Origin and age of coastal groundwaters in Northern Oman
Clark, I.D.; Ravenscroft, P.; Fritz, P. (1989). Origin and age of coastal groundwaters in Northern Oman. Natuurwet. Tijdschr. 70(1-4): 75-84
In: Natuurwetenschappelijk Tijdschrift. L. Walschot/Natuur- en Geneeskundige Vennootschap: Gent. ISSN 0770-1748, more
Also appears in:De Breuck, W.; Walschot, L. (Ed.) (1989). Proceedings of the 10th Salt-Water Intrusion Meeting Ghent (Belgium), 16-20 May 1988. Natuurwetenschappelijk Tijdschrift, 70(1-4). Natuurwetenschappelijk Tijdschrift: Gent. 408 pp., more
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| Authors | | Top |
- Clark, I.D.
- Ravenscroft, P.
- Fritz, P.
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| Abstract |
The coastal plain of northern Oman, bounded by the Gulf of Oman to the northeast and the Northern Oman Mountains to the southwest, is the most intensively cultivated area in the Sultanate. Heavy extraction from the alluvial aquifers for irrigation is linked to recent saline intrusion and groundwater deterioration. The origïns and mean circulation times of coastal groundwaters are investigated to better understand the mechanisms and frequency of recharge of coastal aquifers. Stable isotopes ( 180 and 2H) show that localized convective rainfall in the mountains and piedmont during hot months, identified by a characteristic evaporative enrichment, dominates recharge to shallow coastal groundwaters. The less frequent but larger depression-rainfall systems of winter months, which show no isotope enrichment, is evident only in the deeper confined aquifers, recharged at higher elevations. Mean circulation times, evaluated on the basis of tritium and 14C data, are less than about 5 years for shallow alluvial groundwaters associated with the active runoff network. In interfluvial areas they may be some tens to hundreds of years. Deep confined groundwaters are in the order of several thousands of years. Saline intrusion is occurring in both the shallow and deep coastal groundwaters. Possible mixing with an older connate brine is identified in the deeper coastal zone of one area, which may exacerbate groundwater deterioration. |
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