C—la

Topographical Mapping (Map Series) No field-work was carried out under this heading. Maps published during the year comprise work that was completed in the previous year, the drawings of which were in hand. The summary of maps published to date is as follows :

1:25000 series

1:63360 series

It is hoped to proceed with, the mapping of the Kotorua-Taupo region later in the year when it may be possible to release field staff from other urgent works. The production of topographical maps are essential to the development of this Dominion and are the only basis for the study and planning of works and programmes. Aerial Photography The services of N.Z. Aerial Mapping, Ltd., Hastings, has been fully employed during the year on the production of aerial photographs for all State Departments. This company still maintains a high standard of production and is now engaged in filling in photographic coverage of more difficult terrain where suitable weather conditions are limited. Since the company commenced operations under contract in 1939, an area of 45,500 square miles has been covered with vertical aerial photographs on scales of 20 or 30 chains to an inch. Much of this coverage now extends beyond the areas that are comprised in the topographical map series, and, owing to shortage of staff, it will be many years before such photography can be used for mapping purposes. " To make fuller use of existing photography it is proposed in the coming year to produce mosaic maps, particularly of unmapped areas, which will greatly assist in the study of the lands of the Dominion for many and varied purposes. During the year the company photographed an area of 4,740 square miles, mostly on a basic scale of 20 chains to an inch. Much of the area covered was located in the Westland and Southland Districts, where timber-resource investigations are being carried out by the State Forest Service. Special surveys have also been carried out for river control and soil conservation purposes in various catchment districts,

8

— Area (Square Miles). Number of Sheets. Maps published at 31st March, 1947 Maps published during year Mapping in hand 940* 130 1,044 32* 3 28 Totals 2,114 63 * The number of sheets quoted in last year's report omitted three sheets previously published, and the area actually covered by the sheets was also overestimated.

North Island. South Island. Total. Area (Square Miles). Number of Sheets. Area (Square Miles). Number of Sheets. Area (Square Miles). Number of Sheets. Published at 31st March, 1947 Published during year Drawings completed Mapping in hand 18,036 872 600 4,000 71 2 3 16 27,162 436 436 1,800 86 1 1 5 45,198 1,308 1,036 5,800 157* 3 4 21 Totals 23,508 92 29,834 93 53,342 185 * Includes five sheets (one in North Island and four in South Island) accidentally omitted from previous year's returns.