金沙江下游永善段隐蔽性滑坡隐患综合遥感识别

隐蔽性滑坡隐患是金沙江下游最普遍的地质灾害发育形式，具有隐蔽性强、突发性强、高位远程运动等特点。近年来，特大山区隐蔽性滑坡灾害案件频繁发生，对人民的生命财产造成了极大威胁。如何突破传统地质灾害调查手段的局限性、滞后性，提前有效识别隐蔽性滑坡隐患并探索其发育特征，对指导中国西南地区防灾减灾、工程规划建设具有重大科学意义。本文选择金沙江下游永善段地质灾害高易发区，利用升降轨时序InSAR–光学遥感综合识别方法，精细识别区域性时序地表形变、隐蔽性滑坡隐患光学遥感信息，通过野外考察，深入探索隐蔽性滑坡隐患发育特征。研究显示：1）通过升轨时序InSAR技术识别隐蔽性滑坡隐患26处，降轨时序InSAR技术识别隐蔽性滑坡隐患28处，光学遥感识别隐蔽性滑坡隐患48处（与升降轨时序InSAR识别结果有10处重合），合计识别滑坡隐患92处；对识别结果进行100%的野外考察，将升降轨InSAR和光学遥感识别结果划分为完全一致、部分一致、仅有光学遥感识别结果、仅有InSAR识别变形结果4种情况，识别准确率分别为82.86%、80.77%、75.00%和63.64%，总体识别准确率达78.26%，略高于目前国内滑坡隐患识别平均水平，验证了滑坡隐患识别的可靠性和有效性。2）通过对比分析综合遥感识别结果可知，InSAR技术和光学遥感的识别结果与二者的识别方式、影像成像条件、滑坡活动性关系密切，二者不能直接进行互检。3）通过分析滑坡发育特征可知，隐蔽性滑坡隐患发育规律随着地形地貌、地质条件的变化而变化，升降轨InSAR技术和光学遥感识别的隐蔽性滑坡隐患在地貌空间分布、地层岩性均存在一定差别。结果表明，综合遥感识别技术充分利用了升降轨InSAR技术和光学遥感识别方法的互补性，解决了隐蔽性滑坡隐患看不见、看不清、看不准的难题，提高了滑坡识别的准确率。

Comprehensive Remote Sensing Identification of Hidden Landslides in Yongshan Section of Lower Jinsha River

Hidden landslide hazard is the most common geological hazard in the lower reaches of the Jinshajiang River, which has the characteristics of strong concealment, and sudden and high-distance movement. In recent years, hidden landslide disasters occurred frequently in large mountainous areas, which posed a great threat to people''s life and property. How to break through the limitation and lag of traditional geological disaster investigation means, identify hidden landslide hidden dangers and explore their development characteristics in advance is of great scientific significance for guiding disaster prevention and mitigation and engineering planning and construction in southwest China. The Yongshan section of the lower Jinsha River was selected, which was highly prone to geological disasters, and proposed the lifting rail time series INSAR-optical remote sensing comprehensive identification method. By using this method, we can identify the optical remote sensing information of regional time series surface deformation and hidden landslide hidden danger and explore the development characteristics of hidden landslide hidden danger through field investigation. Research showed that: 1) 26 hidden landslide hazards were identified by rail ascending sequence InSAR technology, 28 by rail descending sequence InSAR technology, and 48 by optical remote sensing (10 overlaps). A total of 92 hidden landslide hazards were identified, and a 100% field investigation was conducted on the identification results. The InSAR and optical remote sensing recognition results of lifting orbit were divided into four types: Completely consistent, partially consistent, only optical remote sensing recognition results, and only InSAR deformation recognition results. The recognition accuracy was 82.86%, 80.77%, 75.00% and 63.64%, respectively, and the overall recognition accuracy reached 78.26%. It was slightly higher than the average level of the identification of landslide hidden danger in China, which verified the reliability and effectiveness of the identification of landslide hidden danger. 2) Through comparative analysis of comprehensive remote sensing identification results, it was found that the identification results of InSAR technology and optical remote sensing were closely related to their identification methods, imaging conditions, and landslide activity, and the two could not be checked by each other directly. 3) According to the analysis of landslide development characteristics, the development law of hidden landslide hidden danger changes with the change of landform and geological conditions. The hidden landslide hidden danger identified by the lifting rail InSAR technology and optical remote sensing has certain differences in geomorphic spatial distribution and formation lithology. The results showed that the complementarity of the two methods was fully utilized to solve the problem of the invisible, unclear, and inaccurate hidden danger of hidden landslides, and improved the accuracy of landslide identification.