区域自然灾害综合区划的二次聚类法及其在山东省的应用

灾害综合区划研究中，定量方法高级单位跨区现象往往不可避免，而定性区划低级单位界线难以确定。针对这一问题，从灾害系统观点出发，在充分分析灾害系统动力学模型的基础上，认为以长时间系列灾害资料为基础，自然致灾因子可反映孕灾环境稳定性信息。通过借鉴多维相似性指数的计算方法，利用Ward聚类得到山东省114个县级统计单元的聚类图谱。然后，根据自然灾害的自然和社会属性设计了各灾种的综合指标，并再次进行聚类分析。经过检验后发现，第一次聚类可以很好地反映灾害系统的中宏观分异，第二次聚类则在微观方面非常理想。因此，根据当地实际情况分别截取了二者合理的部分，组成了完整的区划方案，从而在一定程度上弥补了目前自然灾害综合区划方法的不足。

Study on Dual Cluster Analysis in Synthetic Regionalization of Regional Natural Disasters and Its Application in Shandong Province

In the synthetic regionalization of natural disasters,the different units are usually combined with the upper units in popular quantitative analysis, and it is difficult to divide the boundaries of lower units in qualitative analysis.Based on the theory of disaster systems and after analyzing the disaster system dynamical model,in this paper it is considered that the factors resulting in natural disasters can be used to reflect the information of stability of the disaster-forming environment based on the long-term available data of natural disasters.The cluster atlas of 114 statistical units at county level in Shandong Province is derived by using the ward cluster and the calculation method of multi-dimensional indexes.The synthetic indexes of the various natural disasters are designed based on the natural and social attributes,and their cluster analyses are carried out.The results are as follows:(1) According to the disaster system dynamical model,it is considered that the natural disasters are the results affected by all the factors in the disaster-forming environment,and the factors resulting in natural disasters are corresponding to the disaster-forming environment,so the factors resulting in natural disasters can be used to reflect the disaster-forming environment;(2) The composition of regional natural disasters can be used to reflect the stability of disaster-forming environment and the spatial distribution of natural disasters,which should be considered in regionalization of natural disasters at first;(3) It is difficult to derive an ideal regionalization scheme by one quantitative method only;(4) One of the basic conditions for using the method is to need the long-term available data of natural disasters.