Establishment of a hydrological model in a subbasin of the Sabor river

• Autor(a) principal: Rua, João Carlos Pereira
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/7888

Land cover changes have consequences on hydrological processes of a basin through changes in evapotranspiration and surface and subsurface water movements in the landscape. Concern in the Mediterranean region has grown recently due to the prospects of a reduction in precipitation and the occurrence of large periods of drought potentially affecting human communities and biodiversity. This research consisted in the implementation of a hydrological model in the Upper Sabor river catchment, Northeastern Portugal, to evaluate the impacts of land cover change on hydrological processes, namely water yield. This catchment was chosen to represent landscape composition and configuration in a changing mountain area of the region where types and rates of land use change are known in detail for the last 50 years. SWAT (Soil and Water Assessment Tool) was the model chosen to address the research question. The implementation of SWAT consisted in data gathering, preparation and database development: elevation, land use/land cover, weather, soils and land management practices. Model validation was done considering data on streamflow between 1973 and 2008. Monthly average results have shown that water yield in the watershed depended on proportions of land cover in the landscape. From the scenarios tested through simulation, we can highlight that replacing agriculture by shrublands increased evatpotranspiration and decreased water yield. On the other hand, a considerable augment in water yield was registered when pastures became the dominant land use class. Scenarios with the largest occupations in agriculture or pastures, were the least evapotranspirative. Responses from land cover classes varied over the year.