摘要:
开展危险性评价是灾害多发区预警预报和防灾减灾的重要措施之一。金沙江流域主要位于金沙江-哀牢山结合带，构造背景复杂，山地灾害多发，近年来因水电工程开发建设而逐渐引起学者关注。因此，本文以金沙江流域的泥石流为对象，结合野外调查和GIS技术，获得了金沙江流域干流及主要支流泥石流流域2551条，总体上，金沙江上游泥石流不活跃，以低中频为主，高频泥石流主要分布在下游段，尤以涛源镇至巧家段集中发育；基于泥石流活动特征开展泥石流危险性评价，并通过ROC检验以及空间聚类分析，完成了金沙江流域泥石流危险性区划。研究结果显示：（1）最有利于泥石流灾害形成的因素是：15~35°坡度、地震分布最密集、软硬相间的碎屑岩组中；（2）金沙江流域内中高危险泥石流占比47.48%，接近一半；（3）其中东川-巧家段的高危险区存在高聚集度，与活跃断层高度重合，物源丰富，基本受活跃断层控制。本研究获得的危险性区划图可为水力水电、交通廊道等工程开发建设中规避泥石流风险、制定防灾减灾措施提供参考依据。
Abstract:
Hazard assessment is a crucial measure for early warning, disaster prevention and mitigation in disaster-prone areas. The Jinsha River flows through the Jinsha River-Ailao Mountain suture zone, with complex tectonic background and frequent mountain disasters. Recently, it has gradually attracted the attention of academics due to the development and construction of hydropower projects. Hence, this paper takes the debris flow of the Jinsha River as the object, and combined with field investigation and GIS technology, 2551 debris flow of the main stream and key tributaries of the Jinsha River were acquired. In general, debris flow in the upper reaches of Jinsha River is not active, mainly low and medium frequency, whereas high-frequency debris flow is mainly distributed in the lower reaches, particularly in the Taoyuan to Qiaojia section. The hazard assessment of debris flow was carried out based on the characteristics of debris flow activities, and the zoning map was examined by the ROC test and spatial clustering analysis. The results show that: (1) the most favorable factors for the formation of debris flow are slopes between 15 ~ 35°, the most intensive earthquake distribution areas, and soft and hard alternating clastic rock groups; (2) The medium-high hazard debris flow in the Jinsha River accounts for 47.48 %, nearly half. (3) The high-hazard area of the Dongchuan-Qiaojia section has a high degree of aggregation, which is strongly coincident with the active fault, and the material source is abundant, basically controlled by the active fault. The hazard zoning map obtained in this study can provide a reference for avoiding debris flow risk and formulating disaster prevention and mitigation measures in the planning and construction of projects such as hydropower and traffic corridors.
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