Senarathne SL, Barth J, van Geldern R, Chandrajith R (2024)
Publication Type: Journal article
Publication year: 2024
Book Volume: 25
Article Number: 101175
DOI: 10.1016/j.gsd.2024.101175
We present a preliminary investigation of geological, climatic and anthropogenic influences on groundwater geochemistry in Sri Lanka. This spatially confined island of about 65,000 km2 offers excellent boundary conditions for such an overview because it can be separated into two major geological and three climatic domains. Summary parameters, including electrical conductivity (EC) and total hardness (TH), were chosen as best proxies because they belong to the most frequently measured parameters of this data set. Groundwater quality data are presented from a total of 1318 groundwater samples. They were grouped into selected geo-climatic domains. Groundwater in the dry zone showed higher median EC and TH values (740 μS cm−1 and 199 mg L−1) when compared to the intermediate (400 μS cm−1 and 120 mg L−1) and wet zones (146 μScm−1 and 53 mg L−1). The sedimentary terrain of the county could be characterized by the highest median EC and TH values (1006 μS cm−1 and 261 mg L−1). In the metamorphic terrain that covers over 90% of the island, EC and TH values showed the strongest spatial variations that likely depend on climatic conditions. A correlation between EC and TH correlated with an r of +0.70. This trend suggests that EC can also serve as a robust indirect indicator of groundwater TH. Excessive evaporation, seawater intrusion and agricultural return flows affect groundwater quality, mostly in coastal regions, where freshwater demand increases. Sustainable groundwater management demands continuous and comprehensive monitoring of spatial and temporal fluctuations of groundwater. We also propose managed aquifer recharge to protect the long-term sustainability of groundwater in both sedimentary and metamorphic domains. This becomes particularly important under projected climate change scenarios in which drier regions in the country are expected to expand.
APA:
Senarathne, S.L., Barth, J., van Geldern, R., & Chandrajith, R. (2024). Litho-climatic influences on groundwater geochemistry in Sri Lanka. Groundwater for Sustainable Development, 25. https://doi.org/10.1016/j.gsd.2024.101175
MLA:
Senarathne, Sachintha Lakshan, et al. "Litho-climatic influences on groundwater geochemistry in Sri Lanka." Groundwater for Sustainable Development 25 (2024).
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