Department of Urban Planning, National Cheng Kung University, Tainan, 70101, Taiwan.
The Hong Kong Institute for the Humanities and Social Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, China.
Environ Sci Pollut Res Int. 2021 Aug;28(29):38649-38663. doi: 10.1007/s11356-021-13515-3. Epub 2021 Mar 18.
With the climate change and the acceleration of urbanization, urban flood disaster is becoming increasingly frequent, leading to more severe impact than in the past. The traditional disaster alleviation strategies have gradually expanded to non-engineering disaster reduction strategies. As urban public property, public facility is more available than private land, making it the preferred strategy of site selection for urban land flood diversion. However, due to the limited government finance, how to select public facilities as the multi-use detention basin to maximize the disaster reduction and external benefits is an issue that needs to be considered before planning and decision-making. This study builds an operable decision model of site selection of urban public facilities as multi-use detention basin from the perspective of environmental efficiency. The decision model analyzes the expected costs and benefits of the multi-use detention basin based on data envelopment analysis (DEA) and cross-efficiency analysis, so as to establish the optimal combination of alternative schemes of site selection. It further compares with the traditional detention basin considering only disaster reduction efficiency to summarize how to improve the strategy of selecting multi-use detention basin site within the watershed in the future. This paper uses the watershed of Dajiaxi as a case study, and finds that (I) there is a certain trade-off relationship between the optimized schemes established from the perspective of environmental efficiency and disaster reduction efficiency evaluation. The scheme with the highest disaster reduction efficiency does not necessarily increase the external benefit significantly; (II) for the inefficient schemes, the difference between the site selection schemes and the ideal efficiency value can be measured through slack variable analysis.
随着气候变化和城市化进程的加速，城市洪涝灾害日益频繁，其造成的影响比以往更加严重。传统的减灾策略逐渐扩展到非工程减灾策略。公共设施作为城市公共财产，比私人土地更具可得性，因此成为城市土地调洪的首选选址策略。然而，由于政府财政有限，如何选择公共设施作为多用途蓄滞洪区，以最大限度地实现减灾和外部效益，是规划和决策前需要考虑的问题。本研究从环境效率的角度构建了城市公共设施作为多用途蓄滞洪区选址的可操作决策模型。该决策模型基于数据包络分析（DEA）和交叉效率分析，对多用途蓄滞洪区的预期成本和效益进行分析，从而建立选址替代方案的最优组合。进一步与仅考虑减灾效率的传统蓄滞洪区进行比较，总结未来在流域范围内如何改进多用途蓄滞洪区选址策略。本文以大甲溪流域为例进行研究，发现：（I）从环境效率评价和减灾效率评价的角度建立的优化方案之间存在一定的权衡关系。减灾效率最高的方案并不一定能显著增加外部效益；（II）对于效率较低的方案，可以通过松弛变量分析来衡量选址方案与理想效率值之间的差异。
