Wim Cornelis - Academia.edu (original) (raw)

Papers by Wim Cornelis

Soil and Tillage Research, 2007

Subsoil compaction due to conventional tillage techniques and its relation to subsurface flow and... more Subsoil compaction due to conventional tillage techniques and its relation to subsurface flow and runoff was investigated on a sloped field. The presence of a plow sole was confirmed by significantly higher penetration resistances between 20 and 40 cm depth, a significantly higher soil bulk density and a 14% decrease in drainage pore space compared to the top layer. Ring infiltrometer measurements also confirmed a significant reduction of the saturated hydraulic conductivity at 30 cm depth, indicating a limited permeability. With the use of an extensive grid of tensiometers, matric heads were monitored and the occurrence of a temporary water table on top of the plow sole was confirmed in a number of cases. Equipotential lines in the top saturated layer indicated the occurrence of subsurface flow parallel to the slope surface in a downward direction. For the whole measuring period, when a perched water table was observed, 91% of the rainfall events caused runoff and this number increased with increasing rainfall intensity. For low and medium rainfall intensities (<10 mm h À1), 66% and 63% of the runoff events were related to saturation of the top soil. Therefore, it was concluded that over a period of 20 months saturation excess runoff as a result of subsoil compaction was an important contributor to surface runoff and soil loss.

$Research paper thumbnail of Predicting saturated hydraulic conductivity utilizing fractal principles$

Soil Science Society of …

Preferential movement of surface-applied chemicals to the groundwater has resulted in a great nee... more Preferential movement of surface-applied chemicals to the groundwater has resulted in a great need to physically model the movement of water into and through the soil media. The objective of this study was to develop equations capable of predicting both matrix and macropore saturated conductivity and to relate the equation parameters to readily available soil properties. Equations for predicting the matrix and macropore saturated conductivity were developed by coupling fractal processes with the Marshall saturated conductivity formulation. The equation uses matrix and macropore porosity, maximum pore radius, and number of pore classes. Prediction equations were developed relating the number of pore classes and maximum pore radius to soil properties. The modified Marshall saturated hydraulic conductivity equation appears to provide reasonable estimates of matrix and macropore saturated conductivity and is applicable to a wide range of soil textures.

3),  Verzadigde doorlatendheid (grenswaarde 10 cm d-1),  Macroporiënvolume (grenswaarde 0,04 m ... more 3),  Verzadigde doorlatendheid (grenswaarde 10 cm d-1),  Macroporiënvolume (grenswaarde 0,04 m 3 m-3). Meten: de resultaten De textuur en organische koolstofgehalten van de monsters hebben een grote spreiding, zodat de dataset representatief wordt geacht voor een groot deel van de Vlaamse bodems.

Land Degradation & Development

Earth System Science Data

In this paper, we present and analyze a novel global database of soil infiltration measurements, ... more In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements (∼ 76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76 % of the experimental sites with agricultural land use as the dominant type (∼ 40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it.

International Soil and Water Conservation Research

The Science of the total environment, Jan 8, 2018

Soil erosion by water is critical for soil, lake and reservoir degradation in the mid-hills of Ne... more Soil erosion by water is critical for soil, lake and reservoir degradation in the mid-hills of Nepal. Identification of the nature and relative contribution of sediment sources in rivers is important to mitigate water erosion within catchments and siltation problems in lakes and reservoirs. We estimated the relative contribution of land uses (i.e. sources) to suspended and streambed sediments in the Chitlang catchment using stable carbon isotope signature (δC) of long-chain fatty acids as a tracer input for MixSIAR, a Bayesian mixing model used to apportion sediment sources. Our findings reveal that the relative contribution of land uses varied between suspended and streambed sediment, but did not change over the monsoon period. Significant over- or under-prediction of source contributions could occur due to overlapping source tracer values, if source groups are classified on a catchment-wide basis. Therefore, we applied a novel deconvolutional framework of MixSIAR (D-MixSIAR) to im...

Soil Biology and Biochemistry

... S. Sleutel a , Corresponding Author Contact Information , E-mail The Corresponding Author , L... more ... S. Sleutel a , Corresponding Author Contact Information , E-mail The Corresponding Author , L. Bouckaert a , D. Buchan a , D. Van Loo a , b , WM Cornelis a , HG ... Soil microbial biomass OC was determined immediately with the fumigation–extraction method (Vance et al., 1987). ...

