Spatial distribution of drinking and irrigation water quality indices of Ghizer River Basin, northern Pakistan.

Determining the water contamination of a river that threatens the dependent ecological community is a pillar for sustainable management. For this purpose, the present study aimed to examine the water quality of the Ghizer River Basin (GRB), Gilgit-Baltistan, northern Pakistan, for drinking and irrigation. Water samples (n = 55) were collected from the GRB 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 such as pH, electrical conductivity (EC), total dissolved solids (TDS), iodide (I), chloride (Cl), fluoride (F), nitrate (NO), sulfate (SO), bicarbonate (HCO), turbidity, calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) were noted to be within the drinking water permissible limits set by the World Health Organization (WHO). However, pH and turbidity surpassed their respective limits in 2% and 48% of water samples, respectively. Samples were assessed for water quality index (WQI) and irrigation water quality (IWQ) indices. The WQI values for most samples in the GRB were noted in the excellent (38.2%), good (58.2%), and poor (3.6%) categories. Similarly, most IWQ indices revealed that water is suitable and recommended for irrigation. Gibbs plots showed that most water samples in the GRB were noted in the precipitation dominance zone. The piper plot revealed the calcium-chloride (Ca-Cl) dominant hydrochemical facies.