INFLUÊNCIA DA DINÂMICA DA COBERTURA VEGETAL NA PRODUÇÃO DE SEDIMENTOS

Código

PAP021

Autores

Uilson Ricardo Venâncio Aires, Jasmine Alves Campos, Demetrius David da Silva

Tema

MEDIÇÃO, MODELAGEM, TÉCNICAS E TECNOLOGIAS NO CONTEXTO DA HIDROSSEDIMENTOLOGIA

Resumo

Sediment yield has been directly linked to the water erosion, which is the main responsible for the soil degradation in the world, and it involves several environmental problems, such as water pollution and flooding, due to the silting of the watercourses. In this context, the aim of this work is to analyze the influence of vegetation cover dynamics on sediment yield in Manhuaçu river basin, MG, with remote sense information support. For the analysis of vegetation cover dynamics, we used the Normalized Difference Vegetation Index (NDVI), comprising a period from 1986 to 2014, calculated from Landsat images. For the quantification of sediment yield over time, we use observed data from a ground station operated by National Water Agency (ANA), located in the region downstream of the basin, comprising a period from 1979 to 2016. As the rainfall is largely responsible for the intensity of the runoff, which is connected directly to the water erosion, we used the rain volume information from a ground station located close to study area, also operated by ANA, for a period of 1979 to 2016. We used The Water Normalized Difference Index (NDWI) to evaluate the spectral response of water for the rainy season, because higher NDWI values means that there is a lot concentration of suspended materials in the water. We also obtained the NDWI from Landsat images, covering the period from 1984 to 2016. There was a few variation of vegetation cover over time in the basin, with emphasis on reduction of8.6%inpasture areas and increase of 8.4% in areas with high vigor vegetation. However, there was a reduction in both sediment yield and average NDWI values for relatively similar rain volumes over time. The results show the importance of vegetation cover for attenuation of sediment yield, aiming the preservation of the water resources.