CN106869077A - The method that cold region river freezeup period flow is estimated using Channel Group's phase stage discharge relation - Google Patents

Abstract

The present invention proposes a kind of method that utilization Channel Group phase stage discharge relation estimates cold region river freezeup period flow, comprises the following steps：In the river Channel Group phase, target section is chosen, set up the water level~discharge relation of target section Channel Group's phase；In river freezeup period, measuring point is arranged on target section, measurement determines the average effective depth of water of current under the section ice sheet；Flow rate of water flow maximum point is calculated r apart from the average relative water depth λ of bed surface by λ under measurement ice sheet_m；Calculate the depth of water ratio of ice sheet and bed-surface layerThe conversion factor of freezeup period flow, K=(1+ α are calculated by using Channel Group's phase stage discharge relation^3/2/r_m)/(1+α)^5/3, obtain the flow of target section river freezeup period.The present invention makes full use of Channel Group to be easy to the advantage of hydrologic survey the phase, by relatively simple measurement, determines conversion factor K values, and the stage discharge relation that Channel Group is fitted the phase is used to estimate cold region river freezeup period flow；Compared with conventional method, the workload of field inspection is greatly decreased, substantial amounts of man power and material can be saved.

Description

The method that cold region river freezeup period flow is estimated using Channel Group's phase stage discharge relation

Technical field

It is specifically a kind of cold using Channel Group's phase stage discharge relation estimation the invention belongs to hydraulic engineering technical field The method of area river freezeup period flow.

Background technology

High latitude area river winter is commonly formed ice sheet, the conveyance power of water in river under ice sheet is timely and accurately estimated, to cold The activity of the river managements such as water quality assessment, river engineering design, the ice flood early warning in area river is all extremely important.In river Channel Group Phase, flow is generally by the way that using stage discharge relation, directly conversion is obtained after the water level observed.But, in river freezeup period, ice The appearance of lid increased the resistance of flowing, cause the river Channel Group phase set up stage discharge relation can not be simply for ice-bound The estimation of phase flow.However, ice sheet roughness is influenceed by factors such as waterpower, heating power, generally with time and spatial variations, In the freezeup period of cold region river, it is impossible to set up a unified stage discharge relation.At present, river freezeup period is accurately estimated Flow, can only be studied by field prototype measurement.By arranging a plurality of survey line on testing section, surveyed using current meter The flow velocity of multiple points, is divided into several light sections, then estimate using flow velocity-method of section by testing section on every survey line of amount The flow of freezeup period.This method needs to expend substantial amounts of manpower and time, and hydrologic survey technical staff applies on ice sheet Survey, be susceptible to personal safety accident.Therefore, in the urgent need to a kind of simplicity that can quickly estimate cold region river freezeup period flow Method.

The content of the invention

To solve the problems, such as to determine that cold region river freezeup period flow difficulty is big by direct measurement, the purpose of the present invention is to carry Go out a kind of method that utilization Channel Group phase stage discharge relation estimates cold region river freezeup period flow, can be easy, quickly and accurately The flow in river under ice sheet is estimated by water level.Realized by following technical proposal.

The present invention provides such a computational methods, and one kind is ice-bound using Channel Group's phase stage discharge relation estimation cold region river The method of phase flow, in order to solve the above technical problems, the technical solution used in the present invention is as follows：

Step one, sets up the stage discharge relation of Channel Group's phase.Controlling section is chosen as testing section, natural river leads to Often choose and be difficult the section that washes away, such as discharge site it is regular after measuring section, basement rock river bed cross section etc..Determine testing section Afterwards, the measured profile data (X of target section is measured in Channel Group's phase_i, Z_0i), wherein i=1,2 ..., n, X_iRepresent at i-th point away from disconnected Face starting point X₁Distance, Z_0iRepresent the elevation of the point.The Manning roughness coefficient n in calibration riverbed_bAnd the ratio drop of section where section J, for shallow formula river wide, the Channel Group's phase water level~discharge relation of the section is set up using Manning formula

In formula, Q₀It is the flow of Channel Group's phase, z is water level, Z₀It is the corresponding water level of zero delivery, A is discharge section area.It is right In demarcated section, the stage discharge relation also directly set up using Hydrology department.

