Flow element measuring method for flow in river freezing period

Abstract

The invention relates to a flow element measuring method for flow in a river freezing period. The method comprises the steps: obtaining section water depth distribution; calculating the area of each strip-shaped unit; calculating an accumulated hydraulic radius; calculating a numerical difference value; calculating the value of the relative unit width flow at each measuring point; calculating theunit width flow of each measuring point; drilling and measuring; and calculating total flow. According to the calculation method, an under-ice drilling flow measurement method is greatly optimized, and the number of drilled holes in an ice cover is reduced. Compared with a traditional multi-hole multi-point flow velocity measurement method, only the flow velocities of two points need to be measured, the measurement workload is effectively reduced, the measurement cost in low-temperature severe weather is reduced, the flow measurement time is shortened, the risk of personal accidents of technicians is reduced, and the flow measurement efficiency under ice of northern rivers is greatly improved. Reduction of the number of the drilled holes in the ice cover is beneficial to maintaining flow velocity distribution and flow state under natural river ice, external interference introduced by measurement is reduced and then observation precision is improved.

Description

technical field [0001] The invention relates to a flow element measurement method for the flow of a river during ice-covered periods, which is a calculation and analysis method for water conservancy projects, and is used for flow observation and water-level-flow relationship analysis of partly or completely ice-covered rivers in the north. Background technique [0002] The rivers in northern China are all faced with the influence of seasonal ice cap closures. The existence of ice caps significantly increases the overall resistance of the river channel, which in turn affects the cross-sectional flow velocity distribution, water level and flow relationship, and river channel flow capacity. For example, in the Yellow River, there are about 110 days of ice-covered periods every year, while the average ice-covered period in Heilongjiang is as long as 160-180 days. The relationship between water level and flow under the traditional open channel flow of each hydrological station ca...

AI Technical Summary

Problems solved by technology

However, this method has the following defects: firstly, drilling holes on the ice sheet is not safe during the initial sealing period and the ice melting period, and it is very easy to cause engineering and technical personnel to fall into the water, which is easy to cause accidents; It is difficult to measure flow continuously by punching holes, and the measurement efficiency is low; the third is that the manpower and material cost of flow measurement during glacial period are high, and it is impossible to observe the flow under the ice continuously for a long time and with multiple sections.

However, this method only simplifies the flow measurement work at each ice hole, and still needs to arrange different ice holes along the section. The workload of flow measurement under ice is heavy, and the difficulty and danger still exist.

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