Original Research Article
Chakrit Chatree Lampoon
Abstract
Pumping of 82 MCM/yr from Mujib basin (Eastern Dead Sea), coupled with the 54 MCM/yr recharge rate, has led to diminished groundwater levels and dramatically affects ecosystem services. Climate change compounds these issues by reducing recharge and increasing the ecosystem’s hydrological demand. This paper investigates groundwater resilience to climatic changes in Mujib basin by modeling resilience for the years 2014 and 2050. Resilience of groundwater was modeled to long term changes as “low” in the central parts of the study area due to low saturated thickness and high pumping rates. Resilience was modeled as “high” to “very high” in areas with high saturated thickness and higher replenishment rates. Water budget components were modeled through the J2000 hydrological model; giving a groundwater recharge of 54 MCM/yr. Statistical downscaling of global circulation models indicated a 21% decline in precipitation by the year 2080 with 2 and 3° increases in maximum and minimum temperature respectively. Recharge for the year 2050 was recalculated based on the d ownscaling and prediction results to be 30% less than current recharge. Continuous over-pumping with recharge reduction will cause a 30–70% reduction in saturated thickness by the same year. Modeling groundwater resilience under the new conditions showed a severe impact on the study area especially the central parts which are expected to comprise a semi dry aquifer by 2050.