山地源流域の流出特性に与えるパイプの影響

Abstract

山地源流域の流出特性に与えるパイプ流の影響を明らかにするために, 降雨量, パイプ流量, 山地源流域の流域流量の観測を行い, 以下のような結果が得られた。1) パイプ流量と流域流量の関係は降雨イベント間でほとんど差はない。2) パイプ流が生じると, 流域流量は10倍以上になる。しかし, 流域流量の増加分とパイプ流量は必ずしも等しくない。これらの結果から, 山地源流域においては降雨強度によって流出経路が決まり, 流出経路が決まると流域流量が決まることが示された。さらに, 流出経路の変化によって流域流量が非常に大きく変化することが分かった。

In order to clarify the influence of pipeflow on the runoff characteristics at a valley head, the interrerationship the amount of rainfall, the discharge rate of pipeflow and discharge rate from watershed were observed. and the following points were clarified. 1) For every rainfall event there was little difference in the relationship between the discharge rate of pipeflow and the discharge rate from the watershed. 2) When pipeflow occurs, the discharge rate from the watershed increase on order of ten times the discharge rate of pipeflow. However in contrast, the increamental change of the discharge rate from the watershed did not agree with the discharge rate of pipeflow. These observation results indicate that the rainfall intensity detemines the pathway of runoff, and the pathway of the runoff determins the discharge rate from the watershed. Moreover, it was found that the discharge rate from the watershed greatly changes as the pathway of the runoff change.