Thermo‐hydrological modelling of the climate change effect on water availability in two hydrologic regions of Mexico

Abstract

AbstractFrom the climatologic data bases (SICLIM and CLICOM) built by the Servicio Meteorológico Nacional (SMN) of Mexico, we have defined two normals: one called Period I, from 1950 to 1975, and the other called Period II, from 1976 to 2000. The objective of the present work is to make an estimation of the annual volume of superficial available water in Periods I and II, and the changes between them, in two important hydrologic regions of Mexico, called Lerma‐Santiago‐Pacifico (HR‐LSP) and Balsas (HR‐B), whose population annually demands almost one‐third of the water extracted in all the country.For this purpose, a non‐linear thermo‐hydrological model is used. It consists of two equations applied to the soil, i.e. the thermal energy and water balance equations, which are coupled through the soil temperature and soil moisture.The results show that the change from Period I to Period II was more significant in the HR‐B than in the HR‐LSP. In the HR‐LSP, the conditions of aridity were favoured by a decrease of 3.4% in the precipitation, which affected almost the entire region.On the average, the HR‐B experienced an increase of 7.0% in precipitation, and therefore, a considerable increase in the volume of available water from Period I to Period II. However, in the northern part of this region, the increase in temperature and the decrement in precipitation reduced water availability, while the opposite occurred in the south of the region, where the decrease of the temperature and the increase in the precipitation increased the available water and favoured conditions of humidity in Period II. Copyright © 2008 Royal Meteorological Society