Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Grondwaterdynamiek in kaart en praktijk; symposium bundel
    Hoogland, T. ; Horst, J.B.F. van der - \ 2004
    Wageningen : Alterra (Alterra-rapport 899) - 33
    bodemwaterbeweging - grondwaterspiegel - uitspoelen - monitoring - modellen - bodemkarteringen - kaarten - soil water movement - water table - monitoring - models - leaching - soil surveys - maps
    Sinds 1997 is Alterra bezig met het ontwikkelen van een nieuwe methode en het uitvoeren van projecten om de grondwaterdynamiek (Gd) in kaart te brengen. De nieuwe methode om de grondwaterdynamiek in kaart te brengen is in opdracht van een aantal waterschappen, de provincie Noord-Brabant en het ministerie van LNV toegepast om de, veelal verouderde, Gt-informatie uit de bodemkaart 1: 50.000 te actualiseren. Gd-kaarten worden in het regionaal, provinciaal en landelijk beleid voor verschillende toepassingen gebruikt. Bij waterschappen en provincies worden Gd-kaarten gebruikt bij het vaststellen van het Gewenst Grond- en Oppervlaktewater Regime (GGOR) en voor regionaal waterbeheer. In het landelijk beleid wordt de Gd-kartering o.a. toegepast voor het vaststellen van uitspoelingsgevoelige gronden in het kader van de mestwetgeving. Na een aantal jaren van uitvoering van Gd-projecten voor verschillende opdrachtgevers leek het ons nuttig om met gebruikers en beoogd gebruikers van Gd-informatie van gedachten te wisselen over de gebruiksdoelen, gebruiksmogelijkheden en het omgaan met onzekerheid. Hiervoor hebben we drie (beoogd) gebruikers van Gd informatie uitgenodigd om op het symposium hun wensen en bevindingen te bespreken. De drie sprekers werken voor organisaties die op verschillende schaalniveau opereren en gebruik maken van Gd-informatie voor verschillende toepassingen. Hierdoor kwamen zeer uiteenlopende aspecten, die een rol spelen bij het gebruik van Gd-informatie, aan de orde en ontstond een levendige discussie. U treft in dit rapport een samenvatting van de verschillende voordrachten aan en een beknopt verslag van de discussie.
    Iron and sulphate as possible key factors in the restoration ecology of rich fens in discharge areas
    Kemmers, R.H. ; Delft, S.P.J. van; Jansen, P.C. - \ 2003
    Wetlands Ecology and Management 11 (2003)6. - ISSN 0923-4861 - p. 367 - 381.
    bodemchemie - veengronden - bodemwaterbeweging - calcium - zure gronden - soil chemistry - calcium - acid soils - peat soils - soil water movement
    Seven reference areas in the Netherlandswere selected to trial restoration measuresin acidified rich fens in discharge areas.In about half of the projects the measuresthat aimed to restore the high base statusof the topsoil failed. The aim of thepresent study was to identify the keyfactors and processes in base regulation ofrich fen systems, in order to underpinfuture restoration. We sampled soil andinterstitial water from distinct soilhorizons and analysed it for variablesinvolved in geohydrochemical processes. Wemonitored interstitial water chemistry andredox potentials to calibrate and validatea chemical speciation model, that we usedfor the interpretation of our observations.It appeared that soil pH, Ca2+saturation and iron contents weresignificantly lower at sites whererestoration efforts had failed. At the sametime, soils of these sites were verystratified instead of homogenous. Onlysoils with high iron contents recovered ahigh Ca2+ saturation. All sites werecharacterised by considerable downwardwater fluxes through the soil. Chemicalspeciation modelling was a useful tool forthe interpretation of processes underlyingour observations and helped elucidate thefactors and processes that control therecharge of the CEC by base cations. The modelling results suggested that the mainprocess in proton neutralisation ofsuccessful sites is the production ofinternal alkalinity by reduction of ironoxides. Additional redox capacity can besupplied by the ample presence ofsulphates. From our results we hypothesisethat the CEC will only be rechargedsuccessfully with base cations in thepresence of sufficient redox capacity ofthe soil. It seems that redox processesfacilitate the ionic exchange of protonsfor Ca2+ ions. Sites where restorationefforts failed changed from discharge areasto recharge areas, which caused irondepletion by leaching. We conclude thatproper understanding of the pedological andgeohydrochemical processes that control thebase status of soils is a prerequisite forsuccessful nature restoration. The role ofsoil processes cannot be ignored as itseems that the production of internalalkalinity upon reduction exceeds theexternal supply of alkalinity bygroundwater flow.
