Author(s)

E. Christoffels

Abstract

Entry of solids into surface waters originating from soil erosion is accounted for as an event-specific input which reaches rivers via diffuse pathways. The hydromorphological condition and substance content of surface waters can be significantly impacted by these entries. The sand-gap system on the river bed, the habitat for the greatest part of aquatic fauna, can become clogged by solid entries rich in fine material. Compared to river stretches naturally rich in fine solids, those dominated by gravel substrate are more adversely influenced by entries from soil erosion. Nutrients and pollutants enter surface waters in association with solids. Measurements conducted in the Rotbach catchment in the state of North Rhine-Westphalia, Germany, confirm the importance of entries from soil erosion. The measurement results for Rotbach Creek provide an example of enormous masses of solids entering a surface water through soil erosion. Inputs of phosphorus, cadmium and herbicides are considerable. The good status required by the European Water Framework Directive cannot be achieved without appropriate measures to address farming practice.

Keywords

monitoring, nutrients, pesticides, rainfall erosivity, rainfall intensity, soil erosion