Determinação da fragilidade ambiental de bacia hidrográfica em relação à atividade suinícola utilizando SIG

Abstract

The intensified use of natural resources started after the industrial revolution, with increasing the disorderly occupation of watersheds and environmental degradation over the past century. Studies of environmental fragilities helps to identify areas with greater or lesser fragility regarding to certain aspect or activity analyzed, contributing to the decision making and adoption of strategies to minimize such impacts. The objective of the study was to evaluate the environmental fragility of Lajeado Erval Novo Watershed front the swine farming in order to subsidize the support of the decision taken for the environmental licensing system. Therefore, was held an integrated environmental assessment of the basin from data processing in Geographic Information System using a model based on qualitative and quantitative variables and adding socio-environmental characteristics to hierarchize areas with higher and lower environmental fragility for swine effluents. The areas to the southwest and northeast of the studied watershed were diagnosed as points of high environmental fragility. This fragility was, mainly, related to higher generation of swine effluent load and the conditions that contribute to the process of environmental embrittlement of areas, such as the use and soil type, slope and proximity to water resources. The mapping of environmental fragilities, by addressing the specifics variables and conditions of areas, proved to be a very important tool for decision-making and the maintenance of swine activities and the environmental balance of the watershed.