Controls on Himalayan river channel network structure and stability

Rivers sourced in the Himalayan mountains deliver vast quantities of nutrient-rich sediment and water to the lowland Indo-Gangetic Plain (IGP), supporting ~10% of the world’s population. These are highly seasonal river systems, with distinct high flow (during the Indian Summer Monsoon season) and low flow (winter) periods. Climate and rainfall-runoff models predict increases in the magnitude and frequency of intense rainfall and flooding events during the monsoon season, which is already increasing flooding and river channel migration across the IGP. In contrast, very little is known about how climate change is likely to affect the spatial distribution of water in river systems during the winter low flow periods. With increased monsoonal flooding, it is anticipated that once reliable sources of water during the low flow period will become less predictable in location and quantity, although this has never been tested. Potential research questions could include:

• How do low-flow river channel networks vary in space, time and complexity across the IGP?

• How does channel stability and network complexity respond to extreme flow and sediment generating events originating in the Himalayan mountains?

It is anticipated that these questions would be addressed through remote sensing workflows and analysis of secondary data sources (e.g., hazard databases, gridded climate data). The student will gain extensive training in using cloud-based remote sensing packages (e.g., Google Earth Engine), data processing and analysis using Python (e.g. RivGraph to generate network representations of river networks, and multi-layer network analysis using NetworkX/igraph).

Lead supervisors and email addresses

Dr. Lizzie Dingle (elizabeth.dingle@durham.ac.uk)

Dr. Laura Turnbull-Lloyd (laura.turnbull@durham.ac.uk)

Key references

Cload, C., Creed, M., Dingle, E. and Quick, L., 2026. Flow history effects on river bifurcation dynamics in a Himalayan river. Water Resources Research. https://doi.org/10.1029/2024WR039351

Boothroyd, R. J., Williams, R. D., Hoey, T. B., Brierley, G. J., Tolentino, P. L., Guardian, E. L., ... & David, C. P. (2025). Big data show idiosyncratic patterns and rates of geomorphic river mobility. Nature communications, 16(1), 3263. https://doi.org/10.1038/s41467-025-58427-9

Marra, W.A., Kleinhans, M.G. and Addink, E.A. (2014), Network concepts to describe channel importance and change in multichannel systems: test results for the Jamuna River, Bangladesh. Earth Surf. Process. Landforms, 39: 766-778. https://doi.org/10.1002/esp.3482