JP4708985B2 - River water level calculation apparatus and method - Google Patents

Description

  The present invention relates to an apparatus and method for calculating a river water level, and more particularly to a river water level calculation apparatus and method for calculating a river water level based on a river flow rate.

  In countries and local governments, various efforts have been made to monitor river levels and use them for flood prediction. The most common method is to install a water level gauge at a monitoring target location in a river and monitor the water level based on the detection signal. However, in this method, since a water level meter must be installed at each monitoring target location, there is a problem that it is expensive to install and maintain when monitoring many monitoring target locations.

  Therefore, recently, a method for calculating the river water level based on the river flow has attracted attention. This method sets the monitoring section (reach) in the river and calculates the river flow in this reach, and calculates the water level in the reach based on the river flow, the length of the reach, and the shape of the cross section. To do. Here, if the length of reach i is m, the flow rate at the upstream end of reach i is Qo, the lateral inflow at reach i is Qi, the amount of spring water at reach i is Qoi, and the amount of water intake at reach i is Q1i. The river flow rate Q (m) at i is expressed by the following equation (for example, see Non-Patent Document 1).

Edited by Takao Kunimatsu and Hiroaki Muraoka, “Model Analysis of River Pollution”, Gihodo Publishing, 1989, P147-P148

  Generally, the lateral inflow Qi is the total amount of rainwater and drainage flowing into the river, and can be estimated by investigating the catchment area. The amount of spring water Qoi and the amount of water intake Q1i can also be estimated by survey. On the other hand, since the actual shape of the cross section of the river is generally complicated, it is difficult to obtain the cross section and use it in the calculation of the water level.

  Therefore, it has been considered that the river bed area is obtained for each reach and this river bed area is used for water level calculation. However, there are various river bed shapes such as natural shapes, tapered shapes due to flood control work, and staircase shapes due to dikes, and it is difficult to actually measure such complicated river bed shapes. Even if it can be measured, if the water level is calculated based on the obtained shape, calculation using complicated fluid dynamics calculation or differential integration method is required. There was a problem that it took a long time.

  The present invention has been made paying attention to the above circumstances, and the object of the present invention is to make it possible to calculate the water level of a river easily and in a short time without performing complicated hydrodynamic calculations, etc. It is an object of the present invention to provide a river water level calculation apparatus and method that can monitor water levels in a wide range of monitoring target sections in real time.

  In order to achieve the above object, the present invention captures the river data representing the length of the river monitoring section and the cross-sectional shape of the riverbed, and the data representing the river flow in the monitoring section, respectively, and the captured river data Based on the above, the riverbed structure of the monitored section is modeled by a trapezoid of n (n is an integer of 1 or more) stages. Then, the water level in the monitored section is calculated based on the modeled river bed structure data and the data representing the captured river flow.

  Therefore, the water level in the section to be monitored is calculated based on the river bed structure data modeled by the n-stage trapezoid and the data representing the river flow rate. For this reason, for example, the water level can be calculated easily and in a short time compared with the case where the water level is obtained by hydrodynamic calculation or calculation using a differential integration method based on the riverbed cross-sectional shape obtained by actual measurement. Further, the calculation can be performed by a general-purpose computer such as a personal computer without using a large-scale computer system. That is, it becomes possible to monitor the water level in a wide range of monitoring target sections in real time by a general-purpose computer.

In addition, when modeling the riverbed structure, the n-stage trapezoid in which the lower base, the upper base, and the height are determined based on the cross-sectional shape of the river data is stacked in order from the riverbed, and one trapezoid is formed. Each time the stacks are stacked, the volume of the quadrangular prism whose cross-section is the trapezoid and the length of the section to be monitored is calculated, and the total volume of the calculated n-stage quadrangular prisms is calculated. Then, the sum of the calculated volumes is compared with the river flow rate in the monitoring target section. As a result of the comparison, the river flow rate is larger than the sum of the volume of the square pillars up to the (n-1) th stage and the four volumes up to the nth stage. The trapezoidal stacking process is terminated when the volume of the prisms is equal to or less than the total volume.
Therefore, the riverbed structure can be modeled in accordance with the river flow at that time, and this makes it possible to reduce useless calculations and perform efficient modeling processing.

