Spatial and physicochemical assessment of groundwater quality in the urban coastal region of Sri Lanka

Abstract

This study used the groundwater quality index (GWQI) and Geographic Information System (GIS) techniques to examine groundwater quality in the western coastal region of Sri Lanka. The spatial and temporal variation of 18 groundwater samples' physiochemical parameters [pH, electrical conductivity (EC), turbidity, total dissolved solids (TDS), sodium (Na + ), potassium (K + ), calcium (Ca 2+ ), magnesium (Mg 2+ ), chloride (Cl − ), and bicarbonate (HCO 3 − )] were studied. According to the WHO and SLS, 11% of samples had EC levels that were above the acceptable range, and 22% had turbidity levels that were beyond the acceptable range. When considering, pH, TDS, other cations, and anions analyzed in the study were still below the standard permissible levels. The western coastline region, as well as several areas of the central study region, had signi cant concentrations of physicochemical parameters. According to the GWQI, water was consumable in 77.78% of locations in the study region and unsatisfactory in 22.22%. Furthermore, due to severe coastal erosion, the quality of groundwater in the study region is deteriorating, therefore maintaining a comprehensive groundwater management strategy to promote sustainable water consumption is imperative.

A Study on Hydrochemical Characteristics and Evolution Processes of Groundwater in the Coastal Area of the Dagujia River Basin, China

“…Meanwhile, the average cation and anion concentrations values of the BA had the rank of Ca 2+ > Na + > Mg 2+ > K + and HCO 3 − > Cl − > SO 4 2− > NO 3 − , respectively. Compared to the BA, the QA exhibited higher Cl-and Na+ concentrations, demonstrating the saline water intrusion in groundwater [13].…”

“…The potassium (K + ) and sodium (Na + ) concentrations were analyzed using a flame photometer, while magnesium (Mg 2+ ) and calcium (Ca 2+ ) were determined using the titration method [9]. The sulfate (SO 4 2− ), chloride (Cl − ) and nitrate (NO 3 − ) were measured using ion chromatography [5,13]. The carbonate (CO 3 2− ) and bicarbonate (HCO 3 − ) were analyzed using the acid titration method.…”

“…Moreover, the highest Mg 2+ concentrations were observed in the northwestern part (Figure 2d). Indeed, limestone and sandstone weathering are often the major sources of Mg 2+ in groundwater [13]. The ranges of Na + concentrations were 26.14-1040.60 mg/L and 23.87-144.60 mg/L in the QA and BA, respectively.…”

“…Piper diagrams can be used to determine the types and hydrochemistry evolution of groundwater [13]. The results showed slight differences in the distribution of the sampling points between the QA and BA (Figure 5).…”

“…Kim et al (2017) [12] revealed that the statistical and graphical methods are useful tools for assessing groundwater quality and hydrogeochemical processes. Aminiyan et al (2020) [1] used the principal component analysis and Pearson's correlation to determine the relationship between hydrochemical parameters, whereas Perera et al (2022) [13] used GIS techniques for mapping the spatial variation of physicochemical parameters of groundwater and groundwater quality index.…”