JP2019090197A - Flooding analysis program for a plurality of reservoirs, computer readable storage medium and memory device, flooding analysis method for plurality of reservoirs, and flooding analysis equipment for plurality of reservoirs - Google Patents

Abstract

To provide a flooding analysis method and a flooding analysis equipment capable of performing analysis on a flooding caused by sequential collapses and simultaneous collapses at a plurality of reservoirs.SOLUTION: Flooding analysis equipment is provided with: a display capable of displaying a map for an upper reservoir and a lower reservoir including vicinity thereof; a dam collapse location designation section 21 to designate each of dam collapse locations where water flows out upon collapsing dams; a determining section 22 of a lower reservoir water surface determining an area in corresponding to a water surface of the lower reservoir; a calculation section of outflow amount from the upper reservoir calculating amount of outflow water flew out from a collapse location of the upper reservoir based on information on the upper reservoir input from the reservoir information input section 11; a calculation section 32 of lower inflow amount flowing in the lower reservoir based on a terrain data acquired with a terrain data input section 12 in the outflow amount calculated by the calculation section of the outflow amount from the upper reservoir; a calculation section 34 of water amount reserved in the lower reservoir calculating the water reserved in the lower reservoir from the inflow amount calculated with the calculation section 32 of lower inflow based on lower reservoir information input from the reservoir information input section 11; and a calculation section 36 of outflow amount from the lower reservoir calculating the outflow amount from the lower reservoir at a dam collapse location of the lower reservoir.SELECTED DRAWING: Figure 16

Description

  The present invention relates to a multiple reservoir / water analysis program, a computer readable recording medium, a stored device, a multiple reservoir / water analysis method, and a multiple reservoir / water analysis apparatus.

  Due to natural disasters such as heavy rains, earthquakes, and tsunamis that are thought to be caused by abnormal weather in recent years, flooding analysis is required at the time of reservoir failure such as reservoirs and dams. In the past, facilities such as dams were designed on the assumption that they would not be broken, and the failure analysis at the time of failure has received little attention.

  However, due to the Great East Japan Earthquake that occurred on March 11, 2011, the Fujinuma Reservoir in Sukagawa City, Fukushima Prefecture, was destroyed, and many damage occurred. According to the Japan Large Dam Conference, which consists of the Ministry of Agriculture, Forestry and Fisheries and academic organizations, there have been no reports in the world since 1930 (Showa 5) that casualties have been caused by the destruction of reservoirs and agricultural dams due to earthquakes. It is an extremely rare disaster (source: Wikipedia). In the future, the reservoir may be damaged by earthquakes such as the Nankai Trough or heavy rainfall.

  As a result, from the perspective of disaster prevention, disaster mitigation, etc., attention has been drawn to flooding analysis due to the collapse of the reservoir. Especially in the reservoir, there are many old ones that existed before the Edo period, so it is necessary to consider the risk of destruction.

  However, as mentioned above, attention has been paid to reservoir analysis relatively recently, and as mentioned above, the failure of dams and reservoirs has not been assumed much before. This is thought to be due to the fact that the discussion itself was not made in the first place because dams and reservoirs were designed not to break, and it was assumed that failure was not made. However, in recent years, once every 1000 years, unforeseen disasters such as unprecedented catastrophes occur frequently, and it is necessary to consider disaster prevention that is not a rigid idea that such failure does not prejudice ing.

  Also, in areas where there are multiple reservoirs, it is possible that they will break down in a chained way, but such a chained breakup is hardly considered, and its flooding analysis is not being tackled at present. It is.

  Furthermore, there are a number of parameters in the setting of the analysis of chain breakup, and there is also a problem that the setting becomes extremely difficult for the user.

Patent No. 5600507 gazette

"Verification and analysis of flooding reservoirs destroyed by heavy rain in 2013," Technical report of Rural Engineering Research Institute No. 215 pp 91-101, 2014 Costa, J., Floods from Dam Failure, Flood Geomorphology, 436-439 (1988).

  The present invention has been made in view of such a background, and one object of the present invention is a multi-reservoir 氾濫 analysis program and a program for easily performing 氾濫 analysis caused by chain breakage or simultaneous destruction of a plurality of reservoirs, and A computer readable recording medium, a stored device, a multiple reservoir analysis method, and a multiple reservoir analysis apparatus are provided.

Means for Solving the Problems and Effects of the Invention

  According to the multiple reservoir / reed analysis program according to the first aspect of the present invention, the multiple reservoir analysis including the upper reservoir located upstream and the plurality of reservoirs including the lower reservoir located downstream of the upper reservoir are chainedly broken. Multi-reservoir analysis program for performing analysis on upper and lower ponds, and a function to acquire topographical data of the area to be subjected to flooding analysis, and a map including the vicinity of upper and lower ponds on the display unit In the state where it is displayed, based on the acquired upper pond information, the upper pond and the lower pond, the function of causing the water to flow out at the time of bankruption, the area corresponding to the lake surface of the lower pond, and And a function of calculating the amount of water flowing into the lower basin based on the acquired topographic data among the calculated amounts of runoff, and a function of calculating the amount of runoff of water flowing out from the bank breakage position of the upper pond; , The above mentioned calculated inflow , Based on the obtained lower reservoir information, the water level of lower reservoir, and a function of calculating the lower reservoir runoff flowing downstream from breach position of the lower reservoir can be realized on the computer. This makes it easy to analyze the chain break. In particular, a more flexible flow rate calculation can be realized by designating the bankrupt location, computing the outflow from this location, and calculating the inflow to the lower pond according to the topography.

  In addition to the above, according to the multi-reservoir 氾濫 analysis program relating to the second embodiment, the ground surface layer, which further has information on height difference of the ground surface and calculates the indeterminate flow flowing out from the upper pond, The computer can be realized with a layer association function of associating with the lower pond layer having information on the full water area.

  Furthermore, according to the multiple reservoir / reinforcement analysis program relating to the third aspect, in addition to any of the above, the function of calculating the amount of inflow water flowing into the lower reservoir is one of the associated surface layer layers. It includes a function to calculate the amount of water flowing into the area corresponding to the lower lake surface defined by the lower lake surface setting unit as the amount of water flowing into the area corresponding to the lower lake surface in the lower layer, and the lower pond The function of calculating the amount of runoff calculates the amount of water flowing out of the lower basin based on the amount of storage in the lower basin in the lower layer, and the amount of runoff from the lower basin is previously designated in the surface layer. It can include the function of giving and calculating it as the amount of water discharged from the breakwater position of the reservoir.

  Furthermore, according to the multi-reservoir 氾濫 analysis program relating to the fourth aspect, in addition to any one of the above, the display unit displays a hydrograph showing a temporal change of the outflow from the time of failure of the upper pond. Can include a hydrograph display area.

  Furthermore, the computer-readable recording medium or the stored device according to the fifth aspect stores the program. Recording media include CD-ROM, CD-R, CD-RW, flexible disk, magnetic tape, MO, DVD-ROM, DVD-RAM, DVD-R, DVD + R, DVD-RW, DVD + RW, Blu-ray (registration The media includes magnetic disks such as HD DVD (AOD), optical disks, magneto-optical disks, semiconductor memories, and other media capable of storing programs. The program also includes programs distributed by downloading through a network line such as the Internet, in addition to those stored and distributed in the recording medium. The stored devices include general-purpose or dedicated devices in which the above-described program is implemented in an executable state such as software or firmware. Furthermore, each process or function included in the program may be executed by program software that can be executed by a computer, or the process of each unit may be implemented by a hardware such as a predetermined gate array (FPGA or ASIC) or program software and hardware It may be realized in the form of a mixture of partial hardware modules that realize some elements of hardware.