Step 2, measures the cross dimensions of freezeup period.Freezeup period, according to factors such as river width, current meter yardsticks, with reference to Channel Group The section survey of phase target section, reasonably arranges measuring point, successively labeled as measuring point 1,2 ... ..., N (N >=3).Technical staff exists The hydrology surveys ship or the hydrology is surveyed on bridge and drilled on all measuring points successively, and aperture is measured as control, record to adapt to current meter subglacial The ice sheet upper surface elevation Z of each measuring point_1kWith ice sheet thickness T_k, estimate the dispersed elevation Z of the section ice sheet upper surface₁, averagely Ice sheet thickness T, calculates the average effective depth of water H=Z of current under ice sheet₁-T-Z₀, Z₀It is the corresponding water level of zero delivery, each parameter Meaning refers to accompanying drawing 1.

Step 3, measurement determines the relative water depth of Peak Flow Rate point.While ice sheet thickness is measured, on each measuring point Current meter is placed, and moves up and down the point for finding flow velocity maximum, the distance apart from ice sheet upper surface for recording the point is Y_k, then its Relative water depth apart from bed surface is

In above formula：λ_kIt is relative water depth of the flow rate of water flow maximum point apart from bed surface under measuring point k ice sheets；

y_{I, k}It is distance of the flow rate of water flow maximum point apart from ice sheet lower surface under measuring point k ice sheets；

H_kIt is the available depth of current under measuring point k ice sheets；

Y_kIt is distance of the flow rate of water flow maximum point apart from ice sheet upper surface under measuring point k ice sheets；

T_kIt is measuring point k ice sheet thickness；

Z_1kIt is measuring point k ice sheets upper surface elevation；

Z_0kIt is measuring point k bed level of the river；

Subscript k represents k-th measuring point, and k=1,2 ... N, N are measuring point number, N >=3；

Flow rate of water flow maximum point under each measuring point ice sheet is averaged apart from the relative water depth of bed surface, current under ice sheet are obtained Flow velocity maximum point is apart from the average relative water depth of bed surface

In formula, λ is average relative water depth of the flow rate of water flow maximum point apart from bed surface under ice sheet；

λ_kIt is relative water depth of the flow rate of water flow maximum point apart from bed surface under measuring point k ice sheets；

Subscript k represents k-th measuring point, and k=1,2 ... N, N are measuring point number, N >=3；

Step 4, the vertical characteristics of flow rate of water flow are generally using double power laws under ice sheet

In formula, u_zIt is the flow rate of water flow with the point that the vertical distance of bed surface is z；

η is constant；

Z is water level；

H is the average effective depth of water of current under ice sheet；

m_bIt is the index for characterizing bed resistance；

m_iIt is the index for characterizing ice sheet amount of resistance；

The velocity flow profile is differentiated, obtaining relative water depth of the flow velocity maximum point away from bed surface is

R in formula_m=m_b/m_i；

λ is average relative water depth of the flow rate of water flow maximum point apart from bed surface under ice sheet；Formula (3) derivation, be

Order

Solved by A1,

m_iH-(m_i+m_b) z=0 (A3)

I.e.

If r_m=m_b/m_i, obtain

By formula (5), obtain

In formula, λ is determined by the measurement of step 3.

