ENG-1994 — Page 286

LAND, PUBLIC WORKS AND UTILITIES

government land boundaries in the territory, with all urban area records stored in digital form and the New Territories records kept in graphical form pending digitisation.

The office's mapping coverage of Hong Kong is extensive. The most definitive series of maps serving as the foundation of all other mapping is the large-scale (1:1 000) basic topographic series (3 000 sheets). Conversion of this basic series into digital form is progressing satisfactorily and will be completed in 1995. Smaller-scaled maps include the monochrome map series at 1:5 000 (161 sheets) and the coloured map series ranging from 1:20 000 (16 sheets) to 1:300 000 (one sheet). All topographic maps except the 1:1 000 basic map series are bilingual. The 1:300 000 map entitled 'Hong Kong in its Regional Setting' shows the Zhu Jiang (Pearl River) Delta and has proved popular. Demand for guide books and leisure maps, in the form of the Countryside Series and the Tourist Guide, continues to be strong.____

Maps are obtainable from the Government Publications Centre on the ground floor of the Queensway Government Offices, map publication centres in Hong Kong and Kowloon, and district survey offices in the New Territories.

The Survey and Mapping Office provides extensive cartographic services for many government departments. These include full-colour mapping for the geological series, thematic maps, weather forecasting plans, aeronautical charts, electoral boundary maps and pollution control plans. Its Reprographic Unit also provides services in photo-reproduction and plan copying, and serves as an essential backup for in-house map reduction and other cartographic activities.

The office has to maintain a huge volume of territory-wide land information to meet land administration, land boundary survey and mapping needs. The computerised Land Information Systems being implemented in the District Survey Offices contain all the necessary basic mapping data and land boundary or cadastral survey data. The Land Information Centre of the Survey and Mapping Office is responsible for the initial data conversion work of digitising the paper maps and the land record sheets into computer format. The conversion work will proceed on a district-by-district basis, enabling the phased implementation of the systems. The District Survey Offices which have imple- mented the systems in full, to date, cover the Hong Kong, Kowloon, Kwai Tsing, Tsuen Wan and Shatin districts.

The systems allow many jobs to be performed in a shorter time and with better product quality because of the timeliness of the land information and the wide choice of plan sizes, scales and colours available.

Mapping information in digital form, from the 1:1 000 survey sheets to 1:200 000 topographic maps, is now on sale to the public at the Land Information Centre. The customer is required to sign a data supply contract, which ensures recognition of the government's intellectual property rights in the data. At present, the digital map data is widely used by public utility companies, engineering consultants and construction firms.

The office's Photogrammetric Survey Section provides aerial photographs and photo- grammetric mapping as well as data for engineering design work, volumetric calculations for quarry and controlled tipping operations, environmental studies and town planning work.

The Air Survey Unit is also on call for quick response photography in emergency operations such as storms, flooding and landslips.

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