Water flows ever more slowly in soil when the soil dries out. This can be described by the conductivity curve that accounts for water filling up small spaces, sticking to grains in films, and water vapour diffusion. This paper introduces a relatively simple model for this curve that needs one fewer parameter than most others. It works well for most soils, but some need the extra parameter. The paper also presents a computer program to determine the parameter values of this and other models.

The way infiltrating water moves in soil affects vegetation as well as groundwater recharge. This flow of soil water is captured by a mathematical function that covers all water contents from very dry to water-saturated. We tested several such functions for different soils and climates to see how model-calculated water fluxes are affected. Luckily, the effects of weather and the soil are much more important than the choice of the mathematical function.

Export of dissolved organic carbon (DOC) from riparian zones (RZs) is an important yet poorly understood component of the catchment carbon budget. This study chemically and spatially classifies DOC source zones within a RZ of a small catchment to assess DOC export patterns. Results highlight that DOC export from only a small fraction of the RZ with distinct DOC composition dominates overall DOC export. The application of a spatial, topographic proxy can be used to improve DOC export models.

The way soils capture infiltrating water affects crops and natural vegetation and groundwater recharge. This retention of soil water is described by a mathematical function that covers all water contents from very dry to water saturated. We combined two existing lines of research to improve the behaviour of a popular function for very dry and very wet conditions. Our new function could handle a wider range of conditions than earlier curves. We provide fits to a wide range of soils.