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.

在计划灌溉和其他水利用时，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，建立了实验流域，并观察到雪融化的因素。由于在雪地界面上进行的热传递而引起的snowmelt称为底层雪熔。反映底层融雪对融雪径流机制的研究的影响非常重要。但是很少有例子估计雪覆盖期间底层融雪的量。为了改善这种情况，选择了从北海道到Tohkai地区的11点，因为估计了研究对象和底层融雪的量并进行了比较。另一方面，在融化季节，大多数雪熔现象发生在积雪的表面。融合水随时间滞后将渗透到地面。为了预测融雪的径流，有必要了解积雪中融化渗透的机制。因此，测量了用于估计地面表面熔体和熔融水的气象因素。提出了针对冰川区域的渗滤模型，然后改善了该方法，从表面熔体量估算了地面到达量。结果，确定通过应用该方法，可以在图表的高峰时间之后的时间可以实现可取的重生，而在减震器前部的形成方面损失了损失。作为研究计划的一部分，在几个流域中估计了水等效的降雪，并且测试了春季河流流动的全球温暖流动的影响。