Estimation of soil water storage change from clay shrinkage using satellite radar interferometry
Brake, Bram te - \ 2017
Wageningen University. Promotor(en): S.E.A.T.M. van der Zee; R.F. Hanssen, co-promotor(en): M.J. van der Ploeg; G.H. de Rooij. - Wageningen : Wageningen University - ISBN 9789463431637 - 123
soil water - water storage - satellite imagery - satellites - interferometry - shrinkage - clay - water management - water policy - bodemwater - wateropslag - satellietbeelden - satellieten - interferometrie - krimp - klei - waterbeheer - waterbeleid
Measurements of soil water storage are hard to obtain on scales relevant for water management and policy making. Therefore, this research develops a new measurement methodology for soil water storage estimation in clay containing soils. The proposed methodology relies on the speciﬁc property of clay soils to shrink when drying and to swell when (re-)wetted, and the capabilities of a remote sensing technique called satellite based radar interferometry (InSAR) to measure centimetre to millimetre scale displacements of the soil surface. The objective of this thesis was to develop the application of InSAR for soil water storage change estimation on the ﬁeld scale to regional scale. Two relations are investigated: 1) the relation between water storage change and surface elevation change as a result of swelling and shrinkage of a clayey soil; and 2) the relation between these surface elevation changes and InSAR phase observations.
The shrinkage potential of the soil is very important for successful application of radar interferometry to measure vertical deformation as a result of swelling and shrinkage of clay. Therefore, the shrinkage potential and the water storage change-volume change relation (called the soil shrinkage characteristic, SSC) have been quantiﬁed in the laboratory for clay aggregates from the study area in the Purmer, the Netherlands. The clay content of the sampled soil ranged from 3.4 to 23.6%. The aggregates had moderate shrinkage potential over the soil moisture content range from saturation to air-dryness. Shrinkage phases were distinguished based on the portion of water content change that was compensated by volume change. Approximately 40-50% of water was released in the normal shrinkage phase, where loss of water is fully compensated by volume change. However, the residual shrinkage phase, where volume change is smaller than water content change, started at approx. 50% normalized soil moisture content (actual moisture content with respect to the moisture content at saturation).
In case of normal shrinkage, soil water storage change can be directly derived from soil volume change. If additionally, clay shrinkage is isotropic, the soil water storage change can be derived from vertical shrinkage measurements. The range of normal and isotropic shrinkage has been assessed in a drying ﬁeld soil in the study area. To do so, soil water storage change was derived from soil moisture content sensors and groundwater level, and volume change estimates were obtained from soil layer thickness change measurements by ground anchors. Unlike for the aggregates, normal shrinkage was not observed for the ﬁeld soil, but rather a large degree of linear (basic) shrinkage was observed. In the upper soil layers in the ﬁeld, normalized soil moisture content below 50% has been observed when drying out. Based on the aggregate SSC, this indicates the occurrence of residual and zero shrinkage in this situation, resulting in less than normal shrinkage when the total unsaturated zone is considered. The water content change-volume change relation thus depends on the scale considered. It was also found that the relation depends on drying intensity, from comparison between shrinkage in a period with prolonged drying and shrinkage in a period with alternating drying end re-wetting.
For the ﬁeld soil, volume change larger than soil water storage change was observed when assuming isotropic shrinkage. This unrealistic result made clear that the assumption of isotropic shrinkage is invalid. Therefore a correction of the shrinkage geometry factor rs, including dependence of shrinkage geometry on soil moisture content, has been proposed. This correction yielded rs-values between 1.38 and 3. Dynamics of subsidence porosity (i.e. vertical shrinkage) calculated from the aggregate SSC, and comparison with surface elevation change data from the ﬁeld study also indicated rs-values smaller than 3. Values of rs below 3, indicate that vertical shrinkage (subsidence) is dominant over horizontal shrinkage (cracking).
Satellite based radar interferometry was applied to measure vertical deformation resulting from clay shrinkage, and evaluate the potential for soil water storage change estimation on the ﬁeld scale to regional scale. Phase diﬀerences between adjacent ﬁelds were observed in interferograms over the Purmer area which were hypothesised to be caused by relative motion of the surface level. The combination of a sequence of interferograms covering short time intervals and measurements of soil surface elevation changes in time from ground anchors, indeed revealed similar dynamics in both data. Relative changes between ﬁelds in winter were explained by a diﬀerent eﬀect of frost heave in a bare soil and in a soil permanently covered by grass. Noise in interferograms over agricultural ﬁelds was successfully reduced, by multilooking over entire ﬁelds. The eﬀect of soil type and land use on phase observation was qualitatively assessed, indicating that agricultural crop ﬁelds oﬀer the best phase estimates in winter, while grass ﬁelds are more coherent in summer. The results underline the need for careful selection of agricultural ﬁelds or areas to base InSAR analysis on.
