Evolução do uso e ocupação do solo e do índice de qualidade da água na bacia hidrográfica do Rio Manhuaçu no período de 2011-2020

Abstract

Inadequate management of water resources can jeopardize the multiple uses of water, contributing to the intensification of events that can impact the quality and quantity of water in a basin, thus making their study essential. The change in water quality comes from several factors, such as the growth of urban centers without proper planning, industrialization, deforestation and the way the soil is used in agricultural crops. The objective of this work was to evaluate the influence of land use and occupation on the parameters that make up the Water Quality Index (IQA) in the Manhuaçu/MG river basin from 2011 to 2019. The methodology of this work consisted of to prepare maps of land use and occupation for the 06 monitoring stations in the basin, and maps for the years 2011, 2014, 2017 and 2019 were prepared for each station. Data on water quality were obtained from IGAM through the InfoHidro portal . In order to evaluate the influence of land use and occupation, the evolution of the percentage of the area occupied by each type of land use and occupation in the basin over the study period, the evolution of the parameters that make up the WQI and its relations with the use of the soil. From the data obtained in the work, it was verified that the pasture use class showed a regression in all areas of the contribution basins, and in turn, the agriculture and pasture mosaic class stood out, reaching an increase of 11.06% in the value of your area. The parameters that obtained a limit above that allowed by the legislation were: total solids, thermotolerant coliforms, turbidity and phosphorus, and coliforms gained prominence in all seasons. The IQA ranged from bad to good, the deficiency in the collection and treatment of sewage in the cities located within the watershed has resulted in a significant portion of the polluting load reaching the water bodies, this deficit contributed a lot to the high values of the IQA. In view of the study, there is a need for actions aimed at treating sewage within the basin, and implementation of actions aimed at the restoration and conservation of permanent preservation areas, environmental education programs and environmental preservation incentives aimed at reducing the impacts of the use of the soil in the basin.