Determinación del caudal ecológico y calidad del agua de la microcuenca del río la Chimba

Abstract

This study analyzes the Water Quality Index (WQI) and ecological flow of the La Chimba river microbasin, located in the Olmedo parish, Cayambe canton, Pichincha province. The analysis involved evaluating physicochemical and microbiological parameters at nine sampling points distributed across the upper, middle, and lower zones of the microbasin during April, May, and June. A total of 27 samples were collected to analyze nine key parameters: dissolved oxygen, pH, temperature, total dissolved solids, BOD5, nitrates, phosphates, turbidity, and fecal coliforms. Contamination was detected in all zones. In the upper zone, the páramo is affected by pollution due to nearby livestock activities. In the middle zone, the water is used for agricultural irrigation, while in the lower zone, human activities impact water quality. Despite these contaminations, the analyzed parameters met the limits set by the TULSMA regulations, indicating that overall water quality is acceptable. The WQI in the upper zone remained within the range of 71-95, indicating excellent quality. In the middle zone, water quality was good, with a range of 71-95 in April and May, and 51-70 in June. The lower zone also showed excellent water quality with a range of 71-95 throughout the months. However, increased BOD5 levels were observed due to runoff from animal waste, fertilizers, and pesticides, which contribute to organic matter and algae growth. Agricultural erosion also adds sediments to the river.