Gerenciamento de recursos hídricos em bacias hidrográficas: modelagem ambiental com a simulação de cenários preservacionistas

Abstract

The present study had the objective to implement a numeric computer simulation of the superficial flow of water and of the erosive processes, transforming a geographic information system into a realistic system of the time-space processes to analyze the risks of environmental hazards of the Arroio Grande watershed. Through the environmental modeling process, I tried to create a preservationist scenario, which focused the reduction of the superficial water flow and the erosive process. With this scenario I analyzed the spatial changes happened on the Arroio Grande watershed in the period of 1987 to 2002. This study fits in the activities predicted by the Fundo Setorial de Recursos Hídricos (CT Hidro), through the managing of the hydric resources in South Brazil. One area establish by CT Hidro is the land use and cover changing and soil conservation at water systems where the main problems are the soil erosion and soil compaction, loses of the natural cover and improper reforestation. With that, the program tries to provide the development of conservationist practices and the prevention of the water sources at watersheds. Between the results I point the great relation of the superficial water flow and the erosive processes, being approximately 46,32% of the total of the water that enters in the basin is lost. The high superficial flow carries 437.000 tons of fertile soil per year in a average of 12,36 tons/ha. The data obtained by the process of environmental modeling show the need to reforest an area of 4.500 hectares. I also point out some changes in the patterns of the land cover s usage, which put in evidence the insertion of Arroio Grande watershed in a highly economic exploration system.