  In short, in the present invention, the riverbed structure of the monitoring target section is modeled by an n-stage trapezoid, and the water level in the monitoring target section is calculated based on the modeled riverbed structure data and river flow data. Yes. Therefore, the river water level can be calculated easily and in a short time without performing complicated hydrodynamic calculations, etc., and this makes it possible to monitor the water level in a wide range of monitored sections in real time using a general-purpose computer. Apparatus and methods can be provided.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a functional configuration of a water level calculation apparatus according to the present invention. The water level calculation apparatus 1 is composed of a personal computer and includes a central processing unit (CPU) 11. The CPU 11 has a program memory 13, a data memory 14, a communication interface (communication I / F) 15, an input interface (input I / F) 16, and an output interface (output I / F) 18 via the bus 12. And an external memory interface (external memory I / F) 19 are connected to each other.

  The communication I / F 15 performs communication for downloading data via a communication network with a river information server (not shown) under the control of the CPU 11. For example, TCP / IP (Transmission Control Protocol / Internet Protocol) is used as the communication protocol.

An input unit 17 is connected to the input I / F 16. The input unit 17 is composed of a pointing device such as a keyboard or a mouse. The input I / F 16 takes in the operation information input by the operator who is the person in charge by the input unit 17.
A display unit 19 and a printing unit 20 are connected to the output I / F 18. The display unit 19 includes, for example, a liquid crystal display (LCD). The output I / F 18 is operation information input by the input unit 17 under the control of the CPU 11, river bed data and river flow data stored in the data memory 14, river bed modeling data calculated by the CPU 11, Water level data or the like is displayed on the display unit 19. At the same time, the calculated riverbed modeling data, water level data, and the like are supplied to the printing unit 20 for printing.

  The external memory I / F 21 has a slot. Then, the river bed data and river flow data of the river to be monitored are read from the external storage medium 2 inserted in the slot. Alternatively, the calculated modeling data and water level data of the riverbed structure are stored in the external storage medium 2 inserted in the slot. As the external storage medium 2, in addition to a magnetic disk such as a hard disk, an optical disk such as a CD-ROM or DVD, a memory card, or the like can be used.

  The data memory 14 includes a river bed data storage unit 14a, a river flow rate storage unit 14b, a modeled data storage unit 14c, and a water level data storage unit 14d. In the river bed data storage unit 14a, for example, river bed data for each section of the river to be monitored acquired from a river information server operated and managed by the Ministry of Land, Infrastructure, Transport and Tourism or read from the external storage medium 2 is stored. The river bed data is composed of data representing the length of the monitoring target section (reach) and data representing the cross-sectional shape of the river bed. These data are obtained by actual measurement, for example.

  The river flow rate storage unit 14b stores river flow rate data for each section of the river to be monitored acquired from the river information server or read from the external storage medium 2. This river flow data is calculated according to the above-described equation (1), and is updated regularly in the river information server on a regular basis and as needed when the water increases.

  The modeling data storage unit 14c stores riverbed structure modeling data calculated by executing a modeling calculation processing program 13b described later for each river monitoring target section (reach). The water level data storage unit 14d stores water level data calculated by executing a water level calculation program 13c described later for each river monitoring target section (reach).

  The program memory 13 stores a data input control program 13a, a modeling calculation processing program 13b, a water level calculation processing program 13c, and a data output control program 13e as application programs necessary for carrying out the present invention. ing.

  The data input control program 13a receives river data and river flow data for each section of the river to be monitored from the river information server via the communication I / F 15, or the external storage medium 2 via the external memory I / F 21. The river bed data and river flow rate data are read from the data, and the CPU 11 is caused to execute processing for storing the river bed data and river flow rate data in the river bed data storage unit 14a and the river flow rate storage unit 14b of the data memory 14, respectively.

  Based on the latest river bed data and river flow data stored in the river bed data storage unit 14a and the river flow storage unit 14b, the modeling calculation processing program 13b converts the river structure of the monitored section of the river to n (n is The CPU 11 is caused to perform a process of modeling with a trapezoid having an integer of 1 or more and storing the modeled data in the modeled data storage unit 14c of the data memory 14.

  The water level calculation processing program 13c calculates the water level in the monitoring target section based on the modeling data of the river bed structure calculated by the modeling calculation processing program 13b and the monitoring target section length data included in the river bed data. Then, the CPU 11 is caused to execute processing for storing the calculated water level data in the water level data storage unit 14d of the data memory 14.

