Introduction
Description of the study area
Precipitation
Aquifer system
Groundwater abstraction
Springs
Model development and implementation
Conceptual flow model
3D structural model
GIS data
Triangulations and prisms
Mapping
3D groundwater flow model
Governing equations
Boundary conditions
Source/sink terms
Hydrogeological parameters
Formations | Hydrogeological unit | Hydraulic conductivity (ms−1) | Specific storage |
---|---|---|---|
Amman al Hisa | Aquifer | 2.0 × 10−6
| 1.0 × 10−3
|
Wadi Um Ghudran | Aquifer | 2.0 × 10−6
| 1.0 × 10−3
|
Wadi as Sir | Aquifer | 2.0 × 10−6
| 1.0 × 10−3
|
Shueib | Aquitard | 1.0 × 10−9
| 1.0 × 10−3
|
Hummar | Aquifer | 2.0 × 10−5
| 1.0 × 10−3
|
Fuheis | Aquitard | 1.0 × 10−9
| 1.0 × 10−3
|
Na’ur | Aquitard/Aquifer | 1.0 × 10−5
| 1.0 × 10−3
|
Kurnub Group | Aquifer | 3.0 × 10−5
| 1.0 × 10−3
|
Results and discussions
The steady state model
The transient model
Conclusions and outlook
Achievements
-
A numerical modelling methodology was developed which can handle arbitrary hydrogeological structures such as eroded Wadies or outcropping aquifers. The basis of the complex geometric modelling is an object-oriented finite element (FE) concept which allows arbitrary combinations of finite element types in order to achieve the best possible geometric representation of the hydrogeological system. Moreover, hydrological features such as the Wadi channels are included into the FE discretization. This concept is beyond the layered approach of many groundwater models.
-
The infiltration model is based on the EDK method which includes local topographical information into the data interpolation. Moreover, the finite element discretisation (see above) capturing the Wadi channels allows to include specific infiltration situations (e.g. flash floods). Regardless the assumptions (see "Deficiencies"), the infiltration model is fed by long-term data (more than 13 years).
-
Due to a large number of assumptions, the groundwater model cannot be regarded as a validated. The groundwater model, however, passed a first “validation” test. Based on the long-term calibration of the groundwater model using the data from observation well #1, the trend of groundwater level in observation well #3 could be modeled. This can serve as a first validation step as observation well #1 is in the downstream area close to the south-west catchment boundary whereas observation well #3 is in the central part of the Wadi Kafrein catchment.
Deficiencies
-
The model cannot be considered as a validated groundwater model but it provides a basis for further data integration and model validation. In particular, the recharge mechanism in the Wadi Kafrein area is not completely understood so far, e.g.: Is the catchment domain properly designed? Do we have to take additional in-outflows into account? There is only a poor correlation between temporal recharge pattern and groundwater level. Concerning the groundwater recharge, the assumption was made that 20% of the precipitation are infiltrated.
-
More data, e.g. from local authorities etc., such as return flows from irrigation, should be included into the model to make it more valuable for the purpose of water resources management in this area. This data acquisition needs a close cooperation with the local authorities which should be aimed at in the next project phase SMART-II.