Key groundwater indicators for sustainable social-ecological systems in drylands: a Mexican perspective

Groundwater is an essential component of the natural water cycle, in particular, in drylands where water scarcity is often severe. The recharge/extraction dynamics of aquifers is tightly coupled to the socio-economic development of these regions, which – over just a few decades - have become the most vulnerable biome complex both to climate change and accelerated land use change. This project examined groundwater quality and quantity in 24 aquifers associated with five Socio-Ecological Participatory Observatory. They operate through the emergence of communities of practice; they are social innovations to foster transdisciplinary participatory research aimed at sustainable development in the drylands of Mexico. Within the observatories, interest in exchanging knowledge on groundwater, the review and diagnosis of data records and the results of quality analyses and piezometric levels in wells has been encouraged. Of the water quality trends found, one salinity stands out, and has a high content of chlorides, sulphates and carbonates, as well as reveal the presence of pollutants in some aquifers (As, F mainly) and components of anthropogenic origin such as nitrate. This diagnostic baseline shows the limitations, in various wells, on the quality of water for domestic, livestock and agricultural use. The abatement rates estimated in this process indicate annual values between 0.40 and 1.93 m per year, highlighting the high risk of socio-environmental collapse in these areas where averages rainfall precipitations are of the order of 0.3 and 0.6 m. These advances serve as the basis to better reflect concrete outcomes, e.g., "The findings form a baseline for future groundwater governance and participatory water management planning in arid regions.". • Participatory water quality monitoring allows community learning about groundwater. • Monitoring changes in water quality and depth of aquifers favors sustainability. • The generation of knowledge about dryland groundwater helps local decision-making. • Network of socio-ecological participatory observatories in drylands. • OPSE model: a socio-ecological innovation for neutralising desertification.