RIO DOS SINOS HYDROGRAPHIC BASIN: LAND USE AND LAND COVER INFLUENCE ON WATER QUALITY

The Rio dos Sinos Hydrographic Basin (RSHB), located in the eastern portion of the state of Rio Grande do Sul, in its 3,696 km(2), covers different classes of land use and land cover. This article presents the division of the RSHB in sub-basins, with their respective percentages of Rural anthropic, Urban anthropic, Grassland and Forestry classes, aiming to relate each one of them to eleven water quality monitoring points, checked in the period between 2007 and 2013. The water analysis found that the Rural anthropic class predominates in the basin, with 54.92% of the total area, followed by the Forestry class, with 35.27%, and concluded that the best results of water quality are associated with the highest degree of conservation of the sub-basins, and the worsening in quality occurs gradually, towards its mouth, which has the greater influence of urban areas, industrial activity and agriculture. It is recommended that watercourses with degraded quality be restored and that actions be taken to preserve and maintain the natural vegetation cover in the spring areas.