Hydrochemical Characterization, Classification and Evaluation of Groundwater Regime in Sirsa Watershed, Nalagarh Valley, Himachal Pradesh, India.

Abstract

Nalagarh valley is the southernmost expanse of Himachal Pradesh; belong to the rapid industrial belt of Baddi, Barotiwala and Nalagarh (BBN). The present investigation is to examine the suitability of groundwater quality for drinking purpose and factor prevailing hydrochemistry by collecting 32 groundwater samples during pre and post monsoon. The physical and chemical analyses result shows the parameters like Cl^-, HCO₃^-_, SO₄^2-_, NO₃^2- are well within desirable limit as per BIS. At some locations the concentration of pH, TH and Mg²⁺ exceeded the permissible limits and nearly 50% samples of EC, TDS, Ca²⁺ shows above the desirable limit of BIS which gives us cautions. Classification of hydrochemical facies of groundwater revealed that all the samples belong to the Ca²⁺-Mg²⁺-HCO₃^- water types. Based on the Soltan’s Classification, the groundwater sample are categorized normal chloride, normal sulfate and normal bicarbonate water type. Base-exchange indices and meteoric genesis indices indicates majority of samples belongs to Na⁺- HCO₃^- and shallow water percolating type are 93.75% and 90.63% respectively. According to Gibb’s ratio, the entire water sample fall in the rock dominance field for both season.

Key words: Water resources, Groundwater Quality, Hydrochemical facies, Base-exchange indices, Gibb’s ratio