Visualizing the spatial water quality of Bentota, Sri Lanka in the presence of seawater intrusion
-
Abstract: Seawater flows towards the inlands along with the rivers and canals, through the process of infiltration and leaks in the ground water characterized by high concentrations of soluble salts. High salinity concentrations can make groundwater unsuitable for public consumption and surface water unsuitable for irrigation and agricultural activities. This study envisages the fluctuations of ground and surface water quality of Bentota area in the presence of seawater intrusion. The temporal and spatial variations of eleven water parameters were monitored by collecting the water samples during one year period. Spatial distributions were assessed by applying the Inverse distance weighted (IDW) interpolation method in Arc GIS 10.5 software. Water quality is assessed on the integration of all parameters in terms of an index based on the World Health Organization (WHO) standards. The significant linear relationship between the considered parameters of surface water (SW) and groundwater (GW) were identified applying correlation analysis using SPSS software. All parameters of surface water were above the permissible limits of WHO standards. Surface water quality index values with respect to 60% of canals show very poor quality (>1 250) of surface water indicating their unsuitability for irrigation activities. Those surface water bodies indicated very highly saline conditions during dry months. The spatial distribution of ground water quality index with respect to the highest parameter values of each sampling location indicates that 52.2% of total land extent of Bentota Divisional Secretariat Division (DSD) has good quality of ground water which is suitable for drinking. Its 47.2% of total land extent has poor quality of ground water for drinking purpose and less than 0.5% of the area consists of excellent or very poor quality of ground water in each. This study helps to manage coastal aquifers by understanding the extreme water quality conditions and coastal salinity.
-
Key words:
- Salt water intrusion /
- Coastal salinity /
- Water quality /
- Spatial distribution
-
Gregory De Costa, Jessic Wilson, Mark porter, et al. 2008. Assessment and management of change in coastal zones caused by salinity intrusion-Asia Pacific network for global change research. Open Polytechnic of New Zealand. Tomczak M. 1998. Spatial interpolation and its uncertainty using automated anisotropic inverse distance weighting (IDW). Cross-validation/ jackknife approach. Journal of Geographic Information and Decision Analysis, 2(2): 18-30. Barlow P M, Wild E C. 2003. Bibliography on the occurrence and intrusion of saltwater in aquifers along the Atlantic coast of the United States, U S Geological Survey Open File Report, 02-235: 30. Guevara H P, Ruiz C G, Barrientos J h, et al. 2012. Relationship between chloride concentration and electrical conductivity in groundwater and its estimation from vertical electrical soundings (VESs) in Guasave Sinaloa, Mexico. Ciencia e Investigation Agraria, 39(1): 229-239. Rahman A A, Ravenscroft P. 2003. Groundwater resources and development in Bangladesh background to the Arsenic crisis, agriculture potential and the environment. Bangladesh Centre for Advanced Studies: University Press Ltd. Werner A D, Bakker M A J, Post V E A, et al. 2013. Seawater intrusion processes, investigation and management: Recent advances and future challenges. Advances in Water Resources, 51: 3-26. Hadithi M. 2012. Application of water quality index to assess suitability of groundwater quality for drinking purposes in Ratmao Pa-thri Rao watershed, Haridwar District, India: American Journal of Scientific and Industrial Research: Science Hub. Saxena M M. 1998. Environmental analysis: Water, soil, air. Bikaner, India: Agro Botanical Pub: 186. Jayasekera D, Kaluarachchi J J, Villholth K G. 2008. Groundwater quality impacts due to population growth and land use exploitation in the coastal aquifers of Sri Lanka. Southern Illinois University Carbondale, Open SIUC, Conference Proceedings: 43. World Health Organization (WHO). 2011. Guidelines for drinking-water quality, fourth edition. Switzerland. Ferguson G, Gleeson T. 2012. Vulnerability of coastal aquifers to groundwater use and climate change. Nature Climate Change, 2(5): 342-345. Custodio E, Bruggeman G A. 1987. Groundwater problems in coastal areas, studies and reports in hydrology. No. 45, UNESCO, Paris: 576. Ravikumar P, Mehmood M A, Somashekar R K. 2013. Water quality index to determine the surface water quality of Sankey tank and Ma-llathahalli Lake, Bangalore urban district, Karnataka, India. Applied Water Science, 3: 247-261. Perlman H. 2014. Sediment and suspended sediment. The USGS Water Science School. Cook S, Dixon-jain P, Hocking M, et al. 2013. A national-scale vulnerability assessment of seawater intrusion: Vulnerability factor analysis. Geoscience Australia and National Centre for Groundwater Research and Training, Adelaide.
点击查看大图
计量
- 文章访问数: 528
- HTML全文浏览量: 184
- PDF下载量: 168
- 被引次数: 0