Journal of Soils and Sediments

Methodological perspectives on the application of compound-specific stable isotope fingerprinting... more Methodological perspectives on the application of compound-specific stable isotope fingerprinting for sediment source apportionment Upadhayay, HR

Water Resources Research

The classical determination of the soil water retention curve (SWRC) by measuring soil water cont... more The classical determination of the soil water retention curve (SWRC) by measuring soil water content theta\thetatheta at different matric potentials ψ using undisturbed soil samples is time consuming and expensive. Furthermore, undisturbed soil sampling can be an intricate task when coarse soil fragments (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;2 mm) are present. The objective of this study was to test whether tension infiltrometry could be

American journal of physical anthropology, Jan 19, 2017

This study investigates biomechanical implications of walking with indigenous "Kolhapuri&quo... more This study investigates biomechanical implications of walking with indigenous "Kolhapuri" footwear compared to barefoot walking among a population of South Indians. Ten healthy adults from South India walked barefoot and indigenously shod at voluntary speed on an artificial substrate. The experiment was repeated outside, on a natural substrate. Data were collected from (1) a heel-mounted 3D-accelerometer recording peak impact at heel contact, (2) an ankle-mounted 3D-goniometer (plantar/dorsiflexion and inversion/eversion), and (3) sEMG electrodes at the m. tibialis anterior and the m. gastrocnemius medialis. Data show that the effect of indigenous footwear on the measured variables, compared to barefoot walking, is relatively small and consistent between substrates (even though subjects walked faster on the natural substrate). Walking barefoot, compared to shod walking yields higher impact accelerations, but the differences are small and only significant for the artificial...

PLOS ONE, 2016

The research on wind-driven rain (WDR) transport process of the splash-saltation has increased ov... more The research on wind-driven rain (WDR) transport process of the splash-saltation has increased over the last twenty years as wind tunnel experimental studies provide new insights into the mechanisms of simultaneous wind and rain (WDR) transport. The present study was conducted to investigate the efficiency of the BEST ® sediment traps in catching the sand particles transported through the splash-saltation process under WDR conditions. Experiments were conducted in a wind tunnel rainfall simulator facility with water sprayed through sprinkler nozzles and free-flowing wind at different velocities to simulate the WDR conditions. Not only for vertical sediment distribution, but a series of experimental tests for horizontal distribution of sediments was also performed using BEST ® collectors to obtain the actual total sediment mass flow by the splash-saltation in the center of the wind tunnel test section. Total mass transport (kg m-2) were estimated by analytically integrating the exponential functional relationship using the measured sediment amounts at the set trap heights for every run. Results revealed the integrated efficiency of the BEST ® traps at 6, 9, 12 and 15 m s-1 wind velocities under 55.8, 50.5, 55.0 and 50.5 mm h-1 rain intensities were, respectively, 83, 106, 105, and 102%. Results as well showed that the efficiencies of BEST ® did not change much as compared with those under rainless wind condition.

Transactions of the ASABE, 2015

Knowing the soil water retention curve (WRC) is essential for analyzing soil hydraulic behavior w... more Knowing the soil water retention curve (WRC) is essential for analyzing soil hydraulic behavior within the vadose zone. The van Genuchten (VG) soil hydraulic equation is one of the most frequently adopted models to parameterize the WRC. Some measured water retention points are needed to fit the VG model, but direct measurement of water content versus matric potential is expensive and time consuming. A pedotransfer function (PTF) enables indirect determination of a WRC from basic soil information. The typical method employed to derive a PTF using the VG model (VG-PTF) is to establish a mathematical relationship between the parameters of the VG model and basic soil data. However, both establishing and reusing a VG-PTF for new soils are challenging due to several reasons, such as over-parameterization, low correlation between basic soil data and VG parameters, and interdependency among parameters. In this study, a nonparametric approach based on the k nearest neighbor technique was designed and tested to establish a VG-PTF. A subset of soils from the UNSODA database (n = 554)) and a data set from Belgium (n = 69) were used as the model development and validation data sets, respectively. The proposed PTF showed reasonable accuracy and reliability and was comparable to well-known parametric VG-PTFs available in the literature.

