ENVIRONMENTAL IMPACTS OF URBANIZATION ON WATERCOURSE: WATER QUALITY DIAGNOSIS OF VERTENTE GRANDE STREAM, FRUTAL-MG

Abstract

Urban rivers have suffered from environmental degradation, despite their importance to society and nature. Over the last few centuries, degradation has increased considerably, particularly with the expansion of urban and agricultural areas, raising concerns about sustainability and the limits of resource use. This study aimed to assess the water quality of the Vertente Grande stream, located in the municipality of Frutal-MG, which is important for the city, especially during the driest times of the year when it is used in emergency situations for capturing water for public supply after conventional treatment. The stream has been neglected due to the disposal of solid waste as it passes through the urban area of the city. Monthly water collections were carried out from October 2022 to March 2023 at three points along the stream, each representing different degrees of human impact (rural area, beginning of the urban section, and urbanized section). A Rapid River Assessment Protocol was used to assess ecological aspects and anthropogenic impacts on the watercourse. Physicochemical analyses and quantification of thermotolerant coliforms were conducted at the sampling points, showing that as the watercourse enters the urban area, water quality deteriorates. The variables electrical conductivity, total dissolved solids, nitrate, total ammonia nitrogen, and total phosphorus showed higher concentrations at the point corresponding to the most urbanized location, as well as thermotolerant coliforms. The variables electrical conductivity, total dissolved solids, dissolved oxygen, nitrate, total ammonia nitrogen, total phosphorus, and thermotolerant coliforms showed a statistically significant difference between the points, with lower values at the rural area point and higher values at the urbanized section point. Principal components analysis identified an increase in the degree of eutrophication as the water passes through the urban area. The Rapid River Assessment Protocol demonstrated that urbanization negatively impacts the water system, causing degradation of the banks and accumulation of waste, leading to water quality deterioration, rendering it unsuitable for more demanding uses such as human consumption. Monitoring indicates the contamination of water that has been used as a secondary source for treatment and distribution to residents