An integrated assessment of hydro-meteorological extremes and water scarcity in a mountainous river catchment under climate change

Abstract

The impact of climate change in mountainous regions poses major challenges for water resource management, especially due to anthropogenic activities. This study assesses key factors driving large-scale changes to water security in the mountainous region: hydro-meteorological extremes, droughts, surface and subsurface water availability, and population growth. The study identifies vulnerable areas susceptible to future water scarcity through fuzzy AHP utilizing CMIP6 data products and a hydrological model. The results for the SSP5–8.5 scenario indicate an increase in annual rainfall (+31%), temperature (+30%) and blue water (+40%), while those for SSP2–4.5 indicate an increase in green water flow (+50%), green water storage (−4%), and population density (+40%). Fuzzy AHP analysis identifies 4 out of 9 sub-catchments as highly vulnerable. The high population growth and changes in hydro-climatic projections suggest a paradigm shift in hydro-climatological components under both SSPs, which in turn result in decreased water availability by the end of the century.