Plant and Soil, 2012

Your article is protected by copyright and all rights are held exclusively by Springer Science+Bu... more Your article is protected by copyright and all rights are held exclusively by Springer Science+Business Media B.V.. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your work, please use the accepted author's version for posting to your own website or your institution's repository. You may further deposit the accepted author's version on a funder's repository at a funder's request, provided it is not made publicly available until 12 months after publication.

Constant use of treated wastewater (TWW) for irrigation over prolonged periods may cause buildup ... more Constant use of treated wastewater (TWW) for irrigation over prolonged periods may cause buildup of heavy metals up to toxic levels for plants and animals, and entails environmental hazards in different aspects. However, application of TWW on agricultural land might be an effective and sustainable strategy in arid and semi-arid countries where fresh water resources are under great pressure, as long as potential harmful effects on the environment including soil, plants, and fresh water resources, and health risks to humans are minimized. The aim of this study was to assess the effect of deep emitters on limiting potential heavy metal accumulation in soils and grains, and health risk under drip irrigation with treated municipal wastewater. A field experiment was conducted according to a split block design with two treatments (fresh and wastewater) and three sub-treatments (0, 15, and 30 cm depth of emitters) in four replicates on a sandy loam Calcic Argigypsids, in Esfahan, Iran. The annual rainfall is about 123 mm, mean annual ETo is 1457 mm, and the elevation is 1590 m above sea level. A two-crop rotation of wheat (Triticum spp.) and corn (Zea mays) was established on each plot with wheat growing from February to June and corn from July to September. Soil samples were collected before planting and after harvesting for each crop in each year. Edible grain samples of corn and wheat were collected at harvest. Elemental concentrations (Cu, Zn, Cd, Pb, Cr, Ni) in soil and grains were determined using an atomic absorption spectrophotometer. Results showed that the concentrations of heavy metals in the wastewater-irrigated soils were not significantly different (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.05) compared with the freshwater-irrigated soils. No significant difference (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.05) in heavy metal content in soil between different depths of emitters was found. A pollution load index (PLI) showed that there was no substantial buildup of heavy metals in the wastewater-irrigated soils compared to the freshwater-irrigated soils. Cu, Pb, and Zn concentrations in wheat and corn grains were within the permissible US Environmental Protection Agency (EPA) limits, but concentrations of Cd (in wheat and corn) and Cr (in corn) were above the safe limits of the EPA. In addition, concentrations of Ni in wheat and corn seeds were several folds higher than the EPA standards. A health risk index (HRI) which is usually adopted to assess the health risk to hazard materials in foods showed values higher than 1 for Cd, particularly for wheat grain (HRI &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;2.5). Results also showed that intake of Cu through consumption of edible wheat grains posed a relatively high potential health risk to children (HRI &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;1.4), whereas children might also be exposed to health risk from Cd and Cr from corn grains (HRI &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;1.4). Based on aforementioned results, it can be concluded that the emitter depth in drip irrigation does not play a significant role in the accumulation of heavy metals from TWW in our sandy loam soil. Although their accumulation in the soil was limited and similar to using freshwater, uptake of Cd and Cr by wheat and corn was relatively large and hence resulted in health risk. The results suggest that more attention should be directed towards cultivation of other crops with drip irrigation system for a safe and more productive use of wastewater for irrigation. Alternatively, methods that filter the wastewater before it enters the soil environment might be an option that needs further investigation.

Acta Horticulturae, 2012

ABSTRACT Tomato plant water relations are crucial for fruit production and fruit quality. Irrigat... more ABSTRACT Tomato plant water relations are crucial for fruit production and fruit quality. Irrigation strategies for glasshouse tomato are often based on solar radiation sums. However, due to new energy-saving climate control, current strategies might result in inappropriate irrigation. Because of the limited water buffering capacity of soilless growing media like rockwool, this could have adverse effects on fruit production and quality. The aim of this study was to investigate the effect of decreasing water availability in the rockwool growing medium on stem and fruit diameter variations. This study indicated that a small difference in plant positioning inside the greenhouse could lead to an important difference in plant water uptake, by which some risk might occur for under-watering border plants. The combination of continuous measurements of sap flow and stem diameter allowed a powerful interpretation of the plant water status. Finally, this study has shown that tomato plants are able to extract water from their fruits into the stem under conditions of high leaf transpiration and low water availability in the growing medium.

Journal of Hydrology, 2016