滑坡图像自动识别浅议

A Preliminary Discussion on Landslide Pattern Recognition

识别滑坡须先了解什么是滑坡,广义滑坡包括崩塌、滑坡、碎屑流、泥石流等所有斜坡重力侵蚀现象;狭义滑坡指部分斜坡沿着斜坡内的一个或数个面在重力的作用下作剪切运动的现象。各类滑坡有自已特殊的地表形态特征,发育的基本地质环境条件和触发因素,据这些特征识别滑坡。利用数字滑坡技术进行滑坡识别大致分为2步:(1)通过RS和GIS技术将不同时间的调查区地物现场以不同分辨率展现在数字图像上,并与地理控制及地质环境信息配准、组合,建立解译基础;(2)在滑坡地学理论指导下,通过人机交互方式进行解译和时空分析,获取减灾防灾需要的信息。该方法尚未达到遥感自动识别滑坡的程度,但建立解译基础的过程已可由计算机通过多种程序软件完成,故认为滑坡模式识别的前2个步骤:数字化及预处理已由计算机实现。现需探索的是用计算机实现基于滑坡地学理论知识,以人机交互方式进行的滑坡识别及分析过程。就狭义滑坡而言,基于DEM的滑坡地形识别已可由计算机实现。如能确定地面滑坡壁及滑体与地下滑面、滑床的关系,了解它们的光谱特征并建立计算模型,便可构建遥感技术的滑坡模式识别。

Identification of landslide should first understand what it is. Broad sense of landslide means all the slope gravitational erosion phenomena including rock fall, landslide, clastic flow and debris flow and so on; nar- row sense of landslide means the phenomenon that parts of slope move searing along one or several surfaces in- ternal the slope under the function of the gravitation. Each type of landslide has own special morphological char- acteristics on the ground and basic geological environmental conditions and trigger factors for growing. Accord- ing to the special characteristics the landslide can be identified. Digital Landslide Technique suggested based on the research and practice of RS＋GIS for landslide at home and abroad identification of the landslide can be divid- ed into 2 steps roughly. First, with RS＋GIS technique, ground features at different time were showed on digital images with different solutions. Through registration and combination with geological structure and geographic information, the base for remote sensing interpretation is established. Second, under the guide of theory of land- slide, by means of men-PC interactive mode, the remote sensing interpretation and time-space analysis are car- ried out and the key elements information of landslide for disaster prevention then are obtained. That methodshas not been reached automatic identification of landslide, but the process of establishing the base for remote sensing interpretation has been accomplished with several soft program procedure by PC, so it is considered that the first two steps, digitalization and preprocess for landslide pattern recognition have already realized by PC. Now we should explore the methods of landslide recognition and analysis procedure with computer calculation instead of men-PC interactive mode. For the narrow landslide sense, the landslide topography recognition has al- ready been conducted by computer based on DEM. If the relation between landslide scarp, deposit body on the ground and landslide surface, bed under the ground could be found, their spectral property could be determined and the calculating mode could be established, the landslide pattern recognition based on the remote sensing tech- nique then could be realized.