【作者】 李少达；

【导师】 杨武年；

【作者基本信息】 成都理工大学 ， 地球探测与信息技术， 2011， 博士

【摘要】 地震诱发地质灾害可能造成的破坏和影响是极为严重的,有时甚至超过地震直接造成的灾害损失。充分认识和防范地震诱发地质灾害可能造成的冲击和影响,对防御和减轻灾害具有举足轻重的作用；准确、快速地确定震后诱发地质灾害点,对可能发生的诱发地质灾害作出合理评价,并及时采取相应的防御措施,是尽可能避免和降低地震诱发地质灾害造成巨大损失的有效手段。遥感技术是当代非常重要的科技手段,在灾区信息获取工作方面具有实时、覆盖范围广、数据类型丰富、分辨率高等特点,能够及时快速获取与滑坡、崩塌、泥石流和堰塞湖等地震诱发地质灾害点发育分布特征信息,为救灾计划制定、灾情评估、灾后重建、减轻灾害的影响等提供科学决策依据。遥感技术用于地震诱发地质灾害评价及相关领域,虽然已经有相当多的成功案例和有益经验,但主要集中在灾害点信息提取和宏观区域评价等方面,对基于高精度遥感解译,进行地质灾害体的精细解译、地质灾害体内部结构信息的提取、地质灾害的产生过程的分析,以及对这些信息的综合应用和分析等方面还需要进一步深入研究。本文以汶川地震极重灾区潜在突发性地质灾害易发区为研究对象,结合野外现场调查资料,重点研究与探索遥感技术在突发性地质灾害应急处理工作中遥感图像处理、地质灾害快速信息提取与解读,以及灾害信息库的建立等关键技术。论文主要研究内容和取得的创新成果与认识有以下方面：(1)提出了一种改进的遥感图像增强方法Russo提出了一种模糊图像增强方法,该方法相比其它常用方法有一定的优越性,但是,由于该方法中参数是固定的,所以效果并不理想。有学者针对该方法的参数调节提出了一些自动化方法,使该方法有了一定的改进,但效果仍不理想。本文通过对该方法中两个参数对最终图像增强效果的影响规律进行总结和分析,提出了一种新的自适应参数调节方法。通过与各种传统方法进行仿真实验对比,结果显示,本文方法具有简单、快速、增强效果更好等特点；将改进方法用于本文研究区实际遥感图像的增强处理,其结果进一步表明了本文方法的有效性和实用性。(2)针对汶川地震诱发的崩滑流地质灾害类型多、分布广、内部结构复杂等特点,综合应用3S技术,在利用高精度遥感图像地质灾害影像特征分析及相关信息提取和野外调研基础上,探索、提出了利用3S技术进行地质灾害体精细解译及其内部结构分析的思路及方法,对研究区地质灾害体进行了详细解译,基本查明了其空间形态特征及其空间分布,为地质灾害体风险控制提供了科学依据。(3)考虑到目前灾后泥石流灾害正处于高发期,常规勘察手段很难获取泥石流评价的基础数据的难题,提出了采用3S技术对典型泥石流进行遥感动态调查、分析、评价与预测的方法,并以研究区重点地区即震中附近的牛眠沟为例,详细地剖析了利用遥感和GIS技术分析泥石流物源特征、统计灾害要素信息等具体方法。可有效查明泥石流形成的地形地貌条件和水源条件、泥石流运动特征和规模、灾情和险情。并结合GIS提取的泥石流沟相关参数,对该区泥石流总量与输沙量进行了计算,分析了泥石流易发程度、发展趋势和危险性。(4)设计并实现了基于分布式网络的地震诱发地质灾害信息库在深入分析地震诱发灾害信息库在用户、功能和数据使用等方面需求的基础上,对已取得的数据成果在空间坐标系与参数、地图投影与比例尺、地理空间信息的数据编码规则、要素划分等方面进行了研究,设计并实现了基于分布式网络的地质诱发灾害信息库。信息库主要提供对查询检索、数据输出、数据库管理等三大核心功能,信息库系统涵盖了基础地理空间数据、遥感影像数据、地质灾害专题数据和评价模型数据等综合地质诱发灾害信息。(5)设计了地震诱发灾害数据的元数据模型,并在实际的数据共享服务中得到了应用在数据共享方面,以元数据理论为指导,设计了地震诱发灾害数据的元数据模型,并在实际的数据共享服务中得到了应用。选择Windows2003服务器操作系统作为信息库系统的运行环境,运用Java EE加ArcSDE完成了信息库的开发工作。系统的应用表明：从共享完整性角度分析,信息库满足了对现有研究数据的管理、数据成果的可视化以及为数据使用者提供网络共享的需要；从功能的实现角度,实现了对数据的有效分类、组织与管理,提高了对地质灾害数据的统一、高效管理和科学利用,为相关研究和管理工作提供了决策依据,能够作为同类研究问题的建设示范。更多还原