The diﬀerential analysis between ﬁelds was extended to time series analysis of phase, to obtain deformation estimates with respect to a stable reference, including correction for unwanted phase contributions and temporal phase unwrapping. The correction of unwanted phase contributions speciﬁcally included the soil moisture dielectric effect. This eﬀect was considered by predicting interferometric phase based on in situ measured soil moisture contents. The soil moisture dielectric eﬀect was shown to be much smaller than shrinkage phase in our case study. A simple model was developed to estimate vertical shrinkage, using assumption on shrinkage behaviour (normal and isotropic shrinkage) and an approximation of water storage change from precipitation and evapotranspiration data. Using this model, temporal phase unwrapping results were corrected. The corrections for soil moisture dielectric phase and the correction of phase unwrapping both improved vertical shrinkage measurements from InSAR.
The results in this thesis make clear that vertical clay shrinkage can be estimated from InSAR. At the same time, these results show that clay shrinkage is a considerable phase contribution to interferometric phase and can therefore cause unwrapping and interpretation errors when not accounted for. To estimate vertical clay shrinkage from InSAR, a shrinkage model including assumptions of normal and isotropic shrinkage, proved useful in the phase unwrapping procedure in this case study. However, using the same assumptions to compute water storage change from these InSAR estimates, will in many cases produce inaccurate results. Therefore, in order to use InSAR for estimating soil water storage change in clay soils, the soil shrinkage characteristic, soil moisture dependency of the shrinkage geometry factor, and the eﬀect of variable drying and wetting conditions, need to be considered.
Change of Thought : Findings on Planning for Shrinkage from a Regional Design Competition
Kempenaar, J. ; Lierop, M.J.H.M. van; Westerink, J. ; Valk, A.J.J. van der; Brink, A. van den - \ 2016
Planning Practice & Research 31 (2016)1. - ISSN 0269-7459 - p. 23 - 40.
shrinkage - strategic spatial planning - regional design - design competition - process design
Shrinkage or ‘no growth’ is expected to condition the long-term perspective of many Western cities and regions. Planning for shrinkage differs substantively from planning for growth and therefore calls for a change of thought in spatial planning. In our paper, we analyse how planning professionals responded to a ‘planning for shrinkage’ challenge in a regional design competition. We found that they fully adapted to the shrinking perspective, took a strategic approach, and promoted a leading role for local inhabitants. Collaboration with local inhabitants and entrepreneurs, creating new alliances, and timing emerge as key themes for planning professionals in planning for shrinkage.
Porosity, Bulk Density, and Volume Reduction During Drying: Review of Measurement Methods and Coefficient Determinations
Qiu, J. ; Khalloufi, S. ; Martynenko, A. ; Dalen, G. van; Schutyser, M.A.I. ; Almeida-Rivera, C. - \ 2015
Drying Technology 33 (2015)14. - ISSN 0737-3937 - p. 1681 - 1699.
pore-size distribution - cooked beef product - mercury porosimetry - physical-properties - structural-properties - vacuum impregnation - image-analysis - porous-media - true density - shrinkage
Several experimental methods for measuring porosity, bulk density and volume reduction during drying of foodstuff are available. These methods include among others geometric dimension, volume displacement, mercury porosimeter, micro-CT, and NMR. However, data on their accuracy, sensitivity, and appropriateness are scarce. This paper reviews these experimental methods, areas of applications and limits. In addition, the concept of porosity, bulk density and volume reduction and their evolution as a function of moisture content during drying is presented. In this study, values of initial porosity (¿0) and density ratio (ß) of some food products are summarized. It has been found that ¿0 is highly dependent on the type of food products, while ß ranges from 1.1 to 1.6. The possibility of calculating solid density based on food compositions has also been validated. The inter-predictions between porosity, bulk density and volume density have been made mathematically evident.
