Documentation and Evaluation of Factors Controlling Seismic Slope Stability Using GIS

CMS0085298标题：“利用地理信息系统记录和评估控制地震斜坡稳定性的因素”PI：N.SitarInstitution：加州大学伯克利分校摘要：地震引发的山体滑坡是与山区地震有关的常见现象。1999年9月21日，台湾集集地震及随后的大余震在台湾中部山区引发了1800多起山体滑坡。让这些山体滑坡对后续研究特别感兴趣的是，地震激活了700多个自由场加速站点的仪器。因此，有了这个记录了地面运动的大型数据库，我们现在有了一个独特的机会，可以直接将斜坡破坏的程度和类型与震动的强度联系起来，并评估我们基于地理信息系统的模型在区域和局部尺度上评估地震斜坡稳定性的能力。能够开发基于地理信息系统的准确预测斜坡稳定性模型的主要问题之一是基线信息的分辨率，该基线信息由从不同来源收集的多层数据组成。在台湾，这些数据驻留在集集地震数据库分析与管理系统中，该系统为集集地震数据库中的航空照片、SPOT图像、灾区基本数据集、数字地形图和数字地图等约15-20千兆字节的数据提供在线分析和管理功能。主要问题是确保数据库包含正确类型的信息，并具有足够的精确度，以供未来分析。因此，这项为期一年的努力的近期目标是利用大量数据，并集中精力收集有关山体滑坡的一小部分的详细现场数据。将使用基于GPS定位的数字外业测绘技术，以便用更准确的地形信息来扩充现有的数据库。此信息将用于定义地形中的尖锐间断，例如坡度的顶部和脚趾、河岸、路基、山脊或其他曲面突然变化的位置。此外，还需要对滑坡陡坡、当地地质和强度特征进行准确的测绘。然后，这些数据将与对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.