The threat that climate change poses to water resource systems has led to a substantial and growing number of impact studies. These studies follow two approaches: (a) top-down studies are driven by projections of future climate change provided by downscaled general circulation models (GCMs); and (b) bottom-up studies are driven by the systematic evaluation of exploratory scenarios. Top-down approaches produce realistic scenarios rooted in the simulation of thermodynamic and dynamic processes represented in GCMs, but the internal resolution of these processes make it difficult to link vulnerabilities to discrete components of change. Bottom-up approaches link vulnerabilities to discrete components of change through the structured evaluation of exploratory scenarios, but the lack of insight rooted in climate change processes can lead to the development of implausible scenarios. This paper evaluates exploratory scenarios developed through thermodynamic and dynamical guided perturbations motivated by GCM-bound insights. The result is a hybrid approach that bridges a gap between top-down and bottom-up approaches. This yields several advantages. First, emerging vulnerabilities are linked to distinct thermodynamic and dynamic processes that are modeled in GCMs with differential likelihoods and plausible ranges of change. Second, the structured evaluation of process-informed exploratory scenarios link system vulnerabilities to distinct components of climate change. An illustrative case study demonstrates perturbations linked to thermodynamic and dynamical processes have a large impact on stakeholder-defined flood and drought performance, and the structured evaluation of process-informed exploratory scenarios find nuanced infrastructure-specific vulnerabilities that would be difficult to identify using an alternative approach.

中文翻译：

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弥合自上而下和自下而上的气候脆弱性评估之间的差距：以流程为依据的探索性情景识别基于系统的水资源脆弱性


气候变化对水资源系统构成的威胁导致了大量且数量不断增加的影响研究。这些研究遵循两种方法：（a） 自上而下的研究是由缩小的环流模型 （GCM） 提供的未来气候变化预测驱动的;（b） 自下而上的研究是由对探索性情景的系统评估驱动的。自上而下的方法产生了植根于 GCM 中表示的热力学和动力学过程模拟的现实场景，但这些过程的内部解决方案使得很难将脆弱性与变化的离散组成部分联系起来。自下而上的方法通过对探索性情景的结构化评估，将脆弱性与变化的离散组成部分联系起来，但缺乏植根于气候变化过程的洞察力可能会导致难以置信的情景的发展。本文评估了由 GCM 绑定见解驱动的热力学和动力学引导扰动开发的探索性情景。结果是一种混合方法，弥合了自上而下和自下而上方法之间的差距。这会产生几个优点。首先，新出现的脆弱性与不同的热力学和动力学过程有关，这些过程在 GCM 中建模，具有不同的可能性和合理的变化范围。其次，对过程知情的探索性情景的结构化评估将系统脆弱性与气候变化的不同组成部分联系起来。 一个说明性案例研究表明，与热力学和动力学过程相关的扰动对利益相关者定义的洪水和干旱表现有很大影响，并且对过程知情的探索性情景的结构化评估发现了细微的基础设施特定脆弱性，这些脆弱性很难使用替代方法识别。