Erosive rainfall clustering across Austria's agricultural areas

A few low-frequent but extreme rainfall events generate substantial erosion amounts and, as a result, land degradation negatively affects soil health and agricultural productivity. Determining rainfall erosivity (from small to extreme events) that drive soil erosion will improve our knowledge and understanding of extreme erosion processes and our ability to develop and adapt adequate soil protection strategies. This study aims to analyze rainfall erosivity characteristics across Austria‘s main agricultural production zones using long-term (from 27 to 82 years) with high-resolution (5-minutes) rainfall data from 27 rain gauges. Erosive rainfall characteristics such as rainfall amount, event duration, and the maximum 30-minute intensity were investigated, and typical rainfall types were assessed through a clustering approach based on the k-means algorithm. Results identified three dominant types (clusters) of erosive rainfalls across Austria's agricultural areas. Seasonal distribution analysis showed that the predominant erosive events, characterized by short duration and high intensities, occur during the summer months from June to August. In contrast, the long-duration and low rainfall-intensity events are evenly distributed throughout the year. The spatial distribution of rainfalls related to the largest rainfall erosivities showed a pronounced occurrence in the southeastern pre-alpine areas. Knowledge of the occurrence of erosive rainfall events in space and time eventually supports the implementation of locally adapted Soil Conservation (SC) practices in Austria.