Sustainability of Morocco’s groundwater resources in response to natural and anthropogenic forces

[Display omitted] •IMERG products could be used to complement rainfall gauges over Morocco.•Groundwater in northern and southern Morocco is currently being used sustainably.•50% of Moroccan basins are experiencing severe declines in groundwater levels.•A more comprehensive groundwater policy needs to be enforced in Morocco.•The developed approach could be applied to any hydrologic system across the globe. Morocco is blessed by a large reserve of freshwater resources that is being used in an unsustainable manner. In this study, we use a large suite of remote-sensing observations, land surface models, and field measurements to assess the sustainability of groundwater resources in Morocco and their responses to natural and anthropogenic interventions on both regional (entire Morocco) and local (watershed) scales. Results indicate the following: (1) Global Precipitation Measurement–derived monthly rainfall products (IMERG) could be used as alternatives and/or complements to rainfall gauges over Morocco, especially in areas with lower elevations and temperate climates; IMERG overestimates rainfall rates in higher elevation areas with temperate climate and underestimates rainfall rates in arid and semiarid climates, compared to rain gauges. (2) During the past 18 years (April 2002–April 2020), no significant variabilities were observed in terrestrial water storage or groundwater storage over northern or southern Morocco as a whole; groundwater in both regions is currently being used in a sustainable manner. (3) The groundwater levels in five Moroccan basins are declining (range: −13.32 to −145.8 cm/yr), one shows near-steady-state conditions, and two show increases in groundwater levels (range: +11.32 to + 29.88 cm/yr); these trends are controlled mainly by groundwater extraction rates and rainfall variability. Our results signal an urgent need to enforce a more comprehensive groundwater policy that promotes sustainable use plans for surface and groundwater resources throughout Morocco. Our approach could be applied to develop sustainable use scenarios for groundwater resources in any hydrologic system across the globe.