Author(s): Sandra Garcia-Galiano
Linked Author(s):
Keywords: Flash floods Extreme events Spanish Southeast Climate change Semiarid basins
Abstract: In the last decades, major severity and frequency of flash floods in semiarid basins of Southeast of Spain, have been observed. The main driver is considered climate change, but also the pressures due to both demographic growth and intensive urbanization explain the catastrophic impacts on terrain. These flash floods present the greatest potential danger threat to properties, natural environment, and human life. In recent time, several catastrophic hydrometeorological events were observed in Spanish coastal semiarid basins, such as event presented in October 2024 in Rambla del Poyo wadi (Valencia Region), causing the loss of more than two hundred human lives. Also, the impacts of hydrometeorological event presented in September 2019 in Rambla del Albujon wadi (Murcia Region), with relevant negative impacts on the natural protected area Mar Menor coastal lagoon. In the present work, the impact of observed land-use change – such as urbanization, and deforestation -, on semiarid basin responses to observed extreme events in Spanish Southeast, have been assessed. To this end, it has been worked on with historical land use scenarios provided by the Corine Land Cover (CLC) database for different decades. The SWAT (Soil & Water Assessment Tool) hydrological model has been applied at hourly scale and basin scale. Automatic rain gauges and stream gauges located in the study basin were considered. The basin's response to actual several extreme events has been evaluated, with satisfactory values of Nash-Sutcliffe coefficient (NSE). The aim of the present work is the evaluation of several scenarios to reduce the catastrophic impacts of studied hydrometeorological events. With this objective, an assessment of potential land use change of these very populated coastal basins (such as reforestation in head of basins, naturalization of channels) in the Mediterranean area, has been done with satisfactory results. The proposed methodology could be extrapolated to Mediterranean ungauged basins. The final aim is to improve the strategies to build resilience to extreme events and climate change impacts, in semiarid basins with risk of flash flooding.
Year: 2025