ANALYSIS OF THE WATER QUALITY INDEX (AQI) OF THE RESERVOIR CACHOEIRA I, A MEMBER OF THE AGRESTE BRANCH IN PERNAMBUCO

Abstract

The Agreste region of Pernambuco has a long history of water scarcity, with irregular rainfall and a semi-arid climate characterized by high solar radiation. In order to mitigate these effects in the region, the São Francisco River Integration Project is considered the largest infrastructure project in the country, bringing water to the most water-scarce areas. The Agreste Branch is part of this infrastructure project, with a length of 71 km, aiming to supply rivers and reservoirs in the state of Pernambuco. To ensure that the waters of the São Francisco River are reaching the region in good quality, the Water Quality Monitoring Program has been evaluating parameters at various points in the system, including local rivers and reservoirs. The Cachoeira I reservoir is a significant supply source in the municipality of Sertânia that is included in the monitoring program. This present study aims to assess the water quality of the Cachoeira I reservoir through the analysis of the Water Quality Index (WQI) and Trophic State Index (TSI). Through the analysis of these indices, an overall improvement in the classification of WQI and TSI was observed during the data collection period from 2018 to 2022, encompassing 12 monitoring campaigns, coinciding with the increase in water volume in the reservoir over the years. Understanding these parameters is crucial for the water management entities to make informed decisions in order to consistently improve the parameters and ensure the distribution of quality water to the population.