区域旱灾风险评估与诊断的动态差异度系数模糊数随机模拟方法

Stochastic Simulation Method of Fuzzy Number of Dynamic Difference Coefficient for Regional Drought Risk Assessment and Diagnosis

为更准确、稳健地进行旱灾风险动态评估、关键障碍因子的定量识别,构建了差异度系数随评价指标样本值动态变化的三角模糊数与随机模拟耦合方法,并用于宿州市2007—2017年旱灾风险评估与诊断研究中,得到宿州市置信概率为95%的旱灾风险评价值区间,结果表明:旱灾风险评价结果呈“先增加,后减小,最后趋于稳定”的变化趋势,旱灾风险综合评价结果为“轻险”;危险性、暴露性、抗旱能力三个子系统是影响研究区域旱灾风险综合评价结果趋势变化的主因;耕地率、水库调蓄率、农业人口比例评价指标被诊断为中阻碍型因子,是需要重点调控的对象;置信概率区间增加了风险评价结果的可靠性信息,可反映受多种不确定影响因素综合作用下的实际旱灾风险情况,充分体现了联系数所表征的“不确定性”这一信息。

In order to carry out the dynamic assessment of drought risk and the quantitative identification of key obstacle factors more accurately and robustly,a triangular fuzzy number and stochastic simulation coupling method with the dynamic change of the difference coefficient with the sample value of the evaluation index is constructed,and it is then used in the drought risk assessment and diagnosis study of Suzhou City from 2007 to 2017,and the drought risk evaluation value interval with a confidence probability of 95% in Suzhou City is obtained,and the results show that the drought risk assessment results shows a trend of “first increasing,then decreasing,and finally stabilizing”.The comprehensive assessment of drought risk is “light risk”;The three subsystems of risk,exposure and drought resistance are the main reasons affecting the trend change of the comprehensive assessment results of drought risk in the study area.The evaluation indicators of cultivated land rate,reservoir transfer and storage rate,and agricultural population ratio are diagnosed as medium hindrance factors,which are the objects that needed to be regulated.The confidence probability interval increases the reliability information of the risk assessment results,which can reflect the actual drought risk situation under the combined effect of various uncertain factors,and fully reflects the information of “uncertainty” represented by the number of linkages.