Authors:
Jihad S. Al Mahamid;
Abstract:
Mathematical models and GIS are good tools to study, evaluate and manage groundwater resources in a sustainable way. Groundwater flow model was setup to conceptualize the understanding of groundwater
resources in Jafer basin (South of Jordan), in order to simulate the current groundwater system and provide predictive scenarios to better manage water resources. The specific objectives of this study are to: develop a three-dimensional groundwater flow model for Jafer basin using MODFLOW code for the Upper Cretaceous Aquifer System, determine the sustainability for Jafer basin, investigate different scenarios of groundwater management of Jafer basin including variation of abstraction and determine the effects of increasing natural
recharge by adding 3 recharge dams.
Ten predictive scenarios were conducted in this study. Scenarios 1 to 3 are similar and indicate that regional drawdown at Al-Muhammadiyah Well-field will be greater than 110 m by 2040. Dynamic well losses may
increase the actual well drawdown higher than 150 m. Scenario 6 indicates that small amounts of artificial recharge will not lessen the drawdown at Al-Muhammadiyah Well-field. Scenarios 7, 8,9 and 10 indicate that lowering the abstraction at Eshidiya and Al-Muhammadiyah Well-fields will not decrease the overall drawdown by 2040.Scenarios 4 and 5, increasing annual abstraction by 1.5 and 2 times, will be unsustainable.
It is highly recommended that the current levels of abstraction from Al-Muhammadiyah Well-field are not sustainable. Continuation of agricultural activities in Jafer basin for the long term at current or elevated abstraction levels would require an alternative water source, such as accessing the deep sandstone aquifer. Thus, mathematical modeling (groundwater flow model) is an effective tool and technique in Jordan to understand and exploit groundwater resources in a sustainable way.
Keywords:
Groundwater, Mathematical modeling, Jafer basin, Calibration, Steady state, Sensitivity analysis, Water budget