Step 5, calculates the depth of water ratio in ice sheet area and bed surface area.Ice sheet current are studied by using double-deck hypothesis, i.e., In the two-layer current that current under ice sheet are equivalent to mutually be independent of each other by zero stress face, upper strata is influenceed by ice sheet, referred to as ice sheet, The depth of water is h_i(distance of zero stress identity distance ice sheet lower surface)；Lower floor is influenceed by riverbed, referred to as bed-surface layer, and the depth of water is h_b(zero stress The distance in identity distance riverbed).Zero stress face does not overlap generally with Peak Flow Rate face, but positioned at the Gu Bi and max-flow of relative coarseness Between fast face, the elevation in zero stress face can use document [Chen Gang, Gu Shixiang, Zhou Mi, Huai Wenxin.Boundaryshear stress in rectangular ice-covered channels.Journal of Hydraulic Engineering, 2015,141 (6), 06015005] method determine.The present invention based on the method propose with The computational methods of lower simplification.Found by calculating, bed-surface layer depth of water h_bWith flow rate of water flow maximum point away from riverbed apart from y_bIn the presence of with Lower relation

In formula：c₁And c₂It is constant, c₁=1.72, c₂=-0.55.

By formula (5) and formula (7), the depth of water ratio of ice sheet and bed-surface layer can be determined by following relation

The specific derivation process of formula (8) is as follows：Due to H=y_i+y_b, by formula (5),

Formula (5) is substituted into formula (7), is obtained

Due to H=h_i+h_b, by formula (B2),

Therefore, by formula (B2) and (B3), obtain

Step 6, estimates the flow of freezeup period.Freezeup period flow is estimated using Manning formula

In formula：A is discharge section area, R₀It is the hydraulic radius of the whole cross-section of river, for shallow formula river wide, freezeup period Hydraulic radius R₀=H/2, H are the average effective depth of water of current under ice sheet；n₀It is the comprehensive roughness of section

In formula：n_b, n_iThe roughness coefficien of bed surface, ice sheet lower surface to the resistance of current is respectively characterized, with power exponent m_b, m_iBetween there is following relation

In formula：κ=0.41 is karman constant, and g is acceleration of gravity, R_bAnd R_iThe respectively waterpower of ice sheet and bed-surface layer Radius, for shallow formula river wide, hydraulic radius is approximately equal to the depth of water, i.e. R_b=h_b, R_i=h_i.Therefore, the n in formula (10)_b/n_iCan Determined by relationship below

Formula (12) is substituted into formula (10), is obtained

Formula (9) is substituted into by formula (13), the flow for obtaining the freezeup period of the section is

In formula, H is the average effective depth of water of current under ice sheet, and its elevation is z=Z₀+H.Contrast (1) and formula (14), obtains

In formula：K is the conversion factor that freezeup period flow is calculated using Channel Group's phase stage discharge relation,

Using document [Attar, S., Li S.S.Data-fitted velocity profiles for ice- Covered rivers.CanadianJournal of Civil Engineering, 2012,39,334-338.] and [Tatinclaux,J.C.M..Asymmetric plane flow with application to ice Jams.Journal of Hydraulic Engineering, 1983,109 (11), 1540-1554] in freezeup period prototype see Survey data, verifies to method proposed by the present invention.The result of calculation of proposition method of the present invention is shown in the contrast of measured discharge Accompanying drawing 3, as a result shows that method proposed by the present invention can utilize the stage discharge relation of Channel Group's phase to estimate cold region river exactly The flow of freezeup period.

The present invention compared with prior art, with advantages below and beneficial effect：