Sociale innovatie als veelbelovend concept in krimpregio's
During, R. - \ 2013
Syscope Magazine 2013 (2013)31. - p. 27 - 30.
regionale ontwikkeling - bevolkingsafname - krimp - levensomstandigheden - kwaliteit van het leven - gemeenschapsontwikkeling - sociale interactie - participatie - regional development - population decrease - shrinkage - living conditions - quality of life - community development - social interaction - participation
Steeds vaker nemen burgers en ondernemers het heft in eigen handen voor de leefbaarheid van hun regio. Ze pakken kansen op, gaan nieuwe verantwoordelijkheden aan en doorbreken daarmee de traditionele maatschappijstructuren. Sociale innovatie noemen we dat. Sociale innovaties kunnen krimpregio’s nieuwe perspectieven geven. Deze nieuwe perspectieven gaan dan niet uit van groei, maar van het collectief overeind houden van de leefbaarheid.
De meerwaarde van multifunctionele landbouw in krimpgebied Noordoost-Groningen
Ferwerda-van Zonneveld, R.T. ; Vijn, M.P. ; Engelsma, K.A. ; Migchels, G. - \ 2012
Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 566) - 24
multifunctionele landbouw - krimp - bevolkingsafname - gebiedsontwikkeling - regionale planning - regionale ontwikkeling - duurzame landbouw - groningen - multifunctional agriculture - shrinkage - population decrease - area development - regional planning - regional development - sustainable agriculture - groningen
Uit dit onderzoek naar de meerwaarde van multifunctionele landbouw in het krimpgebied Noordoost-Groningen en de daarbij gevolgde redeneerlijnen, blijkt dat: De agrarische sector niet of nauwelijks betrokken wordt bij de plannen rondom krimp en niet in beeld is als verbindingspartner. De agrarische sector die rol zelf niet oppakt, omdat ze zich onvoldoende realiseert dat het bijdragen aan oplossingen voor het krimpvraagstuk kan worden gezien als een verduurzamingsstap van de landbouw Een belangrijke randvoorwaarde is dat bij zowel de agrarische sector als de andere partijen gewerkt wordt aan bewustwording.
Selection properties of Type II maximum likelihood (empirical bayes) linear models with individual variance components for predictors
Jamil, T. ; Braak, C.J.F. ter - \ 2012
Pattern Recognition Letters 33 (2012)9. - ISSN 0167-8655 - p. 1205 - 1212.
gene-expression data - variable selection - elastic net - regression - regularization - shrinkage - chemometrics - networks - genome - lasso
Maximum Likelihood (ML) in the linear model overfits when the number of predictors (M) exceeds the number of objects (N). One of the possible solution is the Relevance vector machine (RVM) which is a form of automatic relevance detection and has gained popularity in the pattern recognition machine learning community by the famous textbook of Bishop (2006). RVM assigns individual precisions to weights of predictors which are then estimated by maximizing the marginal likelihood (type II ML or empirical Bayes). We investigated the selection properties of RVM both analytically and by experiments in a regression setting. We show analytically that RVM selects predictors when the absolute z-ratio (|least squares estimate|/standard error) exceeds 1 in the case of orthogonal predictors and, for M = 2, that this still holds true for correlated predictors when the other z-ratio is large. RVM selects the stronger of two highly correlated predictors. In experiments with real and simulated data, RVM is outcompeted by other popular regularization methods (LASSO and/or PLS) in terms of the prediction performance. We conclude that Type II ML is not the general answer in high dimensional prediction problems. In extensions of RVM to obtain stronger selection, improper priors (based on the inverse gamma family) have been assigned to the inverse precisions (variances) with parameters estimated by penalized marginal likelihood. We critically assess this approach and suggest a proper variance prior related to the Beta distribution which gives similar selection and shrinkage properties and allows a fully Bayesian treatment.
Penalized regression techniques for prediction: a case study for predicting tree mortality using remotely sensed vegetation indices
Lazaridis, D.C. ; Verbesselt, J. ; Robinson, A.P. - \ 2011
Canadian Journal of Forest Research 41 (2011)1. - ISSN 0045-5067 - p. 24 - 34.
nonorthogonal problems - hyperspectral data - ridge regression - cross-validation - lasso - infestation - shrinkage - selection - forests - imagery
Constructing models can be complicated when the available fitting data are highly correlated and of high dimension. However, the complications depend on whether the goal is prediction instead of estimation. We focus on predicting tree mortality (measured as the number of dead trees) from change metrics derived from moderate-resolution imaging spectroradiometer satellite images. The high dimensionality and multicollinearity inherent in such data are of particular concern. Standard regression techniques perform poorly for such data, so we examine shrinkage regression techniques such as ridge regression, the LASSO, and partial least squares, which yield more robust predictions. We also suggest efficient strategies that can be used to select optimal models such as 0.632+ bootstrap and generalized cross validation. The techniques are compared using simulations. The techniques are then used to predict insect-induced tree mortality severity for a Pinus radiata D. Don plantation in southern New South Wales, Australia, and their prediction performances are compared. We find that shrinkage regression techniques outperform the standard methods, with ridge regression and the LASSO performing particularly well.
