Nation-wide climate variability in Mexico and its effect on water resources

This work shows how the recently developed Mexico's High Resolution Climate Database (MexHiResClimDB) has been extended to include Reference Evapotranspiration obtained with the Hargreaves method. With this extended database and using as reference the 1961-1990 period, it has been found that aridity has increased in Mexico, which affects surface water storage and potential groundwater recharge. The impact of this increased aridity on water resources is shown for the Cutzamala System, which is comprised of seven reservoirs that provide 14 m3/s, representing nearly 30% of the water supplied to Mexico City and its Metropolitan Area. This work also shows that nation-wide studies on climate variability have to focus at the watershed level in order to quantify its impact on water resources.