Climate change and its impact on the projected values of groundwater recharge: A review

Understanding the influence of climate change (CC) on groundwater recharge (GWR) is fundamental for a better long-term planning and management of groundwater supply. To date, several regional research studies have been conducted to quantify climate-induced factors on GWR; however, no study has summarised such recent modelling efforts to provide a global picture of projected changes in groundwater recharge over the long term. In this research, peer-review articles related to CC-GWR over the last 10 years were critically identified, appraised, and analysed. The analysis focused on identifying the sources of uncertainty considered in such studies, the modelling approaches adopted, and finally, the GWR projections. Results show a predominant use of processbased models. Also, only 20% of studies considered inter-model uncertainty, 11% considered emission scenario uncertainty and no studies considered intra-model uncertainty. A decrease in GWR for North Africa, Southern Europe, and Latin America regions was consistently projected. Oceania, North America, Europe, and Asia had varying projections depending on emission scenario and season. Importantly, overall a decline in GWR in most regions of the world can be expected, though often the modelling was not supported by comprehensive quantification of uncertainty. These findings can serve decision-makers and researchers to develop sustainable plans to preserve this resource for future generations.