Evaluation of spatial and temporal dynamics of seawater intrusion in coastal aquifers of southeast India: insights from hydrochemical facies analysis.

Autor: Moorthy P; Centre for Disaster Management and Coastal Research, Department of Remote Sensing, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 023, India., Sundaramoorthy S; Centre for Disaster Management and Coastal Research, Department of Remote Sensing, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 023, India., Roy PD; Instituto de Geología, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510, Mexico City, CP, Mexico., Usha T; National Centre for Coastal Research, Ministry of Earth Sciences, Government of India, Chennai, 600100, India., Dash SK; National Centre for Coastal Research, Ministry of Earth Sciences, Government of India, Chennai, 600100, India., Gowrappan M; French Institute of Pondicherry, Puducherry, 605001, India., Chokklingam L; Centre for Disaster Management and Coastal Research, Department of Remote Sensing, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 023, India. drlaks@bdu.ac.in.
Jazyk: angličtina
Zdroj: Environmental monitoring and assessment [Environ Monit Assess] 2024 Jan 20; Vol. 196 (2), pp. 179. Date of Electronic Publication: 2024 Jan 20.
DOI: 10.1007/s10661-024-12306-w
Abstrakt: This study aims to investigate and understand the temporal and spatial movement of seawater intrusion into the coastal aquifers. Groundwater salinity increase has affected the entire eastern part of the study area and is primarily influenced by direct and reverse ion exchange reactions associated with intrusion and freshwater influx phases, which alternate over monsoons. To gain insights into the spatiotemporal dynamics of the seawater intrusion process, hydrochemical facies analysis utilizing the HFE-Diagram was employed. Additionally, the study considered the major ionic changes during both the monsoons. The HFE-Diagram analysis of hydrochemical facies revealed distinctions in the behaviour of each coastal aquifer concerning seawater intrusion-induced salinization. In PRM 2020, the data shows that approximately 65% of the samples fall under the freshening phase, while the remaining 35% were categorized as intrusion phase. Within the freshening phase, seven different hydrochemical facies were identified, including Na-Cl, Na-MixCl, MixNa-MixCl, Na-MixHCO 3 /MixSO 4 , MixNa-MixSO 4 , Na-HCO 3 , and MixCa-HCO 3 . In contrast, the intrusion phase had four facies: MixCaMixHCO 3 , MixNa-Cl, Ca-Cl, and Na-Cl. Especially, the Na-Cl facies (f 1 ) within the freshening phase attributed for the largest percentage, contributing 30% of the samples. In POM 2021, the distribution of samples shifted slightly, with approximately 72.5% belonging to the freshening phase and 27.5% to the intrusion phase. Within the freshening phase of POM 2021, five hydrochemical facies were identified: Na-Cl, Na-MixCl, Na-MixHCO 3 /MixSO 4 , MixNa-MixSO 4 , and Na-HCO 3 . The intrusion phase of POM 2021 had three facies: MixNa-Cl, Na-Cl, and MixCa-Cl. Similar to PRM 2020, the Na-Cl facies (f 1 ) remained the most predominant in the freshening phase, comprising 30% of the samples. The relation between total dissolved solids (TDS) and various ionic ratios, such as HCO 3 - /Cl - , Na + /Cl - , Ca 2+ /Cl - , Mg 2+ /Cl - , K + /Cl - , and SO 4 2- /Cl - , clearly demonstrates the presence of seawater influence within the coastal aquifers of the study area.
(© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)
Databáze: MEDLINE
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