Regression by L1 regularization of smart contrasts and sums (ROSCAS) beats PLS and elastic net in latent variable model
Braak, C.J.F. ter - \ 2009
Journal of Chemometrics 23 (2009)5. - ISSN 0886-9383 - p. 217 - 228.
least-squares regression - linear-regression - statistical view - selection - shrinkage - lasso - tools
This paper proposes a regression method, ROSCAS, which regularizes smart contrasts and sums of regression coefficients by an L1 penalty. The contrasts and sums are based on the sample correlation matrix of the predictors and are suggested by a latent variable regression model. The contrasts express the idea that a priori correlated predictors should have similar coefficients. The method has excellent predictive performance in situations, where there are groups of predictors with each group representing an independent feature that influences the response. In particular, when the groups differ in size, ROSCAS can outperform LASSO, elastic net, partial least squares (PLS) and ridge regression by a factor of two or three in terms of mean squared error. In other simulation setups and on real data, ROSCAS performs competitively
Effect of pre-drying and par-frying conditions on the crispness of French fries
Loon, W.A.M. ; Visser, J.E. ; Linssen, J.P.H. ; Somsen, D.J. ; Klok, H.J. ; Voragen, A.G.J. - \ 2007
European Food Research and Technology 225 (2007)5-6. - ISSN 1438-2377 - p. 929 - 935.
viscoelastic behavior - structural-changes - potato-chips - fat uptake - products - shrinkage - texture - quality - tests - foods
An experimental design was used to study the effect of pre-drying (to 10, 15 and 20% weight loss) and par-frying conditions (160, 170 and 180 °C) on the crispness of French fries. Par-frying time was adjusted with a software program to obtain equal moisture content and internal texture for all samples. Crispness was evaluated with a sensory panel. Furthermore, samples were analysed with a texture analyser and with confocal scanning laser microscopy (CSLM). Par-frying at 180 °C resulted in a crispier product than at 160 and 170 °C. Pre-drying to 20% weight loss lead to blisters and reduced crispness in comparison with pre-drying to 10 and 15% weight loss. Instrumental texture measurements showed a good correlation with sensory crispness. Large differences in cell structure, such as blisters, could be observed with CSLM. CSLM was useful to explain results from the instrumental and sensory texture evaluation
Quantification of physical properties of dredged sediments during physical ripening
Vermeulen, J. ; Dijk, S.G. ; Grotenhuis, J.T.C. ; Rulkens, W.H. - \ 2005
Geoderma 129 (2005)3-4. - ISSN 0016-7061 - p. 147 - 166.
marine clay soil - hydraulic conductivity - modeling diffusion - unsaturated soils - oxygen diffusion - aggregate size - bulk-density - shrinkage - gas - denitrification
The soil formation process ripening can be used as a bioremediation technique for dredged sediments that are polluted with organic chemicals. Currently, data are lacking that quantify the effects of physical ripening on parameters that affect aerobic bioremediation. We quantified the effects of physical ripening on shrinkage, swelling, moisture retention, hydraulic conductivity, and oxygen diffusion for three freshly dredged sediments using specially designed pressure chambers. We also quantified the effect of physical ripening on structure development by measuring aggregate size distributions for four half-ripe and four ripe sediment samples that were collected from field sediment disposal sites. The course of physical ripening and the aerobic bioremediation process for sediments at above ground (upland) disposal sites can be predicted using the data and information developed in this study when using a combination of existing water and oxygen transport and ripening models
|Verdrogend veen en de stabiliteit van veenkades
Dekker, L.W. ; Ritsema, C.J. ; Oostindie, K. ; Akker, J.J.H. van den; Hemert, H. - \ 2003
Het Waterschap 88 (2003)special. - p. 12 - 14.
