Water wells are closed each year due to various contaminations of the groundwater in Denmark. In order to perform leaching risk analysis the soil water characteristic (SWC) and the hydraulic conductivity are necessary parameters, however determining the SWC and the hydraulic conductivity are laboratory heavy and time consuming. This study evaluates a recent published proxy function to estimate the SWC based on volumetric particle size fractions and three simple but widely used models to predict the saturated hydraulic conductivity (Ksat) based on readily available soil data.
The analysis of the models were based on soils from the state of Arizona with a wide range of soil classes (2-51% clay). The analyzed SWC-model estimates the volumetric water content based on volumetric particle size fractions, and was found necessary to modify in order to achieve accurate predictions for fine textured soils as wells as for sandy soils. A new SWC-model was successfully developed based on the same concept of using volumetric particle size fractions capable of estimating the full soil-water retention curve. The performance of the model was evaluated on more than 200 Danish field soils and found robust with high accuracy based only on texture, organic matter and bulk density.
The analysis of the three Ksat models were also based on the soils from Arizona and was found accurate for the sandy soil or the fine textured soils, although not for all the soil classes. Further analysis within prediction of the Ksat was recommended for full applicability with regards to risk assessments.