کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6334879 1620228 2015 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Hydrochemical variations of a tropical mountain river system in a rain shadow region of the southern Western Ghats, Kerala, India
ترجمه فارسی عنوان
تغییرات هیدرو شیمیایی یک سیستم رودخانه کوهستانی در یک منطقه سایه باران جنوب غربی غربی، کرالا، هند
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
چکیده انگلیسی
River water chemistry of Pambar River Basin (PRB), draining a rain shadow region of the southern Western Ghats, India, with granite gneiss and hornblende-biotite-gneiss lithology, was monitored for three sampling seasons, such as monsoon (MON), post-monsoon (POM) and pre-monsoon (PRM) to ascertain the spatio-temporal trends in hydrochemistry. In PRB, upstream and downstream areas have differing climate (i.e., tropical-wet-dry/humid upstream, while semi-arid downstream) and land use (plantations and farmland dominate the upstream, while pristine forest environment covers the downstream). The hydrochemical attributes, except pH and K+, exhibit distinct temporal variation mainly due to monsoon-driven climatic seasonality. Relative abundance of cations between upstream and downstream samples of PRB shows noticeable differences, in that the upstream samples follow the order of abundance: Ca2+ > Mg2+ > Na+ > K+, while the downstream samples are in the order: Na+ > Mg2+ > Ca2+ > K+. Ca2+ + Mg2+/Na+ + K+, Si/Na+ + K+, Cl−/Na+ and HCO3−/Ca2+ ratios suggest multiple sources/processes controlling hydrochemistry, e.g., atmospheric supply, silicate weathering, dissolution of carbonate minerals and soil evaporites as well as anthropogenic inputs (domestic and farm/plantation residues). Even though weathering of silicate and carbonate minerals is the major hydrochemical driver in both upstream and downstream portions of PRB, Gibbs diagram and scatter plot of Mg2+/Na+ vs. Mg2+/Ca2+ imply the importance of evaporation in the downstream hydrochemistry. Piper diagram and partial pressure of CO2 (pCO2) values suggest that a groundwater dominated discharge exerts a significant control on the downstream hydrochemistry, irrespective of sampling season. Although spatial variability of rainfall in PRB shows a linear downstream (decreasing) trend, the best-fit model for the dissolved load suggests that the downstream hydrochemical variability in PRB (i.e., an increasing trend) follows a power function (f(x)=axk). This study suggests that climate has a significant role in the spatio-temporal variability of hydrochemistry in PRB.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Geochemistry - Volume 63, December 2015, Pages 456-471
نویسندگان
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