TOPOGRAPHICAL CHANGE OF EMBAYMENT-BED AND SANDBER AT KUZUHA, THE YODO RIVER

Abstract

This paper is concerned with the riverbed form evolution in Kuzuha, the Yodo River, where two embayments and the sand bar are located. The embayments were newly reconstructed in March, 2003 in order to promote the enlargement of the shallow water area for aquatic lives in the upper part of the Yodo River, however the degradation of the embayments by flood is concerned. The Kuzuha sandbar is only large scale sand bars in the Yodo River, and it has some temporary waters which is used for spawning by many kinds of fish, and a bared part of the sand bar is used by spawning by birds, however the invasion of the vegetation and the lost of the bared part, and the lost of the temporary water by sedimentation are also concerned. The leveling for these areas has continuously been conducted since 2004, and two floods of medium-magnitude attacked from 2004 to 2006. The paper describes the topographical change of the riverbed forms by these floods in view of the river eco-system.