JP2015113587A - Prediction system for river flow at downstream of dam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a prediction system for river flow at downstream of a dam, capable of highly accurate prediction of the river flow and water level at several points in downstream of a dam at a future time point, through simple calculation.SOLUTION: An arithmetic processing section 6 calculates an estimated river flow and an estimated water level at any observation point at any future time point, based on the actual water volume discharged by a dam 23 since a prescribed duration before the current time, the planned water volume discharged by the dam 23 between the current time and the future time point, the measured rainfall up to the current time in a region that include the river basin between the dam 23 and the observation point, the estimated rainfall between the current time and the future time point in the region, and the measured river flow at the current time at the observation point.

Description

  The present invention relates to a dam downstream river flow rate prediction system that predicts a flow rate and a water level at an arbitrary future time for a plurality of observation points in a downstream river of a dam.

  Conventionally, in rivers downstream of dams where there is a risk of flooding during heavy rains or typhoons, water level gauges and rain gauges are installed at multiple observation points by river managers to monitor the flow rate and water level. In addition, the dam management system attached to the dam measures and manages the discharge and water level of the dam, as well as the flow and water level at several observation points in the downstream river.

  As a management system for monitoring the entire river where a dam is installed, Patent Document 1 measures the inflow of water flowing into the dam, the discharge amount of the dam, the water level of the downstream river, etc., and inputs each measurement data to the computer system. It is used to manage the entire river. However, in this patent document 1, the river water level at the future time is not predicted.

  In addition, in the dam inflow prediction method presented in Patent Document 2, the actual dam discharge amount after a certain time, the subsequent planned discharge amount, the actual rainfall amount and the predicted rainfall amount are obtained, and from the upstream dam using a tank model. The amount of inflow in the downstream dam of a river that has been intentionally released is predicted.

JP 2007-138549 A JP-A-5-297909

  In the conventional dam management system or river management system, the flow rate and water level are measured at multiple points in the river downstream of the dam, but it is difficult to predict the time when the flood will occur from the measured values, and it is appropriate for heavy rain and typhoons. There was a problem that the alarm could not be issued at the right timing. On the other hand, there are several prior arts that have proposed methods for calculating the discharge of downstream rivers from the discharge of dams, precipitation, etc., but modeling of rivers is not easy and requires a lot of time for calculation.

  In the above-mentioned Patent Document 2, a method for calculating the inflow amount in the downstream dam in a short time based on the discharge amount from the upstream dam is presented, but the future flow rate at a plurality of points in the downstream river is predicted. It is not a thing. Further, in the method using the tank model, there are many model constants to be determined, and the number of trials and errors required to determine the constants is increased, which is a burden on the operator.

  The present invention has been made to solve the above-described problems, and predicts the flow rate and water level at future times at a plurality of points in the river downstream of the dam with high accuracy by simple calculation that does not place a burden on the operator. It aims at providing the river flow prediction system which can do the dam downstream.

A dam downstream river flow prediction system according to the present invention is a dam downstream river flow prediction system that predicts flow and water level at an arbitrary future time for a plurality of observation points of a downstream river of a dam managed by a dam management facility. Measured dam discharge from a certain time before the current time, planned dam discharge from the current time to any future time, and current time in the region including the basin from the dam to any observation point Based on the rainfall, the predicted rainfall from the current time in the region to any future time, and the measured flow rate at the observation point at the current time, the predicted flow rate and the predicted water level at any future time at the observation point are calculated. Dumb management of an arithmetic processing unit, an input unit for setting and inputting data and constants necessary for calculation by the arithmetic processing unit, and data necessary for calculation by the arithmetic processing unit A data acquisition unit that acquires from the network from Bei, those having a storage unit for storing the data and constants obtained through the input unit and the data acquisition unit.

  According to the dam downstream river flow prediction system according to the present invention, arbitrary observation can be performed by calculating the current measured flow taking into account the influence of the dam discharge flow and rainfall on a plurality of observation points in the river downstream of the dam. The predicted flow rate and predicted water level at an arbitrary future time of the point can be calculated easily and with high accuracy.

