Chinese use the idiom "relying on heaven for food" to describe farmers in drought areas live at the mercy of heaven for rains.

As China has frequently been plagued by natural disasters, its people have always been encouraged to make great efforts to solve problems without divine intervention.

But now scientists are turning their eyes to the heavens to monitor natural disasters by using spatial information technology to make forecasts.

Spatial information refers to data collected by remote sensing and Global Positioning Systems (GPS).

Officials and experts believe this knowledge is crucial for decision-makers that need the latest reliable information about natural calamities if they are to choose the best course of action to deal with misfortunes.

When natural disasters such as flooding, typhoons and landslides occur, those on the spot usually cannot see a holistic picture of the destruction.

Disasters often destroy ground monitoring and telecommunications facilities, making it difficult for those on the scene to send information to central authorities.

Using traditional methods, it is very difficult to collect disaster-related information quickly.

"Spatial information technology could well overcome these problems," said Professor Li Jing from the National Disaster Reduction Center of China.

Li, with officials and scientists from the United Nations Educational, Scientific and Cultural Organization, the International Institute of Spatial Information Technology and the Digital China Research Institute of Peking University, attended a workshop on the applications of spatial information technology for disaster prevention and reduction.

The workshop was organized as part of activities to mark the International Day for Disaster Reduction, which falls today.

"Spatial information technology is a very good tool to monitor natural disasters and simulate their development process," said Li.

Spatial information technology has unique advantages - it can observe any disaster-affected area and get reliable information in all weather conditions, according to Li.

China's remote sensing system is composed of three kinds of satellites, known as meteorological satellites, resources satellites and oceanic satellites.

"Although these satellites provide a lot of useful data for China's disaster monitoring and prevention work, the biggest problem is that the resolution of these data is not satisfactory," said Li.

As a result, China has to buy certain data from companies abroad to serve its needs.
 
To solve the problem, China has decided to launch a constellation of eight satellites to get relevant data and warn of natural calamities.

According to Vice-Minister of Civil Affairs Jia Zhibang, three satellites of the kinds will be sent into space in the first half of 2007, with five more to join them by 2010.

They will create a network that monitors disasters and environmental changes in China as well as neighboring countries.

The constellation is comprised of five systems, including a satellite carrying and launching system, monitoring and ground application systems.

The ground application system is expected to play a big role in monitoring such disasters as floods, droughts, typhoons, earthquakes, landslides, grassland and forest fires, pests and oceanic disasters.

It is also expected to help officials evaluate and analyze damage, which is very important for post-disaster response.

Besides disaster prevention, the spatial information technology could also be used to help supervise the work of local officials, according to Ma Junru, president of the International Institute of Spatial Information Technology at the Ministry of Science and Technology.

When disasters happen, local officials either report false information such as reduced death tolls to higher authorities to evade punishment, or exaggerate economic losses to get more subsidies.

Data provided by spatial information technology is the best evidence with which to find out the truth, according to Ma.

China is a country that frequently falls victim to natural calamities.

Official statistics show that from 1989 to 1998, the average annual economic losses caused by natural disasters reached 157.7 billion yuan (US$19.5 billion), accounting for 3.6 per cent of the country's annual gross domestic product.

The State Flood Control and Drought Relief Headquarters announced earlier this month that floods and landslides have killed 1,247 people and left another 331 missing so far this year.

Although satellite information has been used in China in disaster reduction efforts for two decades, the country is still frustrated by problems in this field.

The lack of a self-developed, high-quality satellite monitoring platform has bottlenecked the application of spatial information technology in China.

The plan to launch the constellation of eight satellites by 2010 is expected to provide a solution, according to Li.

China needs to build a disaster reduction database to support the country's monitoring work. But time and investment are needed if progress is to be made.

As China's disaster prevention and relief efforts are handled by different government departments, they so far have not established an effective system for sharing disaster information.

Concerted efforts are needed to build an early warning system based on spatial information technology to reduce losses caused by natural disasters, said Li.

(China Daily October 12, 2005)