Technology of Change Detection for the Semi-automatic Rapid Evaluation of Seismic Damage of Buildings

In this paper, we aim at exploring method and process of semi-automatic evaluation of damage of buildings with computer and high resolution remote-sensing images. Change detection of remote-sensing images from IKONOS with a resolution of a meter prior to and after the earthquake was executed and the semi-automatically rapid evaluation of damage of buildings was studied both by case of north area of Dujiang Dam city in Wenchuan Earthquake. The change detection included difference method, ratio method, relevance method and false color composite. This paper proposed the process of semi-automatic evaluation. ENVI was secondarily developed for the suitability of semi-automatic evaluation. At last this concluded the collapse ratio of test area of 15.15%. In comparison with actual result and traditional measures, this method is much more convenient, rapid, credible, and feasible.