Dynamic Flood Topographies in the Terai, Nepal; community perception and resilience

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Rivers that discharge from mountain ranges support vast populations that depend on annual floods for irrigation and nutrient supply to crops. The largest population of this type is that of the Gangetic Plains where nearly 10% of the world's population depend on waters from the Himalaya. Much of this area is also characterised by extremely low income levels such as in Uttar Pradesh and Bihar states in India, and in Nepal. Consequently, these regions have long been supported through the UK's overseas aid budget. Unfortunately, many of the Himalayan rivers are also the source of devastating floods, with effects further compounded where isolated communities, living on the river floodplain, lack disaster risk management and resilience measures. In Nepal, flood disasters were responsible for over USD 130 million losses and nearly one third of all natural disaster-related deaths between 2001 and 20081; this doesn't include the downstream cross-border impact in India. More recent examples include the 2008 Kosi River avulsion that killed hundreds and rendered millions homeless, and the 2013 Uttarakhand floods that killed over 5000 people and is viewed as India's worst natural disaster since 2004. Most of the damage generated by the Uttarakhand floods resulted from major zones of erosion and deposition during peak discharge of the channel; studies by the Edinburgh Land Surface Dynamics group demonstrated that the main signal of change driven by the dynamic nature of the alluvial topography during flooding was broadly predictable. The dangers of changing river morphology during floods has also been highlighted following major earthquakes such as the 2008 Wenchuan and 1999 Taiwan earthquakes where sediment released into the rivers from landslides caused river beds to rise by up to 18 m causing devastating floods in the years following the earthquakes due to re-routing of river courses. The 'seismic gap' left in western Nepal following the 2015 Gorkha earthquake suggests that readiness for a comparable cascade of flood hazards following a major earthquake is imperative for this region. In this proposal, we aim to build a unique interdisciplinary team based at Edinburgh University combining engineers, geomorphologists, social anthropologists, human geographers and sustainable building designers. This team will rise to the challenge of how academic research can help develop local economies and save lives in response to flooding in the Nepalese plains. We are working closely with the international NGO Practical Action who work with local communities and government bodies to improve resilience. Through a series of workshops in Nepal, we will understand the needs of the communities and the nature of the science that needs to be generated. We will use fieldwork in the region accompanied by the generation of remotely sensed topographic maps to reconstruct past floods, and as input into predictive models. Working with engineers, we will build models that not only predict the passage of flood waters, but also the changing shape of the underlying river bed during these enormous floods. Having developed predictions for future floods, we will also investigate the range of local building constructions that will enable more sustainable flood platforms to be constructed. This project represents the foundations for the expansion of this strategy into the future with applications all the way along the Himalayan floodplains in collaboration with the range of different ethnic and political contexts. Through