Evaluación del riesgo de eutrofización del embalse monaicito-piedra azul, estado Trujillo, Venezuela

Abstract

The assessment of eutrophication risk of the Monaicito - Piedra Azul water reservoir located in Trujillo State, Venezuela, is presented through the implementation of the simplified mathematical model for evaluation of trophic status and management of macronutrients in tropical warm lakes / reservoirs (LACAT), developed by the Pan American Center for Sanitary Engineering and Environmental Sciences (CEPIS). As sources of phosphorus, it was considered and quantified wastewater from country towns established in the basin, solid wastes from municipal concentrated and scattered population, animal manure (cows and horses), surface runoff and biomass in the flood area. The results show that, for the filling stage of the reservoir, it is desirable to deforest, at least, 25 % of the biomass in the flood area. During the operation phase, it is demonstrated a change in the trophic status of the reservoir from mesotrophic to eutrophic, beginning the year 20 of the project horizon, due to the accumulation of phosphorus in the reservoir. As a result of the foregoing, the magnitude of the eutrophication risk was quantified as slight (- 1) until year 20 of operation, and then as significant (- 2). The conclusions and recommendations include the need to avoid accumulation of phosphorus in the reservoir, through the implementation of sewage systems covering removal of phosphorus and integrated systems for the management of solid waste and liquid effluents in the agricultural activities of the basin.