VULNERABILITY OF BASINS AND WATERSHEDS IN MEXICO TO GLOBAL CLIMATE-CHANGE

Some conclusions on the vulnerability of hydrologic regions in Mexico to future changes in climate can be drawn from the application of regi onal-scale thermal-hydrological models. Climate changes induced by the doubling of atmospheric CO2 have been predicted for the year 2050 by general circulation models (GCMs) and energy balance models (EBMs). Th e results obtained suggest that potential changes in air temperature a nd precipitation may have a dramatic impact on the pattern and magnitu de of runoff, on soil moisture and evaporation, as well as on the arid ity level of some hydrologic zones of Mexico. However, in other cases climate change is likely to produce a positive effect. Indices were es timated for quantifying the vulnerability of hydrologic regions and of the country as a whole. These vulnerability indices were defined acco rding to criteria previously established for studies of this type. The indices provide information about both the hydrologic zones which are vulnerable even under current climate conditions and others which may be vulnerable to future climate changes.