controls on cave drip water temperature and implications for speleothem based paleoclimate reconstructions while several studies explore cave climate and thermal regimes little is known about the controls on cave drip water temperature yet water temperature significantly influences biogeochemical processes associated with cave drips to identify the processes that control the cave drip water temperature we measured the temperatures at multiple locations along a speleothem flow path and drip sources stalactites concurrently with the drip rates in cathedral cave wellington australia we monitored long term drip water temperature drip rates surface and cave climate and in cave evaporation rates and conducted 3 infiltration experiments with different flow temperature and isotopic conditions our results show that the drip water temperature is controlled by multiple superimposed heat transport mechanisms that act upon the infiltrating water in the epikarst the water film after it enters the cave and before it becomes a drip the two main heat sources sinks for drip water are the cave air and the surrounding rock the subsurface temperature is coupled to the surface temperature by conduction through the soil and rock mass but the cave climate is also coupled to the surface climate by venting on a regional scale drip temperatures are mainly driven by the annual ground surface temperature signal but damped with depth and shifted in time compared to the surface on a local scale the drip water temperature can differ significantly from cave air and speleothem temperature due to the latent heat exchange of evaporation and localised water film convection the main controls are ground surface temperature subsurface depth air density induced ventilation distance from entry and drip rate we present a conceptual model that explains drip water temperature signals and provide signal driven guidance on best type and location for speleothem sampling we anticipate that our results will significantly improve the understanding of temperature dependent paleoclimate signals from speleothem archives

climate and human environment relationships on the edge of the tenaghi philippon marsh northern greece during the neolithization process abstract palynological and sedimentological investigations carried out around the tell of dikili tash eastern macedonia greece one of the oldest neolithic sites in europe improve our understanding of the evolution of the paleoenvironment from the late pleistocene to the neolithic period 6500 3200 cal bc in this region while global climate reconstructions researches based on the study of the tenaghi philippon pollen record located 5 8 km from the tell have focused on forces that drive the environment at regional or global scales we attempt to use the sediment archives on the edge of the marsh to describe the context of the neolithization process and related environmental changes our aim is to provide new data on environmental change during the early holocene by combining pollen non pollen palynomorphs npps and sedimentological analyses to be compared with archaeological information the data give an overview of the original environment prior to the neolithic and thereafter a comprehensive view of the first human impacts on the vegetation cover in local lowland areas two new pollen records located respectively 1 75 km dik4 and 150 m dik12 from the archaeological site provide the first evidence of human agropastoral activities on the landscape associated with the early neolithic communitiessince at least 6400 cal bc largely earlier than observed in the reference pollen diagram in the tenaghi philippon marsh which shows a first human impact from the second millennium cal bc admittedly such impact on the local area around the site cannot be extrapolated to a regional scale raising question of the spatial representativeness of the previous records it also shows the need to develop multi scalar investigations to assess the impact of climatic change and human activities on the landscape during the earliest phase of the neolithic settlement in southeastern balkans

reconstruction of lake level changes in lake xinias central greece during the last 40 000 years abstract the investigation of lake xinias greece deals with lake level changes since about 40 000 b p particular effort was made to obtain a reconstruction of lake level during the last glacial maximum at about 18 000 b p the reconstruction was based on a transect of sediment cores the cores were pollen stratigraphically correlated and the interpretation of the sediment stratigraphy was based on sediment chemical and mineral magnetic analyses the chronology was based on accelerator and conventional radiocarbon datings the most striking change was a lake level lowering at about 32 000 b p resulting in an overgrowing of the whole lake the lake level probably remained generally low until somewhat before 15 000 b p the period around the last glacial maximum must have been characterized by a low lake level which is in contrast to the hitherto common opinion additional investigations are required to demonstrate that the lake level changes reconstructed in lake xinias are regionally significant and record climatic changes however it may already be suggested that the conflict between pollen and lake level evidence which hitherto has produced controversy about the glacial climate perhaps does not exist the low lake level in lake xinias around the last glacial maximum is in accordance with the pollen evidence of steppe vegetation both recording a dry climate another distinct lowering occurred around the late wurmian holocene boundary at about 10 000 b p some minor lowerings are recorded also during the holocene e g at about 6000 5000 and 3000 b p

impact of soil characteristics and land use on pipe erosion in a temperate humid climate field studies in belgium abstract this study investigates the role of soil characteristics and land use in the development of soil pipes in the loess belt of belgium first we tested the hypothesis that discontinuities in the soil profile enhance lateral flow and piping by impeding vertical infiltration we focus on discontinuities in soil characteristics that can vary with soil depth including texture saturated hydraulic conductivity penetration resistance and bulk density these characteristics as well as soil biological activity were studied in detail on 12 representative soil profiles for different land use types twelve sites were selected in the flemish ardennes belgium four pastures with collapsed pipes cp four pastures without cp two sites under arable land without cp and two sites under forest without cp secondly this study aimed at evaluating the interaction of groundwater table positions through soil augerings and cp in a larger area with a focus on pastures pasture is the land use where almost all cp in the study area are observed therefore the position of the groundwater table was compared for 15 pastures with cp and 14 pastures without cp having comparable topographical characteristics in terms of slope gradient and contributing area finally the effect of land use history on the occurrence of pipe collapse was evaluated for a database of 84 parcels with cp and 84 parcels without cp currently under pasture as to the first hypothesis no clear discontinuities for abiotic soil characteristics in soil profiles were observed at the depth where pipes occur but pastures with cp had significantly more earthworm channels and mole burrows at larger depths 120 cm mean of 200 earthworm channels per m 2 than pastures without cp arable land or forest 120 cm depth a few or no earthworm channels left the land use history appeared to be similar for the pastures with and without cp combining all results from soil profiles and soil augering indicates that intense biological activity especially by earthworms and moles in combination with a sufficiently high groundwater table favours the development of soil pipes in the study area

the selection of sites for paleovegetational studies the judicious selection of sites for paleovegetational and paleoclimatic studies permits paleoecologists to answer specific research questions that go beyond primary descriptions of past vegetation we present a model that describes the relationship between basin size and pollen source area and predicts the proportions of local extralocal and regional pollen sampled by lake basins of different size the distinctive sampling properties of lakes peats and small hollows can be exploited to provide details of pattern in paleovegetation so long as attention is given to the limitations and problems of these types of sites combinations of site types in a single study most fully exploit the information contained in sediments

the genesis of the nissi peatland northwestern greece as an example of peat and lignite deposit formation in greece abstract the nissi fen is located in a 12 km 2 intramontane basin in northwestern greece since the last glacial limnotelmatic and pure telmatic conditions controlled mainly by karstic springs and partly by surface waters favoured peat formation in the basin resulting in the accumulation of a peat deposit up to 15 m thick the present fen occupies a large area of almost 9 km 2 flora cover comprises mainly cyperaceae cladium mariscus and carex species while phragmites australis extend along the banks of a river flowing through the basin as well as around a lake in the southern part of the fen these species also contributed to the peat formation the nissi peatland shows many genetic similarities to the philippi peat deposit eastern macedonia and may be considered as a recent analogue to the lignite deposits in the basins of ptolemais western macedonia and megalopolis the peloponnese

soil pipe distribution and hydrological functioning within the humid tropics a synthesis some of the most responsive runoff systems in the world are found within the humid tropics these runoff responses are likely to be affected by the presence of natural pipes within the soil this study provides a synthesis of the hydrological aspects of these phenomena within the humid tropics of the studies reporting the presence of soil piping within the humid tropics most are associated with ultisol soils and locally most pipe outlets are observed on the lower sections of hillslopes while the drainage role of pipes has been observed providing faster and slower components of stream hydrographs the mechanism of their recharge remains less clear in part this is because their spatial extent is poorly mapped within the hillslopes of the humid tropics further studies quantifying the length and recharge of soil pipe networks within the humid tropics are needed

lateglacial and holocene vegetation dynamics in the aegean region an integrated view based on pollen data from marine and terrestrial archives to elucidate the vegetation dynamics in the aegean region during the last 20 kyr we have studied terrestrial palynomorphs in marine core geotu sl152 mount athos basin northern aegean sea at centennial scale 125 to 300 yr resolution the robust chronology of the core allows us to reliably date signals of short term vegetation change in the aegean region for the pleniglacial interval until 14 6 kyr bp our data document steppe vegetation suggesting dry climatic conditions in the borderlands of the aegean sea subaerially exposed parts of the shelf were probably colonized by pinus dominated vegetation until shelf areas were flooded during lateglacial sea level rise the final rapid decrease of pinus pollen percentages between 14 and 13 kyr bp appears to be connected to meltwater pulse mwp 1a the lateglacial interstadial complex ie meiendorf bolling and allerod is characterized by the spread of oak trees but also by the continuous presence of steppe elements indicating only slightly increas

hillslope hydrology in tropical rainforest steeplands in brunei many remaining areas of tropical rainforest in south east asia are located on landscapes dominated by deep valleys and very steep slopes now that logging activities are extending into these steeplands it is essential to understand how the natural rainforest system behaves if any kind of realistic assessment of the effects of such disturbance is to be made this paper examines the hydrological behaviour of an undisturbed rainforest system on steep topography in the temburong district of brunei north west borneo the physical and hydrological properties of the regolith material are generally typical of tropical residual soils the regolith has a clay texture and a low dry bulk density beneath a superficial litter organic horizon the infiltration capacity of the surface soil was several hundred mm h 1 that of the exposed mineral subsoil was an order of magnitude less similar to the saturated hydraulic conductivity ksat of around 180 mm h 1 at a depth of 150 cm there was no indication that ksat reduced with depth except very near the bedrock interface soil tensions were measured using a two dimensional array of tensiometers on a 30 slope during dry season conditions infiltrating rain water contributes to soil moisture and drying of the soil is dominated by transpiration losses during wet season conditions perched water tables quickly develop during heavy rainfall giving rise to the rapid production of return flow in ephemeral channels no infiltration excess or saturation overland flow was observed on hillslopes away from channel margins subsurface storm flow combined with return flow produce stream flow hydrographs with high peak discharges and very short lag times storm event runoff coefficients are estimated to be as high as 40 it is concluded that the most distinctive feature of the hydrology of this steepland rainforest is the extremely flashy nature of the catchment runoff regime produced by the combination of thin but very permeable regolith on steep slopes copyright 2000 john wiley sons ltd

