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The Environment
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HONG KONG is situated on the south-east coast of China, adjoining the province of Kwangtung. It is just inside the tropics, less than 100 miles south of the tropic of Cancer, and lies between latitudes 22°9′ and 22°37′N and longitudes 113°52′ and 114°30′E. It consists of a small part of the Chinese mainland and a scattering of offshore islands, the most important of which is Hong Kong Island. Its economic heart is the magnificent natural harbour which lies between Hong Kong Island and the tip of the Kowloon peninsula on the mainland. The twin cities of Victoria, on Hong Kong Island, and Kowloon overlook the harbour on either side, and are about 90 miles south-east of Canton and 40 miles east of Portuguese Macau. Although the shortest air route between Hong Kong and London is almost 6,000 miles, by modern jet this represents less than 20 hours flying time.
The total land area is 403.8 square miles (including recent reclamations) of which Hong Kong Island itself, together with a number of small adjacent islands, comprises 29.2 square miles. Kowloon and Stonecutters Island comprise another 4.1 square miles. The New Territories, which consist of part of the mainland and more than 230 islands, have a total area of 370.5 square miles.
Topography and Geology
Hong Kong lies on the edge of an eroded mountain chain which extends along the south coast of China. The chain is largely composed of folded and metamorphosed volcanic and sedimentary rocks with younger intrusions of granitic rocks mostly of the Jurassic Period. The oldest sedimentary rocks found in Hong Kong are those of the Tolo Harbour Formation. This formation is exposed at Ma Shi Chau and contains fossils that have been dated as most probably Permian in age. However, its stratig- raphic relationships are somewhat uncertain. Mineralisation, associated with the intrusion of the granitic rocks, has been of limited economic benefit to Hong Kong. Lead, zinc, tungsten, beryl and graphite have been mined but only in small quantities. Iron ore mining has been of greater importance and there is currently an active mine at Ma On Shan, which exports concentrated ore to Japan.
Due to the hilly topography, agricultural land is extremely restricted. The most important area is the flat alluvium around Yuen Long in the Deep Bay area. Outside the alluvial areas, soil cover is usually thin, sometimes no more than two or three inches. In general the natural residual soils are acidic and of low fertility, needing the addition of lime, potash and superphosphates. Given intensive labour input, however, water supply rather than soil condition tends to be the controlling factor in farming. The predominantly crystalline character of the rock formations unfor- tunately makes them unsuitable as aquifers for underground storage and this makes