基于改进突变评价法的黄河凌汛灾害风险评价

The Yellow River Ice Flood Disaster Risk Assessment Based on Improved Catastrophe Theory Evaluation Method

针对突变评价法综合评价值偏高、评价值之间比较接近的问题,提出了一种采用三参数指数型曲线进行回归分析的改进方法,并对改进方法的合理性进行了验证,计算得到的改进评价值与常规评价值相比,不仅大小排序一致,而且极差明显增大,数据在[0,1]的分布更加分散。从凌灾的自然属性和社会属性两个方面出发,建立了4个层次的黄河凌汛灾害风险评价指标体系,并将改进方法应用于黄河内蒙古头道拐至万家寨河段两岸4个旗县的凌汛灾害风险评价中。结果表明:偏关县属于极低风险地区;准格尔旗属于高风险地区;清水河县和托克托县均属于中等风险地区;常规突变评价法得到的综合评价值很接近,除偏关县外,其余均集中在[0.912,0.941],不利于直观有效地区分风险的大小程度,而改进的突变评价法使调整后的综合评价值分布范围有效扩大,极差达到了0.446,具有更高的分辨水平,风险的大小等级更具可比性。评价结果与对各地区实际凌情的分析基本一致。

Considering the problem that the comprehensive evaluation value of the catastrophe theory evaluation method was too high and the evaluation values were relatively close,an improved method for regression analysis using a three-parameter exponential curve was proposed and verified by two examples.Not only the calculated im-proved evaluation value and the conventional evaluation value were the same in size order,but also the range was significantly increased,and the distribution of the data on[0,1]was more scattered.Considering the natural and social attributes of the Yellow River ice flood disaster,established a four-level risk evaluation index system was established,and the improved method was applied to the ice flood disaster risk assessment of 4 counties on both sides of the Yellow River from Toudaoguai to Wanjiazhai in Inner Mongolia.The results showed that Pianguan County was in a very low-risk area;Zhungeer Banner was in a high-risk area;Qingshuihe County and Tuoketuo County were in the medium-risk area.The comprehensive evaluation values obtained by the conventional catastrophe theory evalua-tion method were very close,except for Pianguan,the rest are concentrated in the interval[0.912,0.941],which was not conducive to intuitively and effectively distinguishing the degree of risk.The improved method could effectively expand the distribution range of the adjusted comprehensive evaluation value,and the range reached 0.446,which had a higher level of resolution,and the level of risk was more comparable.The evaluation results were basically consistent with the analysis of actual ice conditions in various regions.