dijken - veengronden - krimp - veengebieden - vochtgehalte - nederland - dykes - peat soils - shrinkage - peatlands - moisture content - netherlands
Overzicht en verspreiding van waterafstotende (moeilijk te bevochtigen) veengronden in Nederland. Achtergrond hiervan en relatie met veendijken
Directzaai van mais biedt perspectief
Pol-van Dasselaar, A. van den; Everts, H. - \ 1999
Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 12 (1999)6. - ISSN 1386-8470 - p. 22 - 24.
maïs - erosiegevoeligheid - precisiezaaimachines - teelt - cultuurmethoden zonder grondbewerking - zware kleigronden - veengronden - löss - krimp - zaaien - maize - erodibility - precision drills - cultivation - no-tillage - clay soils - peat soils - loess - shrinkage - sowing
Maos wordt meestal met een precisiezaaimachine in een goed bewerkt zaaibed gezaaid. Het is echter ook mogelijk om maos zonder een grondbewerking direct in gras of een wintergewas te zaaien. Hiermee wordt bespaard op de grondbewerkingskosten, maar het brengt wel extra teeltrisico met zich mee. In Nederland is directzaai voor bepaalde gebieden mogelijk interessant.
|Vijfentwintig jaar peilverlaging versus polderpeil. Maaivelddaling van veengrasland bij twee slootpeilen in de polder Zegvelderbroek
Akker, J.J.H. van den; Beuving, J. - \ 1997
Landinrichting 37 (1997)3. - ISSN 0922-6419 - p. 15 - 20.
veengronden - graslanden - grondwaterstand - regulatie - scheurvorming - bodem - krimp - peilbeheer - veenweiden - utrecht - peat soils - grasslands - groundwater level - regulation - cracking - soil - shrinkage - water level management - peat grasslands - utrecht
Effects of crust and cracks on simulated catchment discharge and soil loss
Stolte, J. ; Ritsema, C.J. ; Roo, A.P.J. de - \ 1997
Journal of Hydrology 195 (1997)1/4. - ISSN 0022-1694 - p. 279 - 290.
bodem - korsten - scheurvorming - opzwellen - krimp - soil - crusts - cracking - swelling - shrinkage
Sealing, crusting and cracking of crusts of the soil surface has been observed in many parts of the world in areas with sandy, silty and loamy soils. Sealing and crust formation occurs under the influence of rain storm and drying weather. With prolonged drying, surface crusts might crack, leading to complex situations with respect to infiltration and runoff generation. Cracking of crusted loamy soils appears to be a general process. This study aims to measure the hydraulic properties of fully crusted and cracked-crusted areas and to evaluate the effects of these measurements on catchment discharge and soil loss in a loess region of the Netherlands, using the LISEM soil erosion model. Samples with minimum infiltration rates (fully crusted) and with maximum infiltration rates (cracked-crusted surfaces) were taken from fields with bare soil or winter wheat and their soil hydraulic functions were measured. The results of these measurements were used as input in the LISEM soil erosion model. Simulations of discharge and soil loss were done for each of these two land-uses and for two rain events. Additionally, simulated discharge and soil loss under actual recorded land-use were calculated. In all cases, soils with no surface cracks produced higher figures for discharge and soil loss than those where 10% of the surface crust was cracked. For a good interpretation of the results for soil loss, the spatial distribution of cracked-crusted areas and fully crusted areas has to be investigated in detail. To deal with cracked-crusted and fully crusted areas in simulation modelling, care has to be taken to accurately measure the soil physical functions representing the maximum and minimum infiltration rates. An assignment of these functions to calculation grids has to be made. As the LISEM model is capable of assigning different soil physical functions to each calculation grid, an improved prediction of the soil physical behaviour of the catchment can be simulated.
|Emission of solutes in cracked clay soils.