    Soil water - groundwater interaction
    Kroes, J.G. ; Dam, J.C. van - \ 2003
    In: Reference Manual SWAP; version 3.0.3 Wageningen : Alterra (Alterra-rapport 773) - p. 85 - 89.
    bodemwaterbeweging - grondwaterstroming - modellen - soil water movement - groundwater flow - models
    SWAP offers eight options to prescribe the lower boundary condition. These conditions are given in this chapter
    Soil water - surface water interaction
    Dam, J.C. van; Kroes, J.G. ; Groenendijk, P. ; Walsum, P.E.V. van - \ 2003
    In: Reference Manual SWAP; version 3.0.3 / Kroes, J.G., van Dam, J.C., Wageningen : Alterra (Alterra-rapport 773) - p. 51 - 83.
    bodemwaterbeweging - oppervlakkige afvoer - ondergrondse drainage - modellen - soil water movement - runoff - subsurface drainage - models
    Drainage and infiltration are described by Hooghoudt and Ernst equations;
    Water flow and solute transport in the Korenburgerveen site
    Rovdan, E. - \ 2003
    In: Measurement techniques and data assessment in wetlands hydrology / Ignar, S., Nowakowski, P., Okruszko, T., Warsaw : Warsaw Agricultural University Press - ISBN 9788372444868 - p. 103 - 115.
    veengronden - veengebieden - bodemwaterbeweging - uitspoelen - modellen - gelderland - achterhoek - peat soils - peatlands - soil water movement - leaching - models - gelderland - achterhoek
    This paper describes the results of investigation of water flow and tracer transport to estimate the effect of different water management scenarios, climatic conditions and restoration measure. The SWAP model was used in this study
    Nieuwe informatie over de grondwaterdynamiek: wensen en mogelijkheden
    Knotters, M. ; Hoogland, T. ; Gaast, J.W.J. van der - \ 2003
    Wageningen : Alterra (Alterra-rapport 548) - 50
    bodemwater - grondwaterspiegel - bodemwaterbeweging - monitoring - waterbalans - infiltratie - kwel - grondwaterstand - nederland - informatiebehoeften - soil water - water table - soil water movement - monitoring - information needs - water balance - infiltration - seepage - groundwater level - netherlands
    Medewerkers van vier verschillende waterschappen hebben in interviews hun wensen kenbaar gemaakt naar nieuwe informatie over de grondwaterdynamiek. De mogelijkheden om aan deze wensen te voldoen in systematische karteringen van de grondwaterdynamiek zijn geanalyseerd. In het Holocene deel van Nederland, met beheerste peilen, is behoefte naar informatie over de relatie tussen grondwaterstand en oppervlaktewaterstand, om het grondwaterafhankelijk peilbeheer af te kunnen stemmen op de risiconormering voor wateroverlast. Een ontwerp van een karteermethodiek is geschetst, waarin de inventarisatie van de opbolling van de grondwaterstand en de schatting van drainageweerstanden een belangrijke rol spelen.