【Abstract】 The damages and influences caused by earthquake-induced geohazards are very severe, even outnumbering the direct losses from earthquakes sometimes. Therefore, a better understanding and prevention of impacts from earthquake-induced geohazards plays a very important role in mitigating geohazards. Some effective means to avoid or reduce geohazard losses may include accurate and quick determination of geohazard resource, reasonable evaluation of possible induction of geohazards and corresponding measurements.Remote sensing (RS) has shown some outstanding characteristics in information acquisition of geohazard areas such as real time, wide coverage, rich data types and high resolution. Thus, it can rapidly gain information related to landslides, avalanches, debris flows and dammed lakes after earthquakes, and provide scientific decision-making references for geohazard relief, geohazard evaluation and geohazard mitigation. There are many successful cases and valuable experiences of RS applications in geohazards and relevant fields, especially in information acquisition and macroscopic measurements of geohazard regions. However, there has been little studied in high-resolution RS interpretation, refined interpretation of geohazard units, information acquisition of inside structure, analysis of geohazard emerging procedure and integrated management of above-mentioned information.The research object in this thesis is5.12Wenchuan earthquake areas and its incident region. Based on field investigations, several key techniques such as RS image preprocessing, geohazard RS interpretation and geohazard database setting up are studied. Main research contents and contributions are as follows,(1) An improved RS image enhancement method is presented Russo proposed a fuzzy image enhancement method which shows more advantages than other traditional methods. A shortcoming of the method is that the parameters are fixed which leads to unsatisfied results sometimes. Some auto-adjust parameter methods are presented, but not always feasible. In this thesis, A new self-adaption parameter adjusting approach is presented. The simulation results have shown that the proposed approach has several characteristics such as simple, fast and better enhancement effects, compared to other traditional methods. This approach has been applied to image processing in this geohazard research region and has exhibited effectiveness and practical applicability.(2) According to characteristics of the geohazards induced by Wenchuan earthquake, e.g., multiple types, large-scale distributions and complex inside structures, based on the property analysis of geohazard images, relevant feature extraction and spot investigations, the author proposed a method to well explain geohazards and analyze its inside structures, interpreted geogazard bodies of the research zone in details, found out its spatial features and distributions roughly, and provided scientific references for risk controls of geohazards.(3) Considering that debris flows are very active after earthquakes and it is very different for traditional exploration means to obtain basic data for hazardous assessment of debris flows, the author presented a method to dynamically investigate, analyze, evaluate and predict typical debris flows by applying3S technology. Taking Niumiangou, near the quake center of Wenchuan, as an example, the author studied geohazard body features and statistical information of debris flows in details by applying RS and GIS. This method can help effectively ascertain the geological and water source conditions, dynamics and size, damage levels and dangerous situations of debris flows. Combining GIS technique, relevant parameters of debris flows are abstracted; computations of total fluxes and transporting sand fluxes are performed; occurrence degrees, developing trends and danger of debris flows are analyzed.(4) Designing and realizing information database of earthquake-induced geohazard based on WebGIS. In the aspect of quick searching and sharing geohazard data, an element data theory is used as a guide to design an element data model of earthquake-induced geohazards which is applied in practice. This information database mainly provides three core functions:data query, data output and database management. This information system covers comprehensive geology information including basic geographic spatial data, RS image data, special subject data and evaluation model data of geohazard. The practical applications have shown that (1) from the viewpoint of sharing integration, this information database can meet the demands of managing present data, visualizing results and providing network sharing services for users;(2) from the viewpoint of function realization, this system can complete data classification, organization and management, increasing integration and applicability of geohazard data. In general, this work can provide decision-making guidance for related research and management, and can be served as a paradigm for the similar research topics.更多还原