Assessing the Efficacy of Glacier Inventories to Evaluate Climate Change Impacts: Key Takeaways from Baspa River Basin

A glacier inventory is helpful in studying temporal glacier changes, glacio-hydrological regimes, future sea level rise, and climate model optimisation for different scenarios. The compilation of any glacier inventory requires substantial manual and computational efforts. However, the inaccuracies in glacier inventories have implications for modelled glacio-hydro-climatological results, necessitating a need to understand the degree of area uncertainties in the input inventories. In this work, we first developed a glacier inventory dataset using high-resolution images and field validations for our case study site, i.e., Baspa River Basin, India. Subsequently, through spatial comparison, we estimated the extent of area uncertainties across the available regional and global-scale glacier inventories. These area uncertainties are found to be significantly high, within a range of ± 23%, and they can further magnify, if the mapped basin area has a higher proportion of debris-covered glaciers. We further performed a sensitivity analysis to assess the impact of area discrepancies on a glacio-hydrological model outcome. The change in debris-covered glacier area by ± 25% resulted in alteration of average monthly discharge by up to ± 16%. It is significant enough to highlight the need for quality-controlled inventory data for running such models. In the last part of this chapter, we present our recommendations for implementing the probable uncertainty scenarios while discussing the research on the future projections. While we have reached a critical point of climate change in human history, there are existing uncertainties in assessing future water security due to various data and geopolitical reasons. The perspectives offered in this chapter can help better account for glacier area-related uncertainties in glacio-hydrology.