Quantifying Anthropogenic Stress on Groundwater Resources

Abstract

This study explores a general framework for quantifying anthropogenic influences on groundwater budget based on normalized human outflow (hout) and inflow (hin). The framework is useful for sustainability assessment of groundwater systems and allows investigating the effects of different human water abstraction scenarios on the overall aquifer regime (e.g., depleted, natural flow-dominated, and human flow-dominated). We apply this approach to selected regions in the USA, Germany and Iran to evaluate the current aquifer regime. We subsequently present two scenarios of changes in human water withdrawals and return flow to the system (individually and combined). Results show that approximately one-third of the selected aquifers in the USA, and half of the selected aquifers in Iran are dominated by human activities, while the selected aquifers in Germany are natural flow-dominated. The scenario analysis results also show that reduced human withdrawals could help with regime change in some aquifers. For instance, in two of the selected USA aquifers, a decrease in anthropogenic influences by ~20% may change the condition of depleted regime to natural flow-dominated regime. We specifically highlight a trending threat to the sustainability of groundwater in northwest Iran and California, and the need for more careful assessment and monitoring practices as well as strict regulations to mitigate the negative impacts of groundwater overexploitation.

The Groundwater‒Energy‒Food Nexus in Iran’s Agricultural Sector: Implications for Water Security

“…Land management is an effective adaptation strategy to mitigate groundwater depletion in arid and semi-arid areas where profit margins of agricultural production are affected by energy costs or concerns about groundwater sustainability and deteriorating groundwater quality [41]. As groundwater tables decline due to the increasing stress on Iran's groundwater resources [42,43], the energy cost of lifting deeper groundwater should normally increase as a balancing feedback to prevent groundwater depletion. Heavily subsidized, cheap agricultural electric energy essentially removes the negative feedback signal, allowing agronomic crop production to continue to the point that the sustainability of the country's groundwater resources is severely compromised.…”

A Review of the 21st Century Challenges in the Food-Energy-Water Security in the Middle East

“…Groundwater depletion is of high concern in the Middle East especially in the Gulf countries where groundwater has over-exploited for irrigation and agricultural purposes [55]. Extreme pressure on the already scarce groundwater resources in the GCC countries has occurred as a consequence of rapid population growth, urbanization, industrialization, and agricultural production since the 1970s [21,56]. Therefore, currently the Gulf countries are mainly relying on the Nematollahi et al [28] assessed the prospective of solar and wind energy sources in the Middle East.…”

More prolonged droughts by the end of the century in the Middle East

“…As the world's second fastest growing population after sub-Saharan Africa, the population in the Middle East region is projected to double by 2050 (Roudi-Fahimi and Kent 2007), leading to a fall in per capita water availability by half. This projected decrease in water availability will affect the society whose economy highly depends on agriculture (Ashraf et al 2017).…”