Hydrological study of snowmelt flooding during a rain-on-snow event

为了明确雨雪过程中融雪洪水的产生机制，在北方北海道茂尻雪水观测站进行了2011 - 2013年3个融雪季节的雪面降雨模拟试验。在2012年的实验中（雪深：170 cm），在开始浇水后的50至90分钟内，积雪底部开始流出，总流出量为46至48 L，总浇水量为120至170 L。当流入和流出速率处于稳定状态时，使用水和氘质量平衡方程估计流出水中包含的浇灌雨的速率为60%至70%。然后，它原来是一个积雪中的蒸发水在雨雪事件期间表现出不同的径流过程中，在融雪或弱降雨事件。

In order to clarify the generation mechanism of snowmelt flooding during the rain-on-snow event, rain simulation experiments over the snow surface were made in the three snowmelt seasons from 2011 to 2013 at the Moshiri snow hydrologic observatory, northern Hokkaido. In the experiment in 2012 (snow depth: 170 cm), the outflow from the bottom of snowpack began in 50 to 90 minutes after a watering start, and the total outflow was 46 to 48 L to the total watering amount of 120 to 170 L. When inflow and outflow rates were in a steady state, the rate of watering rain contained in outflow water was estimated 60 to 70 % using the water and the deuterium mass balance equations. Then, it turned out that percolating water within a snowpack during the rain-on-snow event showed a different runoff process during the snowmelt-only or weak rainfall event.