valley floors near the sinks intra basin stored sediment was 59 2 of the total annual eroded soil in the catchment the combination of the rmmf and sedd models was an appropriate means of assessing the effects of land uses on soil erosion and obtaining a better understanding of the processes that underlie the geomorphic changes occurring in mountainous environments of the mediterranean region

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

human induced soil erosion and the implications on crop yield in a small mountainous mediterranean catchment sw turkey abstract many hillslopes in the limestone dominated taurus mountain range sw turkey are characterized by severely depleted soils while a significant amount of sediment is being stored in the valley bottoms the same holds true for the 11 4 km2 endorheic gravgaz basin in the vicinity of the hellenistic roman city of sagalassos in sw turkey previous palaeo environmental research in this basin already yielded both detailed sedimentological and palynological information on sedimentation in the valley bottom and vegetation changes that took place during the last several millennia an adapted watem sedem geomorphic model version was used to simulate the impact of the observed changes in vegetation cover climate and hillslope soil properties on hillslope soil erosion and valley bottom sediment deposition over the last 4000 years the calibrated watem sedem model is able to reconstruct the temporal changes of sedimentation in the valley bottom reasonably well to simulate the impact of historic soil erosion on crop productivity a simple crop yield model was coupled to the reconstructed soil thickness maps the main outcomes are that soil erosion was mainly driven by deforestation and hence anthropogenic activity but the resulting soil erosion did not cause a complete collapse of crop yields on the contrary we were able to quantify that the sediment accumulation in the lower lying valley bottoms compensated at least a part of the loss in crop yield from the hillslopes potential crop yield value changed from 2 80 t ha 1 a 1 before widespread deforestation to 2 58 t ha 1 a 1 during roman imperial times and 2 19 t ha 1 a 1 at present these model approaches are tools that allow us to quantify human impact in the past going beyond traditional qualitative descriptions which will ultimately lead to a better understanding of human environment interactions in the past

the formation of alluvial fans and young floodplain deposits in the lieser catchment eifel mountains western german uplands a study of soil erosion budgeting this study deals with the exploration and spatiotemporal quantification of the young holocene nearly skeleton free floodplain sediments of the lieser river a tributary of the mosel river in the eifel mts the deposits are primarily a consequence of anthropogenic triggered soil erosion in the catchment to observe the phenomenon of corresponding soil erosion on multiple levels two small alluvial fans of tributary catchments were investigated for comparison one location in the neighboring salm valley was described the results were compared with those of other streams with extensive fieldwork more than 100 drillings and pits were made at 12 locations for dating the sediments osl dating 14c dating of organic contents and archaeological artifacts were used in the floodplains of the lieser and its tributaries 35 1 106 t of overbank fines are stored to achieve this an average soil erosion of 61 4 mm in the whole catchment would have been necessary about 28 of young floodplain sediments in upper a

the impact of land use and climate change on late holocene and future suspended sediment yield of the meuse catchment abstract in this study we investigate the relative importance of changes in land use and climate on suspended sediment yield sy on millennial timescales in the meuse basin we use a spatially distributed soil erosion and sediment delivery model watem sedem to simulate sy in three time periods 4000 3000 bp minimal anthropogenic influence 1000 2000 ad includes land use and climate change and the 21st century changes in climate are based on climate model output ecbilt clio vecode for the 21st century the model is forced according to two emission scenarios of the intergovernmental panel on climate change ipcc namely the sres scenarios a2 and b1 these scenarios lie towards the higher and lower end of the full ipcc scenario range respectively for 4000 3000 bp the basin is assumed to be almost fully forested for 1000 2000 ad land use is reconstructed using corine data historical sources and land use modelling and for the 21st century land use is based on the european land use change project eururalis whilst rainfall erosivity increases by only 3 between 4000 3000 bp and 1000 2000 ad sy increases from ca 92 000 mg a 1 to ca 306 000 mg a 1 this model prediction is in agreement with the limited regional multi proxy data available our simulations show that almost all of this increase is due to the conversion of forest to agricultural land over the period 1000 1900 ad sy shows a significant increasing trend with a peak of ca 388 000 mg a 1 in the 19th century due to continuing deforestation in the 20th century reforestation and rapid urbanisation result in a decrease to ca 281 000 mg a 1 sensitivity analyses show that although land use change acts as the primary control on long term changes in sy the sensitivity of sy to changes in climate increases as the percentage of deforested land increases for the 21st century the results are highly sensitive to the scenarios used due to relatively large increases in rainfall erosivity sy increases by 12 compared to the 20th century according to scenario a2 or by 8 according to b1 however the associated land use change scenarios cause decreases in sy by 26 a2 and 46 b1 the net effect is thus a decrease of sy this study highlights the potentially significant efficacy of land use planning as a tool to mitigate the negative effects of soil erosion and sediment delivery to rivers

