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

1)在石卡里河中游的一个实验流域进行了融雪、融雪流量和浊度的同步观测。对积雪释放的径流过程进行了研究。通过水温排泄法和河流连续浊度观测，证实融雪径流中存在地表径流，且浊度峰值出现的时间早于流量峰值。2)对基于理论和经验的广义积雪和融雪方程在札幌和新和地区进行了检验。调查的结果是，仅用气温指数就可以很好地估算出相当于雪和日降雪量的水量变化。结果表明，如果没有足够的必要数据，这些变化是可以估计的在北海道大学静井畜牧场的一个实验盆地，积雪和消融季节的融雪流量较多。结合雪箱模型，采用度-小时法对流域融雪径流进行了分析。提出了一种基于热平衡法的融雪模型，并将其应用于全流域融雪预测。在几个流域，利用水槽模型参数识别区域辐射和风速参数，并进行融雪径流长期分析。5)在开阔地和林地进行融雪和气象要素观测。得到了估算林地净辐射的一种中间方法。6)证明了用水量平衡方程估算的全流域降水量与静止降水量的比值具有季节性和年际变化。这些变化导致了设计的额外降雨量与实际降雪量之间的差异。7)尝试在融雪季节将融雪分量从总流量中分离出来。将组分的比例定义为融雪依赖关系。具体来说，这些值在当季是非常大的。较少

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