Modeling the Effect of Climate Change Scenarios on Water Quality for Tropical Reservoirs : A Case Study in Mexico

The effects of climate change scenarios on water quality forecasts were assessed through correlations, prediction algorithms, and a water quality index (WQI) for tropical reservoirs using a case study in Mexico. The expected trends ​​for different water quality parameters were estimated for the 2030-2100 period in association with temperature trends to estimate water quality at Adolfo Lopez Mateos Dam in Mexico. The WQI scenarios were obtained using algorithms supported by global models of representative concentration pathways (RCPs) adopted by the Intergovernmental Panel on Climate Change (IPCC). The RPCs were used to estimate water and air temperature values and extrapolate future WQI values for the water reservoir. The proposed algorithms were validated using historical information collected from 2012 to 2019 and four temperature variation intervals (ranging from 3.2-5.4°C (worst forecast) to 0.9-2.3°C (best forecast)) were used for each trajectory using 0.1°C increases to obtain the trend for each WQI parameter. Variations in the concentration (±30, ±70, and +100) of parameters related to anthropogenic activity (e.g., total suspended solids, fecal coliforms, and chemical oxygen demand) were simulated to obtain water quality scenarios for a future health diagnosis of the studied reservoir. The results projected in the RCP models showed increasing WQI variation for lower temperature values (best forecast WQI = 74; worst forecast WQI = 71). The results of this study will help decision makers ensure sustainable management of water resources in tropical reservoirs