  Furthermore, according to the multiple reservoir / reed analysis method according to the sixth aspect, the multiple reservoir analysis including the upper reservoir located on the upstream side and the plurality of reservoirs including the lower reservoir located downstream of the upper reservoir are chainedly broken. Multiple reservoirs analysis method for performing the analysis, including the steps of acquiring information on the upper and lower ponds and topographical data of the area to be subjected to the flood analysis, and displaying a map including the vicinity of the upper and lower ponds Based on the acquired upper pond information, a step of causing the upper pond and the lower pond to designate the breakwater position where the water flows out at the time of the failure and the area corresponding to the lake surface of the lower pond in the displayed state; Calculating the amount of water flowing out of the upper pond failure position, and calculating the amount of water flowing into the lower basin based on the acquired topography data among the calculated amounts of outflow From the calculated inflow to the lower pond, Based on the obtained been lower reservoir information, the may include a water level of lower reservoir, and a step of calculating the lower reservoir runoff flowing downstream from breach position of the lower reservoir. This makes it easy to analyze the chain break. In particular, a more flexible flow rate calculation can be realized by designating the bankrupt location, computing the outflow from this location, and calculating the inflow to the lower pond according to the topography.

  Furthermore, according to the multi-reservoir 氾濫 analysis method relating to the seventh aspect, in addition to the above, the step of designating the region corresponding to the lake surface of the above-mentioned reservoir has information on height difference on the ground surface, and It is possible to include an association between the ground surface layer which calculates the outflowing unsteady flow and the lower layer which has information on the full area of the lower pool.

  Furthermore, according to the multiple reservoir / reinforcement analysis method according to the eighth aspect, in addition to any one of the above, the step of calculating the inflow to the lower reservoir includes the lower pond lake surface among the associated ground surface layers. The amount of water flowing into the area corresponding to the lower lake surface defined by the setting unit is calculated as the amount of water flowing into the area corresponding to the lower lake surface within the lower layer, and the amount of outflow from the lower reservoir is calculated. In the step of calculating, the amount of water flowing out from the lower pool is calculated based on the amount of storage in the lower reservoir in the lower layer, and the amount of outflow from the lower reservoir calculated is that of the previously designated lower surface of the ground surface layer. It can be calculated by giving it as the amount of water discharged from the bank position.

  Furthermore, according to the multi-reservoir weir analysis method according to the ninth aspect, in addition to any of the above, in the step of calculating the outflow quantity of the downflow, as an algorithm to calculate the outflow quantity of the downflow, And the calculation algorithm after the downfall of the drainage basin, the water level of the drainage basin is from the initial water level to the total overflow head, using the operation algorithm before breakdown of the drainage basin, the outlet depth obtained as information of the drainage basin After that, it is possible to switch the calculation algorithm of the outflow amount of the pond so as to use the calculation algorithm after the collapse of the pond. This makes it possible to more accurately perform flooding analysis after the chain break of the upper pond and the lower pond.

  Furthermore, according to the multiple reservoir / vessel analysis apparatus according to the tenth aspect, the multiple reservoir analysis including the upper reservoir located on the upstream side and the plurality of reservoirs including the lower reservoir located on the downstream side of the upper reservoir are chainedly broken. Water reservoir analysis device for performing the analysis, and a pond information input unit for acquiring information on the upper pond and information on the downstream pond, and topographical information for acquiring topographical data of the area to be subjected to the flooding analysis A breakwater position designation unit for designating a breakwater position where water flows out at the time of breakage to the input unit, a display unit capable of displaying a map including the vicinity of the upper pond and the lower pond, and the upper pond and the lower pond. And the amount of water flowing out from the breakwater position of the upper pond based on the upper pond information input from the lower pond lake surface setting unit for specifying the area corresponding to the lake surface of the lower pond, and the pond information input unit The upper pond runoff calculation unit that calculates Of the outflow calculated in the calculation unit, a lower inflow calculation unit for calculating the amount of water flowing into the lower basin based on the topography data acquired by the topography information input unit, and the lower inflow calculation unit A reservoir storage amount calculation unit for calculating the storage amount of the lower pool based on the lower reservoir information input from the lower reservoir inflow amount calculated from the lower reservoir, and the lower reservoir flowing out downstream from the breakwater position of the lower reservoir It is possible to provide a lower pond outflow amount calculation unit that calculates the outflow amount. According to the above configuration, analysis of chain break can be easily performed. In particular, a more flexible flow rate calculation can be realized by designating the bankrupt location, computing the outflow from this location, and calculating the inflow to the lower pond according to the topography.

  Further, in addition to the above configuration, the bank breach position designation unit can be configured to be able to be set on the mesh-shaped map displayed on the display unit.

  Furthermore, according to the multiple reservoir / recession analysis device pertaining to the twelfth aspect, in addition to any one of the above-described configurations, the bank breach position designation unit designates the bank breach position as the position of the discharge part of the upper pond. Can be configured to According to the above configuration, it is possible for the bank breach position designation unit to automatically designate the bank breach position.

  Furthermore, according to the multiple reservoir / recession analysis device pertaining to the thirteenth aspect, in addition to any of the above configurations, the breach position is designated as the initial value at the location of the discharge portion in the breach position designation unit. In the state, it can be configured to be able to adjust the bank position manually. With the above-mentioned configuration, after the breakwater position is automatically specified as the position of the discharge part, the user can adjust as needed, and more flexible setting can be performed according to the state of the lower pool. Become.

  Furthermore, according to the multiple reservoir / recession analysis device pertaining to the fourteenth aspect, in addition to any one of the above-described configurations, the display unit is a hydrograph showing a time change of the outflow from the time of bank breakage of the upper pond. A hydrograph display area for display can be provided.

  Furthermore, according to the multi-reservoir weir analysis device according to the fifteenth embodiment, in addition to any of the above-described configurations, the ground further includes information on height difference on the ground surface, and calculates the unsteady flow flowing out of the upper pond A layer association unit may be provided that associates the surface layer with the lower layer having information on the full area of the lower pool.

  Furthermore, according to the multiple reservoir / residue analysis device pertaining to the sixteenth aspect, in addition to any one of the above-described configurations, the lower inflow calculation unit calculates one of the ground surface layers associated by the layer association unit. The amount of water flowing into the area corresponding to the lower lake surface defined by the lower lake surface setting section is given as the amount of water flowing into the area corresponding to the lower lake surface within the lower layer, and the lower outflow calculation section In the lower layer, the amount of water flowing out from the lower reservoir is calculated based on the amount of storage in the lower reservoir, and the calculated amount of outflow from the lower reservoir is the lower reservoir designated in the bank position designation portion of the ground surface layer in advance. It can be configured to give as the amount of water that is drained from the location of

Furthermore, based on the upper pond information input from the pond information input unit, the upper pond outflow amount calculation unit assumes that the upper pond is broken at the analysis start time, and is designated by the bank breach position designation unit An algorithm for calculating the upper pond runoff amount can be used as a model in which the amount of water defined by the following formula flows out, with the upper pond failure position as the outflow point.

In the above equation, V _max is the total storage volume [× 10 ⁶ m ³ ], A is the full water area [m ² ], h _b is the spout height [m], q _l (t) is the outflow of the lower pond at time t [ m ³ / s], V _l is the amount of water storage at the time of collapse of the lower pond [× 10 ⁶ m ³ ], H _l is the height of the lower pond bank (m), t is the time from the time when the lower pond was destroyed [sec], t _l is the lower bank collapse Time [sec], q _{l_in} is the amount of water [m ³ / s] which has flowed into the _lower pond after the _lower pond collapse.