    Transport of water, bromide ion, nutrients and the pesticides bentazone and imidacloprid in a cracking, tile drained clay soil at Andelst, the Netherlands
    Smelt, J.H. ; Hendriks, R.F.A. ; Pas, L.J.T. van der; Matser, A.M. ; Toorn, A. van den; Oostindie, K. ; Dijk-Hooijer, O.M. van; Boesten, J.J.T.I. ; Scorza Júnior, R.P. - \ 2003
    Wageningen : Alterra (Alterra-rapport 289) - 213
    uitspoelen - pesticiden - grondwaterverontreiniging - zware kleigronden - voedingsstoffen - bodemwaterbeweging - nitraten - bromide - bentazon - imidacloprid - nitraat - experimenteel veldonderzoek - nederland - leaching - pesticides - groundwater pollution - clay soils - nutrients - soil water movement - nitrates - bromide - bentazone - imidacloprid - nitrate - field experimentation - netherlands
    The aim of this study was to perform a field experiment to collect a high quality data set suitable for validating and improving pesticide leaching models and nutrient leaching models for drained and cracking clay soils. The transport of water, bromide, nutrients and the pesticides bentazone and imidacloprid was studied on a 1.2 ha experimental plot. Moisture profiles and groundwater tables were measured, starting in November 1997. Winter wheat was sown on 23 October 1997 and harvested on 20 August 1998. Bentazone and bromide were applied at 7 April 1998; imidacloprid was applied at 27 May when the soil was almost completely covered by the crop. The amount present in soil was measured within 2 days after application (32 sampling cores) and was found to vary between 80% of the nominal dose (imidacloprid) to 110 % (for bentazone). Manuring and soil cultivations were as usual for the wheat crop. Soil profiles were sampled at eight times (16 cores at each date, last in April 1999). Drain flow was continuously recorded and the water flow proportionally sampled for analysis of the test compounds. Groundwater was sampled periodically from sets of permanently placed filters at four depths at 16 sites. Sorption isotherms of the pesticides were measured with soil from 0-25 cm. Transformation rates of the pesticides were measured at different temperatures in soil material from topsoil and subsoil layers. Soil hydraulic properties and shrinkage characteristics were measured in the laboratory. Meteorological data (i.e. rainfall, air temperature, global radiation, air humidity etc.) groundwater levels and soil temperatures at three depths were monitored continuously. After 56 days, about 80% of the bromide dose was taken up by the crop, which demonstrates that bromide is not a suitable tracer in cropped soil during the growing season. After that time the bromide was gradually released again into the soil. Preferential transport through cracks and macropores of all test compounds was measured both in summer and in winter. This resulted in the highest concentration of bromide and bentazone measured in drain water already 21 days after application following 56 mm rainfall. Imidacloprid was already detected in groundwater at 1.3-1.5 m depth, 11 days after application, following 65 mm rainfall. High peaks in nitrate concentrations in the groundwater at 1.00-1.50 m depth and in the drain water were detected within 14-18 days after the first fertilizer application, following 94 mm of rainfall. Extreme high peaks in concentrations of ortho-P and soluble organic-P were measured in the drain water at respectively 2 days and 37 after slurry application (the only phosphorus application during the experiment). For nitrate concentrations in the drain water there were indications for bypass by preferential flow of `clean` rainwater to the drains.
    Developing and testing a regularization technique
    Loon, E.E. van; Troch, P.A.A. - \ 2003
    In: CAHMDA Workshop, Wageningen, September 2001 / E.E. van Loon and P.A. Troch Wageningen : Sub-department Water Resources - p. 67 - 89.
    bodemwaterbeweging - modellen - bodemwaterbalans - retentie - soil water movement - soil water balance - retention - models
    Investigation of the functional lifetime of TRISOPLASTr in relation to chemical compositions of pore water solutions in barriers
    Boels, D. ; Beest, H. te; Zweers, H. ; Groeneveld, P. - \ 2003
    Wageningen : Alterra (Alterra-rapport 528) - 49
    barrières - chemische samenstelling - permeabiliteit - bodemwaterbeweging - poriën - kationenwisseling - stortterreinen - bodembescherming - membraanpermeabiliteit - membranen - barriers - chemical composition - permeability - soil water movement - pores - cation exchange - landfills - soil conservation - membrane permeability - membranes
    Trisoplastr is a mixture of sand, bentonite and a polymer, used amongst others as landfill cover as well as barriers. Its permeability is generally lower than 1-2 x 10-11 m/s. Trisoplast keeps its functionality even in contact with different kinds of liquids, is not susceptible to cyclic drying and rewetting, and the permeability hardly depends on its dry bulk density. Tests with 10¿iaxial strain show only a slight increase in permeability. The functional lifetime of Trisoplast is governed by exchange of adsorbed sodium ions against dissolved calcium ions. This process depends on the composition of the pore water solution in the soil layers directly in contact with Trisoplast and the displacement rate of dissolved calcium ions either by convectiveor diffusive transport phenomena. The functional lifetime of Trisoplast even under relatively extreme conditions is at least 100 years and scores clearly better than the reference sand-bentonite barrier.
