Identifying susceptible areas to erosive processes in the Cantareira System, based on different scenarios

Abstract

This research work presents, based on geoprocessing and field surveys, erosion-susceptible areas in the Atibaia headwater stream watershed: Cachoeira and Atibainha upstream Cantareira System dams. In addition to slope characteristics, water-saturated areas also intervene in the surface runoff process, being considered, therefore, erosion-susceptible areas. Thus, relief information such as slope and water-saturated areas, land use in two scenarios, in 1986 and 2005, and their respective procedures, were crossed. The results indicated that in 1986 and 2005, land use was represented by native forest, pasture and forestry, with a transition: pasture and native forest are being replaced by forestry. In the studied area, medium wavy relief is predominant, i. e., 20 to 32.5% slope, and water-saturated areas represent 25% of total area. The highly erosion-susceptible areas evolved during the 19-year interval, and the Atibainha watershed presented the highest indices. The identification of erosion-susceptible areas using historical series provides data useful in assisting the recognition of the region’s reality, pointing ways for agriculture-environment planning.