Environmental monitoring of water resources with the use of PoS index: a case study from Subarnarekha River basin, India

Ten surface and ten groundwater samples were collected from the middle part of Subarnarekha River basin, Jharkhand, India, during the pre-monsoon, monsoon and post-monsoon periods in the year 2008 (n = 60) in order to outline the hydrogeochemical signatures and to assess their overall quality. The study area was selected for their significance to diverse physiographic characteristics, mining and cultivation practices. Samples were analyzed for totally 21 parameters, including of physicochemical properties (pH, electrical conductivity and total dissolved solids), major and minor ions (Na⁺, K⁺, Ca²⁺, Mg²⁺, F⁻, Cl⁻, SO₄²⁻ and NO₃⁻) and trace elements (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr and Zn). Results suggest that quality status, in general, is acceptable with few exceptions; however, issues related to the mining and imposed cultivation were identified which in turn could potentially lead to environmental degradation. The geogenic factors and anthropogenic influences are affecting the hydrogeochemical characteristics of water resources in the study area. The results were confirmed by numerical index Poseidon index (PoS) which has classified the samples according to their quality status. The PoS provides a generic water quality assessment through a single score that is representative of the overall hydrogeochemical characteristics of water, regardless of the processes involved, specific goals and characterization. Overall, the geological setup, hydrogeological regime, unmanaged cultivation practices and overexploitation of groundwater have adverse impacts on water resources of the region. Environmental protection and production optimization may be achieved through the implementation of custom actions and appropriate management measures in the region.