It is a figure which shows the whole structure of the dam downstream river flow prediction system which concerns on Embodiment 1 of this invention. It is a figure explaining the dam downstream river flow prediction system concerning Embodiment 1 of the present invention. It is a figure which shows the flow of a process by the arithmetic processing part of the dam downstream river flow prediction system which concerns on Embodiment 1 of this invention. It is a figure which shows the flow of a process of the prediction error simulation which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
Below, the dam downstream river flow volume prediction system which concerns on Embodiment 1 of this invention is demonstrated based on drawing. FIG. 1 is a diagram illustrating an overall configuration of a dam downstream river flow prediction system according to the first embodiment, and FIG. 2 is a diagram illustrating a dam downstream river flow prediction system according to the first embodiment. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

The dam downstream river flow rate prediction system 1 according to the first embodiment includes a plurality of observation points P ₁ , P ₂ , P _{3 in} the downstream river of the dam 23 managed by the dam management facility (not shown) of the dam management system 21. ,... _Pn predicts the flow rate and water level at an arbitrary future time, and is attached to the dam management system 21 as one of the auxiliary functions of the dam management system 21 or as a single system.

  As shown in FIG. 1, the dam downstream river flow rate prediction system 1 includes an input unit 2, a data acquisition unit 3, a storage unit 4, a data extraction unit 5, an arithmetic processing unit 6, and a display unit 7. In the input unit 2, the operator 10 sets and inputs data and constants necessary for calculation by the arithmetic processing unit 6. Specifically, a keyboard, mouse, touch panel or the like of a general-purpose computer is used.

  The data acquisition unit 3 acquires data necessary for calculation by the arithmetic processing unit 6 from the dam management system 21 via the network 20. As the network 20, a LAN (for example, TCP / IP), serial communication (for example, RS232C), WAN, or the Internet can be used. Note that the data acquisition unit 3 by which the data acquisition unit 3 acquires data may be the weather forecast system 22 or a river information system (not shown) in addition to the dam management system 21 and is not particularly limited.

  The storage unit 4 includes data and constants acquired via the input unit 2 or the data acquisition unit 3, and a plurality of databases and files that store calculation results by the arithmetic processing unit 6. In the dam discharge flow rate database 401, the actual discharge flow rate of the dam 23 acquired by the data acquisition unit 3 from the dam management system 21 is stored. In the dam planned discharge database 402, the planned discharge flow of the dam input by the operator 10 via the input unit 2 is stored.

  The measured rainfall database 403 stores the measured rainfall in an area including the basin from the dam 23 to each observation point of the downstream river. The measured rainfall is measured by a rain gauge 24 installed in the area. The measured rainfall is usually a management item of the dam management system 21 and can be acquired from the dam management system 21. Or it can also acquire from the weather forecast system 22 or a telemeter (illustration omitted).

  The predicted rainfall database 404 stores the predicted rainfall in the area including the basin from the dam 23 to each observation point of the downstream river. The predicted rainfall is data input by the operator 10 via the input unit 2, but is expected to be acquired from the dam management system 21 in the future. The predicted rainfall can also be obtained from the weather forecast system 22 via the network 20.

  The measured river flow rate database 405 stores the measured flow rate and the measured water level measured at each observation point of the downstream river. The river flow and water level are measured by flow meters and water level meters installed at each observation point. Since these data are managed by the dam management system 21, they can be acquired from the dam management system 21, but may be acquired from the river information system.

  The data such as the actual discharge amount of the dam 23, the measured rainfall amount, the measured flow rate of the downstream river, the measured water level, and the like managed by the dam management system 21 are transmitted from the dam management system 21 to the data acquisition unit 3 at a predetermined cycle. And automatically stored in each database of the storage unit 4.

  The predicted river flow rate database 406 and the predicted river water level database 407 store the predicted flow rate and the predicted water level at each observation point calculated by the arithmetic processing unit 6, respectively. In the constant 1 file 408, the constant 2 file 409, and the constant 3 file 410, constants used for calculation by the arithmetic processing unit 6 are stored. These constants will be described later.

  Further, the storage unit 4 has an observation point information file (not shown) that stores information on each observation point. The observation point information file stores information such as observation point ID, observation station name, location, contact information, latitude, longitude, altitude, and the like.

