sustainable AQUIfer recharge to enhance resilience of GROundWater services under increased drought risk – AQUIGROW

Future climate, trends in population growth and land use changes are likely to exacerbate the risks associated with environmental and human water security in many parts of the world. For instance, the occurrence of drought events is increasing globally, as shown by recent major droughts in Europe and South Africa, which seriously jeopardized secure access to water resources, not only for human consumption and irrigation, but also for industrial uses and ecological functions. Therefore, there is an urgent need to devise methods to increase the resilience of water supply systems in the face of increasing drought risk. Within this context, groundwater is the most effective and scalable option to store water, being less affected by evaporation compared to surface reservoirs. Groundwater storage is even more important in arid and semi-arid regions as well as where swift reductions in snowfall and rainfall are occurring. Groundwater is also superior in terms of quality, being less exposed to contaminants than its surface counterpart, and benefitting from the role of active soils in retaining and degrading contaminants. However, over the last decades, land use changes (e.g., uncontrolled urbanization) and inefficient management have drastically decreased groundwater recharge fluxes, i.e., aquifers’ replenishing input. In addition, increased groundwater withdrawals for drinking water supply and irrigation (which can account for up to 80% of total water uses), as well as diffuse pollution from intensive agricultural practices, are putting more and more pressure on aquifers worldwide.