human impacts on fluvial systems in the mediterranean region the long history of substantial human impacts on the landscape of the mediterranean region and their effects on fluvial systems is documented these effects have included impacts of deforestation and other land use changes agricultural terracing on a wide scale water transfers and irrigation schemes during the 20th century major changes were made directly to channels through channelisation construction of dams of various sizes and extraction of gravel and indirectly by reforestation these changes have caused a major phase of incision on some rivers runoff and soil erosion have been affected by types of crops and agricultural practices as well as by the varying extent of cultivation and grazing some recent agricultural practices involve wholescale relandscaping of the topography and alteration of surface properties of material the importance of analysing the connectivity within different land units and of the spatial position of human activity within a catchment is illustrated the analysis of connectivity is the key to understanding the variability of impact and the extent of propagation of effects

soil pipes and their role in runoff generation and chemical denudation in a humid tropical catchment in dominica numerous soil pipes are reported from a small catchment in an area of kandoid kaolin rich soils and 2375 mm annual rainfall in the humid tropical volcanic island of dominica west indies two spot surveys in august 1982 at baseflow during the wet season indicated that pipes contributed at least 14 16 per cent of streamflow sampled pipeflow was of similar chemical composition to the baseflow dominated streamwater specific conductance 249 420 s cm 1 and silica 75 mg l 1 levels of pipeflow were high and suggested that the pipes tapped solute rich water close to the soil rock interface the principal pipes flow perennially and showed little response to daily rainfalls of up to 43 mm during the monitoring period

coseismic changes in groundwater temperature of the usu volcanic region observations of groundwater temperature to an accuracy of 0 001 c or better have been made at about 30 wells in various areas of impending earthquakes in japan the main aim of the observations was to monitor the crustal strain and or the movement of groundwater which relate to earthquake occurrence one thermometer was installed at a depth of 200 m in an active volcanic area usu where an upward movement of the magma is occurring we report here that there was a generally increasing temperature trend at this location 0 3 c in the half year of observation decreases in the rate of increase preceded intense local earthquake activity temperature jumps were accompanied by large local earthquakes with magnitudes up to 4 2 and the polarity of the steps corresponded to the location of hypocentres this is probably the first microtemperature measurement made in the proximity of seismic activity

hillslope runoff processes and models abstract hillslope hydrology is concerned with the partition of precipitation as it passes through the vegetation and soil between overland flow and subsurface flow flow follows routes which attenuate and delay the flow to different extents so that a knowledge of the relevant mechanisms is important in the 1960s and 1970s hillslope hydrology developed as a distinct topic through the application of new field observations to develop a generation of physically based forecasting models in its short history theory has continually been overturned by field observation thus the current tendency particularly among temperate zone hydrologists to dismiss all hortonian overland flow as a myth is now being corrected by a number of significant field studies which reveal the great range in both climatic and hillslope conditions some recent models have generally attempted to simplify the processes acting for example including only vertical unsaturated flow and lateral saturated flows others explicitly forecast partial or contributing areas with hindsight the most complete and distributed models have generally shown little forecasting advantage over simpler approaches perhaps trending towards reliable models which can run on desk top microcomputers the variety now being recognised in hillslope hydrological responses should also lead to models which take account of more complex interactions even if initially with a less secure physical and mathematical basis than the richards equation in particular there is a need to respond to the variety of climatic responses and to spatial variability on and beneath the surface including the role of seepage macropores and pipes which call into question whether the hillside can be treated as a darcian flow system

long term patterns and short term dynamics of stream solutes and suspended sediment in a rapidly weathering tropical watershed 1 the 326 ha rio icacos watershed in the tropical wet forest of the luquillo mountains northeastern puerto rico is underlain by granodiorite bedrock with weathering rates among the highest in the world we pooled stream chemistry and total suspended sediment tss data sets from three discrete periods 1983 1987 1991 1997 and 2000 2008 during this period three major hurricanes crossed the site hugo in 1989 hortense in 1996 and georges in 1998 stream chemistry reflects sea salt inputs na cl and so4 and high weathering rates of the granodiorite ca mg si and alkalinity during rainfall stream composition shifts toward that of precipitation diluting 90 or more in the largest storms but maintains a biogeochemical watershed signal marked by elevated k and dissolved organic carbon doc concentration doc exhibits an unusual boomerang pattern initially increasing with flow but then decreasing at the highest flows as it becomes depleted and or vigorous overland flow minimizes contact with watershed surfaces tss increased markedly with discharge power function slope 1 54 reflecting the erosive power of large storms in a landslide prone landscape the relations of tss and most solute concentrations with stream discharge were stable through time suggesting minimal long term effects from repeated hurricane disturbance nitrate concentration however increased about threefold in response to hurricanes then returned to baseline over several years following a pseudo first order decay pattern the combined data sets provide insight about important hydrologic pathways a long term perspective to assess response to hurricanes and a framework to evaluate future climate change in tropical ecosystems

factors controlling the distribution of piping in britain a reconnaissance abstract the distribution of piping in britain has been studied from a survey of 74 piped basins and a number of in depth studies at the individual basin scale the survey suggests that nearly 30 of britain is susceptible to piping erosion this is the area covered by soils with histic and vertic properties or with impermeable subsoil horizons lying in upland regions with high annual water balance and steep slopes at an intrabasin scale the intensity of piping shows a broad correspondence with the a s drainage index although there is no fixed relationship and some significant deviations are found inhomogeneities in soil properties and differential exposure to cracking may be the main cause landuse and vegetation cover may also affect distributions however the clearest intrabasin links between pipe distribution and vegetation patterns are found in upland moorland where the pipes are the cause rather than the product of patterns in both soils and vegetation

diatom response to the last glacial interglacial transition in the ioannina basin northwest greece implications for mediterranean palaeoclimate reconstruction uncertainty as to the pattern of lateglacial and early holocene climate change in the western balkans and greece has persisted despite extensive investigation of the ioannina i 284 lake sediment sequence northwest greece here we present a new diatom record from i 284 for this time period after dominance by eurytopic small fragilariales the lateglacial interstadial ca 14 9 12 7 cal kyr bp is marked clearly by a relative increase in planktonic cyclotella ocellata a return to small fragilariales from ca 12 7 to 11 6 cal kyr bp approximately coincides with the younger dryas chronozone it is followed by a major transition to dominance by cyclotella spp at the pleistocene holocene boundary we interpret these shifts as a response to both lake level and productivity change induced by shifts in effective moisture and temperature demonstrating that the diatom record provides the first strong evidence for a younger dryas event in northwest greece and for both warming and wetting during the lateglacial interstadial and early holocene we also present clear evidence for an abrupt phase of catchment instability during the early holocene in this case we must await the results of further research to test whether it was driven by climatic or tectonic forcing

multi scale permeability estimation for a tropical catchment physically based and spatially distributed modelling of catchment hydrology involves the estimation of block or whole hillslope permeabilities invariably these estimates are derived by calibration against rainfall runoff response rarely are these estimates rigorously compared with parameter measurements made at the small scale this study uses a parametrically simple model topmodel and an uncertainty framework to derive permeability at the catchment scale the utility of expert knowledge of the internal catchment dynamics i e extent of saturated area in constraining parameter uncertainty is demonstrated model derived estimates are then compared with core based measurements of permeability appropriately up scaled the observed differences between the permeability estimates derived by the two methods might be attributed to the role of intermediate scale features natural soil pipes an alternative method of determining block permeabilities at the intermediate or hillslope scale is described this method uses pulse wave tests and explicitly incorporates the resultant effects of phenomena such as soil piping and kinematic wave migration the study aims to highlight issues associated with parameterizing or validating distributed models rather than to provide a definitive solution the fact that the permeability distribution within the borneo study catchment is comparatively simple assists the comparisons the field data were collected in terrain covered by equatorial rainforest combined field measurement and modelling programmes are rare within such environments

holocene environmental change and its impact on sediment dynamics in the eastern mediterranean abstract investigators have studied past environmental change in the eastern mediterranean region from a number of perspectives while climate reconstructions and palynological research have focused on forces that drive the geomorphologic system many researchers have attempted to use sediment archive studies to identify periods of change in sediment dynamics due to the large variability in environmental parameters and the variety of landscapes present in the eastern mediterranean region research has focused on sediment archives ranging from small colluvial sites to deltas of large rivers on the mediterranean coast as the cultural record for the region is extremely rich the main goal of palaeo environmental research in the eastern mediterranean has been to identify the relative importance of human impact on the landscape nevertheless sediment archives have significant limitations chronological control for many palaeo environmental records is highly uncertain and rates of landscape change are oftentimes difficult to assess most palaeo environmental research has been conducted on or near archeological sites where direct human impact may obscure the indirect impact on sediment dynamics through land use changes quantification and modeling of sediment dynamics in the eastern mediterranean environment offer one solution when erosion and sediment transport rate analyses are incorporated periods of relatively important change can be identified using multiple approaches the relative importance of the main driving forces climate and land use become distinguishable since field based data from the actual sediment archives remain vital an overview of numerous studies in the eastern mediterranean is provided in order to draw a general picture for different time periods and the relative scale of regional landscape development during the holocene a comparison of sediment dynamics with the record of driving forces indicates that while climate was the main driver of the geomorphic system during the early holocene at some point human impact became widespread and began to dictate sediment dynamics to a large extent from the byzantine period onward soil properties seem to play an increasingly important role as the hillslope soil reservoir in the eastern mediterranean was progressively depleted during the late holocene