Furthermore, as an algorithm for calculating the amount of runoff in the runoff by the runoff discharge calculation unit, it is assumed that if the total overflow head is a water depth smaller than the cut depth of the runoff portion, the runoff downstream from the runoff portion is assumed downstream Flowed to the
Calculation, assuming that there is a water level up to the lower end of the discharge section, and the desired storage volume of the reservoir
It can be calculated by
(Q is the flow rate [m ³ / s], C is the flow rate coefficient, B is the spout width [m], h _k is the total overflow head [m], V _max is the total water storage amount [m ³ ])

Furthermore, assuming that the reservoir will be destroyed if the total overflow head exceeds the discharge part cut-in depth, the above-mentioned reservoir storage volume operation unit will calculate the storage volume of the reservoir.
(A is full water area [m ² ], h _b is flood discharge height [m])
As an algorithm for calculating the downstream outflow quantity operation unit after the breakdown and calculating the time change of the outflow quantity downstream from the downstream outflow point by the following equation,
(Q _l (t) is the outflow of the reservoir at time t [m ³ / s], V ₁ is the amount of reservoir storage at the time of collapse of the reservoir [× 10 ⁶ m ³ ], H _l is the reservoir height (m), t is the rupture of the reservoir Time from the time when the time [sec], t _l is the time to break down the pond [sec], q _{l_in} is the amount of water that has flowed into the _basin after the break down [m ³ / s])

  Furthermore, according to the multiple reservoir 氾濫 analysis device pertaining to the seventeenth aspect, in addition to any of the above configurations, a downstream end water level input unit for inputting a water level as a downstream boundary condition is further provided. Can.

  Furthermore, according to the multi-reservoir weir analysis device pertaining to the eighteenth aspect, in addition to any of the above-described configurations, the ground surface layer can further be provided with a rainfall amount setting unit for adding rainfall. . With the above configuration, it is possible to calculate the flow caused by rainfall on the ground surface layer of the two-dimensional unsteady flow analysis.

  Furthermore, a tide level calculator can be provided to calculate the time-varying tide level. According to the above configuration, the water level at the downstream end condition of the ground surface layer can be temporally changed according to the tide level.

  Furthermore, according to the multiple reservoir / residue analysis device pertaining to the nineteenth aspect, in addition to any of the above configurations, a water level conversion unit that converts the flow rate flowing from the upper reservoir into the lower reservoir to the water level in the lower reservoir be able to.

FIG. 1A to FIG. 1G are schematic views showing a flow in which a chain break occurs. It is a functional block diagram showing a multiple reservoir flooding analysis device concerning Embodiment 1 of the present invention. FIG. 3A is a schematic diagram showing a digital elevation model in which the center mesh has no known elevation value, and FIG. 3B is a schematic view showing the digital elevation model interpolated by the elevation interpolation function with respect to FIG. 3A. It is an image figure which shows the state which designates the analysis area | region which performs a several reservoir flooding analysis on a map. FIG. 5 is an image view showing a state in which a 10 m mesh numerical altitude model is displayed superimposed on FIG. 4; It is an image figure showing a ground elevation model creation condition setting screen. It is the image figure which accumulated the created 5 m mesh ground elevation model on FIG. 4, and was displayed. FIG. 8 is an image view showing a state in which a 5 m mesh numerical altitude model is displayed superimposed on FIG. 7; It is an image figure showing a ground elevation model creation condition setting screen. It is an image figure which accumulated and displayed the mixed ground elevation model of 5 m mesh and 10 m mesh on FIG. FIG. 11 is an image diagram showing a state in which mesh sizes of the digital elevation model are highlighted to be superimposed on FIG. It is a model top view which shows a stagger and the definition point of a structure grid | lattice and an unknown variable. It is a schematic cross section which shows the case where water flows over unevenness, such as an embankment. It is a schematic cross section which shows the case where a dominant cross section appears between meshes. It is a model top view which shows the running direction of a drainage, and the defining point of a flow. It is a schematic diagram which shows a mode that a ground surface layer and a lower pond layer are associated. It is a schematic diagram which modeled a reservoir. It is a schematic diagram which shows a mode that the bank breakage position of upper pond is designated. It is a schematic diagram which shows a mode that the area | region of the lake surface of a lower pond is designated. It is a schematic diagram which shows a mode that the embankment position of a lower pond is designated.

  Hereinafter, embodiments of the present invention will be described based on the drawings. However, the embodiments shown below are exemplifications for embodying the technical idea of the present invention, and the present invention is not limited to the following. Further, the present specification does not in any way specify the members described in the claims to the members of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention to the scope of the present invention unless otherwise specified. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for the sake of clarity. Further, in the following description, the same names and reference numerals indicate the same or the same members, and the detailed description will be appropriately omitted. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and one member is used in common as a plurality of elements, or conversely, the function of one member is realized by a plurality of members It can be shared and realized.

For example, the connection between the plural reservoirs analysis apparatus used in the embodiment of the present invention and a computer, a printer, an external storage apparatus and other peripheral devices connected thereto for operation, control, display, other processes, etc. Serial connection such as IEEE 1394, RS-232x, RS-422, RS-423, RS-485, USB, etc. Parallel connection, or electrical or magnetic via a network such as 10BASE-T, 100BASE-TX, 1000BASE-T, etc. , Connect optically and communicate. The connection is not limited to physical connection using a wired connection, and wireless connection using wireless LAN such as IEEE802.1x, Bluetooth (registered trademark), radio waves such as other NFC, infrared light, optical communication, etc. may be used. Furthermore, memory cards, magnetic disks, optical disks, magneto-optical disks, semiconductor memories and the like can be used as recording media for exchanging data and storing settings. In the present specification, the plural reservoir / vessel analysis apparatus is used to mean not only a multiple reservoir / vessel analysis apparatus main body but also an inundation degree real time prediction system in which peripheral equipment such as a computer and an external storage device are combined.
(Embodiment 1)

  The multi-reservoir weir analysis apparatus according to the first embodiment of the present invention performs weir analysis in which a plurality of reservoirs including an upper pond located upstream and a plurality of reservoirs located downstream of the upper pond are broken in a chained manner. A device for In the present specification, the term "reservoir" is used in the meaning including dams, farm ponds, and other agricultural reservoirs and adjustment ponds, rivers, natural dams and the like. In addition, it is used in the meaning including the inflow of the earth and sand from hillside collapse for Kamiike collapse.

  First, the process of causing a chain break will be described based on FIGS. 1A to 1G. As shown to FIG. 1A, the case where upper pond RS1 exists above the inclined surface and lower pond RS2 exists below upper pond RS1 is considered. Both the upper pond RS1 and the lower pond RS2 hold the downstream wall so that the water does not overflow. Conversely, when the water level on the lake surface exceeds the height of the wall, the water overflows, resulting in a so-called broken state. Then, in order for a chain break to occur in the upper pond RS1 and the lower pond RS2, it is necessary to first break the upper pond RS1 and then break the lower pond RS2. In the following example, although the chain breakdown of the upper pond RS1 and the lower pond RS2 is explained for explanation, the present invention is not limited to the reservoir, but water accumulated on the upper side such as rivers, waterways, natural dams, landslides on hillsides, etc. Etc. can be applied to the case of flowing into a reservoir or the like accumulated on the lower side. In addition, multiple reservoirs analysis system and multiple reservoirs analysis program can be used for chain breakdown and flooding analysis when multiple reservoirs are broken simultaneously.

  First, considering the collapse of the upper pond RS1, as shown in FIG. 1B, the stored water flows from the upper pond RS1 and flows out to the downstream side. Here, a model or algorithm is adopted in which the amount of water according to the hydrograph calculated using the Costa equation flows down (details will be described later). The Costa equation is a regression equation that calculates the peak flow rate based on the dam data and the water storage capacity as a dam factor based on statistical data (see Non-Patent Document 2). However, the present invention does not limit the method of flow rate calculation to the Costa equation, but other methods such as flow-rich method, cost-effectiveness calculation method of land improvement project, arbitrary hydrograph, etc. can also be used.

  Next, think about the collapse of Shimoike RS2. As shown in FIG. 1C, the water stored in the upper reservoir RS1 flows into the lower reservoir RS2 due to the breakdown of the upper reservoir RS1. Here, as shown in FIG. 1D, the case where the lower reservoir RS2 is not full of water and the case of full water as shown in FIG. 1F will be considered separately.

