A QUANTITATIVE ASSESSMENT OF GROUNDWATER RESOURCES IN THE MIDDLE EAST AND NORTH AFRICA REGION

The Middle East and North Africa (MENA) region is by far the most water stressed region; with its countries constituting 15 of the 20 most water stressed nations worldwide. As a consequence of data paucity, comprehensive regional-scale assessments of groundwater resources in the MENA region have been lacking. The following study addresses this issue by using a distributed ArcGIS model, parametrized with gridded datasets, to estimate groundwater storage reserves in the region on the basis of generated saturated thickness and effective porosity estimates. Furthermore, monthly gravimetric data (GRACE) and land surface parameters (GLDAS) were used to quantify changes in groundwater storage between 2003 and 2014. Total groundwater reserves in the region were estimated at 1.28 million km³ with an uncertainty range between 816,000 and 1.93 million km³. The majority of the reserves were located within the large sedimentary basins of North Africa and the Arabian Peninsula; with Algeria, Libya, Egypt, and Saudi Arabia accounting for approximately 75% of the region’s total reserves. Alternatively low groundwater reserves were found in fractured Precambrian basement exposure. As for groundwater changes between 2003 and 2014, only 8 out of the 16 MENA countries (e.g. Algeria, Iraq, and Saudi Arabia) exhibited a decline in groundwater changes. Nonetheless, the great majority of the nations in the region exhibit a clear decline in groundwater trend that could signal potential future depletion, including in countries with a currently balanced groundwater budget. Given the large groundwater reserve estimates, groundwater changes between 2003 and 2014 are fractionally minimal and represent no immediate short-term threat to the MENA region.