ReliefWeb

Rivers sourced from the Himalaya irrigate the Indo-Gangetic Plain via major river networks that support approximately 10% of the global population and their livelihoods. However, many of these rivers are also the source of devastating floods. This brief captures the collaboration between an interdisciplinary team of geoscientists, engineers, social scientists and architects from the University of Edinburgh alongside practitioners from the NGO Practical Action and the Nepal Department of Hydrology and Meteorology. The teams applied new science and appropriate technology, and conducted research with communities to better understand flood risk in the Karnali river basin, Western Nepal from an interdisciplinary perspective.

RESEARCH FOCUS

• A novel approach was used to assess flood risk in the Karnali River by integrating field techniques used to measure the amount of water flowing down the river (water discharge), channel geometry, and sediment load, with new satellite data coupled with a 2D hydrodynamic flood model (Delft3D).

• The new higher-resolution satellite data and the new field observations were combined to generate a 2D hydrodynamic flood model that was compared to existing flood inundation predictions used by the Department of Hydrology and Meteorology.

• The research aimed to improve understanding of the controls on channel stability versus their susceptibility to migration and switching across the Karnali River system.

• The research explored community views on their flood experiences, their strategies for building flood resilient dwellings, and how they respond to flooding.