  When the lower reservoir RS2 is not full of water, the water flowing in from the upper reservoir RS1 is stored in the lower reservoir RS2 as shown in FIG. 1D, and the water level of the lower reservoir RS2 rises with time. Then, when the water level of the lower reservoir RS2 exceeds the “discharge portion” formed on the wall surface of the lower reservoir RS2, it flows down from the discharge portion to the downstream side of the lower reservoir RS2 as shown in FIG. 1E. This outflow amount is small compared to the case of destruction, and its calculation is calculated from the HQ equation (details will be described later).

On the other hand, when the lower reservoir RS2 is full of water as shown in FIG. 1F, the lower reservoir RS2 is broken, and as shown in FIG. 1G, much water flows out to the downstream side of the lower reservoir RS2. As the outflow amount in this case, a Costa type is adopted.
(Multi-reservoir trap analysis device 100)

A multiple reservoir weir analyzer according to a first embodiment of the present invention is shown in FIG. The multi-reservoir trap analysis apparatus 100 shown in this figure includes an input unit 10, an operation unit 20, a calculation unit 30, a display unit 40, and a data storage unit 50. The multi-reservoir-bed analyzing apparatus 100 may be configured by dedicated hardware, or may be configured by installing a multi-reservoir-bed analyzing program on a general-purpose or dedicated computer.
(Input unit 10)

  The input unit 10 is an input interface for receiving external data input, and functions as a data acquisition unit that acquires necessary information by accessing an external database, for example, by communication with an external device. . The data acquisition unit has a communication function for connecting to a specific network via a general-purpose network line such as the Internet or a dedicated line. The input unit 10 includes a pond information input unit 11 and a terrain information input unit 12.

  The pond information input unit 11 is a member for acquiring information on the upper pond and information on the lower pond. The pond information input unit 11 preferably inputs a reservoir database under the jurisdiction of the Ministry of Agriculture, Forestry and Fisheries. In this way, it is possible to perform the soot analysis without individually inputting the specifications of reservoirs in various places.

The topography information input unit 12 is a member for acquiring topography data of an area to be an object of the grazing analysis. For example, a map created by the Geographical Survey Institute of the Ministry of Land, Infrastructure, Transport and Tourism, three-dimensional point cloud data acquired by a drone, etc. can be used as the terrain data input by the terrain information input unit 12. The multiple reservoir / bed analysis apparatus has a ground elevation model creation function for creating a ground elevation model from such terrain data. For example, base map information (numerical elevation model which is mesh data of elevation) by the Ministry of Land, Infrastructure, Transport and Tourism is input from the topographical information input unit 12 to create a ground elevation model of the area subject to flooding analysis, and displayed on the display unit 40 It can be done.
(Operation unit 20)

The operation unit 20 is a member for performing various operations and settings on the multiple reservoir / bed analysis apparatus, and an input device such as a mouse, a keyboard, or a console can be used. The operation unit 20 implements the functions of the bank breakage position designation unit 21, the lower lake surface setting unit 22, the layer association unit 23, and the rainfall amount setting unit 24.
(Vault position specification part 21)

  The bank breach position designation unit 21 is a member for designating a bank breach position where water flows out at the time of bank collapse for one or more lower ponds. As a result, the user can manually designate the bankruptcy position via the bankruptcy position designation unit 21 or the plural reservoir / recession analysis apparatus can automatically designate the bankruptcy position.

The bank breakage position designation unit 21 can designate the bank breakage position of one or more lower ponds as the position of the discharge part of the lower pond. This makes it possible to automatically specify the breach position. Alternatively, the breakwater position may be manually adjusted in a state where the breakwater position of the reservoir is designated as the initial value at the position of the discharge part. In this case, it is possible to allow the user to make adjustments as needed after automatically specifying the breakwater position as the position of the discharge part, and to perform more flexible setting according to the state of the lower pond. Become. In addition, a user designates one place with respect to one reservoir for a bankruptcy position. In other words, bankruptcy at the same time in two places in one reservoir is not assumed because it is stochastically low.
(Shimoike lake surface setting unit 22)

The lower pond lake surface setting unit 22 is a member for specifying an area corresponding to the lower lake surface.
(Layer association unit 23)

The layer relating unit 23 has information on height difference of the ground surface including the upper pond, and information on the ground surface layer which is a layer of two-dimensional unsteady flow to calculate the unsteady flow flowing out from the upper pond, and information on the full water area of the lower pond. It is a member for associating with the lower pond layer which is a layer of the lake surface having. The layer association unit 23 flows the amount of water flowing into the area corresponding to the lower lake surface defined by the lower lake surface setting section 22 of the ground surface layer into the area corresponding to the lower lake surface within the lower layer. The amount of water flowing out from the lower pool is calculated based on information such as the amount of water stored in the lower pool in the lower layer, and the calculated amount of drained water from the lower reservoir is used as the breakwater position designation unit in the ground surface layer. It can be configured to give as the amount of water that flows out from the location of the breakwater of the lower pond specified in 21.
(Rainfall setting unit 24)

  The rainfall amount setting unit 24 is a member for adding a rainfall amount to the ground surface layer. The rainfall amount setting unit 24 can calculate the flow caused by the rainfall on the surface layer of the two-dimensional unsteady flow analysis. Also, this rainfall can be changed over time. Therefore, not only the amount of water caused by the failure of the upper pond, but also the amount of water caused by the rainfall flows into the lower pond. It is possible to examine the impact of rainfall on reservoir failure by comparing the analysis results considering rainfall with the analysis that does not consider rainfall. Furthermore, actual rainfall may be used as rainfall data. Adoption or rejection of such rainfall data is optional, and analysis can be made without using rainfall data. The rainfall data is acquired by, for example, the input unit 10 via the communication network. This makes it easier to sequentially update the latest information.

  Rainfall data includes analysis rainfall of the forecasted area, short-term precipitation forecast, and arbitrary set rainfall. Here, the analysis rainfall is the rainfall actually rained within a predetermined time in the past from the current time. The short-term precipitation forecast is the rainfall expected to occur within a predetermined time from the current time. In this embodiment, this predetermined time is every hour. For example, the rainfall data distributed by the meteorological service support center is distributed with the analysis rainfall and the short-term precipitation forecast being updated every 30 minutes for the predicted rainfall up to 6 hours ahead of the range obtained by dividing the topography data by 1 km mesh. Therefore, the input unit 10 sequentially acquires such data and sends it to the arithmetic unit 30. Further, the weather data taken in by the input unit 10 can be held in the data storage unit 50.

The collection destination of the rainfall data is not particularly specified. For example, in addition to using rainfall data distributed by the Meteorological Agency or the Meteorological Service Support Center, a unique rainfall observation apparatus may be installed and collected directly. In addition, the predetermined time is not limited to one hour, and may be shorter (for example, 30 minutes) or longer (for example, 2 hours).
(Data storage unit 50)

  The data storage unit 50 is a member for holding various data, and can use, for example, a semiconductor memory, a hard disk, or a portable medium. For example, the function of the terrain data storage unit that holds the terrain data is realized. Terrain data holds height information at each position on the map. For example, it contains information such as the elevation and inclination of each section in the predicted area. The position on the map can be managed by meshed data.

  Here, the division is defined as one division which is a unit of 5 m square in the predicted area. In the first embodiment, the 5 m square range is further combined with 5 × 5 each in the vertical and horizontal directions to make 25 m square into one section. Terrain data used for the calculation unit 30 described later uses the average value within the 25 m square. The data storage unit 50 may store 5 m square terrain data, or may store in advance an average value of 25 m square terrain data.

  The size per section is not specified above. One segment may be smaller than 25 m if precise prediction results are required. For example, one side may be set to an arbitrary size such as 1 m, 2.5 m, or 5 m. Alternatively, when speeding up of the arithmetic processing is prioritized, one section may be enlarged.

