As the number of COVID19 cases is increasing again in Europe and other areas, the interest in flood risk management is declining. The public and politicians are occupied by more urgent issues, such as health, income, and employment. Especially in countries where the last flood occurred long ago, like the Netherlands, the issue of flood risk management may be moved down on the list of priorities.

However, it remains important to continue improving the knowledge on assessing flood risks and developing and evaluating flood risk management strategies. If not, risks may increase, and opportunities for measures may be lost. Climate change will increase flood risks if no counteractions are taken (Haasnoot et al., 2020). Ice sheets are melting faster than anticipated, increasing coastal flood hazards; extreme weather events, and river floods may occur more frequently and become more severe. This may require drastic changes in our flood risk management strategies in the long term. Such changes need time and require debate among scientists, especially policymakers and society. They may also become increasingly difficult by today's decisions, which lock‐in our current strategy. Much money is spent on flood risk management, not only after flood events on repair and recovery but also for flood protection. To make sure this money is spent wisely and to prevent regret from having made the wrong decisions, improved flood risk analyses and new approaches to flood risk management are needed.

The COVID19 crisis may teach us things about crisis management that may also be useful for flood risk management. Although floods are very different from pandemics, important lessons can be learned, for example, on what is vital and must continue functioning (e.g., schools, health care), on how experts and politicians should or could best work together (sharing responsibilities), on the need of involving all relevant stakeholders when taking decisions, and on communication. The crisis reveals societies' abilities to join forces and take care of each other, as well as their innovative capacities, which results in workable alternatives for shortages in supplies, increased hospital capacity, and adapted procedures that allow opening of buildings and participating in activities in a safer way. These contribute to society's resilience to cope with the pandemic and will also contribute to its recovery in the future.

Societal resilience is also crucial in flood risk management. Resilience has been applied to flood risk management for about two decades already (Vis et al., 2003; De Bruijn, 2004). Recently, its popularity has become overwhelming, especially because it has been adopted by three important global post‐2015 agendas: The Sustainable Development Goals (SDGs), The Sendai Framework for Disaster Risk Reduction, and the Paris Agreement under the United Nations Framework Convention on Climate Change (IPCC, 2012). Furthermore, resilience is promoted by scientific communities (especially The Resilience Society, but also by the International Conference on Flood Management [ICFM7], who made it the leading concept in 2017) and picked up by many regional and national authorities (e.g., the ADB and EU (ADB, 2014; EU, 2013), the 100 Resilience City programme of the Rockefeller foundation (ARUP, 2014), and the Netherlands' Delta Program (MOIE, 2015). There is thus a broadly shared vision that enhancing resilience is needed.

However, there is no common understanding on what precisely implies enhancing resilience. Resilience has been defined in different ways, varying from very narrow as “the ability to recover from a response to disturbance such as a flooding” to very broad as: “the ability to cope with disturbances and changes by avoiding or minimizing impacts and having the ability to learn and adapt in order to remain resilient into the future”. Lately, it appears to have become an umbrella concept, covering almost everything that was previously covered by “sustainability” and including adaptation (adaptive management) and transformation (DHS, 2008). Although the resilience concept has been used in many ways, this does not mean it is only a buzzword. As the popularity of the word already shows it covers something that was felt to be missing before.

In flood risk management, decisions are often based on risk analysis. These risk analyses could, in theory, include potential impacts that are relevant to society. However, they are often simplified and focused on direct impacts corresponding with maximum flood depths with a certain probability of exceedance. Sometimes, business interruption of flooded companies and fatality risk are also included, but all other indirect and non‐monetary impacts are generally excluded. As the analyses focus on maximum water depths only and not on the whole chain of events leading to those water depths, measures which do not directly affect that water depth cannot be easily considered. Specifically, measures aiming to increase warning time, improve effective emergency response, enhance recovery, or build differently or, elsewhere, reduce future risk increase are often not considered. Such a limited application of risk analysis may lead to suboptimal choices of measures. Moreover, science favours presenting integrated risk numbers, whereas laypeople do not perceive risk from small‐probability catastrophes as similar to risk linked to frequent small‐impact events. The very extreme events may seem irrelevant for the total risk, but they may be considered relevant by decision‐makers if their potential effects would be shown to them. Although the insurance industry considers the entire flood loss curve, most flood risk analyses give only a single risk number. This number does not reveal deep uncertainties and potential surprises that may occur and their effects (Merz et al., 2015). Finally, flood risk management is still often the responsibility of water authorities, while a more comprehensive and tailored approach towards society would require the engagement of citizens, industries, critical infrastructure operators, and local governments. They are the ones that should benefit from improved flood risk management and, therefore, should be engaged, and they could contribute, although they may not have the full picture. As learned from the COVID19 crisis, to cope with a hazard, engagement of all actors is needed.

