摘要：Traditionally, building‐level disaster risk reduction (DRR) measures are aimed at a single natural hazard. However, in many countries the society faces the threat of multiple hazards. Building‐level DRR measures that aim to decrease earthquake vulnerability can have opposing or conflicting effects on flood vulnerability, and vice versa. In a case study of Afghanistan, we calculate the risk of floods and earthquakes, in terms of average annual losses (AAL), in the current situation. Next, we develop two DRR scenarios, where building‐level measures to reduce flood and earthquake risk are implemented. We use this to identify districts for which DRR measures of one hazard increase the risk of another hazard. We then also calculate the optimal situation between the two scenarios by, for each district, selecting the DRR scenario for which the AAL as a ratio of the total exposure is lowest. Finally, we assess the sensitivity of the total risk to each scenario. The optimal measure differs spatially throughout Afghanistan, but in most districts it is more beneficial to take flood DRR measures. However, in the districts where it is more beneficial to take earthquake measures, the reduction in risk is considerable (up to 40%, while flood DRR measures lead to a reduction in risk by 16% in individual districts). The introduction of asynergies between DRR measures in risk analyses allows policy‐makers to spatially differentiate building codes and other building‐level DRR measures to address the most prevalent risk while not compromising the risk resulting from other hazards. Plain Language Abstract Our study aims to improve our understanding of potentially unwanted effects of measures that reduce the impacts of disasters across different hazards. Traditionally, those measures are aimed at decreasing the risk a building faces of a single hazard type despite their potential of having unwanted effects on other hazard types. For example, building on stilts is an often‐used measure to decrease a building's flood vulnerability, however, it simultaneously increases a building's earthquake vulnerability. In this paper, we refer to these as asynergies. However, in many countries the built environment faces the threat of different hazard types. We define such potentially unwanted effects between measure as “asynergies.” A case study of Afghanistan is presented in which the asynergies of flood and earthquake building‐level measures are assessed. An improved understanding of these asynergies can help policy makers enforce measures that decrease the overall risk.
关键词：asynergies;building back better;DRR Measures;multi‐hazard risk assessment;sustainable development
