Rainfall-runoff-erosion processes in urban areas

Abstract Urban areas comprise a variety of impervious and pervious surfaces leading to complex spatiotemporal rainfall-runoff processes. The extent of paved surfaces diminishes water infiltration and increases runoff after a precipitation event and thus may provide a relevant impact on streamflow regime and flood risk. The magnitude of the impacts of urbanization on the water cycle, however, depends on several parameters including soil properties, landscape structure, and urban patterns. Runoff due to precipitation in urban areas is one of the main causes of soil erosion, enhanced by the typical degradation status of the soils. Besides large amounts of sediments, runoff carries pollutants accumulated on urban surfaces into receiving water bodies, impairing their water quality status. Artificial drainage systems convey and quickly transport urban runoff to the stream network, enhancing the impacts on surface water quantity and quality. With increasing urbanization and negative impacts of climate change, the status of aquatic ecosystems is expected to deteriorate, and thus a paradigm shift on water management, focusing on nature-based solutions, is receiving increasing interest to achieve more sustainable development.