Balancing Prepositioning and Relocation for Efficient Compound Flood Relief

 Floods affect more people every year than any other natural disaster. Compound flooding is when multiple flooding events exacerbate the impact and duration of a flood. This paper studies relief logistics for compound flooding through the case of floods in Sindh province of Pakistan in 2010. The problem is treated as time-varying flows of relief goods from relief warehouses through periodic relief caravans to relief camps or storage close to them; and flows of affectees from shelter sites closest to them to more accessible shelter sites. Results highlight factors that reduce logistics cost and improve demand fulfillment including prepositioning relief goods near shelters, affectee relocation, frequent relief deliveries, and smaller storage modules that reflect relief demand between consecutive relief deliveries more closely. Comparative results indicate that relocation of affectees can be as cost effective as prepositioning of relief goods depending on optimal placement of relief warehouses. In the case of no prepositioning, affectee relocation becomes an instrument of choice compared to relief goods transportation on longer routes during compound flooding. Temporal analysis showed that affectee relocation is most effective in early stages of compound flooding, whereas goods transportation is preferred in later stages. Overall results suggest positioning of relief goods is most effective in the preparedness phase of disaster relief, affectee relocation is most effective in the early response stage and goods transportation takes up most of the logistics activities towards late response.