Effects of deforestation on water quantity and quality, Oaxaca State, Mexico, as estimated from the SWAT simulation model

Potential effects of deforestation on water quantity and quality can be estimated through the SWAT (Soil and Water Assessment Tool) simulation model for forest and water management. The SWAT model was calibrated and validated in the upper part of the forest hydrological watershed basin of the San Pedro "El Alto" Community, Oaxaca State, Mexico. This basin covers an area of 5 hectares. For the first year (1998) data were obtained through continuous recording of hydrological variables under natural soil and vegetation conditions. Between 1999 to 2001 all vegetation cover was removed (understory and overstory) and the soil was disturbed due to deforestation. The SWAT model provided satisfactory results for monthly and annual periods.