干旱灾害调查与风险评估方法（征求意见稿）

21DroughtdisasterinvestigationandriskassessmXXXX-XX-XX发布I 2 3 6 9 本文件按照GB/T1.1—2020《标准化工作导则第1部分：标准化文件的结构和起草规则》的规定起本文件主要起草人：刘鸣彦，赵春雨，周晓宇，崔妍，李经纬，侯依玲，李明倩，敖1干旱灾害调查与风险评估方法GB/T20481-2017气象干旱QX/T597-2021区域性干旱过程监某时间段内由于天气气候异常引起的地表水分短缺的2干旱灾害承灾体暴露度droughtdisa干旱灾害承灾体脆弱性droughtdisastervu干旱灾害发生的可能性及其造成的损失或不利4干旱灾害调查4.1.1气象观测数据4.1.2灾情数据4.1.3承灾体数据区域总人口、国民生产总值（GDP）、农作物4.1.4基础地理信息），4.2干旱过程识别4.2.1气象干旱指数的选取4.2.2干旱过程客观识别方法干旱过程识别以MCI为基础指标，依据《区域4.3干旱灾害调查内容4.3.1历次干旱过程致灾危险性调查3对湿润度指数、受干旱灾害影响的承灾体（人口、经济、农作物）数量和价值量的调查。4.3.2年度干旱致灾危险性调查5.1干旱危险性评估基于30年以上的历史序列，优选拟合分布函数（附录B），计算度阈值，通过权重求和的方法得到干旱危险性评估指数，按公式（1）计H——干旱危险性评估指数；43214注：为区域H的算术平均值，δ为区域H的标准差5.2干旱灾害风险评估···················································将致灾危险性、承灾体暴露度和承灾体脆弱性各指标进行归一化（附录），RI=Hwℎ×Ewe×Vwv·································································(3)基于干旱灾害风险评估指数RI，根据研究范围，按照距标准差的倍数进行等·················································xi——干旱风险评估指数值;——干旱风险评估指数值的区域平均值;标准参考等级划分见表2，分为五级：低、较低、中、较高、高554321α≤-2-2<α≤-1-1<α≤11<α≤2α>26个次次次次次7%℃日天天天天天8次次次次次9俗称n年一遇。重现期的计算方法一般以现有观测数据为基础，使用数理统计方法，用某种分布方式来α−1e−β····································································································································································································································P(x)=P(x≥x)=1−e−e−a(x−b)····················································(B.7)式中：a是尺度参数，b是分布密度的众−0.5772×Sx·········2/2δ····················································1lnXi···················································2···································比重pij：pij=···················································x’=0.5+0.5×(x−xmin)⁄(xmax−xmin)·························