Study on Generalization of the Snowmelt Runoff Estimating Methods

融雪径流估算方法推广研究

基本信息

批准号：
12660213
负责人：
KURASHIMA Eiichi
金额：
$ 2.11万
依托单位：
Iwate University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

When planning irrigation and other water utilization, it is very important to grasp the process of snowmelt, and to understand how the snowmelt affects river runoff. For this purpose the experimental watershed was set up and factors concerned the snow melt were observed.Snowmelt which is caused by heat transfer across the snow-soil interface is called bottom snowmelt. It is very important to reflect the influence of bottom snowmelt on research regarding the mechanism of snowmelt runoff. But there have been very few examples of estimating the amount of bottom snowmelt during snow-covered period. In order to improve this situation 11 points where ranging from Hokkaido to Tohkai Regions were selected as research subjects and amount of bottom snowmelt was estimated and a comparison was conducted.In the other hand in the melt season, most snowmelt phenomenon occurs at the surface of the snowpack. Meltwater percolates to the ground surface with time lag. To forecast snowmelt runoff, it is necessary to understand the mechanism of meltwater percolation in snow cover. Thus, meteorological factors used in estimating surface melt and meltwater at the ground surface were measured. The percolation model, proposed for glacial area, was improved, then using this method, ground arrival amount was estimated from surface melt amount. As a result, it was determined that by applying the method, preferable reproducibiilty could be achieved for the time after the peak time of the graph, while there was amount loss regarding formation of shock front.As a part of the study program, water equivalent of snow was estimated at several watersheds and effects of global warming on spring river flow was tested.

在规划灌溉和其他用水时，掌握融雪过程并了解融雪如何影响河流径流非常重要。为此，设置了实验分水岭，观察了与雪融化有关的因素。由雪土界面传热引起的融雪称为底部融雪。反映底层融雪的影响对于融雪径流机理研究具有重要意义。但估算积雪期间底部融雪量的例子却很少。为了改善这种状况，选择了从北海道到东海地区的11个地点作为研究对象，估算了底部融雪量并进行了比较。另一方面，在融雪季节，大多数融雪现象发生在地表。积雪。融水渗透到地表有时间滞后。为了预测融雪径流，有必要了解融水在积雪中的渗透机制。因此，测量了用于估算地表融化和地表融水的气象因素。对针对冰川地区提出的渗流模型进行了改进，然后利用该方法，根据地表融化量估算了地面到达量。结果表明，通过应用该方法，在图表的峰值时间之后的时间可以实现更好的再现性，但在激波前沿的形成方面存在量损失。作为研究计划的一部分，水当量对几个流域的降雪量进行了估计，并测试了全球变暖对春季河水流量的影响。