Structural Connectivity Shaped by Cryospheric Degradation Modulates Sediment Transport Dynamics in High Mountain Asia

Rapid atmospheric warming has transformed cryospheric landscapes, affecting sediment transport processes. However, our understanding of hillslope and riverine connectivity in large headwaters remains limited. Here, we apply the Index of Connectivity (IC) to model structural connectivity for High Mountain Asia (HMA). Significant spatial heterogeneity in structural connectivity is observed across hillslope, river network, and basin scales associated with cryospheric changes. Structural connectivity regulates the transfer of sediment from hillslope erosion to river channels (ρ = 0.77, P < 0.01) and controls downstream sediment flux at the basin scale (ρ = 0.79, P < 0.01). We also found that climate change has driven geomorphic processes in cryospheric landscapes, thereby modulating the spatiotemporal variability of structural connectivity. Rising temperatures and altered precipitation patterns have intensified sediment supply and transport pathways, increasing cryospheric hazard risks in high-IC mountainous areas like the Himalayas-Hengduan ranges. Our findings underscore the importance of structural connectivity in understanding sediment transport dynamics in cold regions.