基于DEM的东川泥石流地质环境远感研究.doc

基于DEM的东川泥石流地质环境远感研究 【中文摘要】泥石流是我国西部山区常见的一种突发性地质灾难现象,其相关规律研究已引起相关部分与学者的重视。而作为泥石流发育的主要诱导因素,其相关地质环境条件的研究也逐渐深进。影响泥石流发育的地质环境主要包括地形地貌与地质条件地形地貌条件为泥石流提供位能,赋予泥石流一定的腐蚀、搬运和堆积的能量;地质条件为泥石流提供丰富的固体物质来源。因此,研究泥石流相关地质环境条件对于把握泥石流致灾规律及制订防灾减灾措施具有重要意义。远感和摄影丈量技术的发展为泥石流等地质灾难现象建立地表三维模型提供了丰富的数据源和先进的手段。作为地形地貌的一种数学表达,数字高程模型DEM提供了三维分析数据基础。基于DEM模型天生的三维远感影像能更直接、正确、逼真地反映泥石流细部特征,并能实现泥石流特征要素的定量化表达。本文以昆明市东川区为研究对象,充分收集、研究前人资料和有效利用其它信息源资料的基础上,矢量化14幅东川15万地形等高线,构建15万高精度DEM模型;以Landset-7ETM远感数据作为主要远感数据源,探讨泥石流研究中的关键远感技术方法,实现泥石流地质环境远感解译;利用DEM结合远感数据天生研究区远感三维影像图,实现泥石流特征要素的定量识别;最后实现对研究区泥石流危险性评价。基于上述思路实现了基于DEM模型研究区地形地貌相关因子高程、地形起坡度、坡度等及特征线山脊线与山谷线的提取;基于ETM远感数据研究区的岩性、植被等信息的自动提取并发展线性构造机自提取方法;基于三维远感模型对研究区成功解译泥石流沟117条,并对各泥石流沟的流域面积、相对高差、主沟纵坡降、均匀坡度等要素进行定量化表达;基于灰度系统理论中的关联度方法对所选评价因子进行排序,并公道赋予权重,进行研究区的泥石流灾难危险性分区与评价,将研究区分为6级危险区极度危险、高度危险、明显危险、中度危险、轻度危险、无危险。对比分析结果可知,分区结果与泥石流点发育现状吻合较好。; 【Abstract】 Debris flow is a kind of paroxysmal geologic hazard which is familiar in the west mountainous areas of our country. It directly threatens the safety of people\s life and property and hampers local economic development. As the main factor to development of debris flow, the geological environment related to debris flow is gradually in-depth researched. The geological environment which impacts the development of debris flow includes topography and geological conditions topography provides potential energy conditions and endows debris flow with enery for corroding, transiting muds and rocks; the geological condition provides the rich solid matter origin for the debris flow Researching and surveying the geological environment background elements related to the ation and development of debris flows have the vital practical significance and value to people for mastering natural hazards\ rule and alleviating and defending hazards measures.The development of Remote Sensing and Photogrammetric technologies offers rich data sources and advanced s to model the earth\s su***ce for researching geographic phenomena such as debris flow. As a kind of mathematic expression for terrain, Digital Elevation Model DEM can provide basic three-dimension 3-D analyzing data. 3-D images of remote sensing which is generated from remote sensing images based on DEM can reflect detail characteristics of debris flow more direct, accurate and realistic and can realize quantitative expression of debris flow\s correlation essential factors.This article took Dongchuan District of Kunming as the study area. On basis of fully collecting and researching predecessors\ research results, this *** took 150000 topographical data as the basis topographical sorce to discusse s of high-precision DEM modal\s approach and took Landset-7 ETM data as the main source of remote sensing data, combining theoretical knowledge of remote sensing, to discusse the key remote sensing technology on the study of debris flow, and in this way realized interpretation of the geological environment; Based on DEM produced 3-D remote sensing image and realized characteristics Elements of the quantitative identification; Finally realized uationof debris flow risk. Based on the above ideas, this *** finally achieved the following results Based on DEM, factors such as altitude, hypsography, slope, etc and characteristic lines such as ridge lines and valley lines which correlate with physiognomy morphological character of study area were extracted and character statistics were analyzed; Based on ETM remote sensing image, lithology, vegetation and other ination related to geological environment of study area were automatically extracted and linear structures automatic extraction was developed; Based on 3-D remote sensing image of study area, the quantitative identification of debris flow was realized. In this ***, 117 debris flows were successfully interpreted and their morphological characters such as drainage area, relative altitude, valley bed longitudinal slope, average inclination, etc were expressed quantificationally; In this ***, many controlling assessment factors that were used to assess region risk of debris flow were chosen. Based on multi-factors correlation analysis in Grey System Theory, those factors were carried on sorting and each factor was given a logical weight. Accordingly, this *** uated the risk of debris flow of study area and assessed the result. Contrasting the district result and distribution status of debris flow point on study area may know that the result tallies well with the status quo of debris flow point.This applying research not only provides the basic data and scientific basis for drawing measures and establishes a good foundation for further understanding the law of debris flow on study area, but also provides a new reference for natural hazards survey ology. The practice has proved that 3-D visualization of remote sensing images which are structured based on DEM is feasible applied to single debris flow identification, pregnant hazard background checks, risk uation study and so on.