ENG-1987 — Page 228

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LAND, PUBLIC WORKS AND UTILITIES

down to the single small scale sheets at 1:100 000 and 1:200 000. A new single-volume guide map of the developed areas was completed to replace the previous two volumes. Country- side leisure and tourist guide maps remain in high public demand, necessitating continuous action on revision and periodic redesign and replacement.

The wide range of cartographic services provided to other government departments include end-paper maps for the Hong Kong Annual Report, the geological map series, base maps for weather forecasting service, glide path plans, electoral boundary maps, country parks maps and pollution control plans. The Reprographic Unit also provides essential back-up to the cartographic sections in map production as well as the provision of copies of all monochrome series. As a by-product the unit provides extensive and sophisticated photographic and photo-reproduction services to other departments.

The Air Survey Unit operating from Royal Hong Kong Auxiliary Air Force aircraft continued to provide aerial photographs for engineering design work, volumetric calcula- tions of quarries and reservoirs, environmental studies and large scale mapping. Processing and production of the required data continues to be carried out by the Survey and Mapping Office photogrammetric unit. Vertical and oblique photography has been taken using an air survey camera in a RHKAAF helicopter, and has been particularly useful for obtaining photography of dangerous slopes.

The three computing sections in Hong Kong, Kowloon and Tai Po District Survey Offices, each equipped with a microcomputer and a pen plotter, are being fully utilised to process survey calculations and to plot survey plans. All remote district survey offices are linked up with these computing sections through telephone lines for direct and fast data transfer. Three sets of Electronic Theodolite Distancer with on-line data recorders are being used for the survey of large areas and the data captured can be transferred directly to the computing section for processing and plotting.

Work on the implementation of a computerised Land Information System began during the year. The new system will modernise land information management and will be a powerful tool for decision making in land administration. The whole system will go into full operation by mid-1992, while some district units will be operative before that date.

Port Works

Two kilometres of seawall were completed at Aberdeen, Aldrich Bay, Stonecutters Island and Sai Kung Town, which enabled a total of 20 hectares of seabed to be reclaimed for roads, open space and other industrial and government uses. A 180-metre breakwater for naval vessels at Stonecutters Island was completed. Also completed were a pier for the maximum security prison at Shek Pik, and the extension to the existing Yung Shue Wan Public Pier.

Other port works under construction included the extension to the existing ferry pier at Cheung Chau, construction of three piers and a pumphouse fronting the Western Wholesale Market, a slipway and reclamation for the Marine Police Base at Tai Lam Bay and dredging and rock removal work to provide marine access to the proposed boatyard sites at the Ap Lei Chau East Reclamation.

Geotechnical Control

The Geotechnical Control Office (GCO) of the Civil Engineering Services Department exercises control over the geotechnical aspects of public and private building and civil engineering works in the interest of public safety. In 1987 it made checks on 4 365 design proposals for public and private building and civil engineering works. The GCO also