Rapid calculation method for river flow

Abstract

According to the rapid calculation method for the river channel flow, the flow can be calculated only through a river channel wet perimeter L, a river channel slope J and a river channel hydraulic radius Rh according to a final river channel flow calculation formula, and measurement of the river channel wet perimeter L, the river channel slope J and the river channel hydraulic radius Rh can be completed only through a measuring tape. Therefore, quick calculation of the river flow can be completed, and the measurement mode is optimized. According to the method, the year-by-year correction coefficient alpha is obtained by comparing the water level measured value (including the dry season and the peak period) with the theoretical calculation value, and therefore the expected calculation flow in the follow-up time of the current year is calculated according to the river channel form of the current year by means of the correction coefficient alpha. And then the correction coefficient alpha is continuously corrected every year, so that the river flow can be accurately and rapidly calculated.

Description

Technical Field

[0001] The invention relates to the technical field of river flow prediction, and in particular to a method for quickly calculating river flow. Background Art

[0002] With the increase in water consumption in industrial and agricultural production and people's daily life, "the contradiction between water supply and demand is becoming increasingly acute", and planned water use and water allocation are becoming more and more important. The raising and attention of water resources issues "many occasions hope to quickly and accurately measure the open channel flow" is prominently reflected in the water volume calculation, total pollutant control and water resource scheduling and allocation of irrigation areas and water diversion projects. The method that my country has always used is mainly based on the velocity area method, which requires manual operation. Although the measurement accuracy is very high, it does not meet the requirements of automation. The water level flow relationship method, which is used in small quantities, can automatically measure the flow, but the accuracy is not high and cannot meet the requirements of accurate water measurement. There are also very few methods that rely on imported instruments (such as acoustic Doppler profilers, etc.) to automatically measure the flow. Due to the high price and high maintenance costs of the instruments, they cannot meet the needs of automatic measurement of open channel flow in large quantities.

[0003] Therefore, this application proposes a method for quickly calculating river flow, which can realize the rapid calculation of river flow based on the Manning formula. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method for quickly calculating river flow, which is used to solve the problems of low accuracy of water level flow measurement methods in the prior art, and high instrument cost and maintenance cost of a small number of methods that rely on imported instruments to automatically measure flow.

[0005] To achieve the above-mentioned and other related purposes, the present invention provides a method for quickly calculating river flow, comprising the following steps:

[0006] S1: Obtain and collect river topographic data; river topographic data includes river wet perimeter L, river slope J, and river hydraulic radius R h ;

[0007] S2: Calculate the river interception area A; according to the river wet perimeter L and river hydraulic radius R obtained and collected in step S1 h Substitute it into the formula to get the river interception area A, the formula is as follows:

[0008]

[0009] S3: The formula for calculating river flow is: Q = V·A;

[0010] Where Q is the river flow per unit time; V is the river flow velocity;

[0011] S4: According to Manning's formula, we get: Among them, α is the annual correction coefficient; k is the conversion constant; n is the river roughness;

[0012] S5: Substitute the Manning formula in step S4 into the river flow calculation formula in step S3 to obtain:

[0013]

[0014] S6: Measure the flow rate of the river within a certain period of time and calculate α according to the formula in step S5;

[0015] S7: Based on the α calculated in step S6, the river slope J in step S1 and the hydraulic radius R in step S1 are obtained and collected again. h , the channel roughness n in step S4, and then the channel flow Q is inferred according to the channel flow calculation formula in step S5.

[0016] Preferably, the channel roughness n in step S4 is obtained by dividing the channel into several sections, directly looking up the table according to the type of each section of the channel to obtain the corresponding channel roughness n, and then comprehensively calculating the roughness n of the several sections of the channel to obtain the overall channel roughness n; the formula is as follows:

[0017]

[0018] Preferably, the type of each river section can be obtained by obtaining river images through satellite remote sensing technology, and the obtained remote sensing image information is preprocessed to obtain graphic information of several river sections.

[0019] Preferably, the calculation formula of the overall river channel roughness n is substituted into the river channel flow calculation formula in step S5 to obtain:

[0020] Then substitute the river interception area formula in step S2 to obtain:

[0021]

[0022] Preferably, the conversion constant k in step S4 is 1.

[0023] As described above, the rapid calculation method of river flow according to the present invention has the following beneficial effects:

[0024] 1. The rapid calculation method of river flow involved in the present invention. According to the final river flow calculation formula, it can be seen that only the river wet perimeter L, the river slope J, and the river hydraulic radius R are required. h The flow rate can be calculated using only a tape measure to complete the wet perimeter L of the river, the slope J of the river, and the hydraulic radius R of the river. hThe measurement can quickly calculate the river flow and optimize the measurement method.

