抄録
Distribution of old river beds are easily found on aerial photographs excepting city zone which many houses and buildings are crowded. In Niigata City zone, existence of old river beds are presumed only by old documents and maps.
In this paper, the writer shows boundaries old river beds of Old Shinano-gawa and Old Agano-gawa (recently named Tsûsen-gawa) and other sediments, considers the age and history of these old river beds based on boring data and results of photo-interpretation. Relations between photographic density and some related factors, relief of the ground, level of watertable, material of the beds, etc, are also considered.
