Qualidade ambiental de igarapés urbanos no sudoeste da Amazônia

Abstract

This study assessed the environmental quality of urban streams in Humaitá, in the southwestern Amazon, using the Rapid Assessment Protocol (RAP) and analysis of physical-chemical parameters of the water. Sampling took place during the dry season of 2024 at 29 points distributed across four streams in the urban area. The diagnosis integrated morphological and limnological aspects and indicators of anthropic pressure, such as occupation of the banks, disposal of waste, presence of sewage, and alterations in the channel. The results indicated a predominance of environmental degradation, with ratings between “poor” and “fair” in most sections, while Igarapé 4 presented better conditions, with a higher number of points rated as “good.” The physical-chemical parameters showed pH within acceptable limits (6.5 8.5) and high temperature at most points, but high electrical conductivity values and low concentrations of dissolved oxygen (<5 mg/L), indicating the input of organic waste and domestic effluents. The absence of riparian vegetation, erosion of the banks, soil sealing, and improper waste disposal were determining factors in the degradation. The integrated analysis shows that uncontrolled urbanization and poor sanitation compromise the ecological integrity of the streams, reinforcing the need for environmental recovery and urban management actions, in line with SDGs 6, 11, 14, and 15.