ENG-1989 — Page 380

THE ENVIRONMENT

The natural landscape in the urban areas has been extensively modified as a result of site formation associated with development. Many of the natural granitic hills have been removed, and the material used as fill for the various reclamations. Almost 4 000 hectares of the developed land is reclamation.

Much of the undeveloped terrain in Hong Kong consists of steeply-sloping ground where soils are thin and nutrient deficient. These soils support only grassland or shrubland, except in protected valleys where small areas of broad leaf woodland survive, or in water catchments and country parks where re-afforestation has succeeded in establishing pines and deciduous trees.

An important agricultural area is the alluvial plain around Yuen Long in the north-west New Territories. These alluvial lowlands probably formed within the last 33 000 years, and some areas are still prone to flooding. More than 5 000 hectares of floodplain occurs in the territory and much of it is located in the Yuen Long district. The natural deposition of sediment is continuing around the Deep Bay area, where brackish fish ponds have been established successfully in areas that once were mudflats, mangrove swamps or salt-water rice paddies.

As Hong Kong lacks large rivers, lakes or underground water supplies, reservoirs have been constructed in larger valleys such as Shek Pik, Tai Lam Chung, and in coastal areas such as Plover Cove and High Island, where embayments and channels have been enclosed by large dams. In most instances, the catchment areas of the reservoirs have been designated as country parks.

New geological maps are being produced at a scale of 1:20 000 by the Geological Survey of Hong Kong, located within the Geotechnical Control Office, and maps for more than 60 per cent of the territory have been published. Detailed geological mapping will also lead to the publication of 1:5 000 scale maps. Information about the terrain is also contained in the 55 maps and 12 Reports of the Geotechnical Area Studies Programme. Published documents are available through the Government Publication Sales Centre.

Wildlife

The physical and climatic environment of Hong Kong provides woody and grassy habitats for a wide variety of native animal and plant life. Under the pressure of urbanisation, larger animal species are rarely seen, but reptiles and amphibians, birds and many kinds of insects are common.

Most of Hong Kong's countryside is protected by the Forests and Countryside Ordinance, the Wild Animals Protection Ordinance, the Country Parks Ordinance, and the Animals and Plants (Protection of Endangered Species) Ordinance.

One of the most important sites in Hong Kong for wildlife is the Mai Po Marshes. A restricted area under the Wild Animals Protection Ordinance and managed by the World Wide Fund for Nature (Hong Kong), it is an internationally significant site for migratory and resident birdlife. Its 380 hectares of mudflats, shrimp ponds and dwarf mangroves provide a rich habitat, particularly for ducks and waders. More than 250 species of birds have been observed in this area, and at least 110 of them are rarely seen elsewhere in the territory. Yim Tso Ha, also a restricted area, is the largest egretry in Hong Kong. Five species, the Chinese Pond Heron, Night Heron, Cattle Egret, Little Egret, and the rare Swinhoe's Egret, nest there regularly. More than 1 000 egrets can be found there between April and September, the nesting season. Egretries are also found at Mai Po Village, A Chau, Jim Uk, Tsim Bei Tsui and Wu Shek Kok.

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