The present invention establishes the relation between same section Channel Group phase and freezeup period rating curve, makes full use of The advantage of hydrologic survey is easy to the phase in Channel Group, the stage discharge relation that Channel Group is fitted the phase, the stream for estimating river freezeup period Amount.Existing method, generally determines m by substantial amounts of field measurement_bAnd m_iConcrete numerical value, it is necessary to expend substantial amounts of manpower, thing Power, and method proposed by the present invention, when calculating the flow that river ice is frozen over, it is not necessary to determine m_bAnd m_iConcrete numerical value, only need true Both ratio rs fixed_m.When carrying out field measurement using the method for the present invention, it is only necessary to move up and down flow rate of water flow under determination ice sheet Maximum point (pushes away ratio r apart from the average relative water depth λ of bed surface for formula (6) to be counter_m), it is not necessary to read all of point on every vertical line Flow velocity, reduce the workload of field measurement, significantly shorten hydrologic survey technical staff's field measurement time, reduce occur people The risk of body security incident.Further, since ice sheet roughness is continually changing with the time, observation time is shorter, estimation it is real-time Flow accuracy is higher, and method proposed by the present invention can significantly shorten required observation time, and the flow accuracy of estimation is more existing Method it is high.

Brief description of the drawings

Fig. 1 be cold region river freezeup period cross section and main calculating parameter schematic diagram,

Wherein：B is section river width；

Z_1kIt is the ice sheet upper surface elevation of measuring point k；

Z_0kIt is the bed elevation of measuring point k；

H_kIt is the available depth of current under measuring point k ice sheets；

T_kIt is the ice sheet thickness of measuring point k；

h_iIt is the ice sheet depth of water；

h_bIt is the bed-surface layer depth of water；

y_iIt is distance of the flow rate of water flow maximum point apart from ice sheet lower surface under ice sheet；

y_bIt is distance of the flow rate of water flow maximum point apart from riverbed under ice sheet；

n_iIt is the Manning roughness coefficient of ice sheet lower surface；

n_bIt is the Manning roughness coefficient of bed surface；

u_maxIt is the Peak Flow Rate of current under ice sheet；

U is the vertical characteristics of main flow flow velocity；

τ_zxIt is the shearing stress on the vertical plane for acting on target section.

Fig. 2 is the flow chart that the embodiment of the present invention calculates cold region river freezeup period flow.

Fig. 3 is the proof diagram that method proposed by the present invention is verified using field data.

Fig. 4 is the rating curve figure of China northeast river in Channel Group's phase of the embodiment of the present invention.

Specific embodiment

With reference to specific embodiment, the invention will be further described.

Demarcated section is disposed with the river of China northeast, April annual November to next year, the section can all be formed surely Fixed continuous ice sheet.Referring to the calculation process of Fig. 2, the present embodiment is using the section Channel Group phase stage discharge relation estimation freezeup period The step of flow, is as follows：

Step 1:In Channel Group's phase, the size to the section is measured, and river width B=150m, the survey station is disposed with Hydrometric cableway, arranges that a vertical line is measured per 10m, successively labeled as 01,02 ... ..., 14.Discharge site is being set up in riverbed Regular, the corresponding elevation Z of zero delivery of Shi Jinhang₀=140.02m.Using Manning formula, it is smooth that Hydrology department has set up the section The rating curve Q of stream phase₀=f (z), is shown in Fig. 4.

Step 2：Referring to Fig. 1, freezeup period the hydrology survey on ship at 01,03,05,07,08,09,10,12,14 vertical lines according to Secondary drilling, measurement ice sheet upper surface elevation Z_1k, ice sheet thickness T_k, bed level of the river Z_0k, measurement result is shown in Table 1；

Table 1 is that the present embodiment applies section survey achievement unit at China northeast river：m

Step 3：Referring to Fig. 1, while implementation steps 2, successively using current meter successively measurement stream on each measuring point Length Y of the fast maximum point apart from ice sheet upper surface_k, it is shown in Table 1.So far, field measurement work is completed, step below is indoor meter Calculate work.

