摘要
甘肃省迭部县位于白龙江流域上游区段,在构造抬升及极端气候的影响下,泥石流灾害广泛发育。通过遥感解译与实地调查,遴选出流域面积、主沟长度、流域相对高差、主沟纵比降、平均坡度、流域形状系数、岩性因子、距断层距离、1 h最大降雨量、物源参照值共10个主要孕灾因子。结合地理信息系统(geographic information system,GIS)技术,计算区内泥石流在各个孕灾因子的敏感性区间。进一步分别基于灾害熵模型与层次分析法模型对迭部县161条泥石流沟开展危险性评价,并将评价结果与区内历史泥石流灾害数据对比验证。分析结果表明:迭部县泥石流主要分布在流域面积为3~10 km^(2),主沟长度小于3.5 km,流域相对高差在1~1.5 km范围内,主沟纵比降大于200‰,平均坡度为25°~35°,流域形状系数为1.2~1.4,物源参照值介于0.35~0.6,距断层5 km以内,1 h最大降雨量为25~35 mm的沟谷内,沟内岩性以较软岩、松散堆积层及冲洪积层为主。危险性评级为中、高的泥石流沟作为区内最容易发生泥石流的区域,历史泥石流沟分别有74.07%和62.96%处于灾害熵模型与层次分析法模型评价结果的中、高危险性区域,说明灾害熵模型能更为准确地评估研究区泥石流危险性。
Diebu County of Gansu Province is located in the upper reaches of Bailong River Basin.Under the influence of tectonic uplift and extreme climate,debris flow disasters are widely developed.Through remote sensing interpretation and field investigation,10 major disaster factors were selected,including watershed area,length of main gully,relative elevation difference of main gully,longitudinal gradient of main gully,average slope,watershed shape factor,lithology factor,distance from fault,maximum rainfall in one hour and reference value of source.Combined with geographic information system(GIS) technology,the sensitivity interval of debris flow in each hazard factor was calculated.Further,based on disaster entropy model and analytic hierarchy process model,the risk assessment of 161 debris flow ditches in Diebu County was carried out,and the evaluation results were compared with the historical debris flow disaster data in the area.The analysis results show that the debris flow in Diebu County is mainly distributed in the drainage area of 3~10 km^(2),the length of the main gully is less than 3.5 km,the relative elevation difference of the basin is within the range of 1~1.5 km,the longitudinal gradient of the main gully is greater than 200‰,the average slope is 25°~35°,the basin shape coefficient is 1.2~1.4,and the provenance reference value is 0.35~0.6,within 5 km from the fault,the maximum rainfall in one hour is 25~35 mm in the gully.The lithology in the gully is mainly soft rock,loose accumulation layer and alluvial layer.Debris flow gully with medium and high risk rating is the most prone area to debris flow in the study area.74.07% and 62.96% of historical debris flow gully are in the medium and high risk areas evaluated by disaster entropy model and analytic hierarchy process model,respectively,indicating that disaster entropy model can more accurately assess the risk of debris flow in the study area.
作者
冯培华
向灵芝
罗亮
雷青青
崔开林
梁梦辉
FENG Pei-hua;XIANG Ling-zhi;LUO Liang;LEI Qing-qing;CUI Kai-lin;LIANG Meng-hui(Key Laboratory of Geological Hazards Mitigation for Mountainous Highway and Waterway,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《科学技术与工程》
北大核心
2023年第29期12416-12426,共11页
Science Technology and Engineering
基金
第二次青藏高原综合科学考察研究泥石流专题(2019QZKK0902)
国家自然科学基金(41807272)
重庆市研究生联合培养基地建设项目(JDLHPYJD2018001)。
关键词
泥石流
危险性评价
灾害熵
层次分析法
迭部县
debris flow
risk assessment
disaster entropy
analytic hierarchy process
Diebu County
