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THE ENVIRONMENT
also provided to civil aviation, business and industrial communities, port and container terminal operators and the oil-prospecting industry.
Whenever Hong Kong is threatened by tropical cyclones, frequent warnings are widely disseminated together with advice on the precautions to take. A colour-coded rainstorm warning system is activated to warn people of heavy rain that may cause serious road flooding and traffic disruption. The Observatory also issues warnings on thunderstorms, landslips, fire danger, strong monsoon and frost. Special weather bulletins are issued to alert the public to take precautions against heat stroke on very hot days.
Weather programmes for the public are presented regularly on television by the Observatory's meteorologists. During adverse weather, live interviews and briefings are given over the radio and television. Weather information is disseminated to commercial communications and paging services, making it available on various electronic media.
The Dial-a-Weather service operated by the Observatory provides recorded weather messages to the public. In 1999, the total number of calls was close to 25 million.
The Information Enquiry System is an interactive telephone enquiry system through which the public could obtain a variety of meteorological, geophysical and time information in Cantonese, Putonghua and English. In 1999, the system attracted over 1.2 million calls, and was also enhanced to provide weather information via fax. The Observatory maintains an informative home page on the Internet. In October, the Ultraviolet (UV) Index was introduced on the home page to promote public awareness of the potential harm of UV radiation. The total number of visits to the home page in 1999 exceeded 23 million, or about 63 000 per day on average.
A variety of meteorological and climatological publications are produced by the Observatory, most of which are obtainable from the department free-of-charge.
Weather Monitoring and Forecasting
To provide weather forecasts and warnings of hazardous weather, the Hong Kong Observatory maintains a close meteorological watch round-the-clock.
The Observatory exchanges weather observations with the rest of the world through the Global Telecommunications System operated under the auspices of the World Meteorological Organisation. Through its telecommunication lines with meteorological centres in Beijing, Tokyo and Bangkok, about 20 000 weather reports are received each day.
Hourly pictures of cloud and water vapour distribution are received from both the Japanese Geostationary Meteorological Satellite and the Chinese Fengyun-2 Satellite. Satellite pictures provide forecasters with valuable information on tropical cyclones, severe storms and frontal systems approaching the South China coast. A new Weather Radar System was commissioned at Tai Mo Shan in early 1999. The system provides high-resolution radar data for effective monitoring of the movement and development of severe weather systems. It also processes data from the Observatory's weather radar at Tate's Cairn and the Terminal Doppler Weather Radar at Tai Lam Chung for the computation of the wind field over Hong Kong.
Weather observers and automatic weather stations at over 40 locations in Hong Kong provide comprehensive and real-time coverage of regional weather variations,