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标题：CHEMICAL AND ISOTOPIC COMPOSITION OF RAINWATER IN COASTAL AND HIGHLAND REGIONS IN LEBANON
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作者：Zeinab Saad ; Véronique KazpardAntoine G. El SamraniKamal Slim
期刊名称：Journal of Environmental Hydrology (ältere Jahrgänge)
印刷版ISSN：1058-3912
电子版ISSN：1996-7918
出版年度：2005
卷号：13
出版社：IAEH
摘要：Rainwater samples were collected from six stations at coastal and highland regions in Lebanon and analyzed for the major species Ca²⁺ , K⁺, Na⁺, Mg²⁺, NO^3-, NH₄⁺, pH, Cl^-, and SO₄^2-. Absolute concentrations and element-to-sodium ratios show clear variations with higher levels found in coastal stations and lower levels found in continental sites for most of the species. Levels of major species from coastal areas can be twice as high as those of the highlands, in terms of both absolute concentration and element-to-sodium ratio. The contrast between low and high altitudes can be explained by proximity to the Mediterranean Sea and local agricultural pollution sources. Isotopic composition of rainwater in coastal sites presents high values of d ¹⁸O and d D, whereas rainwater in continental areas is characterized by low values of d ¹⁸O and d D. The altitude effect influences the isotopic fractionation in precipitation, including depletion in both d ¹⁸O and d D, especially in stations at high elevation. The Lebanese Meteoric Water Line was defined as d D = 7.13 d ¹⁸O + 15.98. This relation is close to the Regional Meteoric Water Line in the eastern Mediterranean with a lower d-excess indicating a relatively less pronounced secondary evaporation effect in Lebanon. From a series of ³H data of monthly precipitation from six stations within the small country of Lebanon, we concluded that between the stations there are no significant differences in altitude effect. However, a small continental effect is apparent at the Baalbak station.