【作者】 薛东剑；

【导师】 何政伟；

【作者基本信息】 成都理工大学 ， 地球探测与信息技术， 2010， 博士

【摘要】 我国由于地质和地理环境复杂,气候条件时空差异较大,地壳断裂活动分布普遍,是崩塌、滑坡、泥石流等地质灾害发生频繁的国家。同时我国的地震活动强度和频度也较高,全球大陆地区的大地震中,约有四分之一至三分之一发生在我国。由于地震影响区内地形起伏较大,地质构造复杂,加之余震频繁,影响了区内的地质环境条件,常常诱发大量的地质灾害,尤其发生在山区的地震,坡陡谷深,造成的地质灾害更为严重。地震诱发的大量崩塌、滑坡会使交通、通讯等中断,地面调查无法满足时效性要求,很难快速到达灾区,与此同时地震灾区经常气候异常,降雨频繁,仅凭光学影像也很难满足要求,结合微波雷达应用多源遥感技术、GIS技术开展地质灾害调查与风险评价是当今技术发展的必然趋势。遥感技术应用于区域地质灾害评价,虽然已取得了很多进步性成果,但是综合利用高分辨率机载、星载遥感图像、GIS技术进行地质灾害的精细解译、孕灾背景分析及风险评价的研究相对较少。本文以青川、平武县为例,在系统的研究工作中取得了如下研究成果和认识:(1)初步建立了较为系统的利用星载、机载光学与微波遥感技术研究地质灾害的方法体系,结合地质灾害的成因及发育特征,在前人研究的基础上完善了地质灾害遥感解译的方法,结合研究区特征阐明了遥感、地理信息技术在地质灾害调查、风险评价等中的作用。(2)探讨了遥感在地质灾害研究中的关键技术,包括数据源的选取、辐射校正、几何校正、正射校正、雷达成像几何特性及干涉雷达技术,提出了对地质灾害风险评价不同研究阶段及孕灾地质背景环境提取所适用的遥感数据源和处理方法。(3)在卫星过境前、卫星过境后及同步进行了综合遥感实验,进行多源数据同步获取,在多源数据协同处理的基础上提取地质灾害研究所需的相关因子;有针对性、有目的性的对重点研究区域进行了地面调查和雷达定标工作。(4)通过比较灾害前多光谱影像河道范围与灾害发生后X波段机载雷达图像河道提取结果,可以快速检测出河道的变化,这对于导致河道堵塞的大型滑坡提取效果较好;利用0.5米X波段机载雷达图像可以比较清楚的识别滑坡,相对于地面调查不但速度快,而且不受天气的影响,对地质灾害的监测与调查更为可靠和适用。(5)利用多时相SPOT、TM、航拍光学、雷达图像对滑坡等典型地质灾害进行了对比分析研究,实践证明,高分辨率多极化SAR图像对滑坡、堰塞湖、桥梁、房屋等的判读非常有效,特别是在云、雨、夜等气候恶劣条件下,无法获得高分辨率光学图像时,SAR作为光学遥感的补充,能够为应急指挥辅助决策提供及时准确的信息。(6)结合野外调查,利用多源遥感数据,进行了地质灾害孕灾背景、发育状况、承灾体的提取。在对青川、平武县研究区地质背景、灾害分布规律研究的基础上,确定了地质灾害评价的指标体系,利用不同的数学模型进行了地质灾害危险性评价,经对比分析,选取精度较高的模型对研究区进行了危险性评价及风险评价,分析结果与地质灾害发育现状非常吻合,对减灾救灾等有一定的参考价值。更多还原

【Abstract】 Crustal fracture activities is distributed universally because of china’s complex geological and geographical environment and quite different space-time of climatic conditions, thus china is a country where collapse, landslide, debris flow and other geological disasters occur frequently. Meanwhile intensity and frequency of China’s activity is higher than other countries.The world’s major earthquake in the mainland,about a quarter to one third,occurred in China.As undulating terrain in the areas affected by earthquake, complex geological structure, coupled with frequent aftershocks, the local geological environment is influenced and a large number of secondary geological disasters are induced. Especially the earthquake occurred in the mountainous areas often causes severe deformation of the surface and a lot of landslides and results in transportation and communication interrupted. Ground survey can not meet requirement of the timeliness, saving it is difficult to quickly reach the affected area. Coupled with frequent climate abnormal in the earthquake areas and rainfall frequency, so optical imaging alone is difficult to meet the requirements, and application of the multi-source remote sensing technology and GIS technology to carry out investigation and assessment of geological hazards is the inevitable trend of modern high-tech development. Although remote sensing technology in regional geological hazard investigation and evaluation has made many successful experiences, most stay the disaster point’s extraction and macro-regional evaluation in the use of optical images. The fine interpretation of geological disasters by comprehensive utilization of high-resolution airborne and satellite-borne remote sensing images and GIS technology, pregnant disaster background analysis and risk assessment research are relatively small. This paper, taking Qing Chuan and Ping Wu County as the example, has made understanding and research results in the systematic study, as follows:(1) More systematic methods and system which utilizes satellite-borne airborne optical and microwave remote sensing to research geological disaster is initially established; combined with the causes and development characteristics of geological disasters, method of interpretation of geological hazards is improved on the basis of previous research; combination of the study area, the roles of geological disaster survey and risk assessment through remote sensing technology are clarified.(2) Key technologies of remote sensing in the study of geological disaster, including data source selection, radiometric correction, geometric correction, ortho correction, geometric characteristic radar image and interference-in radar technology.(3) Taking a comprehensive remote sensing experiment before crossing the satellite, the satellite after the transit, and simultaneously and simultaneous multi-source data acquisition, geological hazards associated factors required are extracted based on collaborative processing of multi-source data; the ground survey work and radar calibration work are performed targetedly and purposefully to the important study areas.(4) By comparing the disaster-before multi-channel spectral image channel with disaster–after X-band airborne radar image channel extraction results, the changes in river channels can be quickly detected, which is better for the extraction effect of a large landslide leading to channel blocking. Using 0.5 meter X-band airborne radar images can more clearly identify landslide, which is more fast, relative to the ground investigation,and the geological hazards monitoring is more reliable and applicable when it clouds and rains.(5) The comparative analysis on landslide is performed to the major geologic hazards using multi-temporal SPOT, TM, aerial optical, radar images and other. It is proved that high-resolution and multi-polarization SAR image is very effective to interpretation of the landslide, barrier lakes, bridges, housing and so on. Especially in the clouds, rain, night and other bad weather conditions and failing to access to high-resolution optical images, SAR,as a supplementary of optical remote sensing,can provide timely and accurate information to make emergency command and aid decision.(6) Combined with field investigation and using of multi-source remote sensing data, geological disasters pregnancy background, the growth conditions and the extraction of host body are fulfilled. In the study of geology background and disaster distribution the hazard assessment index system is identified with mathematical evaluation models that appraise the geological hazards of the regional risk. By comparative analysis, selecting high precision model makes risk assessment and risk evaluation to study area.Risk assessment, analysis results and status of geological hazards are in good agreement, which have some reference value for disaster reduction and relief.更多还原