How rainfall interception influences soil erosion in agricultural, urban and forest catchments

Rainfall intercepted by vegetation is, in many regions, an important part of the hydrological water cycle. Part of the intercepted rainfall evaporates into the atmosphere, and throughfall and stemflow contribute to runoff generation, control soil moisture and runoff connectivity patterns and affect soil erosion. The question of how changing climate and land cover conditions impact rainfall interception, raindrop microstructure, and their erosive power still needs to be better understood. This presentation introduces the main aims of a bilateral research project between TU Wien, University of Ljubljana and the Slovenian Forestry Institute that focuses on the understanding of the effect of meteorological and vegetation characteristics on changes in raindrop microstructure and, therefore, on the erosive power of rainfall. The main idea of the research cooperation is to analyse and understand the main mechanisms of the rainfall interception process in different climate conditions and vegetation settings. The high-resolution disdrometer measurements from the experimental urban and forest plots in Slovenia and a small agricultural basin in Austria are used to determine and compare raindrop distributions and their changes. The high-resolution observations of discharge, sediment concentrations and isotope analyses contribute to the understanding of the erosion processes and sediment transport in the streams.   Acknowledgment: This contribution is part of the ongoing research project entitled “Evaluation of the impact of rainfall interception on soil erosion” supported by the Slovenian Research and Innovation Agency (J2-4489) and it was funded in part by the Austrian Science Fund (FWF) I 6254-N.