FLOW STRUCTURES DETERMINING RIVER LEVEL IN AN ESTUARY

决定河口河流水位的水流结构

基本信息

批准号：
13450199
负责人：
YOSHIDA Shizuo
金额：
$ 4.35万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

It is essential to find the correct relationship between flow rate and river level in order to have information about the flow rate during flood and about uses of the river water like agriculture and hydroelectric generation. Normally, the river flow rate is assumed to be given by the level through the empirical H-Q equation, where H is the water level (height) and Q is the flowrate, but during drought, it becomes extremely more difficult to apply this expression to the estuary than to locations upstream. This is because the river level can take a large range of values under the influence of the four key factors of tide, atmospheric pressure, wind direction and wind speed. In this study, it was attempted to derive a method for quantitative estimation of the effects of tide, atmospheric pressure, wind direction and wind speed on flowrate in the estuary of the Ishikari River, where these four factors dramatically lower the correlation between water level (H) and river flowrate (Q). It was found that the effect of tide and atmospheric pressure on sea level is almost exactly reflected in the fluctuations of river level. Data from observations of river level under windless conditions and steady river flowrate allowed application of empirical rules for river rise due purely to flowrate, providing a quantitative estimate of the relation between wind and river behavior. Next, the flowrate was estimated at a certain location using the obtained quantitative relation between the four factors and river level, and this was found to be nearly identical to the observed flowrate. This confirmed the practical validity of this study.

为了获取有关洪水期间流量以及河水（如农业和水力发电）使用流量的信息，至关重要的是要了解流速与河流水平之间的正确关系。通常，假定河流流量是通过经验H-Q方程的水平给出的，其中H是水位（高度），Q是流量率，但是在干旱期间，将此表达应用于河口比上游的位置。这是因为在潮汐，大气压，风向和风速的四个关键因素的影响下，河流水平可以采用大量值。在这项研究中，它试图得出一种定量估算潮汐，大气压，风向和风速对Ishikari河河口流量的影响的方法，在这里，这四个因素大大降低了水位之间的相关性（ h）和河流（Q）。发现潮汐和大气压对海平面的影响几乎完全反映在河流的波动中。来自无风条件下河流水平和稳定河流流量的数据允许将经验规则应用于纯流动率，从而对风与河流行为之间的关系进行定量估计。接下来，使用四个因素与河流之间的定量关系在某个位置估算流量，发现这与观察到的流量几乎相同。这证实了这项研究的实际有效性。