Step 4：The average value for using formula (2) and formula (3) to calculate flow velocity maximum point relative water depth is λ=0.5513；

Step 5：Solid wall relative roughness r is characterized in calculating the double power laws of velocity distribution in vertical using formula (6)_m=0.8169；

Step 6：The depth of water of ice sheet and bed-surface layer is calculated than α=0.6555 using formula (8)；

Step 7：The flow-rate ratio K=0.6752 of freezeup period and Channel Group's phase is calculated using formula (16)；

Step 8：Channel Group's phase rating curve is looked into, flow when water level is 141.82 is 428.25m³/s.Using The freezeup period flow that formula (15) calculates this test is 289.17m³/s。

It is emphasized that embodiment of the present invention is illustrative, rather than limited, therefore the present invention is simultaneously The embodiment described in specific embodiment is not limited to, it is every to be drawn by those skilled in the art's technology according to the present invention scheme Other embodiment, also belong to the scope of protection of the invention.

Claims (6)

1. a kind of method that utilization Channel Group phase stage discharge relation estimates cold region river freezeup period flow, it is characterised in that including Following steps：

Step 1, in the river Channel Group phase, chooses target section, sets up the water level~flow of river Channel Group phase target section Channel Group's phase Relation Q₀=f (z)；

Step 2, in river freezeup period, arranges measuring point on target section, measures the cross dimensions of target section, including estimation is broken The average ice sheet upper surface elevation Z in face₁With average ice sheet thickness T, and the average effective depth of water H for calculating current under ice sheet；

Step 3, determines flow rate of water flow maximum point under river freezeup period each measuring point ice sheet, and measure flow rate of water flow under each measuring point ice sheet Apart from the relative water depth of bed surface, this relative water depth refers to distance and the survey of the flow rate of water flow maximum point to bed surface under ice sheet to maximum point The ratio between available depth at point；Flow rate of water flow maximum point under each measuring point ice sheet is averaged apart from the relative water depth of bed surface, is obtained Average relative water depth λ of the flow rate of water flow maximum point apart from bed surface under to ice sheet；

Step 4, calculates r_m：

$r_m=\frac{1}{\mathrm{\λ}}-1$

In formula：r_m=m_b/m_i；m_bIt is the index for characterizing bed resistance；m_iIt is the index for characterizing ice sheet resistance；λ is ice Average relative water depth of the lower flow rate of water flow maximum point of lid apart from bed surface；

Step 5, divides ice sheet and bed-surface layer, calculates the depth of water ratio of ice sheet and bed-surface layer：

$\mathrm{\α}=\frac{h_i}{h_b}=\frac{1+r_m}{c_1{e}^{c_2{r}_m}}-1$

In formula：α is the depth of water ratio of ice sheet and bed-surface layer；h_iIt is the ice sheet depth of water；h_bIt is the bed-surface layer depth of water；c₁And c₂It is constant, c₁=1.72, c₂=-0.55；

Step 6, by the stage discharge relation conversion factor of target section river freezeup period, sets up target section Channel Group's phase and ice Envelope phase stage discharge relation, and then obtain the real-time traffic of target section river freezeup period；

Conversion factor is calculated as follows：

$K=\frac{1+{\mathrm{\α}}^{3/2}/r_m}{{(1+\mathrm{\α})}^{5/3}}$

In formula：K is the conversion factor that freezeup period flow is calculated using Channel Group's phase stage discharge relation；α is ice sheet and bed-surface layer Depth of water ratio；

The real-time traffic of target section freezeup period calculates as follows：

$Q={\mathrm{KQ}}_0=Kf\left(z\right){|}_{z=Z_0+H}$

In formula：For Channel Group's phase stage discharge relation that step 1 is set up, z is water level, Z₀For zero delivery is corresponding Water level, H is the average effective depth of water of current under ice sheet.

2. the method that utilization Channel Group phase stage discharge relation according to claim 1 estimates cold region river freezeup period flow, It is characterized in that：

In above-mentioned steps 1, the stage discharge relation Q of river Channel Group phase is set up₀=f (z), realizes as follows：

Obtain the profile data (X of target section_i, Z_0i), wherein i=1,2 ..., n, X_iRepresent at i-th point away from section starting point X₁Away from From Z_0iRepresent the elevation of the point；

The Manning roughness coefficient n of calibration bed surface_bAnd section where section is than drop J；Target section Channel Group's phase is set up using Manning formula Water level~discharge relation：

$Q_0=f\left(z\right)=\frac{1}{n_b}A{(z-Z_0)}^{2/3}{J}^{1/2}$

In formula, Q₀It is the flow of Channel Group's phase, z is water level, Z₀It is the corresponding water level of zero delivery, A is discharge section area.

