Quantity and Quality of Water in the River LermamLake Chapala Watershed, Mexico  

作　　者：Martin L6pez-Hemandez M. Guadalupe Ramos-Espinosal Manuel Guzmha-Arroyo Fidel Payin-Zelay1 

机构地区：[1]Institute Of Marine Sciences and Limnology, Coyoac6n 04510, Mexico [2]Metropolitan Autonomous University, Coyoac~n 04560, Mexico [3]Institute of Limnology, University of Guadalajara, Jalisco 45920, Mexico

出　　处：《Journal of Environmental Science and Engineering(A)》2012年第11期1231-1242,共12页环境科学与工程（A）

摘　　要：Water overexploitation in the Lerma-Chapala Watershed, located in central Mexico, is linked to the development of a strong federal hydrocracy with the mission to capture as much water as possible in order to satisfy social and political demands through the construction of dams and irrigation systems. The reduction in freshwater quantity and the deterioration of water quality are the outcome of industrial inflows, agriculture and urban untreated wastewater. This study has been leaded to determine hydrological, water quality, seed bioassays and the lake fisheries＇ decreases throughout its historical tendencies （1980-2004） in relation to changes in water levels. Hydrological data and water samples for chemical analysis, inorganic nutrients and seed bioassay, were taken from 10 sites alongside the river and two sites from Lake Chapala in years 2005 and 2009, the WQINsF （National Sanitation Foundation Water Quality Index） was estimated. The dissolved oxygen along the river was from anoxic （0.4） to 7 mg/L and the lake had 6.75 mg/L to 7.36 mg/L; the river had highest nutrients variations, Ntot and Ptot 1 mg/L to 〉 10 mg/L. The lake had few physicochemical variations and the lowest nutrient concentrations; WQINsF （water quality index） in the river-lake system showed very bad-bad quality and contamination in river, bad quality-light contamination in lake. Seed bioassays showed inhibition of root elongation and declining fisheries when low water levels were presented. Chapala Lake had better physicochemical and limnological conditions because of the wind action and water column mixing; in contrast the river, high hidrological variations caused by water administration in middle basin.

关 键 词：Water overexploitation river control water quality index seed bioassays fisheries. 

分 类 号：S965.224[农业科学—水产养殖] TV213[农业科学—水产科学]