Efectos del uso del suelo sobre la calidad del agua, en las captaciones ubicadas en la microcuenca del río Tabacay, pertenecientes a la empresa pública municipal de agua potable, alcantarillado y saneamiento ambiental del cantón Azogues

Abstract

The present study analyzed how the use of soil (shrub vegetation and pasture) around the water abstraction of the municipal public company of potable water, sewage and environmental sanitation of the canton Azogues affects the quality of the water captured for its purification. Through the Universal Soil Loss Equation (USLE) a map was generated that represents the degree of water erosion within the micro basin. Subsequently, extractions of USLE fragments were carried out for the areas near the catchments in order to establish the degree of erosion associated to the catchments and to determine the relevance of the erosion for each catchment. To determine the relationship between the different land uses and the decrease in the water quality that reaches the company's catchments, a variety of laboratory tests were used, an analysis of variance for each variable, a multivariate analysis and discriminant canonical analysis. When the USLE was related to the use and cover of soil around the catchments, it was determined that, in ravines that do not have an adequate degree of conservation, more erosion occurs. And since the Condoryacu stream is the most conserved within the micro-basin, the data of the physicochemical analyzes have lower levels. While the Llaucay creek has the largest pasture extension being a livestock area, high levels of total and fecal coliform concentrations are observed, thus exceeding the norm. In addition, a constant in all ravines is that the true color parameter exceeds what is stipulated in the regulation as a maximum limit. On the other hand, it can be ensured that within the micro-basin there are no erosion problems since most of its territory is in a mild or moderate category, according to the classification established by FAO in 1981. It is established that the variables that most influence the water quality of the micro watershed are: total and fecal coliforms, which are related to the use of soil of the entire ravine and not only to the surrounding area. The physicochemical and microbiological data used were obtained during the period from August 2015 to August 2016.