Collaborative Social Science Research on Urban Earthquake Disaster

在这项研究中，我们开发了一个系统，使我们能够根据国防气象卫星计划（DMSP）操作直线扫描系统（OLS）在事件发生后的第一个24小时内观测到的夜间灯光，定位可能发生在世界任何地方的重大地震的影响区域。这一估计是基于对地震前后两张连续夜间图像中灯光明显减少或消失的检测得出的，因为可以预期，在大地震发生后，由于各种原因，如停电、建筑物倒塌、疏散到避难所和商业活动暂停，城市灯光将明显减少。该系统的处理步骤如下：1)通过互联网获取以USGS为例公布的震源数据；2)通过地震地面运动衰减公式确定图像的采样区域；3)从美国国家海洋和大气管理局、国家地球物理数据中心（NOAA/NGDC）选择并下载相应的夜间DMSP/OLS数据；4)通过分析图像光强的统计显著性下降来估计受损区域。5)制作专题地图，将估算结果以地理信息的形式呈现；6)通过WWW广泛、快速地传播结果地图。1995年日本兵库县南部地震、1999年土耳其科加埃利地震、1999年台湾集集地震等近年来发生的地震灾害，均证实了本文估计的有效性。

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.