a hillslope scale experiment to measure lateral saturated hydraulic conductivity 1 one of the most challenging parameters in hillslope and watershed scale distributed hydrologic models is the lateral saturated hydraulic conductivity ks in this paper we present a methodology to determine the hillslope scale lateral ks above a moderately deep sloping restrictive layer in an 18 35 m hillslope plot using perched water level measurements and drain tile outflow data the hillslope scale lateral ks was compared to small scale ks measured with small soil cores and the guelph permeameter our results show that small scale ks measurements underestimate the actual hillslope scale ks the hillslope scale ks measurements were 13 7 4 1 and 3 2 larger than small soil core measurements in the a b and e horizons respectively we argue that the gap between small scale and hillslope scale ks within the same porous medium is foremost a measurement problem data analysis provided the ks distribution with depth showing a sharp decrease in ks within the first 0 1 m of the soil and an exponential decline in ks below 0 1 m the distribution of ks with depth was best described by a double exponential relationship overall results indicate the importance of macroporosity perhaps of biological origin in determining ks at a hillslope scale

microclimatic characterization of a karstic cave human impact on microenvironmental parameters of a prehistoric rock art cave candamo cave northern spain the candamo cave contains an impor tant group of paleolithic paintings which have been seriously deteriorated due to mass tourism in this work an analysis was carried out of different cli matic parameters co2 temperature humidity 222 rn during annual cycles with the cave closed to the public and during an experimental period of controlled visits the effect of visits on the geo chemical characteristics of karstic water was also analyzed together with the cave ventilation the natural variations in the cave air co2 were above 3000 ppm the increase produced through visits was only 100 110 ppm and since the humidi ty is almost permanently at saturation point the critical parameter which limits the visitor capacity becomes air temperature the temperature changes during the annual cycle are of the order of 1 7c in the external part and less than 0 5 7c in the internal part of the cave and a maximum increase of 0 13 7c was observed during the period of the visits the 222 rn and co2 concentration minimums in the summer period july october show that this is the most propitious time for visits since the greatest ventilation is produced in the cave at this time and therefore the greatest capacity for recovery the geochemistry of the water on the other hand indi cated that this is the period of the year in which processes of wall corrosion can be most easily in troduced although this would be of limited magni tude the visitor capacity calculated was 29 visi tors day

weichselian palynostratigraphy palaeovegetation and palaeoenvironment the record from lago grande di monticchio southern italy abstract the palynostratigraphic record from lago grande di monticchio s italy is presented an independent sedimentation rate based chronology provides an age of 101 530 calendar years bp for the lowermost sediments sampled this chronology enables assessment of the rapidity of vegetation changes during the last glacial contrary to widely held views the vegetation showed numerous large magnitude changes in periods of

spatial variability of tephra and carbon accumulation in a holocene peatland abstract microscopic tephra layers cryptotephras represent important age equivalent stratigraphic markers utilised in many palaeoenvironmental reconstructions when used in conjunction with proximal records of volcanic activity they can also provide information about volcanic ash cloud fallout and frequency however the spatial distributions of tephra layers can be discontinuous even within the same region understanding the deposition and post depositional redistribution of tephra is vital if we are to use cryptotephras as records of ash cloud occurrence and chronostratigraphic markers the discrete nature of tephra layers also allows for detailed study into processes of deposition and reworking which affect many palaeoenvironmental proxy records we undertook a multi core study in order to examine the historical tephrostratigraphy of a raised peatland in northern ireland three tephra layers originating from iceland hekla 1947 hekla 1845 and hekla 1510 are present in 14 of the 15 cores analysed this suggests that in areas not influenced by snowfall or anthropogenic disturbance at the time of tephra delivery the presence or absence of a tephra layer is generally consistent across a peatland of this type however tephra shard counts per unit area vary by an order of magnitude between cores these intra site differences may confound the interpretation of shard counts from single cores as records of regional ash cloud mass density bootstrap resampling analysis suggests that total shard counts from multiple cores are required in order to make a reliable estimate of median shard counts for a site the presence of three historical tephras in 14 cores enables a spatio temporal analysis of the long term apparent rate of carbon accumulation larca in the peatland substantial spatial and temporal variations in larca are identified over the last 450 years this high variability needs to be taken into account when designing studies of peatland carbon accumulation

a re evaluation of the vegetation history of the eastern pyrenees france from the end of the last glacial to the present abstract fourteen pollen records obtained from 10 sites in the eastern pyrenees are presented along with the results of 40 new radiocarbon dates of samples obtained from these sites the data 784 pollen spectra provide a more comprehensive evaluation of the vegetation history of the region than has hitherto been possible the salient elements of the regional plant succession are described in the light of a study of regional pollen rain vegetation relationships vegetational developments during the last glacial interglacial transition and the holocene are compared with those of other regions in france and the western mediterranean this approach therefore provides a new synthesis of published and unpublished information over a large area a consistent and coherent pattern emerges and the new evidence indicates a number of previously held views on the vegetation history of the pyrenees to be erroneous

a discrete particle representation of hillslope hydrology hypothesis testing in reproducing a tracer experiment at gardsjon sweden despite the long history of the continuum equation approach in hydrology it is not a necessary approach to the formulation of a physically based representation of hillslope hydrology the multiple

reconstruction of holocene lake level changes in lake xinias central greece a study of past lake level changes in lake xinias covering the last 40 000 years was presented in an earlier paper in that paper changes during the holocene were only briefly dealt with because of poor sedimentary representation in this paper a supplementary transect of cores is described in which holocene lake level changes are better recorded the correlation of the cores was based on pollen and lithostratigraphic analyses and a curve was constructed showing recorded lake level changes the curve from lake xinias was compared with an earlier compilation of lake level changes from the balkans mainly from greece the compilation shows rising lake levels during the earlier part of the holocene and succes sively lowered levels during the later part most lake levels were high between about 8000 and 5500 cal yr bp the reconstruction from lake xinias indcates similar changes during the early and late holocene however it differs by indicating a lowering in lake level culminating around 7000 cal yr bp interrupting and dividing the period of mid holocene high lake level stand further studies are required to show if this lowering in lake xinias was regionally representative and caused by climate change or was caused by tec tonic disturbance locally affecting lake level

lateglacial and holocene vegetation history at nisi fen and the boras mountains northern greece new pollen data from three contrasting sites in northern greece allow an analysis of spatial and temporal patterns of vegetation change during the holocene and lateglacial in northern greece at the principal site nisi fen six cores from the thickest surficial peat deposits have yielded a detailed composite ams 14c dated pollen record covering the period from 20000 cal bp almost to the present day cores kp 4 and bor 3 were taken from small mires at high elevations in the boras mountains a few kilometres to the north of nisi in which peat has been accumulating since the mid holocene our results show that only pinus expanded significantly during the lateglacial interstadial although small thermophilous tree populations were present in the region the younger dryas chronozone is at best marked by subtle vegetational change in favour of steppe taxa tree cover increased rapidly at the beginning of the holocene with deciduous woodland probably expanding above its present day altitudinal limits ther

landslides in rio de janeiro the role played by variations in soil hydraulic conductivity landslides are natural processes triggered by complex relationships between many conditioning factors in rio de janeiro city intense rainstorms combined with steep slopes usually occupied by slums create favourable conditions for landslide generation in general slope failures are related to high positive pore pressures inside soil mantles which are associated with topographic hollows and hydraulic discontinuities inside the deep weathered profile this study aims to characterize the role played by spatial variations in saturated soil hydraulic conductivity ksat on landsliding in the papagaio basin 2 5 km2 triggered by intense rainstorms 250 mm in less than 2 days in february 1996 field measurements using the guelph permeameter were conducted along soil profiles up to 5 0 m depth around and inside landslide scars representing different geomorphological domains also soil physical properties grain size total porosity macroporosity microporosity etc were evaluated at the 87 sites where ksat was measured despite the many geological and pedological variations inside the basin including changes in lithology fracture density vegetation type and succession stage soil characteristics and weathering stage and human activities 94 of the ksat values varied by only two orders of magnitude 1 0 10 6 9 0 10 5 m s 1 however abrupt changes in ksat were observed along some of the soil profiles studied e g an increase of two orders of magnitude in only 0 30 m these hydraulic discontinuities may contribute locally to the development of high pore pressures during intense rainstorms leading to landsliding the results also suggest that different ksat variation patterns coexist inside the basin which should be considered in mathematical models of landslide prediction copyright 2004 john wiley sons ltd

