Documentation and Evaluation of Factors Controlling Seismic Slope Stability Using GIS

CMS 0085298标题：“利用GIS对地震边坡稳定性控制因素进行记录和评估“PI：N。Sitar机构：加州大学伯克利分校摘要：地震引发的滑坡是山区常见的地震现象。1999年9月21日，台湾集集地震和随后的大余震在台湾中部山区造成了1,800多起山体滑坡。 使这些山体滑坡对后续研究特别感兴趣的是，地震激活了700多个自由场加速度站点的仪器。 因此，委员会认为，有了这个记录地面运动的大型数据库，我们现在有了一个独特的机会，可以将斜坡破坏的程度和类型与震动的强度直接联系起来，并评估基于GIS的模型在区域和局部范围内评估地震斜坡稳定性的能力。能够开发准确的基于GIS的预测性斜坡稳定性模型的主要问题之一是基线的分辨率信息，其中包括从各种来源收集的多层数据。 在台湾，这些数据存在于集集地震数据库分析管理系统中，该系统对集集地震数据库中约15-20千兆位的数据提供联机分析和管理功能，这些数据的形式包括航空照片、SPOT图像、灾区基本数据集、数字地形图和数字地图。 主要问题是确保数据库包含正确类型的信息，并具有足够的准确性，以供未来分析。 因此，这项为期一年的工作的直接目标是利用这一大量的数据，并集中在收集详细的现场数据的一小部分滑坡的任务。 将使用以全球定位系统定位为基础的数字实地绘图技术，以更准确的地形信息充实现有数据库。 这些信息将用于确定地形中的突变点，如坡顶和坡脚、河岸、道路切割、山脊或其他地表突变的位置。 此外，还需要对滑坡陡坎、当地地质情况进行精确测绘，并对强度特征进行评估。 然后，这些数据将与当地地面运动的最佳解释相结合，以校准模型。

CMS0085298Title: "Documentation and Evaluation of Factors Controlling Seismic Slope Stability Using GIS"PI: N. SitarInstitution: University of California at BerkeleyAbstract:Seismically triggered landslides are a common phenomena associated with earthquakes in mountainous regions. The September 21, 1999, Chi Chi, Taiwan earthquake and subsequent large aftershocks generated more than 1,800 landslides throughout the central mountain region of Taiwan. What makes these landslides particularly interesting for follow up studies is the fact that the earthquake activated instruments at more than 700 free-field acceleration sites. Consequently, with this large database of recorded ground motions we now have a unique opportunity to directly relate the extent and type of slope failure to the magnitude of shaking and to evaluate our capability of GIS based models to assess seismic slope stability on a regional and local scale.One of the principal problems in being able to develop an accurate predictive GIS based slope stability model is the resolution of the baseline information, which consists of many layers of data collected from various sources. In Taiwan, such data resides in CEDAMS (Chi Chi Earthquake Database Analysis & Management Systems), which provides on-line analysis and management functions for about 15-20 Giga Bytes of data available in the form of aerial photos, SPOT images, basic datasets of disaster areas, Digital Terrain Maps and digital maps in the Chi Chi Earthquake database. The main problem is making sure that the database contains the right type of information with sufficient accuracy for future analyses. Thus, the immediate objective of this one-year effort is to take advantage of this large amount of data and to concentrate on the task of collecting detailed field data on a small subset of the landslides. Digital field mapping techniques based on GPS positioning will be used in order to augment the existing database with more accurate topographic information. This information will be used to define sharp breaks in the terrain, such as the top and toe of the slopes, stream banks, road cuts, ridges or other locations of abrupt surface change. Furthermore, accurate mapping of landslide scarps, local geology, and an assessment of strength characteristics will be needed. These data will then be coupled with best interpretation of the local ground motions in order to calibrate the model.