Diagnóstico e monitoramento ambiental da microbacia hidrográfica do rio Queima-Pé, MT

Abstract

The availability of fresh water is very restricted in nature; it is therefore mandatory that it be preserved, controlled and used rationally. The constant destruction of the riparian forests in association with the increase in the utilization of pesticides has helped increase the movement of residual chemicals and sediments towards the water courses, thus causing, in addition to its silting, pollution and contamination. The rural roads and internal roads, as well as the inappropriate handling of terraces and level curves has a significant impact in the silting of water springs and creeks; they serve as a track for the superficial flow, thus initiating the erosion processes. The riparian forests, represented by the Permanent Preservation Areas are protected by the Forest Cde, which defines the forests existing in the national territory, as well as the other forms of vegetation, as a common interest property of all in habitants in the Brazil. Since the hydrological basin is the territorial unit for the implementation of public policies for water resources, this work has been developed in the River Queima-Pé hydrological micro-basin, which is the only water supply for the city of Tangará da Serra-MT. The area under study encompasses 15,100 acres, with a perimeter of 23.6 miles. The purpose of this work is to perform the spatial modeling of the River Queima-Pé hydrological micro-basin, also preparing the theme maps, thus facilitating the interpretation of the environmental information. We have also performed an environmental monitoring of the surface waters. This monitoring used the Water Quality Index, WQI ("IQA" in Portuguese) as a tool. The WQI is determined by calculating the weighted multiplication of of the water qualities corresponding to the parameters: Dissolved Oxygen, Biochemical Oxygen Demand, Thermotolerant Coliforms, Temperature, pH, Total Nitrogen, Total Solids, and Turbidity. The findings obtained with the development of the current work allowed us to conclude that: the surveying of the spatial attributes of the basin has helped making the decision regarding revising the study area handling; the bad conservation of rural roads and internal roads, along with the cattle-raising without the appropriate handling were the main causes of the silting of the water springs and the water courses; the absence of riparian forests in the Permanent Preservation Areas has favored the surface flow around water springs and dams; the decay of riparian forests on the River Figueira river banks and the dumping of domestic sewage in it have increased the concentration of Thermotolerant Coliforms and Total Solids, thus reducing the availability of Dissolved Oxygen, which in this way has influenced the fact that the River Figueira has the worst Water Quality Index; the River Pedreira and the River Tapera, and the water spring of the River Queima-Pé have had the best Water Quality Indices.