Author(s): N. Kazakis
Linked Author(s):
Keywords:
Abstract: Groundwater is a primary source of drinking water for almost two billion people worldw ide (Gleeson et al., 2010). Moreover, it is critically important for energy, food security, human health and ecosystems (Gleeson et al., 2015). Yet, depletion of groundwater reserves is a common phenomenon in both humid and semi-arid regions of the world. Although non-sustainable groundwater exploitation has been documented on both regional and global scales (Gleeson et al., 2012), specific spatiotemporal characteristics need to be further studied and quantified. The phenomenon of groundwater depletion occurs when extraction from an aquifer exceeds the recharge, with the extent of the depletion effects being also determined by the aquifer type. A number of research challenges prevail, the most significant being the quantification of factors triggering groundwater depletion. Inevitably, depletion leads to increased pumping costs and the reduction of groundwater discharge to streams, springs and wetlands affecting ecosystems (Sophocleous, 2000). Additionally, lowered water tables induce groundwater flow, which can lead to salinization by seawater intrusion in coastal aquifers (Konikow and Kendy, 2005). Eventually, groundwater depletion can even lead to dry wells. The main cause of groundwater depletion is the excessive extraction for irrigation especially in cases where an aquifer is only replenished in a slow manner, while climate change could potentially exacerbate the phenomenon in some regions (Weider and Boutt, 2010). Global food production has increased dramatically since 1970 due to advances in well-drilling equipment and electrical pumping, and a large number of wells has been operated in a largely unregulated manner, often replacing surfacewater resources. Accordingly, in some areas, groundwater levels have declined at rates even exceeding 1 m per year. On the other hand, climate-related changes might also influence recharge rates and aggravate groundwater depletion as recharge rates are influenced by the distribution and seasonality of snow coverage as well as drought events. Within this study a detailed analysis of hydrogeological, hydrological and climatological data was obtained in order to quantify groundwater depletion develop a software to optimize hydropower generation and managed aquifer recharge.
Year: 2022