In arid, semi-arid and dry sub-humid areas water supply relies heavily on groundwater. Pressure on limited water resources in these areas is intensifying due to rising demand linked to population growth, tourism, urbanization and expansion of agricultural land under irrigation. Excessive groundwater withdrawals have led to groundwater depletion in many regions. Substantial uncertainty remains in recharge projections under climate change.
In drylands precipitation is highly variable both spatially and temporally. At decadal to annual scales, only a small proportion of this precipitation contributes to groundwater recharge. Techniques developed to estimate groundwater recharge under more humid climates are not always applicable. New, innovative and adapted methods are required to broaden currently available tools to quantify groundwater recharge in dryland environments. Modelling groundwater recharge in these often data-scarce regions is also challenging. Current large-scale hydrological models remain rooted in assumptions that are often unrelated to how groundwater recharge is observed to occur in drylands (e.g. the exclusion of focused recharge). Furthermore, it has often been assumed that with climate change drylands will get drier following the “wet gets wetter, dry gets drier” paradigm outlined in 5th Assessment Report of the IPCC. However, this assumption has been shown more recently to be much less certain; further, the intensification of precipitation under warming has been shown to influence the timing and magnitude of recharge in drylands. Improving our understanding of groundwater recharge - the sources and the hydrogeological processes, its spatial and temporal variability, its evolution under global change – still represents a major endeavour in hydrogeology and is critical to ensure sustainable management of water resources in drylands.
This Research Topic aims to bring together the latest advancements in understanding, measuring, monitoring, modelling and managing groundwater recharge in drylands and under global change. Areas to be covered in this Research Topic may include, but are not limited to:
• contributions to the understanding of groundwater recharge processes
• innovative techniques to measure and observe groundwater recharge
• new approaches to mapping and modelling of groundwater recharge
• observations and modelling of surface water and groundwater interactions
• observations and modelling of groundwater fluxes exchanged in the continuum formed by the atmosphere, the land surface, the unsaturated zone and the water table
• impact of climate change on groundwater recharge
• managing groundwater recharge
• managed artificial recharge
• analysis of recharge trajectories and adaptation to global changes
• relevant policies and adaptation strategies to changes in groundwater recharge
In arid, semi-arid and dry sub-humid areas water supply relies heavily on groundwater. Pressure on limited water resources in these areas is intensifying due to rising demand linked to population growth, tourism, urbanization and expansion of agricultural land under irrigation. Excessive groundwater withdrawals have led to groundwater depletion in many regions. Substantial uncertainty remains in recharge projections under climate change.
In drylands precipitation is highly variable both spatially and temporally. At decadal to annual scales, only a small proportion of this precipitation contributes to groundwater recharge. Techniques developed to estimate groundwater recharge under more humid climates are not always applicable. New, innovative and adapted methods are required to broaden currently available tools to quantify groundwater recharge in dryland environments. Modelling groundwater recharge in these often data-scarce regions is also challenging. Current large-scale hydrological models remain rooted in assumptions that are often unrelated to how groundwater recharge is observed to occur in drylands (e.g. the exclusion of focused recharge). Furthermore, it has often been assumed that with climate change drylands will get drier following the “wet gets wetter, dry gets drier” paradigm outlined in 5th Assessment Report of the IPCC. However, this assumption has been shown more recently to be much less certain; further, the intensification of precipitation under warming has been shown to influence the timing and magnitude of recharge in drylands. Improving our understanding of groundwater recharge - the sources and the hydrogeological processes, its spatial and temporal variability, its evolution under global change – still represents a major endeavour in hydrogeology and is critical to ensure sustainable management of water resources in drylands.
This Research Topic aims to bring together the latest advancements in understanding, measuring, monitoring, modelling and managing groundwater recharge in drylands and under global change. Areas to be covered in this Research Topic may include, but are not limited to:
• contributions to the understanding of groundwater recharge processes
• innovative techniques to measure and observe groundwater recharge
• new approaches to mapping and modelling of groundwater recharge
• observations and modelling of surface water and groundwater interactions
• observations and modelling of groundwater fluxes exchanged in the continuum formed by the atmosphere, the land surface, the unsaturated zone and the water table
• impact of climate change on groundwater recharge
• managing groundwater recharge
• managed artificial recharge
• analysis of recharge trajectories and adaptation to global changes
• relevant policies and adaptation strategies to changes in groundwater recharge