Determining the effects of Climate Change on Water Quality of Pátzcuaro and El Sol Lakes in Mexico

The comparative study of the precipitation and temperature of Pátzcuaro meteorological stations (070 and 16087) in the periods 1921-1960 (initial period; 39 years of records) and 1973-2007 (posterior period; 34 years of records) indicated a change in the climate in accordance with the Köppen classification. In addition, the Nevado de Toluca Station (15062) for 1964-1985 (initial period; 21 years of records) and 1986-2008 (posterior period; 22 years of records) also show these climatic changes. The box plots for precipitation, evaporation, observed temperature, minimum and maximum of the air, Student's “t” test, regression analysis and linear correlation indicated significant changes in time at p 0.05 for both lakes. Likewise, the Student’s “t” test, regressions and correlations in the water quality records from 2006 to 2011 for Pátzcuaro Lake, indicated significant changes in some physicochemical variables, due to agricultural, livestock, forestry, fishing, tourism, trade and cyanobacterial blooms. In El Sol Lake the physicochemical changes over time were related to tourism, livestock activity and phytoplankton biomass; changes associated with anthropic and climatic influence in both lakes throught changes in the meteorological variables. For Pátzcuaro and El Sol lakes a decrease in maximum depth, surface area, length and width were associated with an increase in turbidity, nutrients and an increase in phytoplankton biomass and climate change between the initial and posterior periods, due to the change in the heat balance of water through variation in air temperature, precipitation, runoff, and evaporation. A management plan (reforestation, construction of wetlands, water lily harvest, regulation of agricultural activities, domestic, urban, tourist and industrial waste), it is recommended as appropriate for each lake ecosystem.