Exploring adaptation pathways in terms of flood risk management at a city scale – a case study for Shanghai city

¹ Deltares, Boussinesqweg 1, 2629 HD, Delft, The Netherlands
² Delft University of Technology, Faculty of Technology, Policy and Management, P.O. Box 5015, 2600 GA Delft, The Netherlands
³ Utrecht University, Department of Geosciences, P.O. Box 80115, 3508 TC, Utrecht, The Netherlands
⁴ Deltares, Princetonlaan 6-8, 3584CB, Utrecht, The Netherlands

^a Corresponding author: qian.ke@deltares.nl

Abstract

Cities are vulnerable to flooding and historical events, for instance Hurricane Sandy in 2012, have showed that losses in the cities are costly. In the context of climate change and socio-economic development, future flood risk will inevitably rise; adaptive measures, for instance upgrading of sea dikes and floodwalls, improving drainage systems and implementing green infrastructures, are proposed under the changing environment in the cities. A question of when to implement what measures in the cities over time is then brought up. The approach of dynamic adaptive policy pathways is applied to formulate adaptation pathways for a case study of Shanghai to explore the optimal investment strategy in context of deep uncertainties. Adaptation concept is not only aiming to achieve optimal strategy but also to determine when to implement the measures. The adaptation pathways for three types of floods (coastal flood, river flood and pluvial flood) in Shanghai were formulated through a preliminary qualitative analysis. This could provide an insight to the long-term feasibility of adaptive flood risk strategies. This research could provide a rational indication for policy/decision makers on future adaptation strategy at the city scale.