Soil loss in the São Lamberto river basin with use of temporary series of Landsat images

Abstract

The São Lamberto river is an important tributary of the Jequitaí river in the São Francisco river basin. This river is a source of water for several activities as irrigation and, mainly, livestock in the region and almost no study has been done to analyze the surface of its basin submitted to the use and occupation of the soil over the years. The objective of this work was to estimate soil loss in the context of environmental degradation in the São Lamberto River basin, MG, using orbital data and time series of LANDSAT images associated to the application of the Universal Soil Loss Equation-USLE. The procedures to perform the work included the elaboration of the basin delimitation vector using ArcGIS 10.1 software, LANDSAT 5-TM and LANDSAT 8-OLI image acquisition, and supervised classification of these. The factors R, K, LS and CP were obtained for the preparation of the soil loss susceptibility map (factor A) in the years 1995, 2005 and 2015. Using the LEGAL module of SPRING 5.2, the maps of susceptibility to soil loss, for the three years studied. It was verified from the elaborated maps that the dense vegetation class was predominant throughout the years of 1995, 2005 and 2015, with 47.55%, 41.13% and 38.84%, respectively, of the total area of the basin. It is concluded that the São Lamberto River Basin, showed good land cover conservation, with 91.2% of its areas presenting low susceptibility to the occurrence of laminar erosion (0 to 10 ton.ha-¹.year-¹).