Integrated Assessment of Climate Change and Land Use Impact on Runoff Dynamics in the Jhelum Basin 

Abstract

This study addresses the significant factors contributing to warming during the 20th century, namely Greenhouse Gases (GHG) and Land Use (LU), emphasizing the need for localized hydrological impact assessments. Recognizing the limitations of Global Climate Models (GCMs) in predicting local-scale phenomena, the research employs a downscaling approach for hydrological impact studies. Observed datasets and downscaled GCM data are utilized to analyze temperature, precipitation, and potential evapotranspiration (PET) trends. The study integrates downscaled GCM data from the Coupled Model Inter-comparison Project 6 (CMIP6) to project future climate scenarios under Representative Concentration Pathways (RCPs) 4.5 and 8.5. Runoff data from three stations within the Jhelum Basin is collected and analyzed over various time scales, providing a comprehensive understanding of historical and future hydrological trends. Future climate projections are corrected using the Daily Bias Correction (DBC) method). The study then employs the Soil & Water Assessment Tool (SWAT) model, given its suitability for hydrological studies with limited data availability. SWAT is calibrated and validated using SWAT CUP, incorporating observed river discharge. The impact assessment on runoff considers different climate change and land use change scenarios. Future Land Use and Land Cover (LULC) predictions are made for 2025 to 2100, and the model is rerun to analyze the combined impact of changing climate and LULC on runoff. The study aims to achieve a robust understanding of future water resource dynamics for runoff generation; the integrated assessment of climate and land use impact on the hydrological dynamics of the Jhelum Basin uncovers substantial shifts in runoff patterns. The combination of changing climate conditions and evolving Land Use/Land Cover (LULC) scenarios reveals intricate interactions, influencing the basin's hydrological response. Future projections highlight the nuanced interplay between climate scenarios and LULC changes, offering valuable insights into the complex dynamics of water resource management. These results provide essential information for policymakers and decision-makers, guiding the formulation of adaptive strategies to address the evolving challenges in runoff generation within the Jhelum Basin. The research explores runoff responses to LULC and climate change through scenario-based setups. By quantitatively analyzing the effects on runoff and peak discharge across different periods, the study provides valuable insights for policymakers and decision-makers in water resources. This integrated assessment contributes to a more informed and sustainable approach to water resource management in the Jhelum Basin amidst changing climatic and land use conditions.