Identifying the deep groundwater recharge processes in an intermountain basin using the hydrogeochemical and water isotope characteristics
Identifying the deep groundwater recharge processes in an intermountain basin using the hydrogeochemical and water isotope characteristics
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DOI：
10.2166/nh.2019.164
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发表时间：
2019-10
影响因子：
2.7
通讯作者：
B. Shakya;Takashi Nakamura;S. Shrestha;K. Nishida
中科院分区：
文献类型：
--
作者：
B. Shakya;Takashi Nakamura;S. Shrestha;K. Nishida
合并了水的水（ΔD和δ18O）的水型地球化学和稳定的同位素，以研究地质上复杂的地下水层中的深下水补助过程（Kathmandu山谷）（KATHMANDU山谷）（Kathmandu valley）（与全球水线的深层水线相比，分析表明深下在较高的降雨期（潮湿季节）中，在深层地下水中缺乏季节性变化，而在春季水样本中，同位素组成的分布范围很大水类型发现盆地与其他基础知识相比，在中央部分中，由于离子交换过程，样品的离子浓度高于外围。
The hydrogeochemical and stable isotopes of water (δD and δ18O) were combined to investigate the deep groundwater recharge processes in the geologically complex intermountain basin (Kathmandu Valley). Results of the stable isotopic composition of the deep groundwater compared with global and local meteoric water lines and d-excess showed the deep groundwater as a meteoric water origin which is insignificantly affected by evaporation. The analysis suggests the deep groundwater was recharged during high rainfall periods (wet season). Additionally, the control of seasonal variation was absent in the deep groundwater and in the spring water samples. The large range of isotopic composition distribution was due to the altitude affect, whereas variations are from the various geological settings of the infiltration encountered during the recharge processes. The tri-linear diagram showed Na-K-HCO3 and Ca-Mg-HCO3 as the two major water types. The distribution of water types in this intermountain basin was found to be unique compared to other basins. Ionic concentration of the samples was found to be higher in the central part than in the periphery due to the ion exchange processes. This study determines the spatial distribution of various recharge processes that depends upon the environment during rainfall and the geological settings.