3. the method that utilization Channel Group phase stage discharge relation according to claim 1 estimates cold region river freezeup period flow, It is characterized in that：

In above-mentioned steps 2, the calculating of the cross dimensions of river freezeup period is realized as follows：

In target section, the N number of measuring point of reasonable Arrangement, N >=3, and measuring point 1,2 ... N is labeled as successively；

Drilled on each measuring point successively, record the ice sheet upper surface elevation Z of each measuring point_1kWith ice sheet thickness T_k, subscript k represents kth Individual measuring point, k=1,2 ... N；The average ice sheet upper surface elevation Z of section is estimated according to above-mentioned each measuring point data₁With average ice sheet Thickness T, calculates the average effective depth of water H, H=Z of current under ice sheet₁-T-Z₀, Z₀It is the corresponding water level of zero delivery.

4. the method that utilization Channel Group phase stage discharge relation according to claim 3 estimates cold region river freezeup period flow, It is characterized in that：

In above-mentioned steps 3, the Peak Flow Rate point of current under river freezeup period each measuring point ice sheet is determined, and measure Peak Flow Rate point Relative water depth, realizes as follows：

Current meter is placed below the ice sheet of k measuring points, and it is moved up and down vertical, find the stream of current under the measuring point ice sheet Fast maximum point, records this apart from ice sheet upper surface apart from Y_k, then relative water depth of this apart from riverbed be

${\mathrm{\λ}}_k=1-\frac{y_{i,k}}{H_k}=1-\frac{Y_k-T_k}{Z_{1k}-T_k-Z_{0k}}$

In formula, λ_kIt is relative water depth of the flow rate of water flow maximum point apart from bed surface under each measuring point ice sheet；y_{I, k}For under k-th measuring point ice sheet Distance of the flow rate of water flow maximum point apart from ice sheet lower surface；H_kIt is the available depth of current under measuring point k ice sheets；Y_kIt is measuring point k ice sheets Distance of the lower flow rate of water flow maximum point apart from ice sheet upper surface；T_kIt is measuring point k ice sheet thickness；Z_1kFor measuring point k ice sheets upper surface is high Journey；Z_0kIt is measuring point k bed level of the river；Subscript k represents k-th measuring point, and k=1,2 ... N, N are measuring point number, N >=3.

5. the method that utilization Channel Group phase stage discharge relation according to claim 1 estimates cold region river freezeup period flow, It is characterized in that：

In above-mentioned steps 4, relational expressionIt is to carry out derivation by the vertical characteristics to flow rate of water flow under ice sheet to obtain, institute The vertical characteristics of flow rate of water flow under ice sheet are stated using double power laws

$u_z=\mathrm{\η}{\left(\frac{z}{H}\right)}^{1/m_b}{(1-\frac{z}{H})}^{1/m_i}$

In formula, u_zIt is the flow rate of water flow with the point that the vertical distance of bed surface is z；η is constant；Z is water level；H is current under ice sheet The average effective depth of water；m_bIt is the index for characterizing bed resistance；m_iIt is the index for characterizing ice sheet amount of resistance.

6. the method that utilization Channel Group phase stage discharge relation according to claim 1 estimates cold region river freezeup period flow, It is characterized in that：

In above-mentioned steps 5, in the two-layer current that current under ice sheet are equivalent to mutually be independent of each other by zero stress face, upper strata is by ice sheet The ice sheet of influence, lower floor is the bed-surface layer influenceed by riverbed.