Integrated Environmental Studies to Propose Large-scale Zoning for Managing the Texcoco Lake Ecological Park, Mexico

摘要

Lake Texcoco Ecological Park (LTEP) is the last natural area near one of the biggest and most densely populated cities in the world: Mexico City and its metropolitan area. Due to its geographical location, is at serious risk of disappearing in the very short term. A master plan of the park management is necessary. And as a first approach requires a very precise diagnosis of physicochemical conditions to begin the zoning of the area, first step to manage the park. The aim of this study was to perform an integrated environmental diagnostic that would allow us to outline the first step to develop a master plan to manage the LTEP. Integrated environmental studies include geo-environmental procedures as well as water, soil and sediments quality analyses of the Lake Texcoco Ecological Park (LTEP). Geoenvironmental studies comprise vertical electrical sounding and electrical tomographies. Analyses of the quality of water, sediment and soil contamination were assessed monitoring trace metals in the LTEP and most influential rivers in the basin. Three factors have great influence on the quality of the monitored elements in the LTEP: the synergy of ancient human uses with existing uses, the random use of riverbeds that modify the water regime and hydro period of the lake, so that temporary ponds do not work as they should in the shelter of aquatic wildlife and migratory birds and waterfowl from the USA and Canada. And third, the leaching of contaminants deposited on the bed of the lake from the rivers that drain into it. Ecological and evolutionary importance of this natural landscape is that it is a relict of a single lake in the world (Lake hyper saline soda-lake type); Texcoco Lake is home to over 300 biological species. More than 150,000 aquatic birds, mostly migratory, use the lake for wintering, migrating from Canada and the northern United States of America. The wind-blown dust that runs from the lake to the city of Mexico contains spores, microbes and particles (PM_(10)) that cause gastrointestinal diseases to a population of over 22 million people. There were significant differences among areas in the environmental quality of the Park, these results allowed us to develop a first suggestion for zoning LTEP in its management master plan.