the lateglacial quercus expansion in the southern european alps rapid vegetation response to a late allerod climate warming a pollen inferred vegetation shift from pioneer birch pine woodland to mixed pine summergreen oak forests in the southern alpine forelands is commonly attributed to a centennial scale warming that occurred between the gerzensee oscillation go and the younger dryas two microtephra layers bracketing the younger dryas onset the laacher see tephra and the vedde ash improve the chronology at lago piccolo di avigliana northern italy and allowed accurate correlation with central european records where the go is clearly detected we used pollen percentages pollen accumulation rates pars and plant macrofossils to assess the population dynamics of quercus and leaf cuticle analysis for a better taxonomic identification of quercus our results indicate that the species that was locally present was probably quercus robur pars suggest that the population expansion started as early as the bolling and followed an exponential increase through time we attribute this gradual shift to increasing summer temperatures and longer growing seasons which contrast with a gradually decreasing temperature trend as recorded in greenland ice cores and in central europe breaks or set backs in the par record may indicate the biotic response to minor lateglacial cooling events of different life history stages in the quercus population copyright 2011 john wiley sons ltd

lateglacial and holocene vegetation belts in the pirin mountains southwestern bulgaria pollen stratigraphy of a core 270 cm long from lake dalgoto at 2310 m in the northern pirin mountains southern bulgaria was treated by optimal partitioning and compared to a broken stick model to reveal statistically significant pollen zones the vegetational reconstructions presented here are based on pollen percentages and pollen influx on comparisons of modern and fossil pollen spectra and on macrofossil dates from other sites in the mountains during the younger dryas 11000 10200 14c yr bp an open xerophytic herb vegetation with artemisia and chenopodiaceae was widely developed around the lake deciduous trees growing at lower elevations contributed to the pollen rain deposited at the higher elevation sampling sites specifically from 10200 to 8500 yr bp quercus ulmus tilia and betula expanded rapidly at low and intermediate elevations and between 8500 and 6500 yr bp they extended to higher elevations close to the upper forest limit which was formed by betula pendula at about 1900 m coniferous species were limited in the region at this time after 6500 yr bp the expansion of conifers pinus peuce p sylvestris p mugo abies alba at high elevations forced the deciduous trees downward between 6500 and 3000 yr bp the forest limit at 2200 m was formed by p peuce and a alba had its maximum vertical range up to 1900 m later the abundance and vertical range of p peuce and a alba were reduced after 3000 yr bp picea expanded

the lateglacial and holocene environmental history of the ioannina basin north west greece this study centres on palaeoenvironmental analysis of the upper part of a long core from the partially drained tectonic ioannina basin north west greece the data span the lateglacial and holocene and comprise pollen mollusc magnetic susceptibility loss on ignition and particle size analyses these augment previously published ostracod and stable isotope data from the same sediment sequence the age model for the sequence is based on 19 ams dates five of which were obtained using a novel procedure for the separation of microcharcoal from sediment the pollen data suggest that although temperate woodland expanded at the beginning of the lateglacial only limited woodland contraction occurred during the younger dryas chronozone despite strong evidence for a sharp drop in sea surface temperature in the neighbouring adriatic at this time in contrast large scale vegetational and sedimentological changes occur in concert during the holocene some of which may be ascribed to human impact comparison with other records from the ioannina basin suggests that previous more littoral pollen sequences did not constitute a wholly representative record of lateglacial and holocene vegetational change

climate dynamics in the borderlands of the aegean sea during formation of sapropel s1 deduced from a marine pollen record abstract to unravel the climatic and environmental dynamics in the borderlands of the aegean sea during the early and middle holocene and notably for the interval of sapropel s1 s1 formation we have analysed terrestrial palynomorphs from a marine core in the northern aegean sea the qualitative results were complemented by quantitative pollen based climate reconstructions a land sea correlation was established based on pollen data and sediment lightness measurements from the same core and previously published benthic foraminifer data from a nearby core the borderlands of the aegean sea underwent a transition from an open vegetation to oak dominated woodlands between 10 4 and 9 5 ka cal bp a coeval increase in winter precipitation suggests that moisture availability was the main factor controlling holocene reforestation the 50 higher winter precipitation during s1 formation relative to pre sapropelic conditions suggests a strong contribution from the borderlands of the aegean sea to the freshwater surplus during s1 formation the humid and mild winter conditions during s1 formation were repeatedly punctuated by short term climatic events that caused a partial deforestation and a reorganisation within the broad leaved arboreal vegetation in the marine realm these events are documented by improved benthic oxygenation the strongest event represents the regional expression of the 8 2 ka cold event and led to an interruption in s1 formation except for the interval of s1 formation the pollen derived winter temperatures correlate with the smoothed gisp2 k series they support the previously published marine based concept that the intensity of the siberian high strongly controlled the winter climate in the aegean region during s1 formation in the aegean sea however climate conditions in the borderlands were more strongly affected by the monsoonally influenced climate system of the lower latitudes

comparison of methodological uncertainties within permeability measurements permeability measurements are critical to the calculation of water flow within hillslopes despite this errors in permeability measurements are often ignored and can be very large particularly in disturbance sensitive gley soils this work compares the uncertainties associated with six field methods of permeametry applied to a gleyed soil in upland britain slug tests constant head borehole permeametry and falling head borehole permeametry were undertaken on established piezometers additionally ring permeametry and two types of trench tests were evaluated method related uncertainty due to proximity of impeding layers of high sorptivity soils produces under and over estimates of permeability by a factor of up to 0 2 and 5 respectively this uncertainty band is smaller than the observed effects of anisotropy and temporal variability had smearing and soil ring leakage errors not been minimized the methodological uncertainties would have been so large that they would have distorted the true spatial field of permeability and its estimated impact on the balance of vertical and lateral flow

contrasting flow pathways within tropical forest slopes of ultisol soils there are very few experimental studies identifying hydrological pathways within rain forest slopes such knowledge is however necessary to understand why forest disturbance affects rainfall riverflow response and nutrient migration this study examines flow pathways within lowland rain forest slopes comprising udults of the ultisol soil order experimentation was conducted on four se asian hillslope units each 5 5 m in plan in the bukit timah catchment singapore island and in the w8s5 catchment sabah borneo island the flow pathways were identified by artificial tracer experiments we evaluated how well hydrometric calculations based on tensiometry and permeametry measurements predicted the tracer patterns the tracer work indicated much faster subsurface flows at bukit timah than w8s5 for the storms studied some explanation of the greater subsurface waterflows at bukit timah in comparison to w8s5 is afforded by the less steep moisture release curves which maintain hydraulic conductivity as the soil dries vertical flow of the tracer through the upper 1 m of soil predominated 90 per cent of percolation in the bukit timah slopes in some contrast a major component approximately 60 per cent of the tracer percolation was directed laterally within the w8s5 slopes the flow vectors calculated using the hydrometric methods did however grossly under estimate the degree of lateral deflection of waterflow generated at w8s5 and to a lesser extent over estimated it at bukit timah in part these errors may relate to the inability of traditional hydrometric techniques to fully characterize the effect of the large and small natural soil pipes present within both catchments in conclusion the study indicates that marked variations in flow vectors exist within the udult great group of se asian soils and hydrometric calculations may be poor predictors of these dominant pathways copyright 2005 john wiley sons ltd

the role of lateral pipe flow in hillslope runoff response an intercomparison of non linear hillslope response the importance of lateral pipe flow on runoff generation in wet steep hillslopes has been described in many case studies from around the world however most hillslope studies are done in isolation and usually focus on the idiosyncrasies of individual hillslope characteristics and pipe flow response at a single site consequently the first order controls on pipe flow responses remain poorly understood we present a new intercomparison of pipe flow response to storm rainfall at four well instrumented sites panola georgia usa toinotani kyoto japan jozankei hokkaido japan and hakyuchi tokyo japan our objective was to minimize the complexities of lateral pipe flow on hillslopes by looking for commonality across different hillslope types despite the large differences between the study sites in topography climate soil type and soil matrix hydraulic conductivity we found several common pipe flow responses to storm rainfall 1 the relationship between total rainfall amount and total pipe flow volume was highly non linear at each site 2 initiation of measurable pipe flow was threshold dependent controlled by the total rainfall amount and the pre storm wetness 3 once significant pipe flow response occurred the maximum pipe flow rate was sensitive to the measured rainfall intensity and 4 the ratio of total pipe flow to total hillslope discharge for each site was constant regardless of total rainfall amount once the precipitation threshold for significant pipe flow response was reached we used these results to develop a decision tree to determine the general conditions necessary for significant pipe flow to occur the controls derived from our comparisons agree largely with the controls reported by the previous individual hillslope pipe flow studies in the literature the commonality of response between our four very different forested hillslope settings indicates that site intercomparison may be effective for extracting common first order controls on complex hillslope processes we argue that a decision tree may be a useful organizational framework to summarize and organize comparative analyses and may provide a structure for defining the hierarchy of process controls necessary for model development

termination of the last glaciation in the iberian peninsula inferred from the pollen sequence of quintanar de la sierra abstract a 4 5 m thick late glacial pollen sequence supported by 17 ams14c dates has been investigated at the quintanar de la sierra marshland iberian cordillera north central spain pollen zones were defined that correspond to successive phases in vegetation history during the end of the late wurm late glacial interstade and younger dryas periods a transfer function approach has been adopted to derive quantitative climate estimates from the pollen assemblage data a first expansion ofjuniperusandhippophae about 13 50014c yr b p indicates the beginning of the late glacial interstade which is characterized by ajuniperus betula pinussuccession that suggests higher temperatures and moisture than during full glacial time the younger dryas interval is recorded by a 120 cm thick sediment unit that is dominated by herbaceous pollen transfer function estimates suggest that the climate during this period was cold with low precipitation during most of the year although not in summer the holocene arboreal recolonization in the area started about 10 00014c yr b p with a renewedjuniperus betula pinussuccession related to a strong increase in annual temperature and precipitation the start of this process was synchronous with mean sea surface temperature changes as recorded from the nearby su 81 18 marine core the strong affinity with other european late glacial pollen sequences demonstrates that the pattern of climatic changes during the last glacial interglacial transition was similar in both northwestern and southwestern europe

