基于面向对象的云南永胜县金官盆地东缘古滑坡群识别

Objectoriented identification of ancient landslide swarms on the eastern margin of the Jinguan Basin,Yongsheng County,Yunnan

古滑坡在一定内外力作用下可能复活,对区域人民群众生命财产安全存在威胁,因此,古滑坡群的准确识别对其细节特征剖析、稳定性评价和隐患早期判别等工作具有重要的理论及现实意义。文中以云南永胜县金官盆地东缘山地地区为研究区,利用GF-2遥感影像数据和DEM数据,采用面向对象的分类方法,提出一种基于植被覆盖度与目视解译区分植被后,结合光谱、地形和纹理等特征识别古滑坡滑源区的方法,进而建立古滑坡滑源区识别特征规则集,最后结合野外实地调查和目视解译对识别结果进行精度分析。结果表明:(1)在程海-宾川断裂带北端的金官盆地东缘地区共计识别出古滑坡群13处,分布受程海-宾川断裂带控制明显,具有明显的下盘效应,在龙潭滑坡西北方向约4 km范围内沿断裂带连续分布。(2)正确识别的古滑坡滑源区总面积为3.09 km^(2),其中以龙潭滑坡最为典型,滑坡特征清晰,圈椅状地形明显,滑源区后缘高程为2360 m,滑坡后壁崩塌堆积体坡度达30°以上。(3)结合识别结果、目视解译和野外实地调研,采用文中的方法识别古滑坡滑源区的正确识别精度高达91.54%,识别质量百分比为86.26%。本研究提出的方法可为类似古滑坡识别与古滑坡复活隐患评估等研究工作提供参考和技术支持。

Under certain internal and external forces,ancient landslides may be resurrected,which will be a threat to the lives and properties of the people in the region.Therefore,the accurate identification of ancient landslides group has important theoretical and practical significance for its detailed feature analysis,stability evaluation,and early identification of hidden dangers.Taking eastern margin mountain of Jinguan Basin,Yongsheng County,Yunnan Province for research area,and using GF-2 remote sensing image data and DEM data,this paper proposes a method to identify the source region of ancient landslides based on vegetation coverage and visual interpretation,combined with spectral,terrain and texture features based on object-oriented.Furthermore,the feature rule set of ancient landslides source area is established.Finally,the accuracy of the identification results were analyzed by field investigation and visual interpretation.The results show that:(1)13 ancient landslides have been identified in the eastern margin of the Jinguan Basin at the northern end of the Chenghai-Binchuan fault zone,which continuously distributed along the fault zone within a range of about 4km in the northwest of Longtan landslide.The distribution is obviously controlled by the Chenghai-Binchuan fault zone,which has obvious footwall effects.(2)The total area of the correctly identified ancient landslide source area is 3.09km^(2),of which the Longtan landslide is the most typical with clear landslide features and distinct arm-chair shaped topography.The main scarp of the landslide has the maximum elevation of 2360 m,and the slope of main scarp deposit is 30°.(3)Combining the recognition results,visual interpretation and field investigation,the correct recognition accuracy of the ancient landslides source area by this method is as high as 91.54%,and the recognition quality percentage is 86.26%.The method proposed in this study can provide reference and technical support for research work such as identification of ancient landslides and evaluation of hidden dangers of ancient landslides resurrection.