The river Sendai is not only the principal river in Kagoshima Pref., but it is so in Kyushu District. She has given rather menace than benefit to the inhabitant along the river. This study is a part of the co-operative research, named “the Transfiguration of the Region by the Buildings of the Artificial Establishment, ” but the writer have his mind to write the “Potamography” of the river.
The physical characteristics of the river Sendai is first its narrowness compared with its length. It is because the river is like a succession of many short rivers, though it is really one river. Besides this there exist many terraces along the channel, for the flood plain is very narrow and then the floods have been defined to small areas, though happened very often.
The investment to avoid the damages by the floods were very unsatisfactory before 1927, because the construction of embankment by the Government started this year at first. The works were confined to the lower course before the Second World War, but the engineering of the upper course began in 1948.
As the result of these works the damages by the floods have reduced very much, but the floods yet happened, for example in 1954 and 1957. Then the plan to build a multipurpose Dam at Tsuruta started in 1952 and the building finished in 1964.
Nowadays the overflows from the trunk river and major tributaries are nearly shut off, but a new trouble occurs though in a small scale. There remain the overflows from the tiny rivers or ditches and the subsidence of water becomes very slowly, as the cause of the control of Dam. The methods to avoid this trouble must be thought separately, but also there may be exist to consider the new Dam-control method.
Geographical review of Japan series A
Geographical review of Japan, Series B.