soil pipe collapses in a loess pasture of goodwin creek watershed mississippi role of soil properties and past land use little is known about the association of soil pipe collapse features with soil properties or land use history three loess covered catchments in northern mississippi usa were characterized to investigate these relationships soil pipe collapses were characterized for their size type feature and spatial location along with soil properties across the three catchments although mapped as the same soil one of the catchments did not contain pipe collapse features while the other two had 29 4 and 15 4 pipe collapses per hectare these loess soils contained fragipan layers that are suspected of perching water thereby initiating the piping processes pipe collapses associated with subsurface flow paths were not always consistent with surface topography the surface layer tended to be non erodible while layers below even the upper fragipan layers were susceptible to erosion by pipeflow soil properties of the lowest fragipan layer were highly variable but tended to prevent further downward erosion of soil pipes and thus formed a lower boundary for gullies middle to lower landscape positions in one of the piped catchments contained anthropic soils that were highly erodible these anthropic soils were previously gullies that were filled in in the 1950s when forested areas assumed to have been established when land was previously converted from crop to forest land were converted to pasture three decades after this land use change from forest to pasture pipe collapses became evident in contrast the adjacent catchment that does not exhibit pipe collapse features experienced severe sheet and rill erosion prior to the 1930s while in cotton production the surface horizons above the lower fragipan layer were completely removed during this period thus the top soil layer that tends to form a bridge above soil pipes in the more erodible subsoil layers was removed this study showed that knowledge of soil characteristics or topography alone do not explain the distribution of soil pipe collapses as past land use can play a definitive role copyright 2015 john wiley sons ltd

succession of depositional environments in the neogene basin at aliveri evia greece abstract the neogene lignite bearing sequence in the southern part of the aliveri kymi basin was studied with regard to sedimentology palynology and coal petrology in order to establish the type and succession of environments involved and to compare them with modern analogues initial sediments of the prinias group were deposited in a wide shallow depression by means of a low competent drainage system which formed sandy alluvial fans interfan areas and ephemeral lakes as well as sand flats and vegetated mudflats in lateral sequences from the basin margins to a central perennial lake succeeding sediments of the prinias group were formed under the influence of the rising lake level in algal marsh various peat forming and open lake environments sediments of the koustoumalou group were deposited by a highly competent surficial drainage system in alluvial fan to braided and meandering fluvial environments this drainage system followed the south north trending axis of an asymmetrical graben while debris flows moved in from the steep flanks to the east

measurements and interpretations of tilt strain gauges in seismically active areas abstract an overview of different aspects of deformation measurements is given an introduction to the general theory of point crustal deformations with an application to the stress strain relations at the earth surface is made the instrumentation used in crustal deformation measurements is briefly explained emphasizing different constructions of tilt and strainmeters the problems connected with the housing of the instruments i e the cavity and topography effects and with the ambient noise factors as the hydrological and pressure effects are discussed the last part of the paper is concerned with the relation between deformation measurements and seismic events both from a theoretical and observational standpoint a number of examples are shown that report on pre co and post seismic and the secular term deformation in different areas of the world

impact of lateglacial cold events on the northern aegean region reconstructed from marine and terrestrial proxy data marine palynomorph data paired with other indicators of sea surface hydrography planktic foraminiferal assemblages and oxygen isotopes were used to decipher the impact of cold events on the northern aegean region during the last glacial to interglacial transition the data which were derived from marine sediment cores geotusl152 and geotusl148 point to a strong impact of the heinrich 1 and younger dryas cold events on surface water conditions in the northern aegean sea shifts in marine palynomorph assemblages correlate with changes in terrestrial vegetation and climate i e precipitation and temperature reconstruc tions based on pollen assemblages in the northern borderlands of the aegean sea the climate responses of the aegean region to heinrich event 1 h1 ca 17 5 to ca 15 7 cal ka bp and younger dryas ca 12 6 to ca 11 7 cal ka bp events appear similar in magnitude with mean annual temperatures between 6 and 108c and mean annual precipitation between 300 and 450 mm however the annual temperature decline during the h1 relative to the preceding already cold conditions was minor 38c the transition from the relatively warm and humid local equivalent of the allerod interstadial to the younger dryas on the other hand witnessed an annual temperature decline of 68c and an annual precipitation decrease of 300 mm the latter occurring abruptly within only ca 150 a the return to warmer conditions in the northern aegean region after the younger dryas was completed at ca 11 6 cal ka bp copyright 2011 john wiley sons ltd

sedimentology of fraser river delta peat deposits a modern analogue for some deltaic coals abstract on the recent lobe of the fraser river delta peat accumulation has actively occurred on the distal lower dilta plain the transition between upper and lower delta plains and the alluvial plain distal lower delta plain peats developed from widespread salt and brackish marshes and were not influenced appreciably by fluvial activity lateral development of the marsh facies were controlled by compaction and eustatic sea level rise the resulting thin discontinuous peat network contains numerous silty clay partings and high concentrations of sulphur freshwater marsh facies formed but were later in part eroded and altered by transgressing marine waters the peats overlie a thin fluvial fining upward sequence which in turn overlies a thick coarsening upward prodelta delta front succession lower delta plain upper delta plain peats initially developed from interdistributary brackish marshes and were later fluvially influenced as the delta prograded the thickest peats occur in areas where distributary channels were abandoned earliest sphagnum biofacies replace sedge grass dominated communities except along active channel margins where the sedge grass facies is intercalated with overbank and splay deposits the peats are underlain by a relatively thin sequence of fluvial deposits which in turn is underlain by a major coarsening upward delta front and pro delta sequence alluvial plain peats accumulated in back swamp environments of the flood plain earliest sedge clay and gyttjae peats developed over thin fining upward fluvial cycles or are interlaminated with fine grained flood deposits thickest accumulations occur where peat fills small avulsed flood channels overlying sedge grass and sphagnum biofacies are horizontally stratified and commonly have sharp boundaries with fine grained flood sediments at active channel margins however sedge grass peats are intercalated with natural levee deposits consisting of silty clay these levees reduce both the number and size of crevasse splay deposits coal originating from peats of the different environments of the fraser delta would vary markedly in character peats of the lower delta plain will form thin lenticular coal seams with numerous splits and have a high ash and sulphur content peats from the lower to upper delta plain will be laterally extensive and of variable thickness and quality basal portions of the seams will contain numerous splits and have a high sulphur content whereas upper portions will be of higher quality peats from the upper delta plain alluvial plain will form thick isolated and laterally restricted coal seams characterized by low ash and sulphur contents

studies of the low rank greek coals 1 classification abstract physical and chemical measurements of greek coals lead to a classification by rank into five categories ranging from subbituminous c to peat this classification is further documented by esr spectroscopy and powder x ray diffraction in order to accommodate all the deposits a new category is introduced between lignite b and peat designated as lignitized peat which is clearly and operationally distinguished from peat and higher rank lignites

detectability and significance of 12 hr barometric tide in radon 222 signal dripwater flow rate air temperature and carbon dioxide concentration in an underground tunnel summary searching for small periodic signals such as the 12 hr s2 barometric tide and monitoring their amplitude as a function of time can provide important clues on the complex processes affecting fluid transport in unsaturated fractured media under multiple influences here first we show that a modified spectrogram analysis msa is more efficient than simple fourier transform to reveal weak periodic signals secondly we show how transient periodic signals can be monitored as a function of time using spectrograms these methods are applied to time series of radon and carbon dioxide concentration dripwater flow rates and air temperature measured during several years in the roselend dead end tunnel located in the french alps near an artificial lake a weak s2 line is evidenced in radon concentration with enhanced amplitude during transient radon bursts similarly the s2 line is observed using msa in dripwater flow rates which sample mainly fracture flow as suggested by a hydrochemical analysis while it is not seen in dripwater flow rates sampling matrix flow in the absence of a strong 24 hr line the presence of a s2 line suggests sensitivity to barometric pressure and thus a significant advective contribution in radon and some dripwater transport no s2 line is observed in the carbon dioxide time series the temporal structure of the s2 component however is not similar in the radon concentration and the dripwater flow rates suggesting in particular that dripwater does not play a significant role in the generation of radon bursts temperature time series exhibit a significant s2 contribution induced by atmospheric pressure spatially organised in the tunnel decreasing vertically upwards a remarkable transient temperature inversion during radon bursts suggests that the additional advective air contributions responsible for the radon bursts occur from the non saturated rocks below the tunnel

sources of suspended sediment within a tropical catchment recovering from selective logging quantification of the source of suspended sediments generated by selective forestry activities is central to the development of sustainable forestry guidelines this assessment is hampered by a dearth of available studies particularly from the tropics this study involved the monitoring at 10 s intervals of surface discharge and turbidity from 15 contributory areas of a 44 ha catchment the catchment is located within lowland dipterocarp rain forest on borneo island in a region recovering from the first episode of selective timber removal that took place some 5 years previously both the within storm dynamics of the sediment flux and the time integrated sediment yields were analysed to link the source landforms to the catchment behaviour a 10 year rainfall event of 167 mm occurred during the monitoring period and triggered a debris slide and several log culvert collapses along the area s main timber haulage road the sampling design captured this event s dynamics and allowed lumped catchment response to be traced to the new landforms during the 1 day period of the 10 year event some 33 t of suspended sediment were transported from one debris slide comprising a significant proportion of the 105 t discharging from the whole catchment which itself constituted 40 of the annual yield of 592 t km 2 the contributory areas with only ephemeral waterflows including former haulage roads and tracks generated relatively little sediment during this 10 year event or in other storms this work suggests that though some sediment sources recover from the impacts of forest road construction and harvesting collapse of roadfill materials or more local log culvert failure persists for several years after harvesting sustainable forestry guidelines that do not focus on ameliorating these persistent instabilities may not significantly mitigate the geomorphic impacts of conventional selective harvesting copyright 2004 john wiley sons ltd