  The data extraction unit 5 extracts data necessary for calculation by the calculation processing unit 6 from the storage unit 4. Specifically, when the operator 10 inputs a keyword such as an observation point, a target river station, and a time zone from the input unit 2, the data extraction unit 5 searches each database in the storage unit 4 based on the keyword, Extract the necessary data.

  The arithmetic processing unit 6 calculates the actual discharge amount of the dam 23 from a predetermined time before the current time, the planned discharge amount of the dam 23 from the current time to any future time, and the basin from the dam 23 to any observation point. Arbitrary observation points are selected based on measured rainfall up to the current time in the region, predicted rainfall from the current time in the region to any future time, and measured flow rates at any observation point at the current time. Calculate the predicted flow rate and predicted water level at the future time. If there is no data on the measured flow rate at the observation point at the current time, the measured flow rate at the time closest to the current time may be used.

  In more detail, the arithmetic processing unit 6 predicts the rainfall based on the rainfall from the dam 23 to the arbitrary observation point based on the measured rainfall amount and the predicted rainfall in the region including the basin from the dam 23 to the arbitrary observation point. Find the inflow. Further, the predicted water level at the observation point is calculated from the predicted flow rate at the arbitrary observation point obtained by the calculation. These calculation methods will be described later.

  The display unit 7 is a display of a general-purpose computer, for example, and displays a menu screen, a setting screen, a result screen, and the like. In the result screen, the predicted flow rate and the predicted water level at each observation point are shown in a table format or a graph format. By setting the horizontal axis of the graph to the time and the vertical axis to the predicted water level, it is possible to predict the future time to reach the water level at which the flood occurs at each observation point.

  In addition, the display unit 7 displays a monitor screen showing a situation of the entire region including the basin managed by the dam downstream river flow prediction system 1 as a schematic diagram or a situation diagram. The operator 10 can monitor the situation of the entire area on a monitoring screen during heavy rain or a typhoon, and be prepared for an emergency. Further, when a flood is predicted from the predicted water level at a future time, the area and the predicted time are displayed on the monitoring screen, and the operator 10 is notified by a method such as a warning sound or a warning lamp lighting.

Next, the calculation procedure in the arithmetic processing unit 6 of the dam downstream river flow rate prediction system 1 will be described with reference to FIGS. FIG. 3 is a flowchart showing the flow of processing by the arithmetic processing unit 6 of the dam downstream river flow rate prediction system 1. In step 1 (S1) of FIG. 3, the operator 10 inputs an observation point ID, a time zone, or other keywords through the input unit 2. Here, it is assumed that the observation point P ₁ shown in FIG. 2 and the time zone from 2 hours after the current time are input.

In Step 2 (S2), performs a dam discharge amount influence computation at the observation point _{P 1.} The data extraction unit 5 extracts data and constants necessary for the calculation of S2 from the storage unit 4 based on the keyword input in S1.

  As preparation for calculation in S2, step 21 (S21), step 22 (S22), and step 23 (S23) are performed. In S21, the actual discharge amount of the dam 23 from a predetermined time before the current time is acquired. The predetermined time is a time during which the discharge amount of the dam 23 affects changes in the flow rate and water level of the downstream river, and is set in advance. In S <b> 22, the operator 10 sets the planned discharge amount of the dam 23 from the current time to 2 hours later using the input unit 2.

  In S <b> 23, the operator 10 sets the proportional constant A and the delay time T <b> 1 by the input unit 2 while referring to the constant 1 file 408 on the display unit 7. The proportionality constant A is a constant representing the influence of the discharge amount of the dam 23 at each observation point. The dam 23 is immersed in the riverbed until the discharge amount reaches each observation point, and is used for irrigation to the surrounding fields. Set in consideration of water.

The delay time T1 is a time until the discharge amount of the dam 23 affects the river flow rate at each observation point, and becomes a larger value as the distance from the dam 23 to the observation point is longer. The proportional constant A and the delay time T1 are set in a plurality of patterns for each observation point, and are stored in the constant 1 file 408 of the storage unit 4. S21, S22, and after the data, constants were prepared as required by S23, performs dam discharge amount influence computation at the observation point _{P 1} in S2.

