Modelagem da Poluição não Pontual na Bacia do Rio Cuiabá Baseada em Geoprocessamento

Hydrologic modeling has been one of the analytic instruments available to help water resources management. The possibility of water quality monitoring resulting from the leaching of pollutants as a result of agricultural activities, called diffuse(non-point) pollution, is the central hypothesis of this study which seeks to identify and quantify water quality changes in the Cuiaba river basin, as a function of soil cover and land use. This basin was chosen because it lies in the state of Mato Grosso which has an eminently agricultural vocation, and is located upstream from the Pantanal complex, constituting an important area for environmental studies in Brazil. The Cuiaba River basin has a drainage area of approximately 29,000 km2. RBRH – Revista Brasileira de Recursos Hidricos Volume 8 n.4 Out/Dez 2003, 115-135 135 In this context, an attempt was made to develop a distributed hydrologic model based on geoprocessing via a geographic information system (GIS). Specifically, the spatial distribution of total nitrogen and total phosphorus as pollutants in the basin is evaluated, based on the integration of data on hydrometeorology, water quality, physiography, land use and occupation and images from the Landsat 7 – ETM+ sensor in a GIS environment. The results obtained by the model, when compared to historical water quality series in the Cuiaba river basin, indicated the acceptability of the methodology proposed as an indicator of spatial variability of mean water quality.