Influência do uso e cobertura da terra na qualidade da água da bacia hidrográfica do Rio Ingaí - RS

Abstract

The water quality of a watershed is influenced by numerous factors, whether natural or anthropogenic. The human actions have always had a more intense action on these environments being demonstrated by the different uses to which they are subjected to land cover over time. In this sense, this research aims to analyze the influence of land use and coverage of the watershed of Ingaí river the water quality parameters the same, in order to support the management of water resources in this area. For this, we used the system software Georeferenced Information Processing (SPRING 4.3.3) to the achievement the use of maps and land cover with use of images of the Thematic Mapper sensor/Lansat5 for dates: 21/01/2009 (vegetative period – agriculture) and 20/10/2009 (period between harvests - soil exposed). The classes use and land cover were defined: forest, agriculture, soil exposed, urban area, water and field. The limnological parameters analyzed were: total of solids in suspension (TSS), water transparency (DS), chlorophyll a (Chl a), water temperature (temp.), hydrogen potential (pH) e electric conductivity (CE), collected in a single sample point at the mouth of the river Ingaí and obtaining rainfall data. The integrated assessment of aquatic and terrestrial systems, concluded that changing the properties of water from the Ingaí river has strong relationship with changes in land use and land cover of the watershed, mainly from diffuse sources, due to the extensive area intended for agriculture, soil exposed areas, allies the occurrence of rainfall. In this sense, it is evident the importance of water management of the watershed of Ingaí river and it is hoped that the information obtained from this research may support actions aimed at this purpose.