pore characterization of organic rich lower cambrian shales in qiannan depression of guizhou province southwestern china abstract nine organic rich shale samples of lower cambrian black shales were collected from a recently drilled well in the qiannan depression guizhou province where they are widely distributed with shallower burial depth than in sichuan basin and their geochemistry and pore characterization were investigated the results show that the lower cambrian shales in qiannan depression are organic rich with toc content ranging from 2 81 to 12 9 thermally overmature with equivalent vitrinite reflectance values in the range of 2 92 3 25 and clay contents are high and range from 32 4 to 53 2 the samples have a total helium porosity ranging from 2 46 to 4 13 and total surface area in the range of 9 08 37 19 m2 g the estimated porosity in organic matters defined as the ratio of organic pores to the volume of total organic matters based on the plot of toc vs helium porosity is about 10 for the lower cambrian shales in qiannan depression and is far lower than that of the lower silurian shales 36 in and around sichan basin this indicates that either the organic pores in the lower cambrian shale samples have been more severely compacted than or they did not develop organic pores as abundantly as the lower silurian shales our studies also reveal that the micropore volumes determined by dubinin radushkevich dr equation is usually overestimated and this overestimation is closely related to the non micropore surface area of shales i e the surface area of meso and macro pores however the modified bet equation can remove this overestimation and be conveniently used to evaluate the micropore volumes surface area and the non micropore surface areas of micropore rich shales

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

historical erosion and sedimentation in two small watersheds of the southern blue ridge mountains north carolina usa sediment bodies produced during historical periods of human land use sometimes referred to as legacy sediment may be found in various locations within drainage basins and potentially remobilized by hydrogeomorphic processes accompanying land use change the amounts and locations of stored legacy sediment can be significant factors in modern drainage basin function and should be accounted for when possible in this study late nineteenth century erosion and sediment storage were investigated and used to construct approximate sediment budgets for two small blue ridge mountain drainage basins in north carolina usa erosion was quantified using a distributed implementation of the universal soil loss equation usle and calibrated on the separate bases of soil profile truncation data and recent published rates for long term erosion in the region sediment yield information was reconstructed from pond sediments trapped behind a mill dam alluvial sediment storage was quantified using field studies of streambank and floodplain sediment profiles and digital elevation data colluvial storage was calculated as a residual in the sediment budget and further evaluated using soil profile studies of footslope deposits and soil survey maps the proportions of erosion accounted for by the different budget terms in the most reliable budget are 28 sediment yield i e a sediment delivery ratio of 0 28 69 colluvial storage and 3 alluvial storage blue ridge basins with low levels of ground disturbance erode like piedmont basins at high levels of ground disturbance primarily due to higher slope angles sediment delivery ratio is high relative to those given for much larger basins in the adjacent and more frequently studied piedmont province and generally in accordance with published sediment delivery curves that reflect higher hydrogeomorphic connectivities within smaller basins low values for alluvial storage in blue ridge basins may be explained by high sediment transport within steep channels colluvial storage values have high uncertainties because of the well known problem of error accumulation in residual budget terms field data on colluvial deposits reported here are not sufficient to correct for this problem and in general the acquisition of accurate field data on historical colluviation remains an important methodological issue in historical sediment budgeting

