Spatial distribution of drinking and irrigation water quality indices of Ghizer River and its tributaries, northern Pakistan

Abstract The present study examined water quality in the Ghizer River and its tributaries, Gilgit-Baltistan, northern Pakistan. Water samples (n=55) were collected from the Ghizer River and its tributaries and analyzed for physicochemical parameters. Water basic parameters and anions were measured using the multi-parameter analyzer (CONSORT 6030, Belgium) and cations by the atomic absorption spectrophotometer (AAS, AAnalyst 700, PerkinElmer, USA). Physiochemical parameters were noted to be within the drinking water permissible limits set by the World Health Organization (WHO), except for pH (2%) and Turbidity (48%). Samples were assessed for water quality index (WQI) and irrigation water quality (IWQ) indices such as permeability index (PI), Kelley’s ratio (KR), sodium percent (Na%), magnesium hardness (MH), sodium adsorption ratio (SAR), residual sodium carbonates (RSC), and salinity index (PS). This study revealed that the mean WQI values of Ghizer River and its tributaries were observed in the good category at midstream and downstream and noted excellent for upstream. Results of the majority of IWQ indices revealed that water is suitable for irrigation, except that of MH and PI. Gibbs plots showed that the majority of water samples in the Ghizer River and its tributaries were noted in the precipitation dominance zone and that of the Piper plot revealed the CaCl dominant hydrochemical facies.