Next, the water level calculation operation by the water level calculation apparatus configured as described above will be described according to the control procedure of the CPU 11.
The CPU 11 accesses the river information server periodically or as necessary from time to time via the communication I / F 15, thereby acquiring riverbed data and river flow data for each section of the river to be monitored from the river information server, These data are stored in the river bed data storage unit 14a and the river flow rate storage unit 14b, respectively. When the external storage medium 2 is inserted into the external memory I / F 21 and the operator performs a data acquisition operation in this state, the CPU 11 reads the river bed data from the external storage medium 2 via the external memory I / F 21. And the river flow data are read and stored in the river bed data storage unit 14a and the river flow storage unit 14b, respectively.

When new river bed data and river flow data are acquired as described above, the CPU 11 executes river structure modeling calculation processing and water level calculation processing as follows. FIG. 2 is a flowchart showing the procedure and contents of the modeling calculation process and the water level calculation process.
That is, first, in step S1, the CPU 11 assigns 0.0 to sum_H, sum_Q, sum_H_old, and sum_Q_old as initial settings. sum_H and sum_H_old are variables representing the sum of the heights of the n-stage trapezoids, and sum_Q and sum_Q_old are variables representing the sum of the volumes of the quadrangular prisms each having the n-stage trapezoid as a cross section.

  Next, in step S2, the CPU 11 sets n, which indicates the number of trapezoidal stages, to n = 1. In other words, the first trapezoid is stacked. At this time, the lower base, upper base and height of the trapezoid are set based on the latest river bed cross-sectional shape data stored in the river bed data storage unit 14a. For example, in the example shown in FIG. 3, the trapezoid at the first stage is set to the lower base Wl1, the upper base Wu1, and the height H1.

  Next, the CPU 11 proceeds to step S3, and determines whether or not the number n of stages stacked here is less than NBUNK. NBUNK is a fixed parameter that represents the number of trapezoidal steps of the model. If the number of steps n does not reach the fixed parameter NBUNK as a result of this determination, the process subsequently proceeds to step S4, where the height H1 of the nth trapezoid that has just been accumulated is added to sum_H. Is stored as a new sum_H.

  Next, the CPU 11 proceeds to step S5, and calculates the volume of the quadrangular prism having the first trapezoid as a cross section and the monitoring target section length Ln as the length. This volume can be calculated as Wu1 + Wl1 * H1 * L1 * 0.5. Then, the calculated volume of the quadrangular prism corresponding to the first-stage trapezoid is added to sum_Q, and the value after the addition is stored as a new sum_Q. Also, sum_Q before addition is saved as sum_Q_old.

  Next, the CPU 11 proceeds to step S6, where the latest river flow rate Qflow stored in the river flow rate storage unit 14b is compared with the new sum_Q and the sum_Q_old before addition, so that the river flow rate Qflow is equal to or higher than sum_Q_old. And it is determined whether it is less than sum_Q. As a result of this determination, if the river flow rate Qflow does not satisfy the above condition, sum_H after the addition is saved as sum_H_old in step S7, and sum_Q after the addition is saved as sum_Q_old in step S8. When the above processing is completed, the number of stages n is incremented (n = n + 1) in step S9. That is, the second-stage trapezoid is thereby stacked. For the second-stage trapezoid, the lower base, the upper base, and the height are set based on the latest river-bed cross-sectional shape data stored in the river-bed data storage unit 14a as in the first stage.

  When the second-stage trapezoid is stacked, the CPU 11 returns to step S3 to determine whether or not the number of stages has reached the fixed parameter NBUNK. If not, the process proceeds from step S4 as in the case of the first stage. The process according to step S8 is executed. Thereafter, similarly, each time one trapezoid is stacked, the processing from step S3 to step S9 is repeatedly executed. When the number n of stacked stages reaches the fixed parameter NBUNK, the CPU 11 ends the modeling process at that time.

  On the other hand, it is assumed that the river flow rate Qflow is not less than sum_Q_old and less than sum_Q in the determination in step S6. Then, the CPU 11 determines that the total sum_Q of the quadrangular prisms corresponding to the stacked n-stage trapezoids has reached the value corresponding to the river flow rate Qflow, and the trapezoidal upper and lower bases Wui, The values of Wli and height Hi (i = 1 to n) and the monitoring target section length Li are stored in the modeled data storage unit 14c as modeled data. At this time, the modeled data is associated with river identification information (river ID) and information (section ID) for identifying the monitoring target section, and is further stored with date / time data.