holocene floodplain deposition and scale effects in a typical european upland catchment a case study from the ambleve catchment ardennes belgium this study quantifies holocene alluvial sediment deposition in the belgian ambleve catchment 1080 km2 situated in the ardennes uplands an extended coring data set is used for a quantitative description and a quantification of the alluvial depositions the floodplains fall into three main types the upper and lower floodplains and the steep reaches total holocene alluvial sediment deposition amounts to 32 tg or 0 029 tg km2 dating of sediments using iron slag as tracer shows that on average 42 of contemporary storage was accumulated during the last 600 years radiocarbon dating of fluvial deposits at eight sites in the catchment confirms that the majority of the sediment is relatively recent the increased sedimentation rates for this period are related to anthropogenic land use possibly enhanced by climatic variations a fluvial sediment budget was constructed for this 600 yr time period and shows that export from the catchment has about the same importance as storage in the floodplains while la

sediment flux to basins causes controls and consequences there is an increasing trend in the earth sciences towards the integration of many subdisciplines the sedimendatry basin is a fundamental focal point of many studies which as a consequence often neglects the complimentary drainage basin or catchment sedimentary basins provide a record of earth history reflecting the geographical lithological oceanographic and ecological development through the rock record drainage basins in comparison record ephemeral landscape evolution where topography is eroded and provides the flux of sediment to the basin the basin fill reflects the sediment flux from the hinterland and provides evidence of the dynamic geomorphic processes in context the drainage system and sedimentary basin can be regarded as a production line with sedimentary record giving valuable insight into long term landscape evolution and geomorphological processes illuminating the evolution of sedimentary basins this volume assesses the current position of understanding sediment supply to basins with the integration of the many sub disciplines in the earth sciences it documents a mix of hinterland and sedimentary basin studies with a gradation from orogenic belts to the deep marine the authors represent a wide spectrum of earth scientist with leaders in the science providing review papers and new directive papers in their field of specialization

human and climate impact on catchment development during the holocene geul river the netherlands interest in the holocene development of small to medium sized river catchments in western and central europe in relation to changes in land use and climate has increased over the past years in this study we reconstruct the holocene landscape development and fluvial dynamics of the geul river the netherlands and the main forcing mechanisms of environmental change field studies were carried out and we used osl and 14c dating methods to reconstruct the holocene valley development our study shows that 2 periods of deforestation during the roman period and the high middle ages led to severe soil erosion and increased floodplain sedimentation in the catchment of the geul river possibly combined with periods of increased wetness during the high middle ages alluvial fans have been active since the roman deforestation phase our results show that the geul catchment is highly sensitive to changes in land use

correlation of colluvial deposits with the modern land surface and the problem of slope profile description abstract this article focuses on features of spatial distribution of colluvial slope deposits on a micro scale these features were detected by the non parametric rank correlation of spearman rs between thickness of colluvial layers and morphometric variables mvs of the modern land surface the strongest correlation was found between total thickness of colluvial layers and maximal catchment area rs 0 85 a negative correlation was observed between thicknesses of younger and older colluvial layers additionally if young colluvial layers have a negative correlation with slope steepness ga relatively old buried colluvial layers have a positive correlation with ga these facts indicate an inversion of the zones of actual matter accumulation due to transformation of the land surface in profile during long term sedimentation vertical curvature kv characterises acceleration and deceleration of surface flow caused by the shape of the slope profile along flow lines based on this it was expected that kv would have a direct impact on the accumulation of colluvium however in this study the correlations between the thickness of colluvial deposits and kv were low functional relationships between colluvial accumulation and the shape of profiles along flow lines were reflected by correlations with ga based on these observations it is assumed that the regional nature of surface flow velocity affects the shift between existing accumulation zones reflected by colluvial deposits and potential accumulation zones reflected by mvs signs of correlation coefficients between the thickness of colluvial deposits and curvatures reflect the tendency of increased colluvial depositions at three out of 12 local landforms of shary s classification these landforms are located in the valley bottom the mean thickness of colluvial deposits at these three landforms was 167 18 7 cm error range standard deviation the other nine landforms show a mean thickness of 130 1 34 1 cm