Adopting resilience means being willing to address more aspects than usually addressed in flood risk analyses and developing comprehensive strategies that enable societies to cope with hazards of all magnitudes. Resilience analysis involves analysing the response of systems to extreme events (e.g., of cities, countries or societies, also including flood management infrastructure such as embankments or barriers), a response that cannot be expressed “only” by euros per year but should reveal the response to both frequent and very rare events, the effect on economy, well‐being, and all that matters to society during the event, not only in its aftermath and during recovery but also in the long term. Furthermore, adopting resilience as a guiding principle for the design of future strategies may lead to a different starting point: The hazardous events are not considered central but the society and its most important characteristics and developments.

What putting resilience into the practice of flood risk management means is still to be decisively established. Research on this is intensifying but still struggles making things practical. The adoption of a number of guiding principles may be of help in this regard (De Bruijn et al., 2017). Principles such as “applying a systems approach” (vs. local optimization) (Vorogushyn et al., 2018), “also consider beyond‐design events and how to cope with such events”, “assess what must remain functioning” instead of only what damage is expected, “assess the recovery capacity” of a society, and identify trends and developments that may affect or offer opportunities to strengthen “future resilience” are mentioned. To really put these into practice, better indicators, examples, tools methods, and evaluation criteria are needed. Equity (in space, between groups, and between generations) may, next to cost–benefit ratios and effects on nature, be included more often, as covered by the term inclusive green growth.

A focus on resilience thus changes our mindset from quantification of risk to understanding system behaviour and societal needs under a full range of possible events and prolonged time scales. This requires elaborating existing approaches and developing new approaches aimed at enabling societies to cope with flood hazards now and in the future.

在欧洲和其他地区，随着COVID19病例数的再次增加，对洪水风险管理的兴趣正在下降。公众和政客忙于更紧迫的问题，例如健康，收入和就业。特别是在很久以前发生了最后一次洪水的国家中，例如荷兰，洪水风险管理的问题可能会移到优先事项的清单上。

但是，继续提高有关评估洪水风险以及制定和评估洪水风险管理策略的知识仍然很重要。否则，风险可能会增加，采取措施的机会可能会丢失。如果不采取对策，气候变化将增加洪水风险（Haasnoot等人，2020年）。冰盖的融化速度比预期的快，增加了沿海洪灾的危害；极端天气事件和河流洪水可能会更频繁地发生并变得更加严重。从长远来看，这可能需要我们的洪水风险管理策略发生重大变化。这种变化需要时间，需要科学家，尤其是决策者和社会之间进行辩论。根据当今的决定，这些决定可能也会变得越来越困难，因为这些决定会锁定我们当前的策略。不仅在洪水事件发生后进行修复和恢复，而且在洪水保护方面，很多钱都花在了洪水风险管理上。为了确保合理地使用这笔钱并防止因做出错误的决定而后悔，需要改进洪水风险分析和新的洪水风险管理方法。

COVID19危机可能会使我们了解到有关危机管理的知识，这也可能对洪水风险管理很有用。尽管洪水与流行病大不相同，但是可以吸取重要的教训，例如，重要的知识和必须继续发挥作用的知识（例如学校，医疗保健），专家和政客应该或应该如何最好地合作（分担责任），在决策和沟通时需要让所有利益相关者参与。这场危机揭示了社会的团结力量和相互照顾的能力，以及其创新能力，从而导致了替代选择，包括供应短缺，医院容量增加以及允许开放建筑物和参加活动的适应程序。一种更安全的方法。这些为社会做出了贡献

社会适应力在洪水风险管理中也至关重要。抵御力已经应用于洪水风险管理已有大约二十年的历史（Vis等，2003； De Bruijn，2004）。最近，它的受欢迎程度变得势不可挡，特别是因为它已被三个重要的全球2015年后议程所采用：可持续发展目标（SDG），《仙台减少灾害风险框架》和《联合国关于人口与发展框架公约》的《巴黎协定》。气候变化（IPCC，2012）。此外，科学社区（尤其是抗灾协会，以及国际洪水管理大会[ICFM7]于2017年将其成为领导概念）促进了抗灾力，并被许多地区和国家主管部门（例如亚行）采用欧盟（ADB，2014 ;欧盟，2013），洛克菲勒基金会（Rockefeller Foundation）的100弹性城市计划（ARUP，2014）和荷兰的三角洲计划（MOIE，2015），因此，人们普遍认为增强弹性是需要。

但是，关于什么确切意味着增强弹性没有共识。复原力的定义方式多种多样，从非常狭窄的“从洪水等干扰响应中恢复的能力”到非常广泛的定义：“通过避免或最小化影响并避免干扰来应对干扰和变化的能力。学习和适应能力，以保持对未来的适应力。” 最近，它似乎已成为一个保护伞概念，涵盖了几乎以前由“可持续性”涵盖的所有内容，包括适应（自适应管理）和转型（DHS，2008年）。）。尽管已经以多种方式使用了弹性概念，但这并不意味着它只是一个流行词。正如该词的流行程度已经显示出的那样，它涵盖了以前感觉不到的某些东西。