spatial distribution of pipe collapses in goodwin creek watershed mississippi the internal erosion of soil pipes can induce pipe collapses that affect soil erosion processes and landform evolution the objective of this study was to determine the spatial distribution of pipe collapses in agricultural fields of goodwin creek watershed ground survey was carried out to detect pipe collapses and the location size and surface elevation was measured with differential gps a total of 143 of the 145 pipe collapses were found in cropland and the density was approximately 0 58 collapses per hectare the spatial distribution of pipe collapses was not uniform as pipe collapses were concentrated in the flat alluvial plains where the land use was dominated by cropland one of the four parcels had 90 of the pipe collapses with a density of 7 7 collapses per hectare the mean depth area and volume of these pipe collapses were 0 12 m 0 34 m2 and 0 02 m3 respectively and all these properties exhibited a skewed distribution the drainage area slope gradient equation which has been widely used for erosion phenomenon prediction did not represent pipe collapses in this study as the coefficient of determination was 0 01 this is clear evidence that subsurface flow is not represented by surface topographic characteristics the pipe collapses were found to intercept runoff thereby reducing the slope length factor by 6 and the drainage area by 7 both of these factors can reduce the sheet and rill erosion however the increased subsurface flow could enhance ephemeral gully erosion published 2012 this article is a u s government work and is in the public domain in the usa

long term observation of in situ seismic velocity and attenuation 1 we conducted 1 year continuous measurements of in situ compressional wave velocity and attenuation across a distance of 12 m in a vault at the coast of miura bay japan using a piezoelectric transducer as the ultrasonic wave source we detected for the first time periodic variations in both velocity and attenuation with amplitudes of 0 3 and of 4 respectively corresponding to the diurnal and semidiurnal lunar and solar tides these variations correlate well with the in situ areal strain change due to tidal ocean loading estimated from the strain records about 100 m away from the observational site relative minimum velocity and relative maximum attenuation occur at every time of relative maximum areal strain expansion suggesting that opening closure of pores or cracks of in situ rocks is responsible for these periodic variations the velocity variation shows a remarkable 14 day periodicity corresponding to the spring and neap tides arising from a nonlinear response of the velocity change to tidal strain change such that the velocity change depends on how slowly the tidal dilatation departs from its peak value

assessment of grass root effects on soil piping in sandy soils using the pinhole test abstract soil piping is an important land degradation process that occurs in a wide range of environments despite an increasing number of studies on this type of subsurface erosion the impact of vegetation on piping erosion is still unclear it can be hypothesized that vegetation and in particular plant roots may reduce piping susceptibility of soils because roots of vegetation also control concentrated flow erosion rates or shallow mass movements therefore this paper aims to assess the impact of grass roots on piping erosion susceptibility of a sandy soil the pinhole test was used as it provides quantitative data on pipeflow discharge sediment concentration and sediment discharge tests were conducted at different hydraulic heads i e 50 mm 180 mm 380 mm and 1020 mm results showed that the hydraulic head was positively correlated with pipeflow discharge sediment concentration and sediment discharge while the presence of grass roots expressed as root density was negatively correlated with these pipeflow characteristics smaller sediment concentrations and sediment discharges were observed in root permeated samples compared to root free samples when root density exceeds 0 5 kg m 3 piping erosion rates decreased by 50 compared to root free soil samples moreover if grass roots are present the positive correlation between hydraulic head and both sediment discharge and sediment concentration is less pronounced demonstrating that grass roots become more effective in reducing piping erosion rates at larger hydraulic heads overall this study demonstrates that grass roots are quite efficient in reducing piping erosion rates in sandy soils even at high hydraulic head 1 m as such grass roots may therefore be used to efficiently control piping erosion rates in topsoils

the last climatic cycle at kopais central greece thick lacustrine sequences from southern europe provide an opportunity to derive continuous records where the chronostratigraphical position of pre holocene stages can be determined with increased confidence here high resolution sediment and pollen analytical results from a 60 m core recovered from the kopais basin central greece spanning the interval from the last interglacial to the early holocene are presented the record shows distinct shifts between open vegetation periods of increased erosion with sediment inwashing and forest periods associated with calcite precipitation in the lake the sequence of major events of the last climatic cycle contained at kopais bears strong similarities to other records in greece but also reveals the presence of high frequency oscillations with higher amplitudes than previously seen at other sites

spatial and temporal dependence of temperature variations induced by atmospheric pressure variations in shallow underground cavities pressure induced temperature pit variations are systematically observed in the atmosphere of underground cavities such pit variations are due to the compressibility of the air damped by heat exchange with the rock surface it is important to characterize such processes for numerous applications such as the preservation of painted caves or the assessment of the long term stability of underground laboratories and underground waste repositories in this paper we thoroughly study the spatiotemporal dependence of the pit response versus frequency using vertical and horizontal profiles of temperature installed in an abandoned underground quarry located in vincennes near paris the pit response varies from about 20 10 3 c hpa 1 at a frequency of 2 10 4 hz to 2 3 10 3 c hpa 1 at a frequency of one cycle per day an analytical expression based on a simple heat exchange model accounts for the observed features of the pit response and allows for correcting the measured time series having standard deviations of about 10 2 c to residual variations with a standard deviation of about 2 10 3 c however a frequency dependent attenuation of the response corresponding to a reduction in amplitude with a factor varying from 2 to 3 is observed near the walls this effect is not included in the simple analytical expression but it can be accounted for by a one dimensional differential equation solved numerically where temperature variations in the atmosphere are damped by an effective radiative coupling with the rock surface complemented by a diffusive coupling near the walls the tip response is observed to remain stable over several years but a large transient enhancement of about a factor of two is observed near the roof at one location from july to october 2005 in a cavity located below the paris observatory an additional contribution is identified in the pit response function versus frequency for frequencies smaller than 2 10 5 hz this contribution can be described using a modified analytical expression that includes the effect of heat diffusion into the surrounding rock using this expression in this case also the temperature time series can then be corrected giving a residual standard deviation smaller than 1 6 10 3 c transient temporal variations of the pit response are observed in all sites with possible nonlinear components in the pit such effects are not properly understood at this stage and limit the reduction of time series to standard deviations of the order of 2 10 3 c and consequently limit the search for new transient or seasonal temperature signals for example due to the presence of tiny heat sources in the cavity or to geodynamical effects

middle holocene rapid environmental changes and human adaptation in greece numerous researchers discuss of the collapse of civilizations in response to abrupt climate change in the mediterranean region the period between 6500 and 5000 cal yr bp is one of the least studied episodes of rapid climate change at the end of the late neolithic this period is characterized by a dramatic decline in settlement and a cultural break in the balkans high resolution paleoenvironmental proxy data obtained in the lower angitis valley enables an examination of the societal responses to rapid climatic change in greece development of a lasting fluvio lacustrine environment followed by enhanced fluvial activity is evident from 6000 cal yr bp paleoecological data show a succession of dry events at 5800 5700 5450 and 5000 4900 cal yr bp these events correspond to incursion of cold air masses to the eastern mediterranean confirming the climatic instability of the middle holocene climate transition two periods with farming and pastural activities 6300 5600 and 5100 4700 cal bp are evident the intervening period is marked by environmental changes but the continuous occurrence of anthropogenic taxa suggests the persistence of human activities despite the absence of archaeological evidence the environmental factors alone were not sufficient to trigger the observed societal changes

early to mid holocene paleohydrology in northeast mediterranean the detrital record of aliakmon river in loudias lake greece one of the prominent features of northeast mediterranean nem holocene climate are recurrent phases of cold and aridity their impacts on the hydrological cycle remain at large unknown as few existing paleohydrological records are either restricted to lake level fluctuations or focus near the 8 2 kyr bp event here we present the detrital record of aliakmon river in lake loudias between 9500 and 3000 cal bp magnetic susceptibility ms exhibits high correlation with mean grain size r 0 7 of silt sized fractions and is used as a proxy of the distal clastic input of aliakmon river whereas organic matter om carbonate content caco3 water content wc and clay concentrations decipher sedimentological and biological processes in lake loudias periods of high hydrological activity were interrupted by short intervals of low river discharge at c 9400 8600 8200 7500 7000 6200 5300 and 4500 cal bp and during a multi century event centered at 3500 cal bp in agreement with marine and terrestrial paleoclimatic reconstructions from nem with exception of the wet period between c 8 6 and 7 9 cal bp periods of increased hydrological activity are synchronous to contraction of pinus forests and increased sea surface temperatures and silt transport in the aegean sea the long term similar to 580 years variability of ms is in phase with southeast europe pollen inferred annual temperature variations and with north atlantic ice rafted debris ird events

