Espacialização do Risco Intrínseco à Contaminação por Pesticidas em Corpos Hídricos e Determinação de Pontos de Monitoramento

Abstract

The objective of this work is to present an alternative method for the determination of water quality monitoring points from the delimitation of areas more susceptible to contamination by both surface and subsurface pesticides, adopting as a case study the dividing region of the upper Paraguay and upper Araguaia river basins in Mato Grosso. A hierarchical environmental information plan was used in the Geographic Information System to elaborate thematic and synthetic charts. The soil behavior was identified as the intrinsic risk of contamination by pesticides in terms of potential infiltration and runoff. These data allowed the spatialization of the areas with risk of contamination of surface and subsurface water resources. The matrix combination between classes of hydraulic conductivity of soil orders with declivity classes made it less subjective to the spatialization of infiltration and flow potential. It was found that the porous aquifer proportionally presented a higher risk of contamination by pesticides than the fractured aquifer, where the former is located in a recharge area with a higher density of crops with medium to large relative sizes, with high conductivity soils hydraulics in areas with a low topographic gradient. The method demonstrated that the subsurface waters of both aquifers present a proportionally higher tendency to contamination due to the intrinsic characteristics of the terrain allied to the forms of use. Environmental organizations may use this method to identify more favorable points for monitoring water quality in water basins and aquifers, reducing costs and optimizing the management of water resources.