For example, detailed ground height data of 5m mesh (as an example, basic map information by the Ministry of Land, Infrastructure, Transport and Tourism Geographical Survey Institute) and 2m mesh (as an example, 2m mesh elevation data by Japan Mapping Center) are published and sold. In such ground elevation data, drainage channels may be reflected as surface irregularities.
(Elevation interpolation function)

  The multiple reservoir / bed analysis apparatus can also be provided with an elevation interpolation function that interpolates numerical data of elevation when creating a ground elevation model. The above-mentioned base map information is published as latitude and longitude information, and when converted to plane rectangular coordinates due to differences in projection methods, it is not always known that there is one known elevation value known point in a 5m x 5m mesh Absent. For example, in a 5 m × 5 m mesh, there may be two known points or no known points. Therefore, it is possible to provide a complementary function that interpolates the mean value of the ground elevation values of the nearby meshes as the estimated ground elevation value of the mesh without the known points for meshes having no known points. For example, in the digital elevation model shown in FIG. 3A, when there is no known point of elevation value in the center mesh, the average value of the ground elevation values of meshes (here eight pieces) located around the unknown mesh is Interpolate as estimated ground elevation value. Here, the average value is calculated from the sum of the mesh elevation values around the unknown mesh. In the example of FIG. 3A, since (4.0 + 4.5 + 5.2 + 3.9 + 5.3 + 4.2 + 4.9 + 5.4) /8=4.7, interpolation is performed on the mesh without known points as shown in FIG. 3B. Set the altitude of 4.7.

Furthermore, in order to distinguish the mesh in which the ground elevation is interpolated from the mesh having known points in the mesh, both may be colored in different colors and displayed on the display unit. For example, the user can visually grasp the credibility of the displayed ground elevation by displaying a mesh having a known point in blue and a mesh not having a known point and complemented in yellow.
(Mixed ground elevation model creation function)

  Furthermore, the multiple reservoir / bed analysis apparatus can also be provided with a function of creating a mixed ground elevation model in which digital elevation models of different mesh sizes are mixed.

  Among the numerical elevation models described above, the accuracy of the 5 m mesh numerical elevation model is better than that of the 10 m mesh numerical elevation model, but does not cover the whole of Japan. Especially in the mountainous area, there is a place where there is no elevation value of the 5m mesh digital elevation model. In contrast, the 10 m mesh digital elevation model covers the entire area of Japan. Therefore, while using the 5m mesh digital elevation model in places where there is a 5m mesh digital elevation model, and using a 10m mesh digital elevation model in places where there is no 5m mesh digital elevation model, while covering a wide range, A ground elevation model with the highest possible accuracy is obtained.

  Therefore, the multiple reservoir flooding analysis apparatus according to the present embodiment takes in a plurality of digital elevation models with different mesh sizes, such as a 5 m mesh digital elevation model and a 10 m mesh digital elevation model, and creates a mixed ground elevation model Has a creation function. Also, as a ground elevation model setting means for setting conditions when creating mixed ground elevation models, it has ground elevation initialization function and elevation interpolation function.

  The ground elevation initialization function is a function for initializing and then calculating the ground elevation. When this function is set to ON by the ground elevation model setting means, the ground elevation data is read by initializing the ground elevation that has already been set. Further, the elevation interpolation function is a function to interpolate the blank of the elevation value described above. When this function is set to ON, for meshes without known points, the average value of ground elevations of nearby meshes is automatically interpolated as ground elevation.

When taking in multiple ground elevation data with different mesh sizes, these ground elevation initialization functions and elevation interpolation functions are set. Here, an example will be described in which a mixed ground elevation model is created by mixing a 5 m mesh numerical elevation model and a 10 m mesh numerical elevation model.
(When mesh size of ground elevation model to create is less than 10 m)

Here, the case where the mesh size of the ground elevation model to be created is less than 10 m will be described. First, when loading a 10 m mesh digital elevation model, the ground elevation initialization function and the elevation interpolation function are both set to ON to create an elevation model. After that, when the 5 m mesh digital elevation model is read, the ground elevation initialization function and the elevation interpolation function are both set to OFF to create an elevation model. This makes it possible to create a ground elevation model in which a 10 m mesh digital elevation model is placed where there is no 5 m mesh digital elevation model.
(When mesh size of ground elevation model to create is 10m or more)

Next, the case where the mesh size of the ground elevation model to be created is 10 m or more will be described. First, when loading a 10 m mesh digital elevation model, set the ground elevation initialization function to ON and the elevation interpolation function to OFF, and create an elevation model. After that, when the 5 m mesh digital elevation model is read, the ground elevation initialization function and the elevation interpolation function are both set to OFF to create an elevation model. This makes it possible to create a ground elevation model in which a 10 m mesh digital elevation model is placed where there is no 5 m mesh digital elevation model.
(Coloring function)

  Furthermore, when the ground elevation model was created by mixing the 5m mesh digital elevation model and the 10m mesh digital elevation model, the mesh with the 5m digital elevation model adopted in the ground elevation model and the 10m mesh digital elevation model were adopted. In order to distinguish meshes, both can be colored and displayed in different colors.

In addition, as described above, the mesh in which the ground elevation is interpolated may be displayed in different colors by using the complementary function. For example, a 5 m mesh, a 10 m mesh, and an interpolated mesh can be displayed in different colors on the display unit. Thereby, the user can distinguish and grasp the accuracy and reliability of the displayed ground elevation by color. Furthermore, the size of the mesh is not limited to 5 m mesh and 10 m mesh, but other sizes, for example, 2 m mesh, 1 m mesh, 50 cm mesh, etc. can be used, and these can also be displayed in different colors. Furthermore, meshes of any size may be set.
(Procedure of creating mixed ground elevation model)

  Here, the procedure of creating a mixed ground elevation model by mixing a 5 m mesh numerical elevation model and a 10 m mesh numerical elevation model will be described based on FIGS. 4 to 11. First, in FIG. 4, in a state where a map is displayed on the display unit 40, an analysis region in which a plurality of reservoirs are analyzed is specified. In the example of FIG. 4, the analysis region ROI is designated by a square blue frame.

  Next, load a 10 m mesh digital elevation model. In the example shown in FIG. 5, a portion where a 10 m mesh numerical elevation model exists in a rectangular red frame is displayed together with the data file name, superimposed on the map displayed on the display unit 40. Here, it can be seen that the analysis region ROI straddles two 10-m mesh numerical elevation models MM10-1 and MM10-2.

  In this state, the ground elevation model creation conditions are set. Specifically, as shown in FIG. 6, the ground elevation model creation condition setting screen 60 is opened. Here, in order to create a 5 m mesh ground elevation model, both the ground elevation initialization function and the elevation interpolation function are set to ON. When the ground elevation model creating function is executed in this state, as shown in FIG. 7, a ground elevation model of 5 m mesh is created with the 10 m mesh numerical elevation models MM 10-1 and MM 10-2. The area where the ground elevation model is created is highlighted and displayed on the map in a distinguishable manner. In the example of FIG. 7, the 5 m mesh ground elevation model M5M is displayed in a colored manner.

  Next, overlapping with this state, the location where the 5 m mesh digital elevation model exists is extracted. Here, as shown in FIG. 8, an area in which a 5 m mesh numerical elevation model exists in a blue rectangular shape is displayed in a grid pattern. Among these, the 5 m mesh numerical elevation models MM5-1 to MM5-11 overlapping with the 5 m mesh ground elevation model M5M created in FIG. 7 are highlighted in red frames and distinguished.