Then, in step 3 (S3), it performs a rainfall effect calculated at the observation point _{P 1.} As preparation for the calculation in S3, step 31 (S31), step 32 (S32), and step 33 (S33) are performed. In S31, the measured rainfall up to the current time is acquired. In S <b> 32, the operator 10 sets the predicted rainfall amount from the current time to 2 hours later using the input unit 2.

In S <b> 33, the operator 10 sets the proportional constant B, the dominant area C _i , and the delay time T <b> 2 using the input unit 2 while referring to the constant 2 file 409 on the display unit 7. The proportionality constant B is a constant representing the influence of rainfall at each observation point, and is set in consideration of the topography and geology of the surrounding area, land use method, and the like. The controlled area C _i is an area area affected by the rainfall at the point i where the rain gauge 24 is installed.

In addition, the delay time T2 is the time until the measured rainfall affects the flow rate at each observation point, the distance between the installation position of the rain gauge 24 and the observation point, and the control area C _i (indicated by the diagonal lines in FIG. 2) The area is set in consideration of the area of the area to be shown). A plurality of patterns of the proportionality constant B, the dominant area C _i , and the delay time T2 are set for each observation point, and are stored in the constant 2 file 409 of the storage unit 4. S31, S32, and after the data, constants were prepared as required by S33, performs rainfall influence computation at the observation point _{P 1} in S3.

Then, in step 4 (S4), performs the estimated flow rate calculated at the observation point _{P 1.} In preparation for calculation in S4, S2, S3 may further, in step 41 (S41), acquires the measured flow rate and water level in the current time at the observation point _{P 1.} The following formula 1 is used for the dam discharge flow rate calculation in S2, the rainfall effect calculation in S3, and the predicted flow rate calculation in the downstream river in S4.

Q _kn (t + Δt) = Q _k (t) + A × (Q _0t (t−T1 _n ) −Q _k (t))
+ B × Q _r (t−T2 _n ) (Formula 1)

Q _kn (t): River flow rate at observation point P _n at time t Q _kn (t + Δt): River flow rate at observation point P _n at time (t + Δt) A: Proportional constant representing the effect of dam discharge B: Rainfall Proportional constant Q _0t (t−T1 _n ): discharge amount of the dam at time (t−T1 _n ) Q _r (t−T2 _n ): predicted inflow due to rainfall in the basin from the dam to the observation point P _n T1 _n : Delay time until the dam discharge rate affects the river flow rate at the observation point P _n T2 _n : Delay time until the rainfall amount affects the river flow rate at the observation point P _n

Note that the predicted inflow amount Q _r (t) due to rainfall is obtained from the following equation 2.
Q _r (t) = R _i (t) × C _i (Formula 2)

R _i (t): Rain at the i point where the rain gauge is installed C _i : Area area (control area) affected by the rainfall at the i point where the rain gauge is installed

Q _0t (t) includes the actual discharge from a predetermined time before the current time and the planned discharge from the current time to any future time. Further, Q _r (t) is a predicted inflow amount due to rainfall including a measured rainfall amount from the start of the current rainfall to the current time and a predicted rainfall amount from the current time to an arbitrary future time.

Predicted flow rate of the observation point _{P 1} obtained in S4 is stored in the predicted river flow database 406 of the storage unit 4 in step 42 (S42). Subsequently, in step 5 (S5), to predict the water level calculated at the observation point _{P 1.} As preparation for calculation in S5, step 5
1 (S51), the operator 10 sets the proportionality constant E and the addition constant F by the input unit 2 while referring to the constant 3 file 410 on the display unit 7.

In S5, from the predicted flow rate observation point P ₁ obtained in S4, calculates a predicted water level observation point P ₁ with HQ curve showing the relationship between the water level and flow rate. The HQ curve is a schematic representation of the relationship between the river level and the flow rate during a certain period, and is represented by the following formula 3. In the calculation using the HQ curve, the proportionality constant E and the addition constant F are used.

