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

1)在石狩川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。对积雪径流过程进行了研究。通过水温流量法和河流浊度连续观测，认识到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）在札幌和Shinwa对基于理论和经验考虑的积雪和融雪方程进行了检验。研究结果表明，用单一的气温指标可以较好地估计雪水当量和日降雪量的变化。结果表明，在没有足够的必要数据的情况下，这些变化是可以估计的。 ...更多信息 在位于北海道大学静内畜牧场的一个试验池中，在积雪和消融季节进行了融雪流量的试验。融雪径流分析进行了流域使用度小时法结合雪槽模型。建立了基于热量平衡法的融雪模型，并将其应用于流域范围内的融雪量的集总估算。在几个流域，利用水槽模型参数识别出区域辐射和风速参数，并进行了长期融雪径流分析。5）在一个开阔场地和一个干燥的森林场地进行了融雪和气象要素观测。6）证明了由水量平衡方程估算的全流域降水量与固定降水量的比值存在季节和年际变化。这些变化导致了设计降水量与实际降水量之间的差异。7）在融雪期提出了将融雪分量从总流量中分离出来的方法。该组分的比率被定义为融雪依赖性。具体证实，这些价值在本赛季非常大。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