WATER SURFACE SLOPE AND STREAMFLOW HYSTERESIS PATTERNS ACCORDING TO DIFFERENT HYDROLOGICAL FLOODS

摘要

In this study, we provide a contribution toward monitoring the unsteady behavior of discharge-stage hysteresis in a mountainous river. In order to monitor the unsteady patterns of river discharge hysteresis estimated by means of a novel fluvial acoustic tomography system (FATS), we therefore observed the corresponding river water surface slopes hysteresis during different rainfall events. We found that the temporal variations in water surface slope-stage during different scales of rainfall events resulted in different patterns of hysteresis loops which can be classified into three main categorizes: (ⅰ) no hysteresis, (ⅱ) clockwise hysteresis, and (ⅲ) counterclockwise hysteresis. In the case of low intensity rainfall events, no hysteresis behavior was detected. Meanwhile, for medium and high intensity rainfall events resulted in either clockwise or counter clockwise (WS-WL) hysteresis patterns. Finally, for medium and high intense hy-drological events, water surface slope become almost constant after passing a certain level.