The Use of GIS in Aid Analysis of Environmental Impacts Caused by the Hydroelectric Power Plants Passo São João and São José Located in Rio Ijuí – RS

Abstract

In Brazil hydropower is the matrix for power generation, with the remainder distributed among the other generation sources, wind, solar and thermal. Today, hydroelectricity accounts for 71% of total electricity generated in the country. Thus, hydroelectric developments are on the rise in the country, which somehow brings beneficial, but also impacts the environment. The objective of this work is to demonstrate the practicality of using GIS tool to aid in the analysis of environmental impacts in Rio Ijuí after construction cascading two hydroelectric plants, UHE Passo São João and UHE São José. The methodology is to establish different evaluation physical criteria and their respective weights, so the distance criteria of urban seats, distance between buses, flooded area, installed capacity and yield were measured to give a classification (low, medium and high impact to the environment). To give accurate results of each physical criteria, was used Geographic Information System (GIS) and ArcMap software. By performing the average impacts according to agreed criteria, UHE Passo São João was classified as causing moderate to high impact on the environment and São José as causing low to medium impact. The criterion that influenced this final impacts UHEs were: distance between venues urban that damaged the UHE Passo São João that is very close to the town of Roque Gonzales, and wetlands both UHEs that go beyond the 13 km² considered this methodology.