Análisis multitemporal de la calidad del agua en relación con la cobertura de la tierra en la subcuenca media-baja del río Teusacá

Abstract

The Teusacá River sub-basin has a total area of 35,818.42 hectares and a main channel of 69 km, located east of the Eastern Hills of Bogotá and in the central-eastern area of the Bogotá River. This sub-basin also includes the rural areas of the municipalities of La Calera, Sopó, Chía, Bogotá, Choachí, Guasca, Tocancipá, and Ubaque. Mountainous relief , with an average temperature of 12°C and an average precipitation of 750 mm, which favors a great diversity of flora and fauna, characterizes the area. (Corporación Autónoma Regional, 2021).

The purpose of this study is to analyze the relationship between water quality and changes in land cover dynamics in the lower-middle sub-basin of the Teusacá River for the years 2001, 2006, 2011, 2016, and 2020. This is due to concerns about the quality of water consumed by the inhabitants of the municipalities of La Calera and Sopó, who use the water resource for economic activities such as industries, flower crops, livestock, and basic household needs. Initially, an investigation was carried out to identify the location of the study area, along with its environmental, social, and economic characteristics. Subsequently, multi-temporal data on water quality of the Teusacá River for the selected years were requested from CAR Cundinamarca, followed by the search for Landsat satellite images of the study area. Finally, field visits were made in both municipalities to record the present land cover and to understand the perception of the inhabitants regarding changes in the water and land resources through a formulated survey.

Cartographic models were created to classify the land cover types present in the area using the Corine Land Cover methodology, where shrubland, herbaceous cover, clean pastures, mosaic of pastures and crops, continuous urban fabric, and surface water bodies were identified. In addition, the Water Quality Index (WQI), the Remnant Vegetation Index (RVI), and the Rate of Change of Natural Land Cover (RCNLC) were calculated. By relating changes in land cover and water quality in the sub-basin, it was identified that factors such as the loss of shrublands and the increase in urban fabric have an impact on water quality. Finally, an action plan was proposed to improve the quality of both water and soil resources.