IWRA Proceedings

An assessment was performed to evaluate climate change impacts on groundwater resource availability and use in Morocco, specifically groundwater abstraction from the Tadla aquifer complex system that supplies domestic water as well as large irrigation schemes in the Beni Amir agricultural area. The pilot study was based on projections of the Regional Initiative for the Assessment of Climate Change Impacts on Water Resources and Socio-Economic Vulnerability in the Arab Region (RICCAR) which has shown that the Arab region will experience rising temperature and largely decreasing precipitation, as well as changes in runoff and recharge.

A three-dimensional conceptual groundwater model was designed and simulated a comprehensive set of physical processes and was compared, calibrated and verified with observations. Anthropogenic and climate forcing based on two scenarios, RCP 4.5 and RCP 8.5, were implemented in order to project impacts of climate change on the groundwater system and long-term impacts on water and crops.
The main results from this study confirm that groundwater resources in the Tadla aquifer system will be affected by climate change due to a reduction in natural recharge from reduced precipitation (the mean will be 20% less at the end of the century for RCP 4.5; and 50% less for RCP 8.5) and the increase in evapotranspiration caused in part by higher temperatures (the mean is about 2°C increase for RCP 4.5 and more than 4°C increase for RCP 8.5 at the end of the century). This is evident in a reduction of the water balance accompanied by a groundwater table decline for both scenarios varying from 10m for RCP 4.5 to more than 25m for RCP 8.5 which makes some aquifer areas completely dry.

These results are of great importance as key information for decision-makers regarding the future of the sustainable exploitation of groundwater resources in the aquifer. Indeed, the results of the RCP 8.5 scenario present a great concern for the future of irrigation agriculture in the study area since some farms would be abandoned due to the unavailability of groundwater. On the other hand, the results of the RCP 4.5 scenario are less severe but will require rational and economical management of water resources.
Adaptation measures that account for these impacts of climate change on groundwater resources specifically in improving productivity in the agriculture sector are urgently needed.