Assessing Variations in Hydrological Fluxes due to changes in Regional Climate and Land Use Land Cover in the Narmada River Basin, India.

Abstract:

Extrinsic and intrinsic factors that influence climate change have consequently caused an unprecedented water stress condition in the last few decades over the Narmada River basin, India. Evaluating variations in surface hydrological fluxes under the effects of changing climate and land cover is crucial to understand the water resources potential of a region. In this study, hydrological regime of the Narmada River Basin is assessed using Soil and Water Assessment Tool (SWAT). Multi-site calibration (2009-2014) and validation (2015-2018) of the model using observed river discharge shows satisfactory results from a holistic point of view ranging from 0.3 to 0.7 station-wise. The overall assessment period (2009 to 2048) is divided into four decades P1, P2, P3, and P4. Examining the variations in hydrologic fluxes under static and dynamic LULC approach reveals that surface runoff decreases significantly under dynamic LULC conditions. Progressive growth in the area of shrub vegetation has shown a decrease in surface runoff and an increase in ET under both RCP 4.5 and 8.5 scenarios. Decreasing precipitation and alterations in the surface runoff due to the impacts of LULC change are responsible for a decrease in water yield. Results imply that the Narmada River Basin may face water-stressed conditions by the end of 2050. This study provides valuable insights for stakeholders and decision-makers to sustainably manage water resources in the future period under changing climate and LULC conditions.