An Overview of Long‐Term Temporaries After Flood Disasters

ABSTRACT Temporary structures are important for a rapid recovery phase after extraordinary flood disasters we cannot protect ourselves from. Long‐term temporary structures are particularly relevant when infrastructures are destroyed that require a longer reconstruction phase. In addition, they offer the opportunity of more time to build resilient critical infrastructure (CI). The term “long‐term temporary” is used in the study to emphasize that these temporary solutions are not only used for a short period of time (less than 6 months). On the example of the recovery in the Ahr valley after the 2021 flood, the authors diagnosed the importance of practice examples on long‐term temporaries when ad‐hoc solutions are needed, as well as the long persistence of some of the temporary solutions. A systematic literature analysis was conducted, as limited research in long‐term temporaries exists. We evaluated how many scientific papers on the topic of long‐term temporaries for CI after flood disasters can be identified after a parameter‐oriented literature analysis and which aspects are dealt with. The literature analysis is based on seven search parameter combinations and covers the areas of drinking water supply, power supply, sewage disposal, telecommunications, bridges (transport systems) and gas supply. 138 publications were identified as relevant, with 43 broaching the issue of temporary solutions after flooding. The most common keyword is “critical infrastructure” (CI) with only 3.7%, followed by “flood” with only 3.4%. Most studies on temporary solutions evaluate temporary bridges, followed by drinking water supply. Military engineering plays a key role in providing temporary bridges, which explains the good supply and documentation. The authors analysed temporary structural solutions (long‐term temporaries) based on on‐site observations and the close collaboration with municipalities within the KAHR‐project during the recovery phase of the region. The case study presents some specific long‐term temporary solutions for bridge constructions and flying pipes to temporary drinking water treatment systems and sewage treatment plants. Another key finding is that long‐term temporary structures are very diverse and have varying life spans (shorter for telecommunication and drinking water supply and longer for bridges and sewage disposal) as well as different requirements in technicality and durability (e.g., lower challenges in drinking water supply, higher requirements for bridges). It is therefore important to explore this area in terms of risks and design options, which has a direct impact on flood risk management, as it could make the use of long‐term temporary structures more routine during the emergency management phase.