基于最大熵原理的城市防洪标准方案优选智能评价模型

Intelligent evaluation method for optimal selec-tion of urban flood control standard schemes based on the principle of maximum entropy

影响城市防洪标准的因素众多,为处理统计数据的模糊性和随机性,根据城市防洪标准的政治效果、社会效果、经济效果、环境生态效果综合最优原则,基于统计数据的变异性,根据主观性最小、最合乎自然、偏差最小的最大熵原理和使各方案对各分类级别的加权广义距离平方和最小的模糊理论建立目标函数,然后用加速遗传算法解此目标函数,得各指标权重,进而计算出各城市防洪标准方案的相对贴近度,从而建立方案优选智能评价模型,对城市防洪标准方案进行优选。应用结果表明,方案3(500年一遇的城市防洪标准)既能降低防洪费用,叉能达到较好的防洪效益。此模型的评价结果与其他方法虽有差异,但经过具体分析,智能评价方法所得结果是合理、客观的。

The present paper intends to propose its author＇ s evaluation method for optimal selection of urban flood control programs based on the principle of maximum entropy. As is known, whether successful or not, an urban flood control program may directly concern the investment of a city government and the safety and security of its residence. Due to the influence of various factors on the standards of urban flood control, such as those in politics, social public, economics as well as environmental protection, it is necessary to make the optimal selection of the key ones of them by eliminating fuzziness and random decision, the present authors suggested an intelligent evaluation method for optimal selection of urban flood control programs based on the principle of maximum entropy. The integrated principle of maximum entropy and the fuzzy theory that can make a square summation of generalized space with weight between apiece schemes and, classification grades with the smallest established objective function, which can then be uncoiled with accelerating genetic algorithm to get the index weight and then work out the relative close-degrees of the evaluation schemes. Therefore, when the intelligent evaluation method of optimal schemes is established, the optimal choice of such flood control standard schemes can be set up according to the principle of the integrated optimal choice of the factors concerned, such as those in politics, society, economy as well environmental protection, based on the variability of statistic data, trying to avoid the smallest subjectivity and the smallest deviation. The case study shows that scheme 3 can not only reduce the cost of urban flood control but also help to attain benefits of urban flood control. Though the difference between the evaluation results provided by the present method and those of others after the detailed analysis, the results of the given method prove reasonable, ilnpartial and valuable.