Collaborative Social Science Research on Urban Earthquake Disaster

在这项研究中，我们开发了一个系统，使我们能够定位可能受影响的地区，由于重大地震发生在世界任何地方的基础上观察到的夜间灯光国防气象卫星计划（DMSP）业务线扫描系统（OLS）在事件发生后的第一个24小时内。该估计是基于在事件发生前和事件发生后拍摄的两个连续夜间图像中检测到灯光的显著减少或损失，因为可以预期，由于电力故障，建筑物倒塌，疏散到避难所和商业活动暂停等各种原因，大地震后城市灯光将明显减少。该系统经过以下处理步骤：1）通过互联网获取地震震源数据，例如由USGS公布，2）通过地震地面运动的衰减公式确定图像的采样区域，3）从国家海洋和大气管理局、国家地球物理数据中心选择并下载相应的夜间DMSP/OLS数据（NOAA/NGDC），4）通过分析图像的光强度的统计上显著的减少来估计受损区域，5）创建专题地图以将估计结果呈现为地理信息，6）通过万维网广泛而迅速地传播结果地图。我们的估计的有效性已经建立了一些最近的地震灾害，如1995年兵库县，日本南部地震，1999年土耳其科贾埃利地震和1999年台湾集集地震。

In this study, we developed a system that enables us to locate the possible impacted area due to significant earthquakes which occur anywhere in the world based on nighttime lights observed by the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) within the first 24hours after the event. The estimation is based on the detection of significant reductions or loss of lights in two consecutive nighttime images that one is taken before and one right after the event, for it can be expected that city lights will observably decrease after a large earthquake due to various reasons such as electricity failure, building collapses, evacuation to shelters and the suspension of commercial activities. This system goes through the following processing steps : 1) acquiring the earthquake hypocenter data through the Internet, which is for example announced by the USGS, 2) determining the sampled area of images by the attenuation formula of earthquake ground motion, 3) selection and download of the corresponding nighttime DMSP/OLS data from National Oceanic and Atmospheric Administration, National Geophysical Data Center (NOAA/NGDC), 4) estimating the damaged areas by analyzing the statistically significant decrease in light intensity of the images, 5) creating the thematic map to present the estimation results as geographic information, and 6) disseminating the result map widely and quickly through the WWW.The validity of our estimation has been established for some recent earthquake disasters such as the 1995 Hyogo-ken Nanbu Earthquake in Japan, the 1999 Kocaeli Earthquake in Turkey, and the 1999 Chi-Chi Earthquake in Taiwan.