from the Kowloon Government Offices, Kowloon East, Kowloon West and Kowloon Control, and until additional office space is available at the San Po Kong Government Offices, the N.T. East Sai Kung Section is also based there.
General
7.35 A reduction in the number of land transactions observed during the previous financial year continued during this year, reducing the number of title surveys required below that normally required two or three years ago. This enabled staff to be employed on mapping revision work or control work that had tended to fall into arrears during the preceding years due to the unavailability of staff.
7.36 Therefore, although it may be said that the results of the economic recession were felt in the fields of building construction and civil engineering development during the past year, the staff of the Survey Branch have nonetheless been fully employed on tasks carried forward from previous years.
7.37 Metrication of plans and records and the full implementation of the use of metric surveying equipment within Survey Branch has continued during the past year, while the problem of plotting metric contours on sheets at metric scales has been overcome to some extent by obtaining machine plots of certain sheets from the photogrammetric contractors employed by the P.W.D.
7.38 The full use of Survey Branch's air survey capacity can, however, only be reached with the establishment of the proposed P.W.D. Photogrammetric Unit in Hong Kong. In this respect it may be noted that it is proposed during the year to arrange the transfer of the Survey Training School to a refurbished office at Lower Shing Mun, with the P.W.D. Photogrammetric Unit moving into the existing school premises at San Po Kong. The Sai Kung Section of the N.T. East Sub-Division will also be housed in the San Po Kong Office.
7.39 The functional work of the Survey Branch is carried out by five main groups, namely, Control (including Air Survey), Mapping (including Site Surveys), Title, Training School and Cartography.
CONTROL SURVEY
7.40 This work-group is responsible for the provision and maintenance of the precise survey system in both the horizontal and vertical senses. Horizontal surveys are effected via triangulation nets and/or traverse lines and are prompted by the requirement to maintain an integrated survey system upon which all surveys in the territory are based. Vertical surveys are effected via precise level circuits and are necessary to establish fundamental Bench Marks throughout the territory which, in levelling terms, must be strictly consistent with Principal Datum.
7.41 This integrated control survey system is essential for the systematic mapping of the territory and the overall co-ordination of all land and engineering surveys undertaken within the territory. Some important benefits of an integrated control system are: (a) the relationship between any two surveys can readily be evaluated; (b) survey data of one survey can readily be used for another survey; and (c) missing survey points can readily be re-established. Notwithstanding the existence today of very sophisticated photogrammetric
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