により計算される。 When the modeling process is completed, the CPU 11 subsequently proceeds to step S10 where the water level Wdepth is calculated. This water level Wdepth is

Is calculated by

However, the constraint condition of Qflow is expressed by the following equation.

  When the calculation of the water level Wdepth by the above equations (2) and (2) is completed, the CPU 11 stores the calculated water level Wdepth in the water level data storage unit 14d. In this case as well, the water level Wdepth is associated with the river ID and the monitoring target section ID, and further stored with date / time data. The date / time data is generated by a real-time clock built in the apparatus.

  Further, it is assumed that the operator inputs a calculation data output request after specifying the river and the monitoring target section displayed on the display unit 19 with a pointing device or the like in the input unit 17. Then, the CPU 11 reads the corresponding modeled data and water level data from the modeled data storage unit 14c and the water level data storage unit 14d, and supplies the read data to the printing unit 20 via the output I / F 18. Print out.

  As described above, in this embodiment, the river bed data consisting of the river bed cross-sectional shape and the section length Li for each section of the river to be monitored and the river flow data Qflow are respectively acquired from the river information server or the external storage medium 2. Based on the river data obtained, the riverbed structure of the monitored section is modeled by a trapezoid having n (n is an integer of 1 or more) stages. Then, the water level Wdepth in the monitored section is calculated based on the modeled river bed structure data and the captured river flow data Qflow.

  Accordingly, for example, the water level can be calculated easily and in a short time compared to the case where the water level is obtained by hydrodynamic calculation or calculation using a differential integration method based on the riverbed cross-sectional shape obtained by actual measurement. Further, the calculation can be performed by a general-purpose computer such as a personal computer without using a large-scale computer system. That is, it becomes possible to monitor the water level in a wide range of monitoring target sections in real time by a general-purpose computer. In addition, the riverbed structure can be modeled according to the river flow from time to time, thereby reducing unnecessary calculations and enabling efficient modeling processing.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, in the river bed structure modeling process, the trapezoidal height Hi of each stage is variably set based on the data representing the river bed cross-sectional shape. However, the present invention is not limited to this, and the height Hi of the trapezoid of each step may be fixed to a constant value. In this way, the river bed structure modeling process and the water level calculation process can be further simplified.

  In this case, the height Hi of the trapezoid of each step may be variably set according to the required accuracy or calculation speed. In this case, as the height Hi is reduced, that is, as the number of steps n is increased, the approximation accuracy by the trapezoid can be improved. On the other hand, as the height Hi is increased, the number of steps n is reduced. The more you increase, the faster the calculation speed can be reduced.

  Further, a schematic diagram representing a river bed model as shown in FIG. 3 is created based on the calculated modeling data, and this schematic diagram is displayed on the display unit 19 or printed out from the printing unit 20. May be. In this way, the operator can recognize the riverbed structure in an easily understandable form.

Furthermore, the calculated riverbed structure modeling data and water level data may be transmitted from the communication I / F 15 to another terminal, a monitoring center, or the like.
In addition, the configuration of the water level calculation device, the river bed structure modeling processing procedure and its contents, the processing content of the water level calculation, and the like can be variously modified without departing from the scope of the present invention.

  In short, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

The functional block diagram which shows one Embodiment of the water level calculation apparatus concerning this invention. The flowchart which shows the procedure and content of the water level calculation process by the water level calculation apparatus shown in FIG. The figure for demonstrating the modeling process by the trapezoid of the river cross-sectional shape used in the transition calculation process shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Water level calculation apparatus, 2 ... External storage medium, 11 ... CPU, 12 ... Bus, 13 ... Program memory, 13a ... Data input control program, 13b ... Modeling calculation processing program, 13c ... Water level calculation processing program, 13d ... Data Output control program, 14 ... data memory, 14a ... river bed data storage unit, 14b ... river flow rate storage unit, 14c ... modeled data storage unit, 14d ... water level data storage unit, 15 ... communication interface (communication I / F), 16 ... input interface (input I / F), 17 ... input unit, 18 ... output interface (output I / F), 19 ... display unit, 20 ... printing unit, 21 ... external memory interface (external memory I / F).