[0025] 2. The present invention compares the actual water level values ​​(including the dry season and the peak season) with the theoretical calculated values ​​each year to obtain the annual correction coefficient α, and then uses the correction coefficient α to calculate the expected calculated flow rate at the subsequent time of the year according to the river channel morphology of the year. Then, the correction coefficient α is continuously corrected every year, so that the river flow rate can be accurately and quickly calculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of a river channel in a method for quickly calculating river channel flow according to the present invention;

[0027] Figure 2 It is a schematic diagram of calculating the river channel roughness n in the rapid calculation method of river channel flow involved in the present invention. DETAILED DESCRIPTION

[0028] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0029] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0030] The present invention provides a method for quickly calculating river flow, comprising the following steps:

[0031] S1: Obtain and collect river topographic data; river topographic data includes river wet perimeter L, river slope J, and river hydraulic radius R h ; The wet perimeter of the river L, the slope of the river J, and the hydraulic radius of the river R h This can be obtained using only a tape measure and calculation methods known in the art.

[0032] S2: Calculate the river interception area A; according to the river wet perimeter L and river hydraulic radius R obtained and collected in step S1 hSubstitute it into the formula to get the river interception area A, the formula is as follows:

[0033]

[0034] S3: The formula for calculating river flow is: Q = V·A; where Q is the river flow per unit time; V is the river flow velocity;

[0035] S4: According to Manning's formula, we get: Among them, α is the annual correction coefficient; k is the conversion constant; n is the river roughness;

[0036] S5: Substitute the Manning formula in step S4 into the river flow calculation formula in step S3 to obtain:

[0037]

[0038] S6: Measure the flow rate of the river within a certain period of time and calculate α according to the formula in step S5;

[0039] S7: Based on the α calculated in step S6, the river slope J in step S1 and the hydraulic radius R in step S1 are obtained and collected again. h , the channel roughness n in step S4, and then the channel flow Q is inferred according to the channel flow calculation formula in step S5.

[0040] Preferably, Figure 1 , Figure 2 As shown, the channel roughness n in step S4 is obtained by dividing the channel into several sections, directly looking up the table according to the type of each section of the channel to obtain the corresponding channel roughness n, and then integrating the channel roughness n of several sections to calculate the overall channel roughness n; the formula is as follows:

[0041]

[0042] Furthermore, as shown in the following table, the channel roughness n corresponding to different channel types can be directly looked up.

[0043]

[0044] Preferably, the type of each river section can be obtained by obtaining river images through satellite remote sensing technology, and preprocessing the obtained remote sensing image information to obtain graphic information of several river sections. Of course, the type of each river section can also be obtained by sonar, underwater photography, etc.

[0045] For example: based on the river channel images obtained by satellite remote sensing technology, the operator divides the wet perimeter L of the river channel into four sections, namely L1, L2, L3, and L4, where the length of L1 is 5m; the length of L2 is 7m; the length of L3 is 2m; and the length of L4 is 1m.

[0046] Assuming L1 is a general river channel (with a small amount of stones or weeds), the roughness n1 of the river channel in the L1 section is 0.035; assuming L2 is a straight, clean river channel with smooth water flow, the roughness n2 of the river channel in the L2 section is 0.025; assuming L3 is a general river channel (with a small amount of stones or weeds), the roughness n3 of the river channel in the L3 section is 0.035; assuming L4 is an irregular, curved river channel with more stones or aquatic plants, the roughness n4 of the river channel in the L4 section is 0.040;

[0047] n=L1*n1+L2*n2+L3*n3+L4*n4=5*0.035+7*0.025+2*0.035+1*0.04=0.46; in this way, the overall river channel roughness n can be calculated.

[0048] Preferably, the calculation formula of the overall river channel roughness n is substituted into the river channel flow calculation formula in step S5 to obtain:

[0049] Then substitute the river interception area formula in step S2 to obtain:

[0050]

[0051]

[0052] From the above formula, we can know that: when the river channel wet perimeter L, river channel slope J, and river channel hydraulic radius R are obtained h After that, the roughness n of the entire river channel is calculated by relying on satellite remote sensing technology, and the flow rate per unit time is measured by using the automatic flow measurement method. The value of the annual correction coefficient α can then be calculated, and then the subsequent flow rate can be predicted using the annual correction coefficient α.