    Modelconcepten voor de interactie tussen verzadigd grondwater en oppervlaktewater
    Groenendijk, P. ; Lange, W.J. de; Kovar, K. - \ 2002
    Stromingen : vakblad voor hydrologen 8 (2002)2. - ISSN 1382-6069 - p. 11 - 28.
    grondwater - grondwaterstroming - bodemwaterbeweging - interacties - verzadigde stroming - modellen - drainage - groundwater - groundwater flow - soil water movement - drainage - interactions - saturated flow - models
    Uitgaande van de 3 kernbegrippen drainageflux, lekflux en voedingsflux is getracht een koppeling te vinden tussen het topsysteem en het diepe grondwater. Op weg naar deze koppeling zijn een aantal aannames gedaan
    Percolation Thresholds in 2-Dimensional Prefractal Models of Porous Media
    Sukop, M.C. ; Dijk, G.J. van; Perfect, E. ; Loon, W.K.P. van - \ 2002
    Transport in Porous Media 48 (2002). - ISSN 0169-3913 - p. 187 - 208.
    percolatie - bodemwaterbeweging - permeabiliteit - poreus medium - modellen - fractal meetkunde - porous media - percolation - soil water movement - permeability - models - fractal geometry
    Considerable effort has been directed towards the application of percolation theory and fractal modeling to porous media. We combine these areas of research to investigate percolation in prefractal porous media. We estimated percolation thresholds in the pore space of homogeneous random 2-dimensional prefractals as a function of the fractal scale invariance ratio b and iteration level i. The percolation thresholds for these simulations were found to increase beyond the 0.5927... porosity expected in Bernoulli (uncorrelated) percolation networks. Percolation in prefractals occurs through large pores connected by small pores. The thresholds increase with both b (a finite size effect) and i. The results allow the prediction of the onset of percolation in models of prefractal porous media and can be used to bound modeling efforts. More fundamental applications are also possible. Only a limited range of parameters has been explored empirically but extrapolations allow the critical fractal dimension to be estimated for a large combination of b and i values. Extrapolation to infinite iterations suggests that there may be a critical fractal dimension of the solid at which the pore space percolates. The extrapolated value is close to 1.89 - the well-known fractal dimension of percolation clusters in 2-dimensional Bernoulli networks.
    Overland flow: interfacing models with measurements
    Loon, E.E. van - \ 2002
    Wageningen University. Promotor(en): L. Stroosnijder; K.J. Keesman. - S.l. : S.n. - ISBN 9789058085580 - 171
    oppervlakkige afvoer - bodemwaterbeweging - hydraulisch geleidingsvermogen - modellen - runoff - soil water movement - hydraulic conductivity - models
    Index words: overland flow, catchment scale, system identification, ensemble simulations.

    This study presents new techniques to identify scale-dependent overland flow models and use these for ensemble-based predictions. The techniques are developed on the basis of overland flow, rain, discharge, soil, vegetation and terrain observations that were collected over a three year period in two tropical catchments. The merits of the identification technique are its robustness with regard to unknown errors, the ability to adjust model resolution in response to data availability, and to interpret the entities of the identified model structures physically. Compared to a static regression model and a dynamic distributed model the predictive performance of the scale-dependent overland flow models is good, especially when using model ensembles. Further analysis of the scale-dependent models shows that rainfall largely determines overland flow when modelled at coarse resolutions, whereas soil moisture drives overland flow when defined at fine resolutions. Interestingly, the number of model parameters remains constant over the different resolutions. The use of the scale-dependent models for predictive purposes is demonstrated by applying Tikhonov regularization for recursive state as well as parameter estimation.
