**4. Conclusion**

198 Remote Sensing – Applications

Roads were divided into 3 classes (Figure 30): provincial road, urban road and rural road. According to remote sensing assessment result, 2 provincial roads were damaged, with a length of 2 km; 25 urban roads were damaged, with a length of 7.5 km; 5 rural roads were damaged, with a length of 4.8 km. Three bridges of a total length of 242 meters were out of function.

The physical quantity assessment results were used for direct economic losses estimation. It is for the first time for China that remote sensing images are integrated into the national

Fig. 29. Housing damage assessment map

Fig. 30. Road and bridge damage assessment map

catastrophe assessment flow as a major data source.

Throughout the three cases discussed in this chapter, one interesting thing is that the importance of remote sensing images is increasing in the whole process of disaster assessment: preliminary assessment step, disaster scope and damage assessment step, and physical quantity assessment. Also, the resolution of remote sensing images is improved, from 0.5m to 0.2m, providing more accurate data for assessment and decision making.

Although the whole process of integration of remote sensing images and data from ground investigation has been growing mature, the sample region choosing, physical quantity assessment still need further improvement.

Another thing to notice is that, automatic operation system is needed to connect the whole disaster assessment flow to provide efficient and accurate data for decision making. The satellite-airplane-ground disaster monitoring and assessment system is the trend we are and will realize in the near future.