In this state, in order to execute the model creating function again, the ground elevation model creating conditions are set as shown in FIG. Here, the ground elevation initialization function and the elevation interpolation function are both set to OFF. When the mixed ground elevation model creation function is executed in this state, as shown in FIG. 10, the 5 m mesh is superimposed on the 10 m mesh, and the 5 m mesh digital elevation model and the 10 m mesh digital elevation model of higher definition than FIG. A mixed ground elevation model M5-10M mixed is created.
(Highlighting function by mesh)

Furthermore, in this state, the mesh size of the digital elevation model constituting the mixed ground elevation model may be highlighted so that it can be distinguished. For example, as shown in FIG. 11, in the mixed ground elevation model M5-10M, the region H10 created by the 10 m mesh digital elevation model is colored red, and the region H5 created by the 5 m mesh digital elevation model is colored blue. It is displayed on the display unit 40. Thus, the user can visually grasp the accuracy of the altitude value of which region on the mixed ground elevation model.
(Display unit 40)

  The display unit 40 is a member for displaying a map indicating an upper pond or a lower pond, displaying a hydrograph, or confirming a necessary setting or the like. The display unit 40 can use, for example, an LCD, an organic EL display, a CRT, or the like. In addition, by using a touch panel in the display unit, the operation unit and the display unit can be integrally configured.

The display part 40 is providing the hydrograph display area for displaying the hydrograph which shows the time change of the outflow from the time of the bank breakage of an upper pond. A hydrograph is a figure showing the relation between time and flood water level or flood flow rate.
(Calculation unit 30)

  When the storage amount of the lower reservoir calculated by the lower reservoir storage amount calculation portion reaches a condition where the lower reservoir is broken in advance, the calculation unit 30 changes the outflow amount of the lower reservoir to the flow rate after the destruction of the lower reservoir. By this, it is possible to analyze the flooding after the collapse of the lower pond.

  The computing unit 30 includes an upper pond outflow amount computing unit 31, a lower pond inflow computing unit 32, a downstream computing unit 33, a downstream end water level input unit 37, and a water level conversion unit 38.

  The upper pond outflow amount calculation unit 31 is a member that calculates the outflow amount of water flowing out from the upper pond based on the upper pond information input from the pond information input unit 11.

In order to calculate the amount of water flowing into the lower basin based on the terrain data acquired by the terrain information input unit 12 among the total runoff calculated by the upper pond runoff calculation unit 31, the lower inflow calculation unit 32 calculates It is a member of
(下 池 operation unit 33)

  Based on the downstream information input from the pond information input unit 11 from the downstream inflow calculated by the downstream inflow computing unit 32, the downstream computing unit 33 stores the amount of water stored in the downstream and the downstream flowing from this downstream to the downstream. It is a member for calculating the outflow amount. The lower pool operation unit 33 is configured to switch the algorithm for calculating the flow rate after the depth of the lower pool reaches the depth from the initial immersion to the total overflow head and the outlet depth.

The lower pool operation unit 33 realizes the functions of the lower reservoir storage amount calculation unit 34 and the lower reservoir runoff amount calculation unit 36. The reservoir storage amount calculation unit 34 is a member for calculating the storage amount of the lower reservoir based on the lower pool inflow calculated from the lower reservoir inflow calculation unit 32 based on the lower reservoir information input from the reservoir information input unit 11. is there. The downstream outflow calculation unit 36 is a member for calculating the downstream outflow flowing from the downstream to the downstream.
(Lower pond water level calculator 35)

In addition, the reservoir storage amount calculation unit 34 can also realize the function of the reservoir level calculation unit 35 that calculates the water level of the reservoir. For example, the algorithm switching condition is set as the timing when the water level in the lower reservoir reaches the discharge part depth. The information of the discharge part depth which a lower pond has is beforehand acquired by the pond information input part 11. FIG. As a result, it is possible to switch the algorithm for calculating the amount of runoff in the runoff between the time when the water level of the basin is from the initial water level to the total overflow head (there is no break in this period) and after reaching the discharge depth.
(Downstream end water level input unit 37)

The downstream end water level input unit 37 is a member for inputting a water level as a downstream boundary condition that changes with time. The downstream end water level may be separately calculated by the user and may be directly input as a numerical value, or may be obtained by calculation. In addition, where the spring water from the reservoir flows down to the sea surface, it is possible to simulate the inundation situation by the reservoir at high tide and low tide by linking the time change of the downstream end with the tide level. Furthermore, it is also possible to examine the influence of tides on the inundation situation by comparing the analysis results at high tide and low tide. Alternatively, the downstream end water level can be used as the tide level. In this case, the time-varying tide level is acquired and input. Thus, the downstream end water level input unit 37 can change the water level of the downstream end condition of the ground surface layer in accordance with the tide level.
(Water level converter 38)

  The water level conversion unit 38 is a member for converting the flow rate of the upper pond (which flows into the lower pond) into the water level of the lower pond.

It is assumed that Kamiike breaks down at the analysis start time. The amount of water according to the hydrograph calculated using the Costa equation flows out of the mesh set as the upper pond outflow point.
(Analysis model)

Hereinafter, an analysis model used in the present embodiment will be described.
(Flow of spring water on the ground surface)
<Basic formula>

As a basic equation of the surface flood, we use the following two-dimensional unsteady shallow water flow equation and equation of motion.
[Continuous]
[Equation 1]
[X-direction equation of motion]
[Equation 2]
[Y direction equation of motion]
[Equation 3]

In the above equation, t is time; x, y are horizontal two-dimensional coordinates; h is water depth; u, v are flow velocity components in the x, y directions; M, N are flow fluxes in x, y directions (unit width flow) , M = uh and N = vh; H is the water level; r (t) is the amount supplied by rainfall; q _CHAN is the amount of water that overflows from the drainage onto the ground surface, flows out, or flows from the ground surface into the drainage, g indicates the gravitational acceleration; ρ indicates the density of water; τ _{b, x} , τ _{b, y} indicate the surface frictional resistance stress in the x and y directions, respectively. Note that τ _{b, x} and τ _{b, y} are expressed by the following equations.
[Equation 4]
[Equation 5]

In the above equation, n is a synthetic equivalent roughness coefficient.
<Discretization of basic equation>

In the numerical calculation of the convective flow, the equations (1), (2) and (3) are spatially differentiated with respect to the staggered and structured grids and temporally analyzed numerically by the leap-frog method. FIG. 12 shows the definition points of the staggered / structured grid and the unknown variable. In this figure, i and j are division numbers in the axial direction.
<Calculation method for special cases>

Here, we will consider the special case calculation method.
(Overflow such as embankment)

First, as shown in FIG. 13, the case of overflowing unevenness such as embankment is examined. As described above, when a band-like object such as an embankment or a road exists, the equation of motion can not be applied as it is. If the water level on both sides of the strip is lower than the height of the top end of the strip, the flow flux is zero. If this is not the case, the overflow flow flux is calculated according to the book-to-book overflow formula such as Equations 6 and 7.
[Equation 6]
[Equation 7]

In the above equation, h ₁ and h ₂ are water levels from the top end of the band-like object, and the higher one is h ₁ and the lower one is h ₂ . Further, μ is a flow coefficient, and in equation 6, μ = 0.35, and in equation 7, μ = 0.91.
(When a dominant cross section appears between meshes)

Next, consider the case where a dominant cross section appears between meshes. As shown in the cross-sectional view of FIG. 14, when the elevation difference between the adjacent meshes is large and the water surface becomes discontinuous or when the water level rises rapidly, a dominating cross section appears. In this case, the equation of motion is not applied to the calculation of the flow rate flux, and the calculation is performed as a stage drop flow. Here, the flow flux is given as in the equations (8) and (9).
[Equation 8]
However,
[Equation 9]
[Equation 10]
However,
[Equation 11]
h _cx is the limit depth in the x direction in the surface flow, h _cy is the limit depth in the y direction in the surface flow, and E is the energy head.
(2) Flow of water in the drainage channel

  Next, consider the flow of water in the drainage channel. In the present embodiment, as shown in FIG. 15, defined points are defined as the traveling direction of the drainage channel and the flow rate. Thus, the drainage channel is considered to be located only in the direction of the coordinate axis. In addition, it shall pass through the center of the set mesh (definition point of water depth).

