Basic and applied Research on Snow Accumulation and Ablation Models in Snowmelt Runoff Analysis

1)在石kari河中游实验流域同时进行融雪量、融雪流量和浊度观测。研究了积雪释放的水径流过程。水温-流量法和连续河道浑浊度观测表明，融雪径流存在地表流动，且浑浊度峰值出现时间早于流量峰值出现时间。结果表明，地表流动机制似乎是通过积雪层和土层发生的。2)基于理论和经验考虑的广义积雪和融雪方程在札幌和Shinwa进行了验证。研究结果表明，仅以气温为指标，可以较好地估计雪的水当量和日降雪量。研究表明，如果没有足够的必要数据，这些变化是可以估计的。3)在北海道大学静乃畜牧场的试验流域，在积累和消融季节进行了更多的融雪流量观测。采用度时法结合雪槽模型对流域进行融雪径流分析。得到了充分的结果。4)提出了基于热平衡法的融雪模型，并将其应用于集总估算全流域融雪量。在多个流域，利用水槽模型参数识别区域辐射和风速参数，进行长期融雪径流分析。5)在开阔场地和阔叶林场地进行融雪和气象要素观测。得到了估算森林立地净辐射的一种过渡性方法。(6)水量平衡方程估算的全流域降水与稳定降水的比值具有季节和年变化特征。这些变化导致了设计的额外降水与实际的差异。(7)尝试在融雪季节将融雪分量与总流量分离。组件的比率被定义为融雪依赖性。具体证实，这些数值在这个季节是非常大的。少

1)Simultaneous observations of snowmelt, snowmelt discharge, and turbidity were conducted in an experimental basin located at the midstream of Ishikari river. Water runoff processes released from the snow-pack were investigated. It was recognized by the water temperature-discharge method and the continuous river turbidity observation that the surface flow existed in the snowmelt runoff, and a peak hours of the turbidity appeared earlier than that of the discharge. The results were available to make clear the surface flow mechanism which seemed to be occured through the snow-pack and the soil layr2)Generalized snow accumulation and snowmelt equations based on theoretical and emprical considerations was tested in Sapporo and Shinwa. As a result of investigating, chenges of water equivalent of snow and daily snowfall could be estimated favorably using sole index of air temperature. It was shown that these variations could be estimated, if there were not enough necessay data.3)Observation … More of snowmelt discharge was conducted in accumuluation and ablation season at an experimental basin located in Shizunai Livestock Farm of Hokkaido University. Snowmelt runoff analysis was carried out at the basin using the degree-hour method in conjunction with the snow-tank madel. And sufficient results were obtained.4)A snowmelt model based on heat balance method was proposed, and applied in a lumped to estimate basin-wide snowmelt. In several basins, parameters of regional radiation and wind speed were identified by the tank model parameters, and long term snowmelt runoff analysis was carried out.5)Observation of snowmelt and meteorological elements was conducted in an open site and scerose forested site. An interim method which estimated net radiation in the forested site was obtained.6)It was proved that a ratio of basin-wide precipitation estimated by the water balance equation to the stationary precipitation showed seasonal and annual changes. These changes caused the difference between designed extra precipitation and the actual one.7)An attemption was made to separate the snowmelt component from the total discharge in snowmelt season. A ratio of the component was defined as the snowmelt-dependency. It was confirmed concretely that these valuse were very large in that of the season. Less