ENG-1991 — Page 410

THE ENVIRONMENT

Weather in November was dominated by a series of continental anticyclones and the associated north-east monsoon. As a result, the monthly mean pressure of 1019.5 hectopascals was the eighth highest on record for the month of November. It was on the whole cooler and drier than normal. The monthly rainfall of 2.7 millimetres was a mere eight per cent of the November normal of 35.1 millimetres.

December was comparatively warm until the arrival of an exceptionally intense surge of the winter monsoon on December 27. In the afternoon of December 28, the Royal Observatory recorded a minimum temperature of 4.6°C, which was the lowest temperature recorded since December 1975. It was also the second lowest on record for the month of December. With a daily mean temperature of 6.1°C, December 28 was the eighth coldest day on record and the second coldest day for the month of December. Ice and frost were observed on high ground on December 28 and 29. During the cold spell, four aged people were reported to have died of cold, but damage to crops in the New Territories was not serious. The monthly total rainfall of 11.8 millimetres was 57 per cent below the December normal of 27.3 millimetres.

Geophysical, Oceanographic and Other Services

The Royal Observatory carries out geophysical and oceanographic studies and its professional advice is often sought by consultants working on government as well as on private_projects. When an engineering project demands substantial data collection and analysis over a prolonged period, special teams may be organised to tackle the tasks.

The observatory operates a climatological information service to meet the needs of the general public and to cater to the specialised interests of shipping, aviation, agriculture, fishery, engineering, industries, judicial proceedings and recreational planning. Measure- ments of rainfall and water loss as a result of evaporation and the analysis of these measurements are being undertaken for various applications in connection with water resources planning, drainage design, water quality control, reservoir design and operation, irrigation, and hydrological forecasting. Spectral analysis is applied to wave data to derive information useful to engineering design work, and mathematical models are used to elicit the return period of maximum sea levels at locations within bays and inlets. The results are useful for the design of marinas, and for coastal engineering and reclamation programmes.

In line with its responsibilities for emergency response services relating to inclement weather and other natural disasters, the observatory is responsible for co-ordinating and formulating technical emergency advice should an accidental release of radioactivity occur at the Guangdong Nuclear Power Station at Daya Bay. In order to fulfil this responsibility, the observatory has established an Environmental Radiation Monitoring and Assessment Programme to monitor the radiation levels in Hong Kong in the atmospheric, terrestrial, food and water pathways. The programme entails the collection and measurement of samples of air, water, soil and food regularly at a number of locations in the territory. An Early Alerting Network has also been established to continuously monitor the ambient gamma dose rate in the territory. In the event of an emergency, a Monitoring and Assessment Centre at the observatory will be activated to monitor and assess the radio- logical and meteorological information collected, co-ordinate a multi-departmental food and water monitoring programme to estimate the transport, dispersion and deposition of any radioactivity over the territory and to provide technical advice to government on any necessary countermeasures.

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