Analysis of historical water availability and projected surface water trends for decision-making: the case of Mexico

Abstract

Freshwater is a vital resource whose availability, quality, and accessibility have been affected by variability and climate change, population growth, land-use change, social inequality, and socio-environmental conflicts. In the face of these challenges, intersectoral collaboration is required to plan, implement, and monitor actions that ensure water security in Mexico. The aim of this study was to analyze historical water availability and projected surface water trends in Mexico, based on official concession data, hydrological and climate models, as well as spatially explicit maps to support the development of public policies in the country. Results indicated that 54.2% of the national territory currently experiences some degree of water deficit, while 15% lacks both surface and groundwater availability. Besides, the approximate area-specific consumption volumes recommended to be reduced in the national territory were calculated. Additionally, the worst historical performance aquifers, and the sectors with the highest consumption in water-scarce zones were identified. The Xanthos hydrologic model projections under the SSP2-6.0 scenario for the year 2055 indicated that water availability is expected to decrease primarily in the north and central regions of the country. To mitigate and adapt to climate change, it is essential to adjust concessioned volumes in the identified critical zones, improve water-use efficiency in the agricultural and energy sectors, as well as optimize wastewater treatment in regions with limited availability.