永胜刘官河流域泥石流灾害危险性评价

永胜刘官河位于云南省丽江市永胜县期纳镇境内,该流域在地形、地貌、地层岩性、地质构造和气候等相互作用的影响下,易发生泥石流灾害,严重威胁了当地居民正常的生产生活及生命安全。在调查与理论分析的基础上,选取松散物源储量、流域面积、主沟长度、相对高差、日最大降雨量、切割密度和不稳定沟床比等7个评价因子,通过组合赋权法结合多因素综合评价法构建评价模型对该流域危险性进行评价,得到永胜刘官河流域泥石流属于中度危险,评价结果与该流域泥石流的实际调查基本吻合。评价结果表明在未来的一段时间内,刘官河流域存在诱发间歇性中等规模泥石流灾害的可能,尤其是在雨季降雨条件下,诱发中等规模泥石流的可能性仍然较大,为该流域泥石流灾害潜在危险的预防提供了理论基础。

RISK EVALUATION OF DEBRIS FLOW IN THE LIUGUAN RIVER VALLEY OF YONGSHENG COUNTY

The area of the LiuGuan river valley,located in the centre of Qina town Yongsheng county Lijiang city Yunnan province,Affected by the interaction of topography,geomorphology,stratum lithology,geological structure and climate,et al,The debris flow disasters occurred easily in this basin,which threaten seriously the normal production and life safety of local residents.Based on investigation and theoretical analysis of Liuguan river valley,seven evaluation factors,such as,debris flow scale,drainage basin area,main channel length,relative relief,daily maximum precipitation,dissected density and shifting bed proportion,et al,are selected and risk evaluation of debris flow in the LiuGuan river valley is evaluated by using combined weight method and the multiple-factor comprehensive evaluation method to establish evaluation model.It can obtain risk evaluation of debris flow in this valley belong to moderate hazardous level.The evaluation results are basically in line with the actual investigation of mudslides in this basin.Research results show that the valley occur intermittent medium-scale debris flow disaster is possible for future quite a long time,in particular,It will easily induce medium scale debris flow disaster in the rainy season.Research results provide theoretical basis for prevent potential hazards in Liuguan river valley.