Environmental Geophysics Division, National Geophysical Research Institute, (Council of Scientific and Industrial Research), Uppal Road, Hyderabad 500 606, India.
Environ Monit Assess. 2011 Jun;177(1-4):315-35. doi: 10.1007/s10661-010-1636-8. Epub 2010 Aug 17.
The impact of seawater intrusion was investigated using major hydrogeochemical ions to evaluate the origin of salinity in Sadras watershed located between Buckingham Canal and Bay of Bengal in the southeastern coast of India. From empirical data collected twice during pre- and post-monsoon seasons, it was found that groundwater was slightly acidic to mildly alkaline, and more than 44% of groundwater samples had EC > 3,000 μS/cm in both the seasons. Results of principle component analysis (PCA) showed that Na( + ), Cl( - ), Mg(2 + ), and SO[Formula: see text] concentrations had the highest loading factor and the samples affected by saline/seawater were separated from the cluster. Hydrochemical processes that accompany the saline/seawater were identified using ionic changes. It was observed during sampling periods that the mixing due to saline/seawater intrusion varied from 4.82-7.86%. Negative values of ionic change (e (change)) for Na( + ) and K( + ) decreased with the increasing fraction of seawater. Furthermore, salinity, sodium adsorption ratio, percentage of sodium Na (%), and exchangeable sodium percentage in well samples showed that groundwater was unsuitable for irrigation purposes.
利用主要的水文地球化学离子研究了海水入侵的影响，以评估位于印度东南部孟加拉湾和 Buckingham 运河之间的 Sadras 流域盐分的来源。从旱季和雨季两次收集的经验数据中发现，地下水呈弱酸性至弱碱性，两个季节中超过 44%的地下水样本的 EC 值>3,000 μS/cm。主成分分析（PCA）的结果表明，Na( + )、Cl( - )、Mg(2 + )和 SO[Formula: see text]浓度具有最高的加载因子，受咸水/海水影响的样本与聚类分离。利用离子变化确定了伴随咸水/海水的水化学过程。在采样期间观察到，由于海水入侵引起的混合变化范围为 4.82-7.86%。Na( + )和 K( + )的离子变化（e (change)）的负值随海水比例的增加而减小。此外，井样中的盐分、钠吸附比、钠百分比 Na (%)和可交换钠百分比表明地下水不适用于灌溉用途。
