Scenarios of land use change and soil erosion at the Alqueva reservoir area

Περίληψη

Mediterranean landscapes are under enormous pressures towards its alteration, reflecting more and more rapid changeable dynamics. The Alqueva reservoir surrounding in the Alentejo Region, south of Portugal, is an example of remarkable landscape change due to water availability. The Land Use/Cover Change (LUCC) can affect the water erosion problem, an environment and economic problem that can
increase sediment yield at the reservoir. The purpose of this article was to create future LUCC scenarios, as a complementary way to investigate the impact on soil erosion using RUSLE model, through the study of the C factor (vegetation cover change) and Pfactor (management practices). The MAS/LUCC methodology is used to obtain scenarios taking into account the following four prospective directions: production of biomass for bioenergy, agricultural intensification by means of irrigation, increasing rural tourism and development of golf resorts, and climate change. The scenarios created, allowed the study of soil erosion scenarios, showing that the expected LUCC can effectively increase this problem through changes on vegetation cover. The use of sustainable land management (SLM) is a good approach to decrease soil erosion, contributing to the prevention of silting up in the Alqueva reservoir and safeguarding of landscape sustainability. The back casting approach used in this study, showed to be an advantage basis to create decision support system for the region, through the knowledge of the expected LUCC and the impact of them on soil erosion and the understanding of the role of SLM facing these LUCC.