Planning & Management
394746 - Coastal sustainability management using avulsion mitigation strategies in the Yellow River Delta under climate change
Monday, June 4
2:00 PM - 3:30 PM
Location: Greenway GH
Due to high in-channel sedimentation rates, the Yellow River Delta of China has changed course frequently in its history, with huge socioeconomic impacts. We will address the following questions: What is the best timing and location of deliberate (engineered) avulsions? Can use of floodways lessen the negative cost and flooding impacts of avulsion strategies?
To address these questions, a five-step, simulation-based multi-objective optimization model has been developed. The framework considers tradeoffs between cost of avulsion-mitigation strategies and expected flooding risk. The components are: stochastic flow generation reflecting nonstationarities due to watershed land use and climate change; hydraulic and water surface profile modeling of the lower Yellow river stage and flooding; channel bed aggradation and degradation simulation; flood frequency analysis and flood damage estimation; and optimization of the sizes and locations for engineered avulsions and utilization of flood way, together with upstream reservoirs operation policies.
Water infrastructure has a typical lifetime of 10–200 years and its continuing performance is very sensitive to climate change. A so-called robust decision model which refers to a class of methods that are used to identify robust strategies, or strategies that perform relatively well, compared to the alternatives, across a wide range of plausible future states of the world will be implemented. Such frameworks seek to identify policy vulnerabilities under deep uncertainty about the future and propose strategies for minimizing regret in the event of broken assumptions. We discuss alternative decision frameworks to address climate uncertainties and their effects on optimal strategies.