Sensitive or resilient catchment?: A Budyko-based modeling approach for climate change and anthropogenic stress under historical to CMIP6 future scenarios

Abstract

To develop effective adaptation strategies for climate change, particularly in regions where water is scarce, it is crucial to comprehend and quantify how hydrological responses are influenced by anthropogenic activities and climate change. The primary concern nowadays is to identify the hydrologic sensitive and resilient catchment under these diverse conditions. Thus, a framework is developed in this study to analyse the hydrologic sensitivity and resiliency of a catchment incorporating the elasticity-based Budyko approach. The developed framework is applied to three neighbouring catchments (Brahmani, Baitarani, and Subarnarekha) in eastern India that have received less attention in light of resiliency and sensitivity perspectives. The Budyko approach is first applied using hydro-climatic records of historical phase (1979–2018) and then extended for future phase (2025–2064) under four different Shared Socioeconomic Pathways (SSPs) (1-2.6, 2-4.5, 3-7.0 and 5-8.5) of Coupled Model Intercomparison Project Phase 6 (CMIP6) projections which will provide new insights to the hydrological community. The results highlight that streamflow variations of the Subarnarekha is more sensitive to anthropogenic activities in all time phases. In contrast, the Brahmani and Baitarani are more sensitive to climate change in future phases. During historical phase, the Brahmani and Baitarani are identified to be resilient catchments with high water yield and dry climate, whereas the Subarnarekha is found to be sensitive catchment, exhibiting low water yield and dry climate. However, in future phase, all three catchments are predicted to be resilient, characterized by high water yield and wet climate. The major inference from this study is excess anthropogenic activities can disrupt the anticipated hydrological functioning of a catchment, particularly under critical climatic conditions, which can result in decreasing hydrological resiliency. The finding of this study mainly highlights the response of a hydrological system to climate change and anthropogenic activities to explore the approach of sensitivity and resiliency from a socio-hydrological perspective.