Hydrologic Modeling for Assessing Climate Change Impacts on the Water Resources of the Rio Conchos Basin

摘要

This paper presents a hydrologic modeling application to assess climate change impactson the water resources of the Rio Conchos basin, especially for agriculture and domesticwater uses. The study basin is located in the Mexican State of Chihuahua, with a drainagearea around 67,862 km~2. It is one of the most important Mexican tributaries of thebinational Rio Grande basin and contributes major water deliveries (about 55%) to USthrough the 1944 treaty between Mexico and the US. However, during period of drought,for instance in the 1990s, there has been conflict and competition for the water resourcesin the basin, and as a consequence Mexico accumulated an important water debt to theUS. In addition, the hydrological behavior of the basin has recurrent periods of waterstress, problems with long drought periods, allocation and release, and water pollution.Under this reality, it is important to evaluate and predict the available water resources inthe next 50 or 100 years taking account of possible climate change impacts in the basin aswell as assessing the policies to be implemented in order to face drought periods andpreserve the agreements treaty between Mexico and the US. For this purpose, the WaterEvaluation and Planning (WEAP) model is used. The model was calibrated and validatedcomparing the simulated flows resulting from the input of climatic time series withnaturalized flows. Monthly climate time series from 1980-1999 (20 years) were used andsome soil parameters were adjusted for calibration. Also, comparisons between simulatedand naturalized flows were performed for different stations. In addition to this, calibrationconsidering all water management infrastructures, such as, reservoirs, operation rules,canals, and diversions, was also carried out. The results show good correlation betweensimulated and observed flows which indicates that the model reproduces the hydrologicbehavior of the basin, including, natural and historical flows, storage in reservoirs, watersupplies, and water demands for agriculture and urban activities.