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THE ENVIRONMENT
of meteorology and geophysics to meet the demand for services by aviation, shipping, industry and the general public. Many enquiries needed quick answers while a number involved detailed investigation using computer facilities. These included a detailed analysis of meteorological data for a long term planning study of Hong Kong's air transport system.
During the year, nomograms for predicting daily minimum temperature for the winter months were prepared and mean upper-air streamline and temperature charts for Southeast Asia were completed. A joint paper with a staff member of the Univer- sity of Southampton entitled 'A Dimensionless Unitgraph for Hong Kong' was prepared and presented in the Symposium on the Design of Water Resources Proj- ects with Inadequate Data, held in Madrid on June 4-9, 1973. Other papers com- pleted included 'Quantitative Forecasting of the Winter Monsoon', 'Hong Kong Monthly and Annual Mean Temperatures: Their Trend and Persistent Character- istics' and 'Radar Climatology of Hong Kong for the years 1967-69'.
Several case studies on unusual weather in 1972 and 1973 were undertaken and a technical report on the severe rainstorms which caused disasters in Hong Kong during June 1972 was completed.
Pollution Monitoring and Control
The Royal Observatory is responsible for providing basic information to enable warnings to be issued of any possible health hazards from radioactive fallout from old and fresh nuclear explosions. This, and regular measurements of beta and gamma activity in the atmosphere and in rainfall have been made since 1961 at the King's Park Meteorological Station of the Royal Observatory. Radioactivity of filtered water samples from several reservoirs in the territory is also regularly monitored.
Licences for irradiating apparatus and radioactive substances are controlled by the Radiation Board, set up within the Medical and Health Department. The board's effectiveness is assured by two sets of regulations covering radiation control-the Control of Radioactivity Substances, and the Control of Irradiating Apparatus.
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The Advisory Committee on Air Pollution was reconstituted in December 1970 as a permanent advisory committee under the chairmanship of Mr J. L. Marden. Its members are drawn from various government departments, including the Royal Observatory, Public Works, Medical and Health, Urban Services, Labour and Transport, as well as the Colonial Secretariat. A number of unofficial members are appointed for their special interest or expertise in this field. The committee's terms of reference are to keep air pollution in Hong Kong under constant review and advise the government on appropriate measures for its control.
Regulations have been enacted under the Clean Air Ordinance requiring owners of premises to submit plans of all new or proposed modifications of existing furnaces and chimneys. They set standards to ensure that combustion of liquid fuels will produce a minimum of dark smoke. Consideration is also being given to controlling emissions from motor vehicles. With the assistance of the China Light and Power