A state-based and optimal path dependant short-term flood planning

Temporary flood protective defences (TFPD) are supplementary to permanent engineering solutions. In a flood event, asset managers are faced with a challenging task of deploying large-scale temporary defences at multiple locations. As the performance of temporary defences is sensitive to various uncertain weather condition factors, it is difficult to fix a single specific deployment plan as the optimal solution. This, moreover, leads to insufficient and/or underused defences on flood-affected locations. This paper describes a state-based (SB) mathematical modelling approach to deal with above challenge by adapting TFPD strategies consistently to short-term future as they unfold. We employ multistage stochastic and scenario tree to identify a set of alternative SB optimal paths for deployment planning. The proposed model is applied to nine flood-affected locations in Carlisle, northwest England. The results indicate that the inclusion of SB path-dependant solution strategy are beneficial for the flood asset manager faced with making short-term deployment planning decisions.