The whole area of Japan was covered by topographic map of 1/50, 000 scale.
The new covering by the basic topographic map of 1/25,000 scale has been in
progress by using the aerial photographic survey. The covered area up to the
present has become about 70 % of the total land. The large scale maps of 1/5, 000
and 1/2,500 have also being made for various social and economic projects.
Covering by aerial photograph is made by G.S.I. ( mainly plain area ) and by
Foresty Agency of Ministry of Agriculture and Forestry (mainly mountain area).
The revision of theseaerial photographs are made every 3 or 5 years according
to change of surface conditions. The civil engineering surveys, which is a
principal part of the law, are to execute works of the national organizations,
such as Ministries of Construction, Transport, Agriculture and Forestry, National €
Railways, public corporations ( road, housing, etc.) and local government
( prefecture, city, town and village).
Plans and specifications of these surveys must be reported to G. S.I. before
their execution and the final results must be reported and checked by the same
agency. In order to secure the uniform accuracy and simplify the troublesome
treatments on documental reports, standardization of specifications has been
in progress in accordance with various aims of surveyings. The yearly amount
of work and expenditure of the civil engineering surveys are increasing remarkably
in proportion to the progress of social and economic reorgnizations. The amount
of expenditure in 1970 was about 1350 million dollers.
The practical works of the civil engineering surveys are carried out mainly ‚©
by many surveying enterprise companies. The situation is very different from