Linking the present and future scenarios of soil erosion modeling in Tagus International Transboundary Biosphere Reserve, Portugal

Soil erosion by water is considered one of the processes leading to land degradation, affecting soil fertility, and consequently the loss of production capacity. According to recent studies, the projected increase of soil loss rate in the next few decades in European Union agricultural areas is about 22.5%. In Portugal and other countries in the Mediterranean basin, under a climate pattern unfavorable to maintaining an effective soil cover, and many times with rainfall peak events, an increase in soil erosion rates in climate change scenarios is expected. The main goal of this study is to evaluate the present and project the future rate of soil erosion in the Portuguese part of the Tagus International Transboundary Biosphere Reserve, located in the central-eastern part of Portugal, and the surrounding area, where agricultural use and livestock grazing are dominant. The soil loss calculation was performed for the present situation and projected for 2050, considering two Representative Concentration Pathways (RCP 4.5 and RCP 8.5). We used the Revised Universal Soil Loss Equation (RUSLE) methodology to model water soil erosion. The projected total annual rainfall will decrease for both RCP, however, the erosivity index increased in both future scenarios. Our findings provide insights into how future scenarios of socioeconomic development will affect soil erosion by water. Improving knowledge of the future rates of soil erosion is important for designing pol-icy instruments to mitigate the future impact of climate change on water erosion. The results of this study provide insights into how future scenarios of socioeconomic development, and changes in rainfall patterns, will affect soil erosion by water. Understanding better the soil erosion process, by using modeling tools and others, it´s very important for designing policy instruments to prevent the future impact of climate change on soil erosion.