Evaluación del impacto de cambios de cobertura vegetal en la producción de agua de la Sub cuenca del Río Burgay-Parroquia Nazón, Cantón Biblián

Abstract

Abstract: Vegetation cover degradation in high Andean watersheds alters the hydrological cycle and affects water production. In the Burgay River sub-basin, located in Nazón parish (Biblián, Ecuador), processes such as deforestation, agricultural expansion, and urbanization between 2015 and 2022 have compromised water sustainability. This study evaluated the impact of land cover changes on water quantity and quality, identifying critical areas. Remote sensing and GIS techniques were applied using Landsat 8 (2015) and Sentinel-2 (2022) imagery. A supervised land-use classification and NDVI analysis were conducted to estimate vegetation loss. The SCS curve number method was used to model changes in infiltration and surface runoff, and water samples were analyzed for physicochemical and microbiological parameters. Results show a reduction in forest cover and an increase in agricultural and urban areas. Infiltration decreased by approximately 18%, while runoff increased by 22%. High levels of fecal coliforms and phosphates were detected, indicating contamination. The most affected areas are steep slopes and headwaters. The study concludes that vegetation loss reduces both water quantity and quality, recommending reforestation, ecosystem protection, and sustainable land management.