Assessment of extreme rainfall erosivities and soil loss events under a changing climate

Soil is one of the most important resources for humans but is limited and of huge social, economic and environmental significance. The major threat to this resource is soil erosion which is a world-wide phenomenon that largely determines the degradation of soils and the fate of landforms, vegetation and the humankind. the long-term average soil loss is used to express the erosion risk of agricultural used fields. The most commonly used erosion model is the Universal Soil Loss Equation (USLE) (Wischmeier and Smith, 1978) which estimates a 22-year average annual soil loss by sheet and rill erosion. The circumstance that only a few severe erosion events control the long-term response of an eroded area leads to the conclusion that single extreme soil erosion events need to be identified. Therefore, these are the goals of this study: - rainfall erosivity of extreme events in China and Austria across selected agricultural areas in future will be derived from available long-term observations and from the GCM models simulated data, and the corresponding soil loss of extreme events will be assessed. - The rainfall erosivity of such events will be better estimated due to field measurements of rainfall kinetic energy (KE) and the development of its relationships to specific rainfall characteristics. - The site-specific estimation of the range of event-based soil erosion rates – including the extreme events – and the knowledge of return periods of such events will improve our knowledge and understanding of extreme erosion processes and our ability to develop and adapt soil protection strategies.