The 42nd UN Assembly convened in 1987 named the last 10 years of this century the "Decade of International Natural Disaster Reduction". It aims to apply the most up-to-date technology to reduce natural calamities by 30 percent by the end of the century.

According to statistics, worldwide losses created by natural disasters have climbed in recent years, with the amount soaring from $70 billion per year in the 1970s to $120 billion per year in the 1980s and further to $170 billion per year in the mid-1990s. Using advanced technology to reduce natural calamities has thus become an important guarantee for the sustainable development of human society.

The progress of space and computer technologies has provided a necessary basis for disaster reduction. In particular, the application of satellites has been highly effective. By using communication satellites to transmit information collected by meteorological and resources satellites and by relying on the navigation and positioning system to search and define the position of rescue satellites, complete information from the comprehensive satellite data information system composed of satellites can be acquired. This information can be used to prevent and control natural disasters.

The satellite system is greatly favored in disaster reduction because it has the advantage of "standing on a high plane and seeing far ahead". Moreover, it remains unaffected even when ground facilities and communication systems are destroyed and can transmit information under any conditions.

Initial results

As a developing country, China has actively participated in activities connected to the UN's decade of natural disaster reduction and has attached high importance to natural calamity forecasts. The successful launching of the Fengyun-I and Fengyun-II meteorological satellites has helped China achieve noticeable results in using satellites to reduce natural disasters.

In 1986, about 24 hours before the No. 8607 typhoon hit Guangdong Province's Shantou, the provincial meteorological department sounded the alarm. The local government immediately notified the more than 3,000 fishing vessels out at sea, organized the farmers to harvest 200,000 hectares of crops and adopted safety measures to protect the 35 large and medium-sized reservoirs in the locality. This helped reduce the losses by nearly 1 billion yuan.

During the fight against the floods in the Yangtze, Nenjiang and Songhuajiang river valleys last summer, the meteorological department used satellite data images to monitor the floods and acquired meteorological information covering an area of 320,000 square km. The information provided a scientific basis for relevant authorities to make the decision of "defending the dikes to the last".

Short-term earthquake forecasting has remained a difficult problem for scientists. In the 1990s, the satellite earthquake forecast study group headed by senior engineer Li Lingzhi of the No. 503 Institute under the China Space Industry Corp. worked together with seismologist Qiang Zuji on the use of satellite remote sensing technology to forecast earthquakes. Between 1996 and September 1998, they made 46 short-term and prompt earthquake forecasts, with 19 proven successful and 20 of an average level. In 1998, they successfully forecast an earthquake measuring 4.7 on the Richter scale in Hebei Province's Tangshan on April 14 and another earthquake measuring 6.6 in Jiashi, Xinjiang Uygur Autonomous Region, on August 14. China is a country prone to forest fires. According to statistics, during the 36 years between 1950-86, fire affected areas covered 960,000 hectares. The situation has improved since the application of the satellite system. During the catastrophic forest fire that took place in the Greater Hinggan Mountain between May 6-June 1, 1987, relevant department used a meteorological satellite to monitor the disaster. The satellite transmitted back more than 800 radiophotos of the forest fire, providing effective information support for fire-control headquarters.

Prospects

Chinese scientists expect to make greater contributions to satellite disaster reduction.

In November 1998, the China Satellite Disaster Reduction Center was formally established. Following the successful launching of Fengyun-I and two other meteorological satellites, China is expediting the development of Fengyun-III, a new-generation meteorological satellite. Fengyun-III is designed to study the laws governing the global climate and its changes, monitor wide-range climate changes, natural disasters and the ecological environment, and provide related departments with meteorological information from different regions throughout the world.

China also expects to launch Ziyuan-I, a resources satellite developed jointly with Brazil, in mid-1999. Since resources satellite can provide remote sensing data accurately, quickly and directly, it can be used to monitor red tides, the ocean environment, floods, forest fires, environmental pollution, farm crop diseases, waterlogging, earthquakes, sandstorms and other natural calamities. The operation of Ziyuan-I will raise China's satellite disaster reduction to a higher plane.

Another technological development trend today is to use modern small satellite technology to intensify the monitoring of natural disasters. In accordance with the needs of clients, some Chinese enterprises devoted to the space industry are currently making efforts to develop Haiyang-I, the first of its kind in China for marine surveying. It will be mainly used to observe water color, and laws governing waves, tides, typhoons and the distribution of sand in various ports. The satellite is expected to be launched next year.

The China Space Technology Institute and other related departments have already completed a technological feasibility study for the formation of an environmental disaster small satellite constellation. The constellation, composed of six small satellites, can carry out all-weather observation of environmental disasters. It has received support from many clients.

In addition, the satellite data collection system established on the basis of astronomical remote metering, remote control and remote monitoring technologies has passed expert appraisal and is under construction as a demonstration project. In line with the different requirements of clients, the system will automatically collect related data for water resources, meteorological, environmental protection, forestry and other departments. The satellite will transmit the data it receives on a regular basis to the data center for processing. The information thus gained can provide a scientific basis for responsible departments to make policy-decisions, thereby pushing the satellite disaster reduction project onto a new level.