Avaliação dos impactos ambientais no reservatório Encanto RN

Abstract

The use of reservoirs is a fundamental part of controlling the amount of water available for supply in any region, especially in the semi-arid region of the Northeast, where their use become essential due to extended periods of drought that constantly occur. Besides the irregular rainfall regime, anthropogenic activities in permanent protection area of the reservoirs can compromise both the stored water volume and the water quality of the reservoirs. In the Upper West Potiguar region, the drought period occurred in the 2011 to 2014 period extended to most of the state and compromised water availability in the region. This study aimed to identify and quantify the environmental impacts that cause changes in the water quantity and quality of Encanto reservoir. As a result the final impact matrix shows the correlation of each degrading activity with the environmental component affected. The results showed that activities of soil use and ocupation in the drainage basin directly affect the quality of the reservoir water, the input of nutrients and contaminants from uses, such as agriculture, livestock activities and landfill. The landfill was appointed as an activity that leaves the soil exposed to erosion processes, which are also favorated by the removal of riparian vegetation, contributing to the process of silting of the reservoir. Agriculture, though requiring high demand did not affect the hydric balance of the system, but in periods of low volume stored it can become a problem for water a vailability. The occupation of the margins in addition to illegal, to be in a permanent protection area, affects all environmental components analyzed. Therefore , the analyzed environmental impacts have direct influence in the reservoir and can instensify over time, thus requiring mitigation actions to control the quality of the reservoir.