A comprehensive assessment of temporal limit and efficacy of Budyko framework in capturing various climate change and human intervention scenarios using a controlled synthetic environment over ten Indian basins

Study Region 10 Indian basins Study Focus The traditional Budyko framework (TBF) is a simple model developed for studying the long-term mean behaviour of natural catchments, assuming negligible storage change. However, efficacy of the framework under climate change is still debated, with limited clarity on timescales at which the model can be applied. Moreover, how does storage change driven by climate and humans affect the traditional and modified Budyko framework, remains an open question. Since answering these questions require analysis of alternate scenarios, we developed a controlled synthetic environment that simulates catchment hydrology for various scenarios characterised by plausible climate change and anthropogenic activities, further validated by observation data. New Hydrological Insights for the Region We found that TBF is appropriate for capturing climate change signals but not anthropogenic storage changes, with precipitation change dominating over temperature change in modulating water-balance. The conventional approach of substituting precipitation with effective precipitation (Precipitation – Storage change) is limited in its efficacy and fails when storage changes are anthropogenic. The optimal temporal length over which TBF can be applied is 2 years for arid regions and 1 year for semi-arid regions. These findings advance our insights into TBF’s applicability in regional conditions and the extent to which it can be used in changing environments and prompts a re-evaluation of how the storage change term is incorporated within the framework.