在洪水风险管理中，决策通常基于风险分析。从理论上讲，这些风险分析可以包括与社会相关的潜在影响。但是，它们通常被简化并集中在与最大洪水深度相对应的直接影响上，并具有一定的超越概率。有时，还包括淹没公司的业务中断和死亡风险，但通常排除所有其他间接和非货币影响。由于分析仅关注最大水深，而不关注导致这些水深的整个事件链，因此不容易考虑不直接影响水深的措施。具体而言，旨在延长警告时间，改善有效的紧急响应，增强恢复能力，或改建或其他地方的措施，降低未来风险的增加往往不被考虑。风险分析的这种有限的应用可能导致措施的选择不理想。此外，科学倾向于提供综合的风险数字，而外行人士并不认为小概率灾难的风险类似于与频繁的小影响事件相关的风险。极端事件似乎与总风险无关，但如果可以向他们展示其潜在影响，则决策者可能会将其视为相关事件。尽管保险业考虑了整个洪水损失曲线，但大多数洪水风险分析只给出了一个风险数字。这个数字并未揭示可能带来的深远的不确定性和潜在的意外及其影响（Merz等，风险分析的这种有限的应用可能导致措施的选择不理想。此外，科学倾向于提供综合的风险数字，而外行人士并不认为小概率灾难的风险类似于与频繁的小影响事件相关的风险。极端事件似乎与总风险无关，但如果可以向他们展示其潜在影响，则决策者可能会将其视为相关事件。尽管保险业考虑了整个洪水损失曲线，但大多数洪水风险分析只给出了一个风险数字。这个数字并未揭示可能带来的深远的不确定性和潜在的意外及其影响（Merz等，风险分析的这种有限的应用可能导致措施的选择不理想。此外，科学倾向于提供综合的风险数字，而外行人士并不认为小概率灾难的风险类似于与频繁的小影响事件相关的风险。极端事件似乎与总风险无关，但如果可以向他们展示其潜在影响，则决策者可能会将其视为相关事件。尽管保险业考虑了整个洪水损失曲线，但大多数洪水风险分析只给出了一个风险数字。这个数字并未揭示可能带来的深远的不确定性和潜在的意外及其影响（Merz等，而外行人并不认为小概率灾难带来的风险类似于与频繁的小影响事件相关的风险。极端事件似乎与总风险无关，但如果可以向他们展示其潜在影响，则决策者可能会将其视为相关事件。尽管保险业考虑了整个洪水损失曲线，但大多数洪水风险分析只给出了一个风险数字。这个数字并未揭示可能带来的深远的不确定性和潜在的意外及其影响（Merz等，而外行人并不认为小概率灾难带来的风险类似于与频繁的小影响事件相关的风险。极端事件似乎与总风险无关，但如果可以向他们展示其潜在影响，则决策者可能会将其视为相关事件。尽管保险业考虑了整个洪水损失曲线，但大多数洪水风险分析只给出了一个风险数字。这个数字并未揭示可能带来的深远的不确定性和潜在的意外及其影响（Merz等，大多数洪水风险分析仅给出一个风险数字。这个数字并未揭示可能带来的深远的不确定性和潜在的意外及其影响（Merz等，大多数洪水风险分析仅给出一个风险数字。这个数字并未揭示可能带来的深远的不确定性和潜在的意外及其影响（Merz等，2015）。最后，洪水风险管理仍通常是水务部门的责任，而对社会而言，更全面，更量身定制的方法将需要公民，企业，关键基础设施运营商和地方政府的参与。他们可能会从改进的洪水风险管理中受益，因此应该参与其中，尽管他们可能没有全面了解，但他们可以做出贡献。从COVID19危机中了解到，为了应对危险，需要所有参与者的参与。

采取抗灾力意味着愿意比洪灾风险分析更能解决更多的问题，并制定使社会能够应对各种危害的综合战略。复原力分析涉及分析系统对极端事件的响应（例如，城市，国家或社会的响应，还包括堤防或障碍之类的洪水管理基础设施），这种响应不能用每年“仅”欧元表示，而应显示出应对频繁和非常罕见的事件，对经济，福祉的影响以及事件发生期间对社会的一切影响，不仅在事件的后果，恢复期间，而且在长期内。此外，将弹性作为未来策略设计的指导原则可能会导致不同的起点：

在抵御洪水风险管理的实践中采取何种手段仍有待确定。对此的研究正在加强，但仍难以使事情实用。在这方面采用多项指导原则可能会有所帮助（De Bruijn等人，2017）。诸如“应用系统方法”（相对于局部优化）（Vorogushyn等人，2018），“还考虑超越设计事件以及如何应对此类事件”，“评估必须保持运行状态的原则”等原则提到了预期的损害，“评估社会的恢复能力”以及确定可能影响或提供机会来增强“未来复原力”的趋势和发展。为了将它们真正付诸实践，需要更好的指标，示例，工具方法和评估标准。正如“包容性绿色增长”一词所涵盖的那样，在成本效益比和对自然的影响之后，公平（在空间，群体之间以及世代之间）可能会被更多地包括在内。

因此，在所有可能发生的事件和较长的时间范围内，对抵御能力的关注使我们的思维方式从量化风险转变为了解系统行为和社会需求。这就需要详细阐述现有的方法并开发新的方法，以使社会能够应对现在和将来的洪水灾害。