Impact of climate change on groundwater resources in Jordan: a case study of Amman Zarqa basin

Climate change has added new challenges to water resource management in Jordan. Climatic change was determined for 27 climatic indicators using Climdex software. In addition, the Statistical Downscaling Model software (SDSM) based on three emissions scenarios (RCP 2.6, RCP 4.5, and RCP 8.5) was used to obtain future predictions related to rainfall rates, humidity, and minimum and maximum temperatures. For the groundwater system, MODFLOW was used for groundwater modeling in the study area. The results of Rclimdex analysis showed decreasing trends in precipitation indices during the study period, with a decrease of 0.048/year in the simple daily intensity index (SDII) and a decrease of 0.299/year in the annual count of days with PRCP ≥ 10 mm (R10mm). The results also showed a decrease in the extremely wet days index (R99p) with a slope of 1.458/year. The results of SDSM suggest a possible decrease in annual precipitation in 2070 compared to 2020 by approximately 34%, 22% and 12% for RCP 8.5, RCP 4.5 and RCP 2.6, respectively. The simulation results showed that the groundwater levels in the study area could drop dramatically at rates of more than 1 m/year, 0.7m/year, and 0.45m/year for RCP 8.5, RCP 4.5 and RCP 2.6, respectively.