Q = E (H + F) ² (Formula 3)
H: Water level Q: Flow rate E: Proportional constant F: Addition constant

  For the parameters necessary for the proportionality constant E, the addition constant F, and the HQ curve, a plurality of patterns are set for each observation point, and are stored in the constant 3 file 410 of the storage unit 4. The operator 10 refers to the constant 3 file 410 and inputs parameters necessary for the proportional constant E, the addition constant F, and the HQ curve from the input unit 2. The following formula 4 is used for the prediction water level calculation in S5. Equation 4 is a variation of Equation 3 above.

H _n (t + Δt) = (Q _kn (t + Δt) / E) ^1/2 −F (Formula 4)
H _n (t): Water level at observation point P _n at time t Q _kn (t): Flow rate at observation point P _n at time t

Prediction level of observation points _{P 1} determined in S5 is stored in the predicted river levels database 407 of the storage unit 4 in step 52 (S52). Further, in step 6 (S6), the calculation results of S4 and S5 are displayed on the display unit 7, and the process is terminated.

As described above, according to the dam downstream river flow prediction system 1 according to the first embodiment, a plurality of observation points of the river downstream of the dam _{23 P 1, P 2, P} 3, the · · · _{P n,} the current Predicting the predicted flow rate and water level at any future time at any observation point easily and accurately by calculating the measured flow rate at each observation point in consideration of the effects of dam discharge and rainfall Can do.

  Moreover, since the time to reach the water level at which the flood occurs at each observation point can be predicted from the predicted water level at any future time, it is possible to issue a warning at an appropriate timing during heavy rain or typhoon. Moreover, it becomes possible to make the discharge plan of the dam 23 which considered the influence on a downstream river based on a calculation result.

Further, constants necessary for calculation (proportional constants A, B, E, addition constant F, delay times T1, T2, and dominant area C _i ) are set in advance in a plurality of patterns and stored in the storage unit 4. The operator 10 can input appropriate constants while referring to them, thereby reducing the burden on the operator 10 and performing highly reliable prediction calculation.

Embodiment 2. FIG.
In the second embodiment of the present invention, a prediction error simulation for minimizing a prediction error by the system 1 is performed using the predicted flow calculated by the dam downstream river flow prediction system 1 according to the first embodiment. This prediction error simulation may be executed by the arithmetic processing unit 6 of the river flow prediction system 1 downstream of the dam, or may be executed by another computer. The result of the prediction error simulation is stored in the constant 1 file 408 and the constant 2 file 409 and is reflected in the subsequent prediction calculation by the arithmetic processing unit 6.

The flow of the prediction error simulation according to the second embodiment will be described using the flowchart of FIG. In step 7 (S7) of FIG. 4, the measured flow rate at the observation point _Pn at an arbitrary time before the current time is acquired. The measured flow rate is stored in the measured river flow rate database 405 of the storage unit 4.

  Next, in step 8 (S8), the predicted flow rate calculated by the calculation processing unit 6 of the dam downstream river flow rate prediction system 1 is acquired for the same observation point at the same time as the past arbitrary time selected in S7. The predicted flow rate is stored in the predicted river flow rate database 406 of the storage unit 4. That is, in S7 and S8, the measured flow rate and the predicted flow rate at the same observation point at the same time are acquired.

Subsequently, in step 9 (S9), a prediction error simulation is executed. Here, the measured flow rate and the predicted flow rate at the same time are compared, and the proportional constant A, the proportional constant B, the delay time T1, and the delay time T2 that minimize the difference between the two are obtained using the following equation (5). Specifically, the proportional constant A, proportional constant B, the delay time T1, by changing the delay time T2 by brute, detects a combination of the prediction error D _j is minimum.

D _j = Σ (Q _kn (t) −Q _sn (t)) (Formula 5)
Q _kn (t): measured flow rate at time t at observation point P _n Q _sn (t): predicted flow rate at time t at observation point P _n

In step 10 (S10), accumulation prediction error D _j detects the smallest constant and delay time, the proportionality constant A which is set based on the detection result, the proportional constant B, the delay time T1, and the delay time T2 The data is stored in the constant 1 file 408 and the constant 2 file 409 of part 4. Further, in step 11 (S11), the detection result is displayed as a table or a graph. At that time, a plurality of combination patterns may be compared and displayed. In Equation 5, calculation is performed using the measured flow rate and the predicted flow rate of the river downstream of the dam, but it is also possible to calculate using the measured water level and the predicted water level.

