IKONOS卫星影像在城市防震减灾及震害评价中的应用研究

APPLICATION OF IKONOS IMAGERY TO EARTHQUAKE DISASTER REDUCTION AND DAMAGE ASSESSEMENT IN URBAN AREA

文中探讨了IKONOS卫星影像在地震灾害评价中应用的可行性 ,认为高分辨率卫星影像在城市基础数据获取与更新、震害的快速评估和地震应急决策中有广阔的应用前景。在IKONOS卫星影像上 ,可以轻易分辨出城市防震减灾工作中需要的基本要素、如建筑物、构筑物、道路和桥梁。利用遥感图像处理软件可以从IKONOS数字影像中自动提取地物的形状、位置和属性等信息 ,从而节省大量的人力和财力。由于IKONOS卫星影像的更新速度远远高于城市地震灾害评价所需要的航空相片或大比例尺地形图 ,因此可以保证数据的实效性 ,从而解决“九五”震害预测与减灾对策研究中的数据老化问题。IKONOS卫星影像的重复周期为 3天 ,在理想的天气状况下 ,地震发生后的 3天之内 ,用户就可以得到震区影像 ,因此可用于震害的快速评估 。

IKONOS satellite launched in 1999 is one of the commercial satellites with highest spatial reso^lution, which has five spectral bands including red, green, blue, near-infrared and pan. The maximum spatial resolution of IKONOS is 1 meter. From the imagery, researchers can easily identify the basic elements needed for earthquake hazard reduction business in urban areas, such as buildings, structure, roads and bridges. With the aid of computer, a great amount of information including the shape, position and attribute of ground objects can be automatically or semi-automatically extracted from IKONOS digital imagery by using the remote sensing imagery processing software. In this way, lots of manpower and finance can be saved. Because the renewal of IKONOS imagery is faster than aerial photos or large-scale maps that are used for urban earthquake hazard assessment, the latest information can be ensured. It is very useful for solving the aging of data for the Ninth Five Year Project on the Research of Seismic Hazard Assessment and Disaster Prevention and Mitigation. The repetition interval of IKONOS imagery is about 3 days, so the imagery can be applied to the rapid assessment of earthquake disasters. Under ideal weather condition, users can get IKONOS imagery of earthquake-stricken area within 3 days (even several hours) when an earthquake occurs. Owing to the high resolution of IKONOS, researchers can use it for earthquake site investigation instead of aerial photos. Remote sensing imagery including IKONOS is in digital format, and thus it can be easily processed and analyzed by computer, so that it is convenient for the computer-aided assessment and emergence decision of earthquake disaster. The methodological feasibility of IKONOS application to earthquake disaster is discussed in this paper. It is concluded that the high-resolution satellite imagery including IKONOS has the broad prospects in obtaining and renewing the basic data of urban areas, as well as in the rapid assessment and emergence decision of earthquake disaster.