突变级数法在区域生态系统健康评价中的应用

目前在多目标综合评价方面有层次分析、因子分析、模糊评判等诸多方法．但有些方法对权重的确定主观性较大或计算过程过于复杂。介绍了突变理论用于多准则决策问题的基本思想和步骤，该法不需对评价指标赋以权重。它只考虑指标的相对重要性。避免了直接使用难于确定且主观性较大的“权重”概念。因而显得简易。同时．突变级数是一种多维模糊隶属函数。用它来计算通常模糊数学的多目标评价决策问题。就更适宜和更准确。以广东省生态系统健康评价为实例．引用相关文献中的数据构建了适用于突变级数法的层次结构指标体系．运用突变理论中的归一公式。计算了广东省生态系统的健康得分，发现健康排名与实际情况较为符合．证明了该方法的可行性。文章同时使用了加权平均法对指标体系进行计算，通过比较。发现原文献的结果与本文采用的两种方法的评价结果基本一致。尤其是健康程度较好和较坏的区域。实例表明．突变级数法较为简便、快捷和可靠。这为解决区域多目标评价问题提供了一种新的思路。

Application of Catastrophe Progression Method to Evaluation of Regional Ecosystem Health

There have many methods for multiple object comprehensive evaluation, such as analytic hierarchy process, factor analysis, fuzzy evaluation and so on. But some methods have defects with more subjectivity on weight decision or too complex processes in calculation. The paper introduces the main steps and idea of a method using catastrophe theory-called catastrophe progression method. Its characteristic is combining catastrophe theory with fuzzy mathematics and only considers the relative importance of the index, so the method avoids the subjectivity for weight decision. Catastrophe progression method also has advantages in solving problems of fuzzy multiple object decision because the catastrophe progression is a multidimensional fuzzy membership function. With these characteristics, the method is easier and the results are more precise. We take evaluation of regional ecosystem health in Guangdong province as an example to test the effectiveness of the method. Taking data from reference and constructing the hierarchy based on catastrophe progression method, we calculate the health scores of ecosystem in Guangdong province using normalizing formula. The results are found to be coincident with practical situation, so it proves the catastrophe progression method works well. We also use the weighted average method to calculate the index system and compared the results with catastrophe progression method and original reference. It shows the conclusions are almost consistent, especially those with the health evaluation of better and worse. From the calculation process we found that catastrophe progression method works simply and quickly. So the method was proved feasible in practice and provides us a new way in solving the problems of multiple objects comprehensive evaluation.