STUDY ON RELATION BETWEEN SHELFISH FAUNA AND RIVER COURSE CHARACTERISTICS TO ESTABLISH RIVER MPROVEMENT TECHNOLOGY FOR ENVIRONMENTAL CONSERVATION IN RIVER ESTUARIES

Abstract

Estuaries are distinctive environment which fluctuates continually by mixing fresh water and sea water due to the influence of the tide and waves. However, disappearance of habitats is a serious problem in estuaries since river improvement technology in consideration of the environment has not been established. In this study, we investigated the relation between shellfish fauna and physical factors of watershed scale and river course characteristics. As a result of single correlation analysis, sinuosity, river bed complexity, comparable height difference in low flow channel, depth ratio, bed slope and number of types of habitat had significant positive correlation to abundance of shellfish fauna. These results suggest that the securement or creation of high attitude area in low flow channel should be considered when conducting the river bed excavation, or diversity of shellfish fauna can be secured by increasing the depth ratio when conducting river improvement.