lateglacial and holocene climate and environmental change in the northeastern mediterranean region diatom evidence from lake dojran republic of macedonia greece abstract the juncture between the west east and north south contrasting holocene climatic domains across the mediterranean is complex and poorly understood diatom analysis of lake dojran republic of macedonia greece provides a new insight into lake levels and trophic status during the lateglacial and holocene periods in the northeastern mediterranean following a very shallow or even desiccated state at the core base at ca 12 500 cal yr bp indicated by sedimentological and hydro acoustic data diatoms indicate lake infilling from a shallow state with abundant benthos to a plankton dominated relatively high lake level and eutrophic state thereafter diatom inferred shallowing between ca 12 400 12 000 cal yr bp and a very low lake level and eutrophic oligosaline state between ca 12 000 11 500 cal yr bp provide strong evidence for younger dryas aridity the earliest holocene ca 11 500 10 700 cal yr bp was characterised by a high lake level followed by a lake level reduction and increased trophic level between ca 10 700 8 500 cal yr bp the lake was relatively deep and exhibited peak holocene trophic level between ca 8 500 3 000 cal yr bp becoming shallow thereafter the diatom data provide more robust evidence and strengthen previous lake level interpretation based on sedimentological and geochemical data during the earliest mid and late holocene and also clarify previous uncertainty in interpretation of lateglacial and early holocene lake level change our results are also important in disentangling regional climate effects from local catchment dynamics during the holocene and to this end we exploit extant regional palynological evidence for vegetation change in the highlands and lowlands the importance of seasonality in driving holocene climate change is assessed by reference to the summer and winter latitudinal temperature gradient ltg model of davis and brewer 2009 we suggest that increased precipitation drove the high lake level during the earliest holocene the early holocene low lake level and relatively high trophic state may result climatically from high seasonality of precipitation and locally from limited nutrient rich catchment runoff we argue that the mid holocene relatively deep and eutrophic state was driven mainly by local vegetation succession and associated changes in catchment processes rather than showing a close relationship to climate change the late holocene shallow state may have been influenced by a temperature induced increase in evaporative concentration but was coupled with clear evidence for intensified human impact this study improves understanding of lateglacial and holocene climate change in the northeastern mediterranean suggests the important role of the ltg on moisture availability during the holocene and clarifies the influence of catchment processes on palaeohydrology

impacts of logging disturbance on hillslope saturated hydraulic conductivity in a tropical forest in peninsular malaysia using a constant head permeameter we found an abrupt natural decrease in saturated hydraulic conductivity ks within the upper 1 0 m soil profile of an orthoxic tropudult at the bukit tarek experimental catchments research area in tropical peninsular malaysia the depth at which low ks could cause a perched water table in response to high intensity rainfall however was too great to generate saturation overland flow on planar hillslopes in the study area the effects of logging activity on ks at five subsurface depths 0 1 0 25 0 5 0 75 and 1 0 m on the non roaded portion of the harvest area were examined at the three following sites which differed in the degree of disturbance and recovery since timber harvesting 1 selective logging conducted in the 1960s 2 mechanized selective tree removal conducted 4 years ago and 3 high impact clear cutting just prior to measurement this recent logging greatly disturbed the soil surface via compaction topsoil subsoil mixing burning and produced comparatively high variability in near surface ks changes in ks at or below 0 25 m however were not detected with certainty at any sites in terms of hillslope hydrologic response the connectivity of zones of low ks in the harvest area with dense networks of skid trails and terraces was identified as one of the most important consequences of timber harvesting although this phenomenon was not quantified we estimate the recovery time for near surface ks on the non roaded hillslope to be less than 40 years d 2006 elsevier b v all rights reserved

pressure induced temperature variations in an underground quarry abstract temperature measurements have been performed in the rock and atmosphere of an underground limestone quarry in vincennes france in the atmosphere temperature variations associated with variations of the atmospheric pressure are continuously observed with an average coupling of 70 m c hpa at a period of 4 min 35 m c hpa at 1 h and 3 m c hpa at 1 day and an increasing phase advance for increasing period at the highest frequencies the coupling is close to its adiabatic value of 80 m c hpa the reduction of coupling with decreasing frequency is interpreted as diabatic thermal stabilisation of the atmosphere by heat flow and coupled feedback due to phase changes of water during extreme events such as the tempests that occurred in france in december 1999 additional effects were observed in the atmosphere and in the rock material as well pressure induced temperature variations may be important to study in underground monitoring experiments and may be a useful tool for the characterisation of nuclear waste storage sites

overland flow generation in two lithologically distinct rainforest catchments streams on uniformly rainforest covered but lithologically very diverse barro colorado island in central panama show remarkable differences in their runoff response to rainfall this lithological diversity is reflected in equally diverse soilscapes and our objective was to test the hypothesis that contrasting runoff responses derive from soilscape features that control the generation of overland flow we determined the soil saturated hydraulic conductivity ks of two neighboring but hydrologically contrasting catchments lutz creek with a flashy and conrad trail with a delayed response to rainfall and quantified the spatial and temporal frequency of overland flow occurrence the median ks values at a depth of 12 5 cm are large enough to rule out hortonian overland flow but a marked decrease in ks in lutz creek catchment at 30 cm suggests the formation of a perched water table and the generation saturation overland flow the decrease in ks in the conrad trail catchment is more gradual and a perched water table is expected to form only at depths below 50 cm in lutz creek overland flow was generated frequently in time and space and regardless of topographic position including near the interfluve with very low thresholds of storm magnitude duration intensity and antecedent wetness whereas in conrad trail overland flow was generated much less frequently and then only locally we conclude that soilscape features and microtopography are important controls of overland flow generation in these catchments our results contribute to the growing evidence that overland flow and forests are not a priori a contradiction in terms

a 12 000 year pollen record from lake maliq albania abstract pollen data from lake maliq the first from albania contribute new information to the discussion of the vegetational hydrological and climatological history of the balkans since 12 000 yr b p during late glacial time a perennial lake expanded at maliq it was surrounded by a complex vegetation association composed of steppe and mixed forest elements the highly diverse forest flora suggest that late glacial forest refugia were more developed here at middle altitude rather than at higher altitude as previously suggested the forest developed after 9800 yr b p while the water level remained high in the korce basin until 5000 yr b p different environmental conditions characterized by lower available moisture and warmer winters progressively took place after this date human activity in the korce basin ca 4500 yr b p was coeval with conditions characterized by an increase in winter temperatures and a decrease in summer moisture

a conceptual model of preferential flow systems in forested hillslopes evidence of self organization preferential flow paths are known to be important conduits of subsurface stormflow in forest hillslopes earlier research on preferential flow paths focused on vertical transport however lateral transport is also evident in steep forested slopes underlain by bedrock or till macropores consisting of decayed and live roots subsurface erosion surface bedrock fractures and animal burrows form the basis of a backbone for lateral preferential flow in such sites evidence from field studies in japan indicates that although individual macropore segments are generally 0 5 m in length they have a tendency to self organize into larger preferential flow systems as sites become wetter staining tests show clear evidence of interconnected macropore flow segments including flow within decayed root channels and subsurface erosion cavities flow in small depressions of the bedrock substrate fracture flow in weathered bedrock exchange between macropores and mesopores and flow at the organic horizon mineral soil interface and in buried pockets of organic material and loose soil here we develop a three dimensional model for preferential flow systems based on distributed attributes of macropores and potential connecting nodes e g zones of loose soil and buried organic matter we postulate that the spatially variable and non linear preferential flow response observed at our japan field site as well as at other sites is attributed to discrete segments of macropores connecting at various nodes within the regolith each node is activated by local soil water conditions and is influenced strongly by soil depth permeability pore size organic matter distribution surface and substrate topography and possibly momentum dissipation this study represents the first attempt to characterize the spatially distributed nature of preferential flow paths at the hillslope scale and presents strong evidence that these networks exhibit complex system behaviour

climate and environmental change in the balkans over the last 17 ka recorded in sediments from lake prespa albania f y r of macedonia greece this paper presents sedimentological geochemical and biological data from lake prespa albania former yugoslav republic of macedonia greece the 320 cm core sequence co1215 covers the last 17 ka calbp and reveals significant change in climate and environmental conditions on a local and regional scale the sediment record suggests typical stadial conditions from 17 1 to 15 7 ka calbp documented through low lake productivity well mixed conditions and cold resistant steppe catchment vegetation warming is indicated from 15 7 ka calbp with slightly increased in lake productivity gradual expansion of trees and decreasing erosion through disappearance of local ice caps between 14 5 and 11 5 ka calbp relatively stable hydrological conditions are documented the maximum in tree taxa percentages during the bolling allerod interstadial 14 5 13 2 ka calbp indicates increased temperatures and moisture availability whereas the increase of cold resistant open steppe vegetation taxa percentages during the younger dryas 13 2 11 5 ka calbp is coupled with distinct colder and drier conditions the holocene sequence from 11 5 ka calbp indicates ice free winters stratification of the water column a relatively high lake trophic level and dense vegetation cover over the catchment a strong climate related impact on the limnology and physical parameters in lake prespa is documented around 8 2 ka through a significant decrease in productivity enhanced mixing strong decomposition and soil erosion and a coeval expansion of herbs implying cool and dry climate conditions intensive human activity in the catchment is indicated from around 1 9 ka calbp this multiproxy approach improves our understanding of short and long term climate fluctuations in this area and their impact on catchment dynamics limnology hydrology and vegetation

palynology after y2k understanding the source area of pollen in sediments pollen grains preserved in lake and bog sediment provide a record of past vegetation that has been an important source of information about climate and land cover during the quaternary period yet from the beginning questions have been raised about the source area of pollen in sediment interpretation has been hampered by the lack of well developed theory treating the relationship between the spatial distribution of trees on the landscape and the percentages of pollen in sediment within the past decade however new theory models and empirical data show how heterogeneous vegetation is represented by pollen the distinction between local and regional pollen is explained by the prentice sugita dispersal deposition models which predict how the ratio of regional to local pollen changes with lake size sugita s model simulating a landscape with heterogeneous vegetation predicts the size of the relevant source area the area of vegetation reflected in between lake variations in pollen loading while demo