    Modelling Water Flow and Solute Transport for Horticultural and Environmental Management
    Feddes, R.A. ; Dam, J.C. van - \ 2002
    Acta Horticulturae 573 (2002). - ISSN 0567-7572 - p. 107 - 117.
    grondwaterstroming - bodemwaterbeweging - simulatiemodellen - voedingsoplossingen - tuinbouw - agrarische bedrijfsvoering - milieubeheer - bodemoplossing - groei - bodemmorfologie - groundwater flow - soil water movement - simulation models - nutrient solutions - horticulture - farm management - environmental management - soil solution - growth - soil morphology
    During the past 10 years, the simulation model SWAP (Soil, Water, Atmosphere, Plant) was developed by the Sub-Department Water Resources of Wageningen University jointly with the Department Water and Environment of Alterra Green World Research. SWAP simulates vertical transport of water, solutes and heat in variably saturated, cultivated soils at field scale level and during whole growing seasons. Different versions of the model have been applied worldwide in research, education and as a decision support tool in the management of agricultural, horticultural and natural systems water flow in homogeneous and heterogeneous soils with or without the influence of groundwater. The main features of and theoretical concepts behind SWAP are described, in particular soil water flow, solute transport and crop growth.
    Water repellency of soils; the influence of ambient relative humidity
    Doerr, S.H. ; Dekker, L.W. ; Ritsema, C.J. ; Shakesby, R.A. ; Bryant, R. - \ 2002
    Soil Science Society of America Journal 66 (2002)2. - ISSN 0361-5995 - p. 401 - 405.
    bodemwater - afstoting - temperatuur - relatieve vochtigheid - meteorologie - bodemwaterbeweging - zandgronden - bodemfysica - bodemvocht - waterafstotendheid - soil water - repellency - temperature - relative humidity - meteorology - soil water movement - sandy soils
    Adverse effects of soil water repellency (hydrophobicity) are of concern during or following rainfall or irrigation, and are often preceded by conditions of high atmospheric relative humidity (RH). Assessments of repellency are, however, commonly conducted on air-dried samples at ambient laboratory conditions. This study explores the effects of differing antecedent RHs (32-98%) on the water repellency of air-dried soils of wide ranging characteristics under laboratory conditions using water drop penetration time (WDPT) and ethanol-percentage tests. Most samples exhibited considerably higher water repellency after exposure (< 1 d) to 98% RH compared with lower RHs, typical of ambient laboratory conditions. This work suggests that previous studies mayhave incorrectly classified some soils, likely to exhibit water repellency in the field, as wettable, and that tests carried out following exposure of samples to high RH provide assessments that best reflect critical field conditions.
    The solute leaching surface as a tool to assess the performance of multidimensional unsaturated solute transport models
    Rooij, G.H. de; Stagnitti, F. - \ 2002
    In: Computational methods in water resources : proceedings of the XIVth international conference on computational methods in water resources (CMWR XIV), June 23-28, 2002, Delft, The Netherlands. - - p. 639 - 646.
    bodemwaterbeweging - uitspoelen - hydraulisch geleidingsvermogen - modellen - ruimtelijke variatie - soil water movement - leaching - hydraulic conductivity - spatial variation - models
    Spatial and temporal distribution of solute leaching in heterogeneous soils: analysis and application to multisampler lysimeter data
    Rooij, G.H. de; Stagnitti, F. - \ 2002
    Journal of Contaminant Hydrology 54 (2002). - ISSN 0169-7722 - p. 329 - 346.
