Investigating the Effects of Agricultural Water Management in a Mediterranean Coastal Aquifer under Current and Projected Climate Conditions

Abstract

Coastal delta plains are areas with high agricultural potential for the Mediterranean region because of their high soil fertility, but they also constitute fragile systems in terms of water resources management because of the interaction of underlying aquifers with the sea. Such a case is the Pinios River delta plain located in central Greece, which also constitutes a significant ecosystem. Soil and Water Assessment Tool (SWAT) and SEAWAT models were combined in order to simulate the impact of current water resources management practices in main groundwater budget components and groundwater salinization of the shallow aquifer developed in the area. Moreover, potential climate change impact was investigated using climate data from Regional Climate Model for two projected periods (2021–2050 and 2071–2100) and two sea level rise scenarios (increase by 0.5 and 1 m). Modeling results are providing significant insight: although the contribution of the river to groundwater inflows is significant, direct groundwater recharge from precipitation was found to be higher, while capillary rise constitutes a major part of groundwater outflows from the aquifer. Moreover, during the simulation period, groundwater flow from the aquifer to the sea were found to be higher than the inflows of seawater to the aquifer. Regarding climate change impact assessment, the results indicate that the variability in groundwater recharge posed by the high variability of precipitation during the projected periods is increasing the aquifer’s deterioration potential of both its quantity and quality status, the latter expressed by the increased groundwater Cl− concentration. This evidence becomes more significant because of the limited groundwater storage capacity of the aquifer. Concerning sea level rise, it was found to be less significant in terms of groundwater salinization impact compared to the decrease in groundwater recharge and increase in crop water needs.

A Hydrogeological Conceptual Model Refines the Behavior of a Mediterranean Coastal Aquifer System: A Key to Sustainable Groundwater Management (Grombalia, NE Tunisia)

“…where R is the runoff in mm; P is the average annual precipitation in mm; and ETP is the average annual potential evapotranspiration calculated using the Thornthwaite method in mm. Finally, the effective infiltration (I eff ) was determined using Equation (6).…”

“…Indeed, Mediterranean coastal aquifers constitute important reservoirs widely used for domestic, agricultural, industrial, and tourist purposes [2]. However, degradation of water quality, climate variability, and population growth are limiting the availability of water in these regions [3][4][5][6][7]. This leads to an increase in the exploitation of groundwater resources.…”

Framework for Assessing Collective Irrigation Systems Resilience to Climate Change—The Maiorga Case Study

“…Its sources are under great pressure due to the rapid increase in population, its intensive use by agriculture, industry and tourism, pollution and increased water scarcity due to extreme climate variability [3,4]. The agriculture sector is the main freshwater consumer in the Mediterranean region, e.g., as described in [5,6]. The water demand by this sector will be exacerbated in the future, particularly in some areas where it is projected that water needs for irrigation will increase by 35% due to increased crop water demand [7][8][9].…”

A Participatory Approach to Exploring Nexus Challenges: A Case Study on the Pinios River Basin, Greece

“…Resolving natural resource scarcity, particularly in arid and semi-arid regions, including the Mediterranean region, constitutes a critical challenge for supporting human lives and improving well-being in the context of sustainable development [8][9][10]. These regions face common natural pressures, such as increasing temperature, decreasing precipitation, and spatiotemporal imbalances between natural resource supply and demand [11], apart from the management challenges related to stakeholders' involvement in the decision and policy making processes [12,13].…”