Evaluación de la contaminación en cuencas por medio de un Sistema de Información Geográfico. Caso de estudio: cuenca del Río Grande de Morelia

Abstract

Hydrological simulation attempts to reproduce -with the aid of a computer-, all physical processes that shape the hydrological cycle in a watershed, using a mathematical model to represent them properly. One present advantage is that current models have been developed and are incorporated into the GIS, which allows the spatial management of large volumes of information. This work was implemented by the SWAT model, which allows us to predict the impact of soil management in the generation of sediment and water control basins. Due to its characteristics, it was chosen for the determination of flows, sediment and nutrients such as nitrogen and phosphorus, generated in the basin. The Rio Grande de Morelia basin, is one of the main basins of Lake Cuitzeo contributors, which by its characteristics is an endorrheic system in which all generation and production of pollutants is transported and deposited in the lake, causing serious problems for nearby towns and for the environment. In this region there are high socio-economic pressures on water resources and land, large land use changes have endangered several areas of the basin, especially in regard to the city of Morelia, Michoacán. The availability of water is increasingly scarce in quantity and quality. The basin is formed by a great biodiversity of biological species, ranging from mountainous areas with pine trees, to a wetland area that is precisely the mouth of the Rio Grande in Cuitzeo Lake, this lake is the third in extension surface in Mexico, hence, it is of utmost importance for the management analysis of the main input to the lake basin. The issue of water quantity and quality becomes more acute in the middle and lower basin areas, where the sediment materials and nutrients dragging is larger. It is also there, where most farming practices take place, and in some cases, polluted water is reused for irrigation, or it is drop into the lake of Cuitzeo with all its pollution load. It is for all the above mentioned, that a geographic information system intends to facilitate the analysis of environmental pollution in the watershed, thereby assisting in making agile and quick decisions. Keywords: Land use; water resources; water supply; watershed; SWAT Model; point and nonpoint pollution, Geographic Information System; Morelia, Río Grande de Morelia, Michoacan, Mexico.