Modelling saline water upconing in inland saline aquifers
Aliewi, A.S.; Mackay, R. (1999). Modelling saline water upconing in inland saline aquifers. Natuurwet. Tijdschr. 79(1-4): 7-16
In: Natuurwetenschappelijk Tijdschrift. L. Walschot/Natuur- en Geneeskundige Vennootschap: Gent. ISSN 0770-1748, meer
Ook verschenen in:De Breuck, W.; Walschot, L. (Ed.) (1999). Proceedings of the 15th Salt-Water Intrusion Meeting Ghent (Belgium), 25-29 May 1998. Natuurwetenschappelijk Tijdschrift, 79(1-4). Natuurwetenschappelijk Tijdschrift: Gent. 307 pp., meer
|  |
| Trefwoorden |
Modelling
Water > Ground water
Water > Saline water
Israel, Jordan R.; Pakistan [Marine Regions]
|
| Abstract |
Fresh-groundwater lenses overlying saline water in groundwater systems are a vital water resource where other surface and subsurface resources of water are not sufficient. The objective of this study is to describe the behaviour of saline water upconing when extracting the maximum amount of fresh water from inland saline aquifers whilst preventing the mixing of bath fresh and saline waters. Two inland saline aquifers with different lithology were taken as case studies; the first is the Indus Plain in Pakistan and the second is the Pleistocene Aquifer in the Jordan Rift Valley of Palestine. A finite-difference simulation model (RASIM) that couples density-dependent fluid flow and solute transport in a multilayer confined/phreatic aquifer system with isotropic/anisotropic properties was used. The numerical-simulation results of saline upconing under bath scavenger and skimming wells show that the steady-state transition zone is asymmetric around the 0.5 isochlor. The location of the well screen and whether it is installed as one or more sections control the narrowing/widening mechanisms in the transition zone. The upconing mechanism seems to continue until saline water enters the well screen even when the pumping rate is reduced. The recovery ratio of fresh water to saline water is improved if the well screen is located in the upper part of the aquifer. It is shown in this study that high vertical velocities exist in the area immediately below the well screen, which results in more dispersion in this zone, resulting in a wider transition zone. |
|