The following continuous equations and equations of motion are used as the basic equations for drainage channel flow. The equation of motion is the two-dimensional shallow water flow with the advection term omitted.
[Continuous]
[Equation 12]
[Direction equation of motion]
[Equation 13]
[Direction equation of motion]
[Equation 14]

In the above equation, h is the water depth, q is the unit width flow rate in the drainage channel, and when the flow direction coincides with the direction of the coordinate axis, it takes a positive value, and in the opposite case it takes a negative value. q _{GROUND '} is the amount of water that overflows from the drainage channel onto the ground surface, flows out, or flows from the ground surface into the drainage channel. H indicates the water level, and τ indicates the frictional resistance stress. In addition, x and y shown by a subscript show that it is an expression for drainage which runs in the x and y directions, respectively. Further, the frictional resistance term is expressed as the following equation.
[Equation 15]
[Equation 16]

In the above equation, R is the diameter depth, and n is the Manning roughness coefficient. Also, the suffixes x and y indicate that they are expressions for drains running in the x and y directions, respectively.
(3) Setting of reservoir 1) Upper pond

It is assumed that the upper pond breaks at the analysis start time when the analysis by the multiple reservoirs analysis device is started as described above. The amount of water according to the hydrograph calculated using the Costa equation flows out of the mesh set as the upper pond outflow point. Here, the Costa equation is shown in Equation 17 and the time change of the outflow amount is shown in Equation 18. The number 18 is set such that the total outflow amount becomes the storage amount, that is, the number 19 is satisfied.
[Equation 17]
[Equation 18]
[Equation 19]

In the above equation, q _u (t) is the upper pond runoff amount at time t [m ³ / s]; V _u is the upper reservoir storage amount [× 10 ⁶ m ³ ], H _u is the upper pond bank height [m], t is time [sec].
(2) Lower pond (inflow to lower pond)

First, we set the Shimoike lake surface. The mesh set on the Shimoike Lake surface always has no water depth. Therefore, the amount of water flows from the adjacent mesh to the mesh set as the lower lake surface. This is the inflow to the lower pond. The amount of water flowing into the lower reservoir shifts from the ground surface model to the lower reservoir model (described later) as shown in FIG. Then, the amount of water corresponding to Eqs. 20 and 23 described later shifts from the lower pond model to the ground surface model, and flows down the ground surface.
(Outflow from discharge part of lower pond)

The concept of the lower pond model is shown in FIG. Here, the reservoir is modeled as a rectangular solid. In addition, in the downstream part of the reservoir, a discharge part is provided to discharge part of the stored water. The discharge part is a spout such as a reservoir, or an overflow part such as a river embankment, and for example, when a part of a concrete reservoir is cut into a slit shape, when the water is almost full, It is constructed so that the water of the part can flow down stably. The shape of the outlet portion may be a polygonal shape such as a triangle or square, or a rectangular notch. In the example of FIG. 17, a rectangular notch is employed. Moreover, in this specification, the cut height of the discharge part is called the depth of the discharge part. If the water level in the reservoir exceeds the depth of the outlet, it can be determined that the water overflows. If the total overflow head is smaller than the depth of the discharge part, it is assumed to flow downstream from the discharge part, and is discharged downstream from the equation (20) HQ. In addition, the initial storage volume of the reservoir is set to the number 21 and the water level is set to the lower end of the discharge part.
[Equation 20]
[Equation 21]

In the above equation, Q is the flow rate [m ³ / s], C is the flow rate coefficient, B is the spout width [m], H _max is the levee height [m], h _k is the total overflow head [m], and V _max is The total storage volume [m ³ ] and A indicate the full water area [m ² ], respectively.
(Breakdown of Shimoike)

If the total overflow head exceeds the cut depth of the discharge section, it is assumed that the reservoir will be destroyed and it will flow downstream from the Costa type. Here, the Costa equation is shown in Equation 23, and the time change of the outflow amount is shown in Equation 24. Here, Eq. 23 is set such that the total outflow of the upper pond is the stored water quantity, that is, Eq. 24 below is satisfied. In addition to the Costa formula, the inflow to the lower pond is made to flow out from the lower pond outflow point because the inflow to the lower pond is assumed after the lower pond collapse and in addition to the Costa equation, for the time change of the outflow (equation 23).
[Equation 22]
[Equation 23]
[Equation 24]
[Equation 25]

In the above equation, q _l (t) is the outflow from the lower pond at time t [m ³ / s], V ₁ is the amount of storage at the time of the collapse of the downstream [× 10 ⁶ m ³ ], H _l is the height of the lower embankment (m), t time [sec] from the time that collapse lower reservoir, t _l is lower reservoir collapse time [sec], q _{L_in} is the amount of water [m ³ / s] that has flowed into the lower reservoir after collapse lower reservoir, respectively.
3. Setting method

Next, the procedure of the setting method at the time of performing the sputum analysis at the time of a chain break is described.
(Setting of 1 upper pond collapse position)

First, the upper pond breaking position is set as shown in FIG.
(Setting of 2 lower lake side)

Next, as shown in FIG. 19, a mesh corresponding to the lake surface of the lower pond is set. The spring on the mesh set by this moves from the ground surface model to the reservoir storage model. And when the water level is higher than the discharge part, it flows out from the lower pond break position to the surface model.
(Setting of 3 Shimoike breaking position)

  Furthermore, as shown in FIG. 20, the break position of the lower pond is set.

  In this way, the break positions of the upper pond and the lower pond are set.

  In the example explained above, the example of performing the weir analysis including the chain breakdown was explained about two ponds of the upper pond and the lower pond. However, depending on the situation, there may be multiple downstream ponds downstream of the upper pond. Also, it is conceivable that there are multiple ponds with different heights, for example, three ponds in three stages, such as upper pond, middle pond, and lower pond, may be placed on slopes. Thus, the present invention can be applied even in a mode in which a plurality of lower ponds are connected.

  The multi-reservoir analysis program and the computer-readable recording medium as well as the stored apparatus, the multi-reservoir 氾濫 analysis method, and the multi-reservoir 氾濫 analysis apparatus of the present invention are used to perform the multi-reservoir analysis. During actual rainfall, we can analyze flooding in real time, calculate in advance the flood pattern and estimate it, analyze past flooding mechanism, forecast the future flooded area, disaster prevention such as damage prediction and evacuation route formulation It can be used to

100 ... multiple reservoirs analysis device 10 ... input unit 11 ... pond information input unit 12 ... topography information input unit 20 ... operation unit 21 ... breakwater position specification unit 22 ... lower pond lake surface setting unit 23 ... layer association unit 24 ... rainfall amount setting Unit 30 ... Calculation unit 31 ... Upper pond runoff calculation unit 32 ... Lower pond inflow calculation unit 33 ... Lower pond calculation unit 34 ... Lower reservoir storage amount calculation unit 35 ... Lower reservoir water level calculation unit 36 ... Lower reservoir outflow amount calculation unit 37 ... Downstream end Water level input unit 38 ... Water level conversion unit 40 ... Display unit 50 ... Data storage unit 60 ... Ground elevation model creation condition setting screen RS1 ... Upper pond RS2 ... Lower pond ROI ... Analysis area M5M ... 5 m mesh ground elevation model MM5-1-MM5- 11 ... 5 m mesh digital elevation model MM 10-1, MM 10 2 ... 10 m mesh digital elevation model M 5-10 M ... mixed ground elevation model H 10 ... 10 m mesh digital elevation model Area that was created without the area H5 ... 5m mesh digital elevation model

Claims (19)

