筑後川流域における土砂収支の推算と有明海ヘの砂の流出量に関する研究

抄録

A series of environmental issues reporting a lack of sand supply from the Chikugo river to the Ariake sea have been made on the basis of few investigation data of flood flows and sediment transport rate in the Chikugo river. To make clear the amount of sand supply from the Chikugo river estuaries, the authors estimated sediment transport rate through the location of the Chikugo barrage from the sediment balance in the Chikugo river basin. We also developed a new method of river bed variation analysis based on sediment and water content in alternate layers of the river bed. The analysis demonstrated that gravel and sand was transported about a hundred thousand cubic meter per year from the Chikugo river to the Ariake sea. Both computational results showed nearly equal sand transport rate to the Ariake Sea.