横断山区汶川县滑坡泥石流降雨致灾阈值研究  

On disaster threshold of landslide and debris flow rainfall in Wenchuan County

作　　者：孙鹏 胡磊 胡玉乾 张强[4] 李虎 湛睿 SUN Peng;HU Lei;HU Yuqian;ZHANG Qiang;LI Hu;ZHAN Rui(School of Geography and Tourism,Anhui Normal University,241002,Wuhu,Anhui,China;Faculty of Geographical Science,Beijing Normal University,100875,Beijing,China;State Key Laboratory of Earth Surface Processes and Resource Ecology,Beijing Normal University,100875,Beijing,China;Advanced Interdisciplinary Institute of Environment and Ecology,Beijing Normal University,519087,Zhuhai,Guangdong,China;Urban Geological Survey and Monitoring Institute of Hunan,410007,Changsha,Hunan)

机构地区：[1]安徽师范大学地理与旅游学院,安徽芜湖241002 [2]北京师范大学地理科学学部,北京100875 [3]北京师范大学地表过程与资源生态国家重点实验室,北京100875 [4]北京师范大学环境与生态前沿交叉研究院,广东珠海519087 [5]湖南省城市地质调查监测所,湖南长沙410007

出　　处：《北京师范大学学报（自然科学版）》2023年第2期187-195,共9页Journal of Beijing Normal University(Natural Science)

基　　金：第二次青藏高原综合科学考察研究资助项目(2019QZKK0906);安徽省自然科学基金优青资助项目(2108085Y13);安徽省高校协同创新资助项目(GXXT-2021-048;GXXT 2019047);安徽省高校优秀青年人才支持计划重点资助项目(gxyqZD2021094);湖南省地质院科研项目(HNGSTP202210);安徽省大学生创新创业训练资助项目(202010370186,202010370183,S202010370400)。

摘　　要：基于2001−2020年GPM L3降水数据和第二次青藏科考所获取的2018年汶川县汛期滑坡泥石流灾害隐患点目录,从强度、相对性、绝对性和持续性方面遴选11个极端降水指标,揭示汶川县极端降水时空演变规律;通过构建累积降雨量-降雨时间关系阈值(E-D)模型、优化雨场分割法、量化汶川县降雨型滑坡泥石流样本降雨阈值,分级预测2001−2020年降雨型滑坡泥石流灾害隐患点的危险等级.研究结果表明:1)极端降水指标在汶川县大部分乡镇点位的趋势变化不显著,大多数指标呈现北低南高、西低东高的空间分布特征.极端降水的相对性指标、强度性指标以及部分持续性指标在空间分布上具有一致性,高值区主要分布在汶川县东部和南部地区,其发生由极端降水诱发的滑坡泥石流地质灾害事件的可能较大.2)汶川县降雨型滑坡E-D阈值曲线为E=41.69·D^(0.84)(3≤D≤6),降雨型泥石流E-D阈值曲线为E=81.28·D^(0.36)(3≤D≤23).3)汶川县“易发生”的降雨型滑坡隐患点占比46.2%,集中位于水磨镇北部、漩口镇东部、草坡乡东南部、绵虒镇中南部、耿达镇东南部、映秀镇东部以及卧龙镇东北部,“易发生”的降雨型泥石流隐患点占比13.84%,集中位于草坡乡东南部和银杏乡西部,该些区域未来需重点关注其降雨预警.“易发生”“较易发生”的滑坡泥石流隐患点的分布与极端降水的强度性、相对性和部分持续性指标的高值分布具有高度的吻合性.本研究可为汶川县极端降雨诱发滑坡泥石流灾害事件的防灾减灾提供精细化预报预警.Data of GPM L3 precipitation from 2001-2020,catalogue of hidden danger points of landslide and debris flow disasters in flood season in Wenchuan County in 2018 from the second Qinghai-Tibet scientific expedition,were used to select 11 extreme precipitation indexes taking into account of intensity,relativity,absoluteness and sustainability,to reveal the spatiotemporal evolution law of extreme precipitation in Wenchuan County.Cumulative rainfall-duration relationship threshold(E-D)model was constructed,rain field segmentation method was optimized,rainfall threshold of rainfall-type landslides and debris flows in Wenchuan County was quantified,risk grade of hidden danger points of rainfall-type landslides and debris flows were evaluated for period 2001-2020.The change of extreme precipitation index in most villages and towns in Wenchuan County was found not obvious,most indexes showed spatial distribution of low in the north,high in the south,low in the west and high in the east.The relativity index,intensity index and partial persistence index of extreme precipitation were very similar in spatial distribution.The precipitation in the eastern and southern areas of Wenchuan County showed high intensity,relativity and persistence,likelihood for geological disasters due to extreme precipitation was high.The E-D threshold curves of rainfall-type landslides and debris flows in Wenchuan County were:E=41.69·D^(0.84)(3≤D≤6)and E=81.28·D^(0.36)(3≤D≤23),respectively.The“easy-to-happen”hidden danger points of rainfall-type landslides in Wenchuan County accounted for 46.2%,being concentrated in the north of Shuimo Town,the east of Xuankou Town,the southeast of Caopo Township,the south-central of Mianqi Town,the southeast of Gengda Town,the east of Yingxiu Town and the northeast of Wolong Town.The“easy-to-happen”hidden danger points of rainfall-type landslides accounted for 13.84%,being concentrated in the southeast of Caopo Township and the west of Yinxing Township.The distribution of“easy to occur”and“r

关 键 词：极端降水 降雨致灾阈值 滑坡泥石流 汶川县 

分 类 号：P467[天文地球—大气科学及气象学]