Occurrence and Relevance of Vertical and Lateral Preferential Flow Pathways across Land-uses and Landscapes

Abstract:

There seems to be less and less doubt that preferential flow pathways in soils have a profound impact on hydrology by enhancing infiltration rates, reducing the filter function of soils or by enhancing fast subsurface flow in hillslopes. Soil hydrological or catchment models have been developed including the different kind of preferential flow pathways like earthworm like macropores (e.g. earthworm channels), pipes, roots, etc. and they have been successfully applied to make predictions at a range of spatial scales. One of the biggest issue using hydrological models including preferential flow routines is the parameterization. What are the landscape features influencing the occurrence and quantity of specific preferential flow features? Will certain macropres be more probable to occur under forest than under grassland soils? In this study, I will highlight several studies looking at the effect of land-use and landscape features on preferential flow properties and parameters. Several field experiments studied on the one side the properties among topographic locations or vegetation cover, but also at the hydrological functions and hence the relevance of preferential flow pathways. In the second part the soil hydrological model ROGER is introduced, which will further evaluate and predict the relevance of vertical and lateral preferential flow pathways at the plot, hillslope and catchment scale.