vegetation and climate changes in the south eastern mediterranean during the last glacial interglacial cycle 86 ka new marine pollen record the eastern mediterranean located at the meeting between the mediterranean vegetation of the eurasian continent and the desert vegetation of the saharan arabian desert belt is ideal for tracking changes in regional vegetation as function of climate changes reconstruction of these changes in the south eastern mediterranean during the last 86 ka is based on a palynological record from deep sea core 9509 taken by r v marion dufresne off the southern israeli coast the chronological framework is based on the correlation of d 18 o records of planktonic foraminifera with the high resolution well dated u th speleothem record from the soreq cave israel and the occurrence of sapropel layers several cycles of humid dry periods were documented during the last 86 ka the record starts with the moderate humid and warm sapropel s3 marking the end of marine isotope stage mis 5 the climate during the last glacial period 75 5e16 2 ka was cold and dry with low arboreal pollen ap levels and high values of semi desert and desert vegetation e g artemisia sagebrush the driest and coldest period during the last 86 ka corresponds to mis 2 27 1e16 2 ka characterized by the lowest tree cover along the sequence and the dominance of steppe vegetation some slightly more humid fluctuations were identified during the period of 56 3 and 43 5 ka with its peak between 56 0 and 54 4 ka the most pronounced climate change started at the beginning of the deglaciation 16 2e10 ka and continued throughout the holocene last 10 ka notwithstanding some short fluctuations high ap levels were dominated by quercus callipprinos evergreen oak suggesting that the mediterranean forest was more extensive in the area and the climate was wet sapropels s3 and s1 were clearly recognized here by the high concentrations and good state of preservation of pollen because of the development of anoxia in the bottom water that may be related to more extensive nile discharge coinciding with high insolation values at 65

sea land correlation of pollen records in the eastern mediterranean for the glacial interglacial transition biostratigraphy versus radiometric time scale abstract pollen diagrams based on marine cores from the eastern mediterranean and arabian seas and land cores from greece turkey the levant and western iran during the last deglaciation reveal a similar succession of conspicuous pollen abundance maxima an early phase with chenopodiaceae signaling the highest aridity a late phase with pistacia and gramineae in the mediterranean domain and tropical humid taxa in the arabian sea domain indicating conditions of mildest winter and wettest summer between these two phases the record for deciduous oak in the mediterranean and near east shows a continuous increase that points to rising moisture the chronology of this succession and its exact relationship with the marine isotopic record of global climate are established using marine cores the marine records dated by the ams 14 c method show that the chenopodiaceae phase correlates with the younger dryas chronozone globally dated 11 000 to 10 000 bp during which the climate reversed to quasi glacial conditions at least in the northern hemisphere they also show that the pistacia phase during which the mediterranean climate reached its seasonal optimum occurred from 9000 to 6000 14 c years bp boreal and early atlantic chronozones defined in nw europe in the first half of the holocene the oak pollen abundance increases rapidly from 10 000 to 9000 bp preboreal chronozone thus in terms of climate the younger dryas chronozone is regionally expressed by wide spread desert conditions as a cold and arid period during the pistacia phase the climate was most favourable both for plants that require frost free winters such as the mediterranean pistacia and those that need spring summer moisture such as gramineae at low annual moisture level seasonally 300 mm and deciduous oak at higher levels 600 mm all year without summer drought during the brief intermediary phase the climate changed drastically through an increase of winter temperature and of spring summer moisture the chronologies of the land cores however based on few 14 c dates show significant discrepancies with the marine based time frame these discrepancies imply a lack of coherence in the climate history of this mediterranean irano turanian region we propose using the chronology derived from the marine records for the entire region the local 14 c dates generally appear too old perhaps because of geological contamination of the material by older carbon

geomorphologic and paleoclimatic evidence of holocene glaciation on mount olympus greece this study investigates the possibility of holocene glaciation on mount olympus greece with a respective local temperature precipitation equilibrium line altitude tp ela at c 2200m a s l based on geomorphologic and paleoclimatic evidence at present the local tp ela is situated above the mountain s summit c 2918 m a s l but permanent snowfields and ice bodies survive within megala kazania cirque between c 2400 and c 2300 m a s l because of the cirque s maritime setting that results from its close proximity c 18km to the aegean sea and of the local topographical controls the snow and ice bodies occupied a considerably larger area and attained a stabilization phase between ad 1960 and 1980 also manifested from aerial photographs a period characterized by increased winter precipitation pw with subsequent tp ela depression to c 2410m a s l mid to late 20th century pw and tp ela variations exhibit negative correlations with the winter north atlantic oscillation index naow at annual and multidecadal 30 years timescales late holocene ad 1680 1860 reconstructed summer mean temperatures were lower by ts 1 1 c in relation to the reference period between ad 1960 and 1980 and were also superimposed to negative naow phases thus bracketing this time interval as a favorable one to glacial formation and or advance millennial scale annual precipitation reconstructions at the hypothesized tp ela c 2200m a s l point the period between 8 and 4 kyr bp as another glacier friendly candidate the mid holocene rather simplistic sequence of potential glacial advance phase was disturbed by short lived cold climatic deteriorations well documented over the northern aegean region that may partly explain the multicrested shape of the highest c 2200 m a s l morainic complex of megala kazania cirque

late glacial and holocene history of the northeast mediterranean mountain glaciers new insights from in situ produced 36cl based cosmic ray exposure dating of paleo glacier deposits on mount olympus greece in this study we present a new glacial chronology based on 20 in situ produced 36cl based cosmic ray exposure datings from moraine boulders and bedrock from the throne of zeus tz and megala kazania mk cirques on mount olympus the 36cl derived ages of glacial landforms range from 15 6 2 0 to 0 64 0 08 ka spanning the late glacial and the holocene the late glacial recorded in both cirques is partitioned in three distinct phases lg1 3 an initial phase of moraine stabilization at 15 5 2 0 ka with subsequent deglaciation starting at 14 ka lg1 followed by a shift to marginal conditions for glaciation at 13 5 2 0 ka lg2 sustained by large amounts of wind blown snow despite regional warming glacial conditions returned at 12 5 1 5 ka lg3 and were characterized by low air temperatures and glacier shrinking the holocene glacial phases hol1 3 are recorded only in the mk cirque likely due to its topographic attributes an early holocene glacier stillstand hol1 at 9 6 1 1 ka follows the regional temperatures recovery no glacier activity is observed during the mid holocene the late holocene glacier expansions include a moraine stabilization phase hol2 at 2 5 0 3 ka during wet conditions and solar insolation minima while hol3 corresponds to the early part of the little ice age 0 64 0 08ka our glacial chronology is coherent with glacial chronologies from several cirques along the northeast mediterranean mountains and in pace with numerous proxies from terrestrial and marine systems from the north aegean sea

temporal behavior of a ventilated claystone at the tournemire url cross spectral analyses focused on daily harmonics abstract the main topic of this communication is the presentation of study auscultation and supervision procedures of deep geological radioactive waste storage repositories using natural harmonic forcings in this paper the effects of natural ventilation on the macroscopic behavior of a clayrock are investigated by means of time series recorded underground over a period of two years in the eastern part of gallery 1996 at the tournemire underground research laboratory url this study is based on time series acquired in the atmosphere at the gallery wall surface and inside the rock mass it includes measured signals from 6 thermo hygrometers 5 crack meters measuring the displacement of 2 shrinkage cracks and 3 tectonic fractures and a 1 meter fdr frequency domain reflectometry profile probe equipped with 6 sensors for measuring the volumetric pore water content into the rock mass auto spectral and cross spectral analyses using the concept of singular spectrum harmonics sshs and cross sshs are developed our analyses and interpretations focus here mainly on the solar diurnal atmospheric tide denoted s1 this tide corresponds to the insolation cycle of the earth atmosphere during a mean solar day 24 h 00 min this component is tracked throughout the various measured signals spectral tracking of tide fluctuations across signals this is equivalent in a way to analyzing the temporal behavior of the url during a mean solar day on earth results indicate that the daily natural forcing caused mainly by a combination of barometric and temperature related fluctuations is the most important effect overall on our various signals the daily harmonic induces the fluctuations of gallery air temperature relative and absolute air humidity and it leads to desaturation of the claystone which in turn leads to the claystone deformation and damage the effects of the annual harmonic sa may also be significant it was fully analyzed in the more complete version of this work however the sa results are not presented here because the spectral resolution on the annual harmonic is insufficient at this stage with only 2 years and 2 months of clean recorded data focusing the present study on daily fluctuations the cross spectral time shifts were obtained from the phase spectrum for the daily component s1 for various pairs of pore water content sensors located at different distances from the gallery wall these time shifts were then used to quantify a spectral velocity which is found to be on the same order than the hydraulic conductivities deduced previously from pneumatic tests performed in the excavation damaged zone of gallery 1996

two methods for the tracing of pipe flow on hillslopes abstract two techniques for the determination of soil pipe networks on hillslopes which avoid the logistic difficulties associated with the unpredictable and ephemeral nature of pipe flow are described passive detectors of activated charcoal in conjunction with fluorescent dyes proved to be most useful for the general definition of networks over moderate areas whereas artificial injections of water permitted much more detailed information to be obtained the networks comprised anastomosing bands with definite tributary and distributary zones the gross network form was stable over a five year period but the function of individual links could change even during a storm event velocities of pipe flow were comparable with those of overland flow in the area and very much faster than observed rates of throughflow a complex interrelation between these three flow processes was observed during the experiments