Importance of diffuse pollution control in the Patzcuaro Lake Basin in Mexico.
In the catchment area of the Lake Patzcuaro in Central Mexico (933 km2) the apportionments of erosion, sediment, nutrients and pathogen coming from thirteen micro basins were estimated with the purpose of identifying critical areas in which best management practices need to be implemented in order to reduce their contribution to the lake pollution and eutrophication. The ArcView Generalized Watershed Loading Functions model (AV-GWLF) was applied to estimate the loads and sources of nutrients. The main results show that the total annual contribution of nitrogen from point sources were 491 tons and from diffuse pollution 2,065 tons, whereas phosphorus loads where 116 and 236 tons, respectively during a thirty year simulation period. Micro basins with predominant agricultural and animal farm land use (56% of the total area) accounts for a high percentage of nitrogen load 33% and phosphorus 52%. On the other hand, Patzcuaro and Quiroga micro basins which comprise approximately 10% of the total catchment area and are the most populated and visited towns by tourist 686,000 people every year, both contributes with 10.1% of the total nitrogen load and 3.2% of phosphorus. In terms of point sources of nitrogen and phosphorus the last towns contribute with 23.5% and 26.6% respectively. Under this situation the adoption of best management practices are an imperative task since the sedimentation and pollution in the lake has increased dramatically in the last twenty years.
Carro
Marco Mijangos
MM
Department of Hydrobiology and Environmental Assessment, Mexican Institute for Water Technology, Paseo Cuauhnáhuac 8532, Progreso, Jiutepec 62550, México. mijangos@tlaloc.imta.mx
Dávila
Jorge Izurieta
JI
Balandra
Antonieta Gómez
AG
López
Rubén Hernández
RH
Delgadillo
Rubén Huerto
RH
Chávez
Javier Sánchez
JS
Inclán
Luís Bravo
LB
D000383:Agriculture; D004058:Diffusion; D017753:Ecosystem; D004787:Environmental Pollution / Q000517:prevention & control*; D005618:Fresh Water / Q000382:microbiology; D005843:Geography; D019015:Geologic Sediments / Q000737:chemistry; D008800:Mexico; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D012987:Soil
D012987:Soil; D010758:Phosphorus; D009584:Nitrogen