Surface water quality assessment for drinking and irrigation using DEMATEL, entropy-based models and irrigation hazard indices

The rapid population growth across the world escalates the demand for water for domestic and commercial uses, which converts freshwater resources into deficit conditions both quantitatively and qualitatively. Damodar Fan Delta, a semi-critical community development block dominated region, experiences immense population growth and is famous for irrigation-based crop production which decreases the quality and quantity of water resources. The present study focused on assessing drinking water quality using an integrated water quality index and irrigation water quality based on irrigation hazards depending on the primary surface water quality datasets. The water quality index reveals that most of the sample sites (similar to 78%) are characterized as very good to moderate quality, however, similar to 22% of the sample water has been defined as poor to very poor quality for drinking. In terms of irrigation water quality, most of the indices have been considered suitable for irrigation purposes except percentage nitrogen, residual sodium carbonate and Kelley's ratio. It is also depicted that turbidity, sodium, sulphate and nitrate are the dominant pollutants originating from the point (industrial, municipal, and domestic sewage) and non-point (agricultural land) sources of the study area. Therefore, it indicates that surface water management has been imperative for the planner and other stakeholders.