Institute of Hazard, Risk and Resilience, Durham University, Durham, UK.
Philos Trans A Math Phys Eng Sci. 2011 May 13;369(1942):1784-806. doi: 10.1098/rsta.2010.0346.
The mantra that policy and management should be 'evidence-based' is well established. Less so are the implications that follow from 'evidence' being predictions of the future (forecasts, scenarios, horizons) even though such futures define the actions taken today to make the future sustainable. Here, we consider the tension between 'evidence', reliable because it is observed, and predictions of the future, unobservable in conventional terms. For flood risk management in England and Wales, we show that futures are actively constituted, and so imagined, through 'suites of practices' entwining policy, management and scientific analysis. Management has to constrain analysis because of the many ways in which flood futures can be constructed, but also because of commitment to an accounting calculus, which requires risk to be expressed in monetary terms. It is grounded in numerical simulation, undertaken by scientific consultants who follow policy/management guidelines that define the futures to be considered. Historical evidence is needed to deal with process and parameter uncertainties and the futures imagined are tied to pasts experienced. Reliance on past events is a challenge for prediction, given changing probability (e.g. climate change) and consequence (e.g. development on floodplains). So, risk management allows some elements of risk analysis to become unstable (notably in relation to climate change) but forces others to remain stable (e.g. invoking regulation to prevent inappropriate floodplain development). We conclude that the assumed separation of risk assessment and management is false because the risk calculation has to be defined by management. Making this process accountable requires openness about the procedures that make flood risk analysis more (or less) reliable to those we entrust to produce and act upon them such that, unlike the 'pseudosciences', they can be put to the test of public interrogation by those who have to live with their consequences.
“政策和管理应该以证据为基础”这个口号已经得到了很好的认可。但不太为人所知的是，“证据”是对未来的预测（预测、情景、视野），即使这些未来定义了今天为实现可持续性而采取的行动，这其中所隐含的意义。在这里，我们考虑了“证据”与对未来的预测之间的紧张关系，“证据”是可靠的，因为它是被观察到的，而对未来的预测在常规意义上是不可观察的。对于英格兰和威尔士的洪水风险管理，我们表明，未来是通过政策、管理和科学分析交织在一起的“实践组合”而积极构成的，也是想象出来的。由于洪水未来可以以多种方式构建，管理必须限制分析，而且由于对会计核算的承诺，需要用货币术语来表达风险。它是基于数值模拟的，由遵循政策/管理准则的科学顾问进行，这些准则定义了要考虑的未来。需要历史证据来处理过程和参数不确定性，而想象出来的未来与所经历的过去联系在一起。由于概率（例如气候变化）和后果（例如洪泛区的开发）发生变化，对过去事件的依赖是预测的一个挑战。因此，风险管理允许风险分析的某些要素变得不稳定（特别是与气候变化有关），但迫使其他要素保持稳定（例如，援引法规以防止在洪泛区进行不当开发）。我们的结论是，风险评估和管理之间的假设分离是错误的，因为风险计算必须由管理来定义。要使这个过程负责，就需要向我们委托进行风险分析的人公开说明程序，使他们能够对洪水风险分析的可靠性（或不可靠性）进行更多（或更少）的评估，以便与“伪科学”不同，他们可以接受那些必须承受其后果的人的公开质疑。