Groen, K.P. ; Feddes, R.A. ; Boesten, J.J.T.I. ; Schultz, E. ; Koopmans, R. ; Dam, J.C. van - \ 1996
In: Crop - water - environment models : selected papers to the workshop at the occasion of the 16th congress of the International Commission on Irrigation and Drainage at Cairo, Egypt, 17 September 1996 : [47th International executive council meeting]. - - p. 29 - 41.
zware kleigronden - scheurvorming - uitspoelen - modellen - persistentie - pesticidenresiduen - pesticiden - gewasbescherming - onderzoek - krimp - bodem - opzwellen - clay soils - cracking - leaching - models - persistence - pesticide residues - pesticides - plant protection - research - shrinkage - soil - swelling
|Water and bromide transport in cracking clay soils
Hamminga, W. ; Hendriks, R.F.A. ; Oostindie, K. ; Bronswijk, J.J.B. - \ 1995
In: Samenvatting van de voordrachten en posters bodem breed '95 : aktief bodembeheer : noodzaak voor beleid, uitdaging voor de wetenschap : nationaal symposium bodemonderzoek, 18 en 19 december 1995, De Blije Werelt, Lunteren / Lexmond, M.J., - p. 158 - 159.
zware kleigronden - infiltratie - hydraulisch geleidingsvermogen - kwel - bodem - scheurvorming - opzwellen - krimp - clay soils - infiltration - hydraulic conductivity - seepage - soil - cracking - swelling - shrinkage
Magnitude, modeling and significance of swelling and shrinkage processes in clay soils
Bronswijk, J.J.B. - \ 1991
Agricultural University. Promotor(en): R.A. Feddes; A.L.M. van Wijk. - S.l. : Bronswijk - 145
zware kleigronden - bodem - scheurvorming - opzwellen - krimp - clay soils - soil - cracking - swelling - shrinkage
The dynamic process of swelling and shrinkage in clay soils has significant practical consequences, such as the rapid transport of water and solutes via shrinkage cracks to the subsoil, and the destruction of buildings and roads on clay soils. In order to develop measuring methods and computer simulation models to take swelling and shrinkage processes into account in agricultural and environmental studies, experiments were conducted on soil aggregates, small soil cores, with a lysimeter, and in the field.
Determination of shrinkage characteristics of soil aggregates revealed some clay soils from the Netherlands to be among the strongest swelling and shrinking soils of the world with a maximum volume decreases upon drying of 49 %. Normal shrinkage and residual shrinkage are significant within pressure head ranges occurring in field conditions. Shrinkage was isotropic for all horizons of a heavy clay soil, at overburden pressures corresponding to field loads.
The shrinkage behaviour of a clay soil in a lysimeter may be explained by the occurrence of structural shrinkage, normal isotropic shrinkage and residual isotropic shrinkage. Field experiments confirmed this picture. A newly developed equation to relate vertical soil movements to water content changes during structural, normal, residual and zero shrinkage, for any shrinkage geometry, was successfully applied in the field.
The obtained knowledge about the swelling and shrinkage process was used to develop a computer simulation model, FLOCR, to calculate the water balance of a clay soil, including preferential flow through shrinkage cracks, on a daily basis. Besides, crack volume and surface subsidence are computed. Model calculations for a heavy clay soil during 1985 were in good agreement with field observations. Comparing FLOCR with a rigid-soil model showed a considerable influence of shrinkage cracks on the soil water balance, on the groundwater level and on the topsoil bearing capacity. The simulation model was also applied to predict the effect of drainage on actual swelling and shrinkage processes in a heavy clay soil profile.
Finally, the principles of incorporating evaporation from shrinkage cracks, oxygen diffusion in cracking clay soils, and lateral infiltration during preferential flow into the present model approach are presented.
Shrinkage of Dutch clay soil aggregates.
Bronswijk, J.J.B. ; Evers-Vermeer, J.J. - \ 1990
Netherlands Journal of Agricultural Science 38 (1990)2. - ISSN 0028-2928 - p. 175 - 194.
clay soils - cracking - shrinkage - soil - swelling
Bodemfysische karakterisering van potgrond voor teelt op eb- en vloedsysteem
Bakker, J.A. ; Kabat, P. - \ 1990
Wageningen : Staring Centrum (Rapport / Staring Centrum 71) - 59
groeimedia - bodemwater - bodemkarteringen - kaarten - bodem - scheurvorming - opzwellen - krimp - growing media - soil water - soil surveys - maps - soil - cracking - swelling - shrinkage
Water and salt transport in irrigated cracking clay soils of the Kachhi plaines, Pakistan. Part II. Horizontal transport.
Kamphorst, A. - \ 1989
Soil Technology 2 (1989). - ISSN 0933-3630 - p. 101 - 107.
zware kleigronden - scheurvorming - verbetering - irrigatie - uitspoelen - verzilting - krimp - natrium - bodem - opzwellen - clay soils - cracking - improvement - irrigation - leaching - salinization - shrinkage - sodium - soil - swelling