Evaluation of the Intrusion Extent of Maharlu Lake Saline Water into the Maharlu Coastal Aquifer Using Hydrochemical Parameters

Document Type : Research

Authors

1 Research Assistant, Central Laboratory, Shiraz University, Shiraz, Iran

2 School of Civil and Environmental Engineering, Shiraz University, Shiraz, Iran

3 Department of Earth Sciences, Shiraz University, Shiraz, Iran

Abstract

The management of freshwater resources in the coastal aquifers of salt lakes requires understanding the dynamics of the flow system, geochemical evolution, etc. The salinity of coastal aquifers is mainly due to direct saltwater intrusion, or is associated with complex geochemical interaction of lake and Ground water. The purpose of this study is to investigate the extent of intrusion and entry of saline water of Maharlu Lake into the coastal aquifer of the Maharlu aquifer, employing hydrochemical parameters and delineating the chemical evolution of its groundwater. The information used in this study includes the water level fluctuations and spatial, depth, and temporal changes in water salinity, and the chemical composition of the aquifer groundwater. For this purpose, several methods including water table maps and salinity changes, diagram of hydrochemical evolution of water, Stiff diagram, and chloride to bromide ions ratio have been used. According to the results obtained in the whole study period (February 1997 to February 1998), the water table elevation of a large area of the aquifer is lower than the elevation of the lake floor and, therefore, the Lake saline water flows into the aquifer under the reverse hydraulic gradient. Hence, in addition to the normal phenomenon of saline water intrusion, which occurs due to density gradients, aquifer salinization is also strongly influenced by the entry of saline water under the influence of hydraulic gradients. Based on the results of this study, the aquifer in terms of salinity and the effect of the Lake water on its salinity is subdivided into three zones, including; an area that starts from the lake margin up to a maximum distance of 1000 meters, which is completely affected by the entry of saline lake water, an area starts from 1000 meters to about 1500 meters as a middle area affected by both phenomena and the area from 1500 meters to about 2200 meters, located in the foothills of the southern karst boundary,  the alluvial feeding area of the aquifer, which it's water quality is relatively suitable for agriculture.

Keywords

References

Andersen MS, Nyvang V, Jakobsen R, Postma D. 2005. Geochemical processes and solute transport at the seawater/freshwater interface of a sandy aquifer. Geochimica et Cosmochimica Acta. 69(16): 3979–3994.
Appelo CAJ, Postma D. 2005. Geochemistry, groundwater and pollution, 2nd Edition, Balkema, Rotterdam. 673 p.
Barlow PM, Reichard EG. 2010. Saltwater intrusion in coastal regions of North America. Hydrogeology Journal, 18(1): 247–260.
Davis SN, DeWiest RJM. 1966. Hydrogeology. John Wiley and Sons, New York, 463 p.
Ghader F. 2009. Investigating changes in salinity relative to the depth to determine the boundary between saltwater and fresh water in a coastal aquifer located on the northwest margin of Maharlu Lake. M.Sc. Thesis, Shiraz University.
Ghiglieri G, Carletti A, Pittalis D. 2012. Analysis of salinization processes in the coastal carbonate aquifer of Porto Torres (NW Sardinia, Italy). Journal of Hydrology. 432(1): 43–51.
Giménez-Forcada E. 2010. Dynamic of seawater interface using hydrochemical Facieses evolution diagram. Ground Water, 48(2): 212–216.
Giménez-Forcada E. 2019. Use of the hydrochemical facies diagram (HFE D) for the evaluation of salinization by seawater intrusion in the coastal Oropesa Plain: Comparative Analysis with the Coastal Vinaroz Plain, Spain. Hydro Research, 2(1): 76–84.
Khosravi R, Zarei M, Bigalke M. 2018. Characterizing major controls on spatial and seasonal variations in chemical composition of surface and pore brine of Maharlu Lake, Southern Iran. Aquatic Geochemistry, 24(1): 27–54.
Naseem S, Bashir E, Ahmed P, Rafique T, Hamza S, Kaleem M. 2018. Impact of seawater intrusion on the geochemistry of groundwater of Gwadar District, Balochistan and its appraisal for drinking water quality. Arabian Journal for Science and Engineering, 43(1): 281–293.
Pujari PR, Soni AK. 2008. Sea water intrusion studies near Kovaya limestone mine, Saurashtra coast, India. Environmental Monitoring and Assessment, 154(1–4): 93–109.
Regional Water Company of Fars, Research Committee. 2021. Assessing the intrusion of saline water of Maharlu Lake to the coastal aquifers of the southeastern part and identifying their source of salinity, 119 p. (In Persian).
Seddighi E. 2000. Investigating geological and sewage pollution entering the Shiraz Khoshk River and Maharlu Lake with emphasis on heavy metals pollution. M.Sc. Thesis, Shiraz University.
Shi X, Wang Y, Jiao JJ, Zhong J, Wen H, Dong R. 2018. Assessing major factors affecting shallow groundwater geochemical evolution in a highly urbanized coastal area of Shenzhen City, China. Journal of Geochemical Exploration, 184 (17): 17–27.
Sridharan M, Senthil Nathan D. 2016. Hydrochemical facies and ionic exchange in coastal aquifers of puducherry region, India: Implications for Seawater Intrusion. Earth Systems and Environment, 1(5): 1–14.
Tajul Baharuddin MF, Taib S, Hashim R, Zainal Abidin MH, Rahman NI. 2013. Assessment of seawater intrusion to the agricultural sustainability at the coastal area of Carey Island, Selangor, Malaysia. Arabian Journal of Geosciences, 6(10): 3909–3928.
Todd D, Mays L. 2005. Groundwater hydrology. 3rd Edition, John Wiley and Sons, Inc., Hoboken, 652 p.
Werner AD, Bakker M, Post VEA, Vandenbohede A, Lu C, Ataie-Ashtiani B, Simmons CT, Barry DA. 2013. Seawater intrusion processes, investigation and management: recent advances and future challenges. Advances in Water Resources, 51(1): 3–26.
Zak I, Gat JR. 1975. Saline waters and residual brines in the Shiraz-Sarvestan basin, Iran. Chemical Geology. 16(1): 179–183.

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History

  • Receive Date: 04 March 2022
  • Revise Date: 23 April 2022
  • Accept Date: 21 June 2022

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