Assessment of irrigation suitability of water in Hirakud reservoir and Bargarh main canal, Odisha, India: A multivariate analysis

Abstract

The present study assesses the chemical characteristics and irrigation suitability of water in the Hirakud reservoir and main canal. Water samples were collected from 10 different sites during the premonsoon, monsoon, and postmonsoon seasons. The pH, EC, TDS, major ions, and trace metals were estimated using standard methods. The pH of water samples was slightly alkaline in a few sites. The concentration of all the major ions was below the permissible limit except for K+. The concentration of cations and anions in water was in the order of Ca2+ > Na+ >Mg2+ > K+ and HCO3− > Cl− > SO42− > NO3− respectively. Piper's trilinear diagram revealed that water samples were of Mg-HCO3− and mixed type. A strong correlation of Cl– with other ions suggested precipitation dominance in the hydrogeochemistry of water. The concentration of all trace metals in water samples was above the permissible limit across the season. Although reservoir water was of excellent category as per EC and SAR, RSC remained above the limit across the season. PCA suggested that anthropogenic and geogenic processes regulate water quality in the reservoir. The present work provides a baseline for water quality management policy for the Hirakud reservoir as well as the command area. HIGHLIGHTS Water in the Hirakud reservoir is of moderate quality for irrigation.; Water quality varies significantly across the seasons.; Fe, Cu, and Cr concentrations were found above the permissible limit.; Multivariate analysis indicates anthropogenic activities influencing water quality in the reservoir.;

Keywords

• bargarh
• hirakud reservoir
• irrigation suitability
• multivariate analysis
• water quality