    bodemwaterbeweging - uitspoelen - hydraulisch geleidingsvermogen - modellen - ruimtelijke variatie - soil water movement - leaching - hydraulic conductivity - spatial variation - models
    Accurate assessment of the fate of salts, nutrients, and pollutants in natural, heterogeneous soils requires a proper quantification of both spatial and temporal solute spreading during solute movement. The number of experiments with multisampler devices that measure solute leaching as a function of space and time is increasing. The breakthrough curve (BTC) can characterize the temporal aspect of solute leaching, and recently the spatial solute distribution curve (SSDC) was introduced to describe the spatial solute distribution. We combined and extended both concepts to develop a tool for the comprehensive analysis of the full spatio-temporal behavior of solute leaching
    Inversely estimating soil hydraulic functions using evapotranspiration fluxes
    Jhorar, R.K. ; Bastiaanssen, W.G.M. ; Feddes, R.A. ; Dam, J.C. van - \ 2002
    Journal of Hydrology 258 (2002). - ISSN 0022-1694 - p. 198 - 213.
    bodemwaterbeweging - hydraulisch geleidingsvermogen - evapotranspiratie - modellen - soil water movement - hydraulic conductivity - evapotranspiration - models
    Modeling the sink term under variable soil water osmotic and pressure heads
    Homaee, M. ; Feddes, R.A. - \ 2002
    In: Computational Methods in Water Resources : XIVth International Conference on Computational Methods in Water Resources , Delft, June 23-28, 2002 / Majid Hassanizadeh, S., Schotting, Ruud J., Gray, William G., Pinder, George F., Elsevier - ISBN 9780444509758 - p. 17 - 24.
    bodemwatergehalte - bodemwaterbeweging - plant-water relaties - modellen - hydraulisch geleidingsvermogen - soil water content - soil water movement - hydraulic conductivity - plant water relations - models
    Chloride transport in a recently reclaimed Dutch polder
    Vos, J.A. de; Raats, P.A.C. ; Feddes, R.A. - \ 2002
    Journal of Hydrology 257 (2002). - ISSN 0022-1694 - p. 59 - 77.
    bodemwaterbeweging - drainage - ontginning - polders - grondwaterspiegel - waterkwaliteit - chloride - modellen - flevoland - soil water movement - water table - water quality - chloride - drainage - reclamation - polders - models - flevoland
    Tikhonov regularization as a tool for assimilating soil moisture data in distributed hydrological models
    Loon, E.E. van; Troch, P.A. - \ 2002
    Hydrological Processes 16 (2002). - ISSN 0885-6087 - p. 531 - 556.
    bodemwatergehalte - bodemwaterbeweging - hydrologie van stroomgebieden - modellen - ruimtelijke variatie - geostatistiek - soil water content - soil water movement - catchment hydrology - spatial variation - models - geostatistics
    Discharge, water table depth, and soil moisture content have been observed at a high spatial and temporal resolution in a 44 ha catchment in Costa Rica over a period of 5 months. On the basis of the observations in the first 3 months (period A), two distinct soil moisture models are identified and calibrated: a linear stochastic time-varying state-space model, and a geo-statistical model. Both models are defined at various spatial and temporal resolutions. For the subsequent period of 2 months (period B), four different ways to predict the soil moisture dynamics in the catchment are compared: (1) the application of the dynamic models in open-loop form; (2) a re-calibration of the dynamic models with soil moisture data in period B, and subsequent prediction in open-loop form; (3) prediction with the geo-statistical models, using the soil moisture data in period B; (4) prediction by combining the outcomes of (1) and (3) via generalized cross-validation. The last method, which is a form of data assimilation, compares favourably with the three alternatives. Over a range of resolutions, the predictions by data assimilation have overall uncertainties that are approximately half that of the other prediction methods and have a favourable error structure (i.e. close to Gaussian) over space as well as time. In addition, data assimilation gives optimal predictions at finer resolutions compared with the other methods. Compared with prediction with the models in open-loop form, both re-calibration with soil moisture observations and data assimilation result in enhanced discharge predictions, whereas the prediction of ground water depths is not improved
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