基于GIS的云南省盐津县地震地质灾害危险性评价研究

发布时间：2018-12-21 10:43

【摘要】：盐津县位于云南省东北部,境内山高坡陡、地形地貌复杂,新构造运动强烈,褶皱、断裂发育,地质条件十分恶劣,加之受人类活动、强降水、地震等影响,地质灾害频繁发生,是全国地质灾害的多发县。特别是近年来,随着全球气候的进一步恶化,人类工程活动的日益频繁,地质灾害有着发展并蔓延趋势。地质灾害已成为威胁人民生命安全、制约当地经济发展的重要因素之一。因此对本地区进行地质灾害易发性和危险性评价是十分有意义的。本文在广泛收集资料及在盐津县开展地质灾害调查的基础上,总结盐津县内滑坡、崩塌等地质灾害发生发育的规律,并对本区地震活动进行了初步的研究,采用证据权模型和地震危险指数模型,以ArcGIS为平台,进行了盐津县地质灾害易发性和危险性评价工作,主要取得了以下成果:盐津县发育的地质灾害主要是小型的滑坡、崩塌灾害。在空间上,本区地质灾害主要集中分布在关河、白水江及其支流等河谷两岸附近。在时间上,本区地质灾害主要发生在当地的雨季。影响滑坡、崩塌灾害发生主要因素有岩土类型、地形地貌(坡度和坡向)、构造活动、水文地质等,诱发因素主要包括降雨、人类工程活动、地震活动等。以ArcGIS为平台,采用证据权评价模型,用Model Builder建立了自动化的地质灾害易发评价系统,对盐津县地质灾害易发程度进行区划评价,并对地质灾害各分区进行了详细评价。收集了盐津县及其周边地区1965年以来的地震活动资料,对盐津县地震活动的时间、空间以及深度特征进行了初步分析,并对盐津县未来可能发生的强震潜在震源区进行了探讨。在此基础上,以无限边坡模型和拟静力法为基础,在参考Newmark方法的基础上适当简化,将滑体视为一个刚体,以牛顿第二定律为准则,用坡体单元的临界加速度来衡量斜坡单元的危险性,采用地震危险指数模型对盐津县地震地质灾害危险性进行了初步评估。
[Abstract]:Yanjin County is located in the northeast of Yunnan Province, with steep mountains and steep slopes, complicated topography and landforms, strong neotectonic movements, fold, fault development, and very bad geological conditions, in addition to being affected by human activities, heavy precipitation, earthquakes, and so on. Geological disasters occur frequently and are the most common counties in China. Especially in recent years, with the further deterioration of the global climate and the increasing frequency of human engineering activities, geological disasters have a tendency to develop and spread. Geological hazard has become one of the important factors that threaten people's life and restrict the development of local economy. Therefore, it is of great significance to evaluate the vulnerability and risk of geological hazards in this area. On the basis of extensive data collection and geological hazard investigation in Yanjin County, this paper summarizes the occurrence and development of geological disasters such as landslides and collapses in Yanjin County, and makes a preliminary study on seismic activities in this area. Based on the evidence weight model and seismic hazard index model, the vulnerability and risk assessment of geological hazards in Yanjin County are carried out on the platform of ArcGIS. The main results are as follows: the geological hazards developed in Yanjin County are mainly small landslides. Collapse disaster In space, the geological hazards in this area are mainly distributed near both sides of the river valley, such as Guanhe, Baishui River and its tributaries. In time, geological disasters in this area mainly occurred in the local rainy season. The main factors affecting landslide and collapse are rock and soil type, landform (slope and direction), tectonic activity, hydrogeology and so on. The induced factors mainly include rainfall, human engineering activity, seismic activity and so on. Based on ArcGIS and Model Builder, an automatic geological hazard risk assessment system was established. The geological hazard vulnerability degree in Yanjin County was assessed and the geological hazard zones were evaluated in detail. The seismicity data of Yanjin County and its surrounding areas since 1965 are collected, the time, space and depth characteristics of seismic activity in Yanjin County are preliminarily analyzed, and the potential focal areas of strong earthquakes that may occur in the future in Yanjin County are discussed. On this basis, based on the infinite slope model and pseudostatic method, the sliding body is treated as a rigid body, and Newton's second law is taken as the criterion, which is properly simplified on the basis of referring to the Newmark method. The critical acceleration of slope unit is used to measure the risk of slope unit and the seismic hazard index model is used to evaluate the risk of seismic geological hazard in Yanjin County.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P694;P315.9

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