Assessment of physicochemical properties and irrigation suitability of surface water along rural and transition zones of Bengaluru

Abstract:

The surface water resources are the major source of irrigation in the rural and transition zones of Bengaluru. These water resources are deteriorating due to unpredictable changes in rural areas and transitions in Bengaluru city caused by rapid urbanization and human activities. So, the present study was conducted in rural and transitional zones of the southern and northern transects of Bengaluru, one of the fastest-growing cities in India. Surface water samples collected from various agroecosystems at the end of October (representing the post-monsoon season) were analyzed for physicochemical properties such as pH, electrical conductivity, total dissolved solids, turbidity, total hardness, major anions, cations, and heavy metals, which are considered critical in water quality assessment for irrigation purposes. The different physicochemical properties of surface water in the rural zone were less polluted than in transition, and all the water samples collected from transects were within the permissible limits of BIS except phosphates. The heavy metal concentration was found to be lower in rural and transition zones, but the iron concentration was slightly higher than the BIS standards. The water quality was assessed for irrigation suitability and parameters like SAR, RSC, SSP, and percent sodium were calculated. Most of the water samples were suitable for irrigation purposes based on SAR values and RSC values were in good and marginal water classes. The percent sodium and soluble sodium percentage were in the excellent to permissible water class. The present study found that the surface water is less contaminated and well-suited for irrigation purposes.