Chinese experts on remote sensing have succeeded in quantitative assessment of the landslide in Bomi County, the Tibet Autonomous Region, based on digital images sent back by the Ziyuan-1 Satellite sent to orbit last year.
It was the first time for the Ziyuan-1 Satellite to play a significant role in disaster assessment, and it demonstrated China's capability to make forecast of natural disasters using image data obtained by its own satellite.
The satellite data showed that an exceptionally serious landslide had occurred in Bomi on April 9, 2000. The data was delivered to the Remote Sensing Technology Application Center of the Chinese Water Conservancy Research Institute by the Chinese Resource Satellite Application Co. It had been obtained by the Ziyuan-1 Satellite on January 26, April 13 and May 9. The center used its computer system to process the data the very evening it received it. With the help of the 1: 250,000 electronic map drawn by the State Bureau of Surveying and Mapping, the center completed the task within 10 hours, making a three-dimensional image of the landslide site, showing the overall extent of the landslide and the flooded region.
To estimate the possible extent of further damage to the lower reaches of the local river and prepare counter-measures, the center made a computerized calculation of the river slope degree between the lower reaches of the main body of the landslide and the Maitong Bridge. As June is the start of the rainy season in southeast Tibet, when the river flow reaches 700 cubic meters per second, the objective, comprehensive and accurate data sent back by the Ziyuan-1 Satellite enabled the departments concerned to make timely relief decisions.
For decades, China had to rely on foreign satellite data when natural disasters occurred. This was both expensive and time-consuming, and as a result the western border areas were a blank space as far as remote sensing data was concerned.
However, the Ziyuan-1 Satellite, with its three ground stations, is capable of monitoring the entire territory of China. It is expected to play an even bigger role in disaster appraisal as the flood season approaches in most parts of China.