[0053] For example, the peak period of a river is generally from June to October each year. In June, operators measure the wet perimeter L, the slope J, and the hydraulic radius R of a river. h The data are collected and the roughness n of the river channel is measured. The flow rate of the river channel is measured by automatic flow measurement method. According to the above formula, the value of the annual correction coefficient α in June can be obtained.

[0054] Then the operator uses the annual correction coefficient α to re-measure the river channel wet perimeter L, river channel slope J, and river channel hydraulic radius R every month from July to October. h, the roughness n of the entire river channel, and then the above formula can be used to get the predicted flow of the river channel from July to October, which can solve the problems of low accuracy of the water level flow measurement method in the prior art, and high instrument cost and high maintenance cost of a very small number of methods that rely on imported instruments to automatically measure flow.

[0055] Correspondingly, the dry season of a river is generally from November to May of the following year. In November, operators can measure the wet perimeter L, slope J, hydraulic radius R of a river. h The data are collected and the roughness n of the river channel is measured. The flow rate of the river channel is measured by automatic flow measurement method. According to the above formula, the value of the annual correction coefficient α in November can be obtained.

[0056] Then the operator uses the annual correction coefficient α to re-measure the river channel wet perimeter L, river channel slope J, and river channel hydraulic radius R every month from December to May. h , the roughness n of the entire river channel, and then use the above formula to get the predicted flow of the river channel from December to May.

[0057] When measuring the flow of a river channel using the above-mentioned method of automatically measuring flow, multiple measurements may be performed and the average of the measurements may be used to obtain the value of the annual correction coefficient α, thereby making the value of the annual correction coefficient α as accurate as possible.

[0058] The present invention relates to a rapid calculation method for river flow. According to the final river flow calculation formula, it can be seen that only the river wet perimeter L, the river slope J, and the river hydraulic radius R are required. h The flow rate can be calculated using only a tape measure to calculate the wetted perimeter L, the slope J, and the hydraulic radius R of the river. h The measurement can complete the rapid calculation of river flow and optimize the measurement method. The annual correction coefficient α is introduced, and the correction coefficient α is used to calculate the expected calculated flow in the subsequent time of the year according to the river morphology of the year. Then the correction coefficient α is continuously corrected every year, which can achieve accurate and rapid calculation of river flow. In this way, the automatic flow measurement equipment or method in the existing technology only needs to be used once a year to obtain the annual correction coefficient α of this year, and the target flow in the subsequent months of this year can be predicted. There is no need to use the automatic flow measurement equipment or method in the existing technology again, which reduces costs and reduces the maintenance costs of automatic flow measurement equipment.

[0059] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0060] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for rapid calculation of river flow, characterized in that: The steps include: S1: Obtain and collect river topographic data; river topographic data includes river wet perimeter L, river slope J, and river hydraulic radius R h ; S2: Calculate the river interception area A; according to the river wet perimeter L and river hydraulic radius R obtained and collected in step S1 h Substitute it into the formula to get the river interception area A, the formula is as follows: S3: The formula for calculating river flow is: Q = V·A; Where Q is the river flow per unit time; V is the river flow velocity; S4: According to Manning's formula, we get: Among them, α is the annual correction coefficient; k is the conversion constant; n is the river roughness; S5: Substitute the Manning formula in step S4 into the river flow calculation formula in step S3 to obtain: S6: Measure the flow rate of the river within a certain period of time and calculate α according to the formula in step S5; S7: Based on the α calculated in step S6, the river slope J in step S1 and the hydraulic radius R in step S1 are obtained and collected again. h , the channel roughness n in step S4, and then the channel flow Q is inferred according to the channel flow calculation formula in step S5.

2. The rapid calculation method of river flow according to claim 1 is characterized in that: The roughness n of the river channel in step S4 is obtained by dividing the river channel into several sections, directly looking up the table according to the type of each section of the river channel to obtain the corresponding river channel roughness n, and then comprehensively calculating the roughness n of several sections of the river channel to obtain the overall river channel roughness n; the formula is as follows:

3. The rapid calculation method of river flow according to claim 2 is characterized in that: The type of each river section can be obtained by obtaining river images through satellite remote sensing technology, and the obtained remote sensing image information is preprocessed to obtain graphic information of several river sections.

4. The rapid calculation method of river flow according to claim 2 is characterized in that: Substituting the calculation formula of the overall river channel roughness n into the river channel flow calculation formula in step S5, we get: Then substitute the river interception area formula in step S2 to obtain:

5. The rapid calculation method of river flow according to claim 1 is characterized in that: The conversion constant k in step S4 is 1.

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