Data_Sheet_2_Sensitivity analysis of indicator weights for the construction of flood vulnerability indexes: A participatory approach.docx

The assessment of flood vulnerability is a complex task that involves numerous uncertainties. Within this context, sensitivity analyses are crucial to better understand the variability of vulnerability index outcomes according to different input parameters. The present study sheds light on the importance of assessing the sensitivity of different criteria weights to construct flood vulnerability indexes using the Maquiné basin (Brazil) as a case study. Specifically, we compared vulnerability scores based on weights derived from a participatory survey with 44 stakeholders to those based on an equal weighting scheme. Results helped us identify areas with low and high uncertainty and the variables contributing to this. Overall, the preference for indicator weights did not vary significantly among stakeholders with distinct socioeconomic characteristics. Furthermore, the choice of weights only had an impact on the spatial distribution of flood vulnerability in certain regions. Compared to equal weights, the flood vulnerability outcomes obtained by averaging the stakeholder scenarios were similar, indicating that the results were robust and not highly sensitive to the choice of weights. By adopting a participatory approach, we were able to consider multiple stakeholders' views, which helped to provide a more comprehensive perspective of flood vulnerability and potentially increased the acceptance of the results. Based on our findings, end-users can better understand the relative importance of each indicator and how they contribute to vulnerability. Furthermore, our results can help identify points where stakeholders disagree, which can be used to facilitate dialogue and consensus building. The methodology applied is straightforward and could be easily adapted to other multi-criteria decision-making problems.

洪水脆弱性（flood vulnerability）评估是一项涉及诸多不确定性的复杂任务。在此背景下，敏感性分析（sensitivity analyses）对于明晰不同输入参数下脆弱性指数结果的变异性至关重要。本研究以巴西马基尼耶流域（Maquiné basin）为研究案例，阐明了针对不同准则权重开展敏感性分析以构建洪水脆弱性指数的重要性。具体而言，本研究将基于44名利益相关者（stakeholders）参与式调查（participatory survey）所得权重计算的脆弱性得分，与基于等权重方案（equal weighting scheme）的得分进行了对比。研究结果明确了不确定性程度高低不一的区域，以及造成该不确定性的相关变量。总体而言，不同社会经济背景的利益相关者对指标权重的偏好并无显著差异。此外，权重的选择仅对部分区域的洪水脆弱性空间分布产生影响。与等权重方案（equal weighting scheme）相比，通过对利益相关者情景取平均所得的洪水脆弱性结果并无显著差异，这表明研究结果具备稳健性，且对权重选择的敏感性较低。本研究采用参与式方法，兼顾了多类利益相关者的观点，有助于更全面地刻画洪水脆弱性的内涵，同时也提升了研究结果的认可度。基于本研究结果，终端用户能够更清晰地认识各指标的相对重要性，以及其对脆弱性的贡献机制。此外，本研究结果可用于定位利益相关者存在分歧的议题，从而为开展对话、凝聚共识提供支撑。本研究所采用的方法简便易行，可轻松适配其他多准则决策（multi-criteria decision-making）问题。