Claims (4)

Means for fetching river data representing the length of the monitored section of the river and the cross-sectional shape of the riverbed, and data representing the river flow in the monitored section,
Means for modeling the riverbed structure of the section to be monitored by a trapezoid having n (n is an integer of 1 or more) stages based on the captured river data;
Based on the modeled river bed structure data and the data representing the captured river flow, means for calculating the water level in the monitored section ,
The means for modeling is
For each of the n-stage trapezoids, calculate the volume of a quadrangular prism having the trapezoid as a cross section and having a section length corresponding to the trapezoid in the monitored section as a length,
The river flow rate is larger than the sum of the volumes of the quadrangular columns from the bottom of the river bed to the (n-1) th stage, and less than or equal to the sum of the volumes of the quadrangular columns from the bottom of the river bed to the nth stage. Determining the number of steps n of the trapezoid,
The means for calculating the water level is:
Qflow is the flow rate of the river, and the upper, lower, and height values of the trapezoid of the i (i = 1 to n) stage from the bottom of the n-stage trapezoid are Wui, Wli, and Hi, respectively. , The section length corresponding to the i-th trapezoid in the monitored section is Li, and the water level Wdepth in the monitored section is expressed by the equation

A water level calculation device characterized in that it calculates using The means for modeling is
Means for stacking n-stage trapezoids in which the lower base, upper base and height are determined based on the cross-sectional shape of the river data in order from the bottom of the river bed;
Means for calculating a volume of a quadrangular prism each having a stacked trapezoid as a cross section and having a section length corresponding to the trapezoid in the monitoring target section length as a length each time the trapezoid is stacked one stage;
Means for calculating the total volume of the calculated n-stage quadrangular prisms, and comparing the calculated total volume with the river flow of the monitored section;
As a result of the comparison, the river flow rate is greater than the sum of the volumes of the quadrangular columns from the bottom of the river bed to the ( n-1) th stage, and less than the sum of the volumes of the quadrangular columns from the bottom of the river bed to the nth stage. The water level calculation apparatus according to claim 1, further comprising means for ending the trapezoidal stacking process in some cases. A process of fetching river data representing the length of the monitored section of the river and the cross-sectional shape of the riverbed, and data representing the river flow in the monitored section,
A process of modeling the riverbed structure of the monitored section based on the captured river data by a trapezoid of n (n is an integer of 1 or more) stages;
A process of calculating a water level in the monitoring section based on the modeled river bed structure data and the data representing the captured river flow ,
In the modeling process,
For each of the n-stage trapezoids, calculate the volume of a quadrangular prism having the trapezoid as a cross section and having a section length corresponding to the trapezoid in the monitored section as a length,
The river flow rate is larger than the sum of the volumes of the quadrangular columns from the bottom of the river bed to the (n-1) th stage, and less than or equal to the sum of the volumes of the quadrangular columns from the bottom of the river bed to the nth stage. Determining the number of steps n of the trapezoid,
In the process of calculating the water level,
Qflow is the flow rate of the river, and the upper, lower, and height values of the trapezoid of the i (i = 1 to n) stage from the bottom of the n-stage trapezoid are Wui, Wli, and Hi, respectively. , The section length corresponding to the i-th trapezoid in the monitored section is Li, and the water level Wdepth in the monitored section is expressed by the equation

Level calculation wherein the <br/> be calculated using the. The modeling process includes
A process of stacking n-stage trapezoids in which the lower base, upper base and height are determined based on the cross-sectional shape of the river data in order from the bottom of the river bed,
Each time the trapezoid is stacked one stage, a process of calculating a volume of a quadrangular prism having a cross section of the stacked trapezoid and a section length corresponding to the trapezoid in the monitoring target section length.
Calculating the total volume of the calculated n-stage quadrangular prisms;
Comparing the calculated volume sum with the river flow in the monitored section;
As a result of the comparison, the river flow rate is greater than the sum of the volumes of the quadrangular columns from the bottom of the river bed to the ( n-1) th stage, and less than the sum of the volumes of the quadrangular columns from the bottom of the river bed to the nth stage. The water level calculation method according to claim 3, further comprising a step of ending the stacking process of the trapezoid in some cases.

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