獨逸 EKBE江 河口의 河底地形 : 其I. 河底大砂丘

Abstract

Fluvial Morphology of the Elbe Estuary in Germany (1. Submarine Megaripples). The Submarine megaripples in the river bed of the Elbe estuary in Germany were studied with reference to the distribution, origin development. Writer has drawn the following conclusion. 1) The Submarine megaripples appear only in the sandy river bed. 2) The area of megaripples is increasing. 3) The largest ripple height is about 6m. A megaripple with interposed large scale ripple has greater ripple height than one without it. 4) The wave length lies between ca. 23-250m. The megaripples with interposed large scale ripples have greater wave length. 5) Ripple height and wave length are positively related. 6) The ripple index ( vertical form index of Burcher, 1919) lies between 10-85. Ripple index of megaripples with interposed large scale ripples are greater than ones without them. There is a tendency that as the ripples get farther from the thalweg the ripple index becomes greater. 7) The deeper the water, the larger the ripples formed. 8) The larger the grain size, the bigger the ripples are.