急流礫床河川における洗掘深センサーの開発

抄録

Recently floods in steep slope rivers have caused serious damages on levees and revetment works, highlighting urgent need to monitor local scour near river banks. The present study proposes a new sensing method that can measure scour depth continuously and quantitatively during floods. The sensor consists of blocks with internal resistors and conductive interfaces on the block surfaces. The principle to measure scour depth is to detect the number of blocks washed away by measuring the change in resistance of the sensor. Prototypes are produced and their performance is tested not only in a flume under active transport of coarse gravels but also in a river with man-made flood. It is confirmed that the present sensor can reasonably detect scour depth and that it gives similar results with those by conventional methods using bricks or colored gravels. A formula is also developed to specify the weight and dimension of the sensor block. Weak points of the sensor are also discussed to improve its performance.