Hydrogeochemical characterization of Yercaud lake southern India: Implications on lake water chemistry through multivariate statistics

Abstract

In this paper, a study on the surface and deeper waters of the Yercaud Lake, Tamil Nadu, South India, was carried out to understand the geochemistry of the lake waters and also to determine its utility for agricultural purposes. Totally, 50 surface and deep water samples were collected from Yercaud Lake. Major ion and heavy metals were measured. The data obtained were interpreted using the lake water composition. The mean concentration of physicochemical parameters and heavy metals for the surface and deep waters have the following values, pH (7.6), EC (263.4), Ca2+(16.3), Mg2+(7.4), Na+(19.2), K+(1.5), Cl−(18.2), NO3−(1.5), SO42−(1.5), HCO3– (97.9), Fe (1.3), Mn (0.1), Cr (0.4), Cu (0.005), Pb (0.31), Zn (0.01), Co (0.095) and Ni (0.075). The data generated reflects that the water samples are dominated by recharge process, especially due to the monsoonal rains and natural springs within the lake. The geochemical data reveals that the lake water is suitable for the agricultural purpose and the chemistry of water is mainly influenced by the weathering of bedrock, especially the charnockites bedrock. The sodium adsorption ratio and sodium percentage (%Na) values indicate that the lake water is suitable for irrigation. Dominant heavy metals in the lake waters are mainly because of the lithogenic as well as through minor anthropogenic inputs. Based on our data it is noted that proper management plans are required to monitor the pollution source in the lake, with strict policy measures.