ENG-1992 — Page 421

THE ENVIRONMENT

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graphs are operated at the Observatory Headquarters and Tate's Cairn. About 130 earth tremors with epicentres within 320 kilometres of Hong Kong are detected annually. Reports of significant tremors are routinely made known to the general public via the media. Seismic data are used by structural engineers in the design of buildings. Such data are also made available to local and overseas scientific institutions for their studies.

The Hong Kong Time Standard is provided by a caesium beam atomic clock at the Observatory Headquarters. Accuracy within fractions of a microsecond a day is main- tained. The time service is operated by relaying a six-pip time signal to Radio Television Hong Kong for broadcast.

The State of the Environment

Hong Kong is known above all as one of the world's great cities. It has seen in the past half century a rate of growth in industrial and commercial prosperity that is unrivalled. This growth has brought environmental problems that are common to cities around the world, but may be experienced less in Hong Kong in future because of the government's strong commitment to improving the environment.

One of the ways in which the community has managed to sustain economic growth has been by developing new cities in what were formerly rural areas, on the nuclei of small fishing or market towns. The government's planners and builders have taken some care for the environment in creating these new cities. The 20-year record of marine water pollution, for example, shows that a steep decline in water quality in Victoria Harbour in the seventies, did not continue in the eighties, when the decline was much less steep. On the other hand, areas like Tolo Harbour, with the impact of massive new town growth, showed a steep decline in water quality in the early eighties; this decline has been halted and is expected to reverse soon, as the benefits of pollution control are felt.

Despite the intensity of its urban development, there are still parts of Hong Kong that remain rural, and there are great areas of open water. Some of these areas are badly affected by livestock rearing and cottage industries; others are free from the threat of pollution and offer tremendous opportunities for conservation and recreation.

The following sections consider the environmental problems and opportunities in each of these broad landscape groups in turn. Hong Kong's environmental quality is usually measured in terms of environmental quality objectives. These state in measurable terms the quality of the environment that is just adequate to restore or maintain desired conservation goals, such as the protection of health or the ability of the environment to sustain some beneficial use such as fishing or swimming.

Urban environmental quality

Hong Kong's older urban areas have a dense mix of housing, community facilities, commerce and industry, with an infrastructure that falls short of modern standards. Poor urban landscape, air and water pollution, noise, and waste disposal problems are common. The government has committed a great deal of money and effort to meeting these challenges.

Hong Kong's objectives for air quality are comparable to internationally recognised air quality standards for the protection of general public health. The actual air quality does not always meet the objectives. Total suspended particulates, respirable suspended particulates and nitrogen dioxide are often high. In 1992, the highest annual averages