5.Pilot operation of the system and application examples

5.1 Sandstorm Monitoring in 15^th April,1998 GMS-5 data of visible light and thermal Infrared channels in 15^th -17^th April were used to extract sandstorm information (see Picture l the red areas in white frame are the areas affected by sandstorm and float dust. Which were quite corresponding to be ground truth). In 15^th April, 1998 effected by a developing Mongolia cyclone of temperate zone, a sandstorm of large scale appeared in south Mongolia and China's north (picture 1- a); 4 hours later, following the reinforce of cold front cloud land and swiftly pressing towards south, the sandstorm areas expended to the north of the yellow river bend and Ningxia. Gansu etc. (picture 1-b); 24 hours later, in 16th April floating dust formed and spreaded rapidly pushed forward east China by the high altitude northwest airflow and effected a large area of the Yangzi river valley (picture 1-c); in the morning of 17^th by the influence of west in the back of ground cold front, the floating dust got into China;s east sea and yellow sea areas. It also affected Korea and Japan (picture 1 -d).

Picture 1 The GMS-5 Images of Sandstorm on 15^th-17^th April. 1999
5.2 Sandstorm monitoring and disaster assessment in 1999.
In the 1^st January, 1999, a very strong sandstorm procedure happened at China's west Inner Mongolia and Gansu. It was two months earlier than the normal year. As soon as the project group abstracted the relevant sandstorm information through processing the satellite cloud images immediately, the information was released at the meterological decision-making service system and broadcasted at CCTV. After this one, in succession many times of sandstorm, raising dust and floating dust occurred in China's north and northwest in 4^th, 11^th, 24^th April and 13^th May etc. The project group pilot operated the system, one by one edited "The Brief Report of Sandstorm Disaster affecting Estimation by Satellite Remote Sensing" in real-time submitting to the Office of China National Committee for the IDNDR and the Department of Disaster and Social Rehief, Ministry of Civil Affairs etc. It would help the reduction of disaster losses and got good social benefits. For example, the third issue of the Brief Report analyzed as bellow By the affection of a very strong cold front cloud land from Xinjiang toward east, at the afternoon of 24^th April, 1999 a sandstorm weather occurred in a huge area of west, east and south Xinjiang, west Gansu and northwest Qinghai provinces. Occurring to our satellite remote sensing monitoring, this disaster affected about millions of people and vast land area. Among it a large areas of cultivated land and grassland were affected. The figure could be break down in each province and county Although this disaster mainly passed desert region but also harmed large areas of oasis farmland and grazing land in south Xinjiang, Tolufan basin, Yili river valley and the reclamation area of Shule river region. These areas are of Shule river region. These areas are main production region of crop, cotton, oil, best variety of fruits and melons, as well as best animal husbandry region. When the sandstorm happened it was just the time of Those crop seeds and fruit trees sprouted. This brought about a fierce attack on vast area of cropland, grassland, residential district and roads etc. It would cause a rather big economic loss. The picture 2 shows the special processed images of 24^th April, 1999 at 16 o'clock (Beijing time). The golden-brown color areas are the affected regions of sandstorm and raising dust by remote sensing monitoring. The picture 3 shows the affected administration region of sandstorm and raising dust edited by GIS according to the information got from NOAA data mentioned above. This sandstorm weather procedure also influenced part region of Hazakstine and Mongolia.

Picture 2 NOAA of 24th April 1999



Picture 3 Map of Sandstrom and Raising dust Areas on 24th April 1999.
6.Conclusion
It is a very efficient method to monitoring sandstorm disaster by using satellite remote sensing, GIS and computer network technologies. The development and pilot operation of the project system would play a positive role in disaster prevention and relief of sandstorm. Though some technical progress has been made in this field, several key techniques should be still research on and the system should be integrated and more properly too. The project group now continuously work hard to fulfill this challenge task. Through this efforts to make more achievements by application of such high technologies as satellite remote sensing, GIS and computer network etc.