Assessment of groundwater quality using GIS and CCME WQI techniques: a case study of Thiruthuraipoondi city in Cauvery deltaic region, Tamil Nadu, India

Abstract

A B S T R A C TThis research evaluated the groundwater quality of Thiruthuraipoondi city in the southern part of Tamil Nadu, India during summer and monsoon seasons in 2011. Eighteen groundwater samples were collected throughout Thiruthuraipoondi city and its surroundings. This case study represented that the combined analysis of ordinary kriging and CCME WQI in GIS was effective to evaluate the groundwater pollution sources, as well as for the spatial interpolation and assessment of groundwater quality. Groundwater samples evaluated by CCME WQI values belonged to good quality sectors in summer and monsoon, but to poor quality sectors at small patches of south and southeast directions in both seasons. Moreover, the higher concentration of Na and Cl was designated as irrigation waste and also seawater incursion. Based on the Piper plot, most of groundwater samples belong to Ca-Mg-Cl 2 type and followed by Ca-Cl 2 and Na-Cl types in summer season. In case of monsoon season, most of the groundwater samples dropped in Na-Cl type and followed by Ca-Mg-Cl 2 and Ca-Cl 2 water types. In Wilcox diagram, most of groundwater samples in both seasons occupied S2 and C4 categories of medium sodium hazard and very high salinity hazard, respectively. This research represented that higher concentration Na and Cl resulted from anthropogenic activities and seawater incursion due to overpumping of groundwater. An effective groundwater management plan of artificial recharge is necessary to conserve valuable groundwater resources in Thiruthuraipoondi city.

Naturally Occurring Potentially Harmful Elements in Groundwater in Makueni County, South-Eastern Kenya: Effects on Drinking Water Quality and Agriculture

“…Among the dominant cations, the high concentrations of Na, Ca, Mg, K, and Fe observed in the water could be attributed to the weathering of rocks such as biotite-gneisses, migmatites, granitoid gneisses, and basaltic rocks, which are rich in feldspars, biotite, muscovite, hornblende, and pyroxenes [13]. For anions, high Cl − and SO 4 2− in the water may be derived from weathering of biotite and apatite in gneisses and schists in the area [7,13]. High F − may be associated with the dissolution of fluorapatite, hornblende, and biotite, which are common in biotite-gneisses and basalts in the area [7,13].…”

“…The clusters formed by the parameters also indicate their strength of correlations. For example, the dominant parameters, Ca, Mg, Cl − , SO 4 2− are observed in a close cluster in the far-right end of Figure 8 together with the physical parameters they influence (water hardness, conductivity, and TDS). Similarly, water colour, Fe, and turbidity, which highly influence each other, appear in the same cluster in the left side of the plot.…”

“…There was a significant weak positive correlation (r 2 = 0.43, p < 0.01) between Ca and TDS, while Mg, Na, Cl − , and SO4 2− show a significant moderate to strong positive correlation (with r 2 values between 0.54 and 0.81 and p < 0.01) with TDS. Cross plots were then used to further determine the possible sources of ions in groundwater in the area by plotting the correlation of major ions (Ca, Mg, Na, Cl − , and SO 4 2− ) against TDS as shown in Figure 7. There was a significant weak positive correlation (r 2 = 0.43, p < 0.01) between Ca and TDS, while Mg, Na, Cl − , and SO 4 2− show a significant moderate to strong positive correlation (with r 2 values between 0.54 and 0.81 and p < 0.01) with TDS.…”

“…Therefore, these three components are substantial and can be used to investigate the study samples association [33]. The loading matrix in Table 3 shows that PC1 accounted for 28.02% of the total variance and is dominated by TDS, conductivity, Mg, SO 4 2− , total hardness, Cl − , Na, and Ca with factor loading values (in bold) greater than 0.60. The second component (PC2) accounted for 14.95% of the variance and was dominated by Mn, Pb, Zn, alkalinity, HCO 3 , and free CO 2 which have factor loadings (in bold) greater than 0.68.…”

“…The high salinity and alkalinity of most of the samples analysed, renders the water unsuitable for irrigation in the study area.Geosciences 2020, 10, 62 2 of 22 not address the ongoing issue of poor groundwater quality that is characterized by elevated levels of naturally occurring potentially harmful elements.In arid regions across the world, groundwater resources are highly relied upon, for the provision of drinking, agricultural, and industrial water [3]. Natural processes such as volcanism and the high dissolution of harmful elements from both natural and anthropogenic processes including overexploitation, mining and agricultural activities, industrial impacts, and the addition of animal and human waste, can render this important drinking water resource unhealthy or unsafe [3,4]. Poor groundwater quality threatens millions of people's health and agricultural production and quality in most arid areas [5] and in many instances, the main geochemical processes controlling the release and concentration of potentially harmful elements are not well understood.…”