A multi-reservoir analysis program for performing a weir analysis in which a plurality of reservoirs including an upper pond located upstream and a plurality of reservoirs located downstream of the upper pond are broken in a chain,
Information on upper and lower ponds, and a function to acquire topographical data of the area to be subjected to inundation analysis,
In a state where the map including the vicinity of the upper pond and the lower pond is displayed on the display unit, the upper pond and the lower pond are made to designate the breakwater position where water flows out at the time of the failure and the area corresponding to the lake surface of the lower pond. Function,
A function of calculating the amount of runoff of water flowing out from the bank breakage position of the upper pond based on the acquired upper pond information;
A function of calculating the amount of water flowing into the lower basin based on the acquired topography data out of the calculated outflow amount;
Based on the acquired inflow information, the computer is realized on the basis of the acquired inflow information and the function of calculating the outflow amount of the outflow flowing downstream from the break position of the inflow based on the acquired inflow information. Multiple reservoir flooding analysis program. The multi-reservoir weir analysis program according to claim 1, further comprising
A surface layer that has information on height differences on the surface and calculates the unsteady flow that flows out of the upper pond,
A multi-reservoir コ ン ピ ュ ー タ analysis program for causing a computer to realize a layer association function of associating with a reservoir layer having information on the reservoir full area. The multi-reservoir weir analysis program according to claim 2, wherein
The function to calculate the amount of inflow water flowing into the above mentioned basin is
The amount of water flowing into the area corresponding to the lower lake surface defined by the lower lake surface setting unit in the associated surface layer,
In the lower layer, it includes a function to calculate the amount of water flowing into the area corresponding to the lower lake surface,
The function to calculate the above mentioned outflow volume is
In the lower layer, the amount of water flowing out of the lower pool is calculated based on the storage amount of the lower pool,
A plurality of reservoirs analysis program including a function of giving the calculated amount of runoff water from the reservoir as the amount of water flowing out from the pre-designated breakwater position of the reservoir on the ground surface layer. The multi-reservoir weir analysis program according to any one of claims 1 to 3, wherein
The multiple reservoir flooding analysis program includes a hydrograph display area for displaying a hydrograph indicating a temporal change in the amount of outflow from the time when the upper pond breaks down.   A computer-readable recording medium or an apparatus storing the program according to any one of claims 1 to 4. A multi-reservoir analysis method for performing a weir analysis in which a plurality of reservoirs including an upper pond located upstream and a plurality of reservoirs located downstream of the upper pond are broken in a chain,
Obtaining information on upper and lower ponds, and topography data of an area to be subjected to inundation analysis;
In a state where the map including the vicinity of the upper pond and the lower pond is displayed on the display unit, the upper pond and the lower pond are made to designate the breakwater position where water flows out at the time of the failure and the area corresponding to the lake surface of the lower pond. Process,
Calculating an amount of runoff of water flowing out from the bank breakage position of the upper pond based on the acquired upper pond information;
Calculating the amount of water flowing into the lower basin based on the acquired topography data out of the calculated outflow amount;
The method for analyzing multiple reservoirs including the step of calculating the water level of the lower pool and the outflow volume of the lower pool flowing downstream from the bank break position based on the acquired lower pool information from the calculated lower pool inflow amount . The method for analyzing a plurality of reservoirs according to claim 6, wherein
In the step of designating the area corresponding to the lake surface of the above-mentioned pond,
A surface layer that has information on height differences on the surface and calculates the unsteady flow that flows out of the upper pond,
A multi-reservoir analysis method including association with a lower pond layer having information on the full area of the lower pond. The method for analyzing a plurality of reservoirs according to claim 7, wherein
The step of calculating the inflow to the lower pond is
The amount of water flowing into the area corresponding to the lower lake surface defined by the lower lake surface setting unit in the associated surface layer,
In the lower layer, the region corresponding to the lower lake surface is given and calculated as the inflowing water amount,
The step of calculating the outflow from the lower pond is
In the lower layer, the amount of water flowing out of the lower pool is calculated based on the storage amount of the lower pool,
The plurality of reservoirs 方法 analysis method, which is calculated by giving the calculated amount of runoff water from the downwater as the amount of water flowing out from the pre-designated breakwater position of the downhill of the ground surface layer. The method for analyzing a plurality of reservoirs according to any one of claims 6 to 8, wherein
In the step of calculating the outflow quantity of the above-mentioned pond, as an algorithm to calculate the outflow quantity of the pond, there are an arithmetic algorithm before the collapse of the Shimoike and an arithmetic algorithm after the destruction of the Shimoike,
The water level of the pond is
From the initial water level to the total overflow head, use the calculation algorithm before
After reaching the discharge part depth acquired as information on the lower pond, the multiple reservoir flooding analysis method consists of switching the calculation algorithm of the outflow of the lower pond so as to use the calculation algorithm after the collapse of the lower pond. A multi-reservoir analysis apparatus for performing a weir analysis in which a plurality of reservoirs including an upper pond located upstream and a plurality of reservoirs located downstream of the upper pond are broken in a chain,
A pond information input unit for acquiring information on the upper pond and information on the lower pond,
Terrain information input unit for acquiring topographic data of the area to be subjected to flooding analysis;
A display unit capable of displaying a map including the vicinity of the upper pond and the lower pond;
A breakwater position designation unit for designating a breakwater position where water will flow out at the time of failure with respect to the upper and lower ponds,
The lower pond lake surface setting section for specifying the area corresponding to the lake surface of the lower pond,
An upper pond runoff amount calculation unit that calculates the amount of runoff of water flowing out from the breakwater position of the upper pond based on the upper pond information input from the pond information input unit;
Among the runoff calculated by the upper pond runoff calculation unit, a lower pool inflow calculation unit for computing the amount of water flowing into the lower basin based on the topography data acquired by the topography information input unit;
A lower reservoir storage amount calculation unit for calculating the storage amount of the lower reservoir based on lower reservoir information input from the lower reservoir inflow amount calculated from the lower reservoir inflow amount calculator;
Downstream runoff calculation unit for computing the runoff outflow amount flowing downstream from the location of the breakup of the runoff;
Reservoir 氾濫 analysis device equipped with. The multi-reservoir weir analysis device according to claim 10, wherein
The bank failure position designation unit is configured to be settable on the mesh map displayed on the display unit. The multiple reservoir / bed analysis apparatus according to claim 11, wherein
The reservoir failure analysis apparatus according to claim 1, wherein the bank breach position designation unit is configured to designate a bank breach position as a location of a discharge part of the upper pond. The multiple reservoir / bed analysis apparatus according to claim 12, wherein
The multiple reservoir 氾濫 analysis device configured to be able to manually adjust the breach position in the condition where the breach position is designated as an initial value at the location of the discharge unit in the breach position designation unit. The multi-reservoir weir analysis device according to any one of claims 1 to 13, wherein
The multiple reservoir weir analysis device according to claim 1, wherein the display unit includes a hydrograph display area for displaying a hydrograph indicating a temporal change in the amount of outflow from the time when the upper pond breaks down. The multiple reservoir / bed analysis apparatus according to claim 14, further comprising:
A surface layer that has information on height differences on the surface and calculates the unsteady flow that flows out of the upper pond,
The multi-reservoir レ イ ヤ ー analysis device comprising a layer association unit that associates a reservoir layer having information on the reservoir full area with a reservoir layer. The multiple reservoir / bed analysis apparatus according to claim 15.
The lower inflow calculation unit
The amount of water flowing into the area corresponding to the downstream lake surface defined by the downstream lake surface setting unit among the ground surface layers associated by the layer association unit,
In the lower layer, the area corresponding to the lower lake surface is given as the amount of water flowing in,
The downstream outflow calculation unit
In the lower layer, the amount of water flowing out of the lower pool is calculated based on the storage amount of the lower pool,
The plurality of reservoirs 氾濫 analysis apparatus configured to give the calculated amount of runoff water from the basin as the amount of water flowing out from the breakwater position of the basin, which has been designated in advance by the breach position designation unit in the ground surface layer. The multi-reservoir weir analysis device according to any one of claims 10 to 16, further comprising:
Multi-reservoir basin analysis device with downstream end water level input for inputting water level as downstream boundary condition. The multi-reservoir weir analysis device according to any one of claims 10 to 17, further comprising:
The multiple reservoir 氾濫 analysis device comprising a rainfall amount setting unit for adding a rainfall amount to the ground surface layer. The multi-reservoir weir analysis device according to any one of claims 10 to 18, further comprising:
A multi-reservoir weir analysis device with a water level converter that converts the amount of water flowing from the upper pond into the lower pond into the water level of the lower pond.