  According to the second embodiment, by reflecting the detection result of the prediction error simulation in the prediction calculation by the arithmetic processing unit 6, the accuracy of the calculation by the river downstream prediction system 1 can be further improved, and the reliability of the system is improved. Improves. It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  The present invention can be used as a dam downstream river flow rate prediction system that is attached to a dam management system.

1 River downstream flow prediction system, 2 input section, 3 data acquisition section, 4 storage section,
5 Data extraction unit, 6 Arithmetic processing unit, 7 Display unit, 10 Operator, 20 Network, 21 Dam management system, 22 Weather forecast system, 23 Dam, 24 Rain gauge,
401 Dam discharge DB, 402 Dam discharge DB, 403 Measurement rainfall DB,
404 Predicted rainfall DB, 405 Measured river flow DB, 406 Predicted river flow DB,
407 Estimated river water level DB, 408 Constant 1 file, 409 Constant 2 file,
410 Constant 3 file.

Claims (8)

A dam downstream river flow rate prediction system that predicts the flow rate and water level at an arbitrary future time for a plurality of observation points in the downstream river of a dam managed by a dam management facility,
The actual discharge of the dam from a predetermined time before the current time, the planned discharge of the dam from the current time to any future time, and the current time of the region including the basin from the dam to any observation point Based on the measured rainfall up to, the predicted rainfall from the current time in the region to any future time, and the measured flow rate at the observation point at the current time, and the predicted flow rate at any future time at the observation point, and An arithmetic processing unit that calculates the predicted water level,
An input unit for setting and inputting data and constants necessary for calculation by the arithmetic processing unit,
A data acquisition unit for acquiring data necessary for calculation by the arithmetic processing unit from the dam management facility via a network;
A dam downstream river flow rate prediction system comprising a storage unit for storing data and constants acquired via the input unit and the data acquisition unit.   The accumulation unit includes a dam discharge database that stores the actual discharge of the dam, a dam planned discharge database that stores the planned discharge of the dam, and a measurement in an area including a basin from the dam to the observation point. A measured rainfall database for storing rainfall, a predicted rainfall database for storing predicted rainfall in the region, a measured river flow database for storing river flows and water levels measured at the observation points, and the arithmetic processing The dam downstream river flow prediction according to claim 1, further comprising: a predicted river flow database for storing the predicted flow calculated by the unit, and a predicted river water level database for storing the predicted water level calculated by the arithmetic processing unit. system.   The arithmetic processing unit is based on the measured rainfall up to the current time in the region including the basin from the dam to any observation point, and the predicted rainfall from the current time in the region to any future time, The dam downstream river flow rate prediction system according to claim 1 or 2, wherein a predicted inflow amount due to rainfall into the basin from the dam to the observation point is obtained.   The arithmetic processing unit uses a proportionality constant A that represents the influence of the discharge amount of the dam at the observation point and a proportionality constant B that represents the influence of rainfall at the observation point, at any future time of the observation point. The prediction flow rate is calculated, The dam downstream river flow prediction system according to any one of claims 1 to 3 characterized by things.   The proportionality constant A and the proportionality constant B are set in a plurality of patterns for each of the plurality of observation points, and are stored in the storage unit.   The arithmetic processing unit uses the delay time T1 until the discharge amount of the dam affects the flow rate at the observation point and the delay time T2 until the measured rainfall affects the flow rate at the observation point. 5. The system for predicting river flow downstream of a dam according to claim 4, wherein the predicted flow at any future time of the point is calculated.   The delay time T1 and the delay time T2 are set in a plurality of patterns for each of the plurality of observation points, and are stored in the storage unit. Proportional constant A and proportionality constant B that minimize the difference between the predicted flow rate at any future time at any observation point calculated by the arithmetic processing unit and the measured flow rate at the observation point at the same time as this future time. 7. A combination of delay time T1 and delay time T2 is detected by simulation, and proportionality constant A, proportionality constant B, delay time T1, and delay time T2 are set based on the detection result. The dam downstream river flow prediction system described.

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