ENG-1970 — Page 146

LAND AND HOUSING

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zoning plan for this area. The draft plan has been exhibited and 21 objections were received and considered by the board.

SURVEY

Land survey in Hong Kong serves two main purposes; first the delineation of town planning layouts, the setting out of public works and the boundaries of private lots and government sites, etc, i.e. cadastral survey; and second the production of plans and maps.

The demand for cadastral surveys and plans continued to rise during the year with the increased interest in private development and surveys for government sites and the setting out of building works also showed a steady increase.

Control surveys included the completion of a precise levelling network on Hong Kong Island. As a result of the construction of radio, radar and television installations on the higher hills, several main triangulation stations were destroyed or obstructed and these had to be rebuilt elsewhere and tied into the Colony network by first order triangulation.

The implementation of the programme of 'cyclic' revision of large-scale plans continued. The total number of plans of the Colony now approaches 1,900, about 690 at 1:600 scale of the urban areas and over 1,200 at 1:1,200 scale of the New Territories. The value of these plans, especially in the developing areas—would be lost unless they are kept up-to-date. All plans of Hong Kong Island, Kowloon and New Kowloon are therefore revised at one, two or three yearly intervals, depending on the rate of change in the areas they cover. Most of the plans of the New Territories cover remote and hilly areas where little change occurs and these will be checked every five years or so, but plans of built-up areas must be revised every two or three years and a few sheets in areas of rapid development, such as Kwai Chung and Castle Peak, are revised annually. To maintain even the minimum necessary programme the equivalent of over 500 plans a year must be revised. This requires the sustained efforts of a large proportion of survey and cartographic staff.

The original large-scale air survey contract was virtually com- pleted during the year but at the request of the District Commissioner