12. Analysis of a Joint Impact of Climate Change and Anthropogenic Interventions on Groundwater Depletion in Arid and Semi-Arid Areas

Availability of groundwater has been largely impacted by climate change worldwide, especially in arid and semi-arid areas where water is limited. In arid and semi-arid areas, which are heavily rely on groundwater to meet their water demands, there is a high risk of excessive use of groundwater, particularly during successive dry periods. This paper aimed at assessing changes in groundwater levels due to seasonal and annual variations in precipitation when storage of groundwater aquifers is largely depending on the amount of precipitation. Erbil province in Iraq was chosen as a representative example for many arid and semi-arid areas that suffering from overexploitation use of groundwater resources. Climate change has contributed to increase the pressure and stress on the availability of groundwater and increases environmental concerns. In this work, the long-term falling of groundwater levels is also examined. Monthly records of groundwater level between January 2004 and January 2016 observed at 54 observation wells in Erbil were assessed. Findings revealed that nearly 91% of the observation wells are associated with a drop in groundwater level, the remaining 9% were linked to steady or slight rising in groundwater level. Approximately 50% of those linked to a fall in groundwater level is associated with a significant drop (> 1.73 m/year), and 24% are linked to moderate drops (0.58 m/year ≤ drop ≤ 1.73 m/year), whereas the remaining 26% relate to low falls (< 0.58 m/year) in groundwater level. The slopes of groundwater level fall between 0.005 and 0.32, with a mean of 0.11. The outcomes of this study would support the decision makers and water managers to sustainably manage groundwater in the study area and other similar areas. Moreover, the study represents an important step towards launching nation-wide groundwater assessment programmes to achieve sustainable abstraction and rational utilization and management of groundwater resources.