Climate Variability and Land-Use Dynamics: Implications for Groundwater Recharge in the Motril–Salobreña Coastal Aquifer (MSCA), Spain

Climate and land-use change significantly impact the hydrological cycle and water resources. Accordingly, assessing groundwater recharge under varying climatic conditions and land use/land cover (LULC) is crucial for effective integrated water resource management and the development of robust adaptation strategies. Such evaluations are indispensable for the sustainable management of water systems, supporting the long-term resilience of both human and ecological water demands. Therefore, this research work emphasizes the influence of climate change and land-use dynamics on groundwater recharge of the Motril Salobreña coastal aquifer over the period 1980–2020, using a hydrological model, the WetSpass model. Four scenarios were used in the present study. Scenarios 1 and 2 examine the influence of climate variability, while Scenarios 3 and 4 analyze the impact of land-use/land-cover (LULC) change on the groundwater recharge.

The climate results of the study area indicated a decrease in precipitation of approximately 2% and an increase in temperature of 2%, and evapotranspiration of 4% from 1980–2000 period to 2001–2020 period. Land-use/cover results showed that the agriculture and orchard were the dominant land-use types in 2000 and 2020. Agriculture land decreased 15% from 2000 to 2020. Conversely, the building zone and orchard land increased 10% and 3%, respectively. Because of all these environmental changes, the amount of the groundwater recharge varied in the study area, where the annual average groundwater recharge was approximately 212, 197, 206 and 174 mm in scenarios 1, 2, 3 and 4, respectively.

In conclusion, the findings of this study indicate that annual groundwater recharge in the study area during the 1980–2020 period decreased by approximately 7% due to climate variability and by around 16% as a result of land use/land cover (LULC) change. In addition, the study results shown that recharge from irrigation is much more important than that from precipitation, leading to an error of approximately 67% if it is overlooked. This comprehensive analysis is vital for sustainable water resource management in the study area.