抄録
As for river flowing through urban or residential area, careful consideration should be given to the prevention of the flood disaster and conservation of river environment. Having lots of flood prevention installations such as motor pump houses, sluices and sluice pipes, the confluence space of river is a section of especial importance for river management. Since the effects of rising stage and turbulent flow on the river structure such as revetment and groin on the downstream from the confluence cause anxiety, it is desirable to analyze these phenomena quantitatively. On the assumption that the distance of a river flow in which a homogeneous mixture of suspended and dissolved solids is made has a close relation with the length of confluence section through main river and tributary, it is thinkable that the confluences section length may be estimated quantitatively by statistically processing the spectral reflectance characteristics of the ground surface substance obtained from satellite remote sensing data.
In this study a method to estimate the length of confluence section was examined, reading turbidity with the aid of spectral reflectance characteristics obtained from the data of the earth observation satellite. The investigation site was the confluence section of the Kise River which joins the Kano River at Tokura region on its downstream. The Kano River empties into Suruga bay in the neighborhood of Numazu City, Shizuoka Pref.
