JP6774101B2 - Multiple reservoir flood analysis program and computer-readable recording medium and stored equipment, multiple reservoir flood analysis method, multiple reservoir flood analysis device - Google Patents

Description

The present invention relates to a plurality of reservoir flood analysis programs, a computer-readable recording medium and a storage device, a plurality of reservoir flood analysis methods, and a plurality of reservoir flood analysis devices.

Due to natural disasters such as guerrilla rainstorms, earthquakes, and tsunamis that are thought to be caused by abnormal weather in recent years, flood analysis is required when reservoirs such as reservoirs and dams collapse. Conventionally, flood analysis at the time of collapse has received little attention on the premise that facilities such as dams are designed so as not to collapse.

However, the Great East Japan Earthquake that occurred on March 11, 2011 broke the Fujinuma Reservoir in Sukagawa City, Fukushima Prefecture, causing a lot of damage. According to the Japan University Dam Conference, which is composed of the Ministry of Agriculture, Forestry and Fisheries and academic societies, there have been no reports of casualties in the world since 1930 (Showa 5) due to the collapse of reservoirs and agricultural dams due to the earthquake. It is said to be an extremely rare disaster (Source: Wikipedia). Reservoirs may continue to be damaged by earthquakes such as the Nankai Trough and heavy rains.

In response to this, from the viewpoint of disaster prevention and mitigation, attention has also been focused on flood analysis due to the collapse of the reservoir. In particular, there are many old ponds that existed before the Edo period, so it is necessary to consider the risk of collapse.

However, as mentioned above, attention has been focused on the flood analysis of reservoirs relatively recently, and as mentioned above, the collapse of dams and reservoirs has not been expected so much. This is probably because the dams and reservoirs were designed so that they would not collapse, and it was assumed that they would not collapse, so the discussion itself had not been held in the first place. However, in recent years, disasters beyond expectations, such as unprecedented catastrophes, have become more frequent once every 1000 years, and there is a need to consider disaster prevention that is not a rigid idea on the premise that such disasters will not collapse. ing.

In addition, in areas where there are multiple reservoirs, it is possible that they will collapse in a chain, but such chain collapse has hardly been examined, and flood analysis has not been undertaken at present. Is.

Furthermore, there are many parameters in the setting of the flood analysis of chain breakage, and there is also a problem that the setting is extremely difficult for the user.

Japanese Patent No. 5600507

"Flood analysis verification of collapsed pond due to heavy rain in 2013" Rural Engineering Research Institute Technical Report No. 215 pp91-101, 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 of the purposes thereof is a plurality of reservoir flood analysis program that facilitates flood analysis caused by chain collapse or simultaneous collapse of a plurality of reservoirs. It is an object of the present invention to provide a computer-readable recording medium and a storage device, a plurality of reservoir flood analysis methods, and a plurality of reservoir flood analysis devices.

Means for Solving Problems and Effects of Invention

According to the multiple reservoir flood analysis program according to the first aspect of the present invention, a flood analysis in which a plurality of reservoirs including an upper pond located on the upstream side and a lower pond located on the downstream side of the upper pond collapse in a chain reaction. It is a multi-reservoir flood analysis program for performing flood analysis, and has a function to acquire information on the upper and lower ponds and topographical data of the area subject to flood analysis, and a map including the vicinity of the upper and lower ponds on the display unit. Based on the function to specify the location of the bank where water flows out at the time of flooding and the area corresponding to the lake surface of the lower pond, and the acquired upper pond information, in the displayed state. The function to calculate the outflow amount of water flowing out from the bank breakage position of the upper pond and the calculated outflow amount to calculate the inflow amount of the lower pond flowing into the lower pond based on the acquired topographical data. A function and a function to calculate the water level of the lower pond and the amount of the lower pond outflow flowing downstream from the bank breakage position of the lower pond based on the acquired lower pond information from the calculated lower pond inflow amount are realized in the computer. Can be made to. This makes it easy to analyze the chain break. In particular, a more flexible flow rate calculation can be realized by designating the bank breakage position, calculating the outflow amount from this position, and calculating the inflow amount to the lower pond according to the topography.

Further, according to the multiple reservoir flood analysis program according to the second form, in addition to the above, a ground surface layer that has information on the height difference of the ground surface and calculates an indefinite flow flowing out from the upper pond, and a lower pond. It is possible to realize a layer association function in which a computer is associated with a Shimoike layer that has information on the full area of the water.

Further, according to the plurality reservoir flood analysis program according to the third embodiment, the addition to any, function of calculating the lower pond inflow amount, of the associated ground surface layer, the lower reservoir lake setting unit The amount of water flowing into the defined area corresponding to the lake surface of the lower pond is calculated by giving the amount of water flowing into the area corresponding to the surface of the lower pond as the amount of water flowing into the area corresponding to the surface of the lower pond. function, in the lower reservoir layers, based on the amount of water stored lower reservoir, calculates the amount of water flowing out of the lower reservoir, the amount of water flowing out of the lower reservoir, which is the operation of the ground surface layer, of the lower reservoir pre-specified breach It can include a function of giving and calculating the amount of water flowing out from the position.

Furthermore, according to the multiple reservoir flood analysis program according to the fourth aspect, in addition to any of the above, the display unit displays a hydrograph showing the time change of the outflow amount from the time of the breach of the upper pond. Can include a hydrograph display area for.

Furthermore, the computer-readable recording medium or storage device according to the fifth embodiment stores the above program. Recording media include CD-ROM, CD-R, CD-RW, flexible disc, magnetic tape, MO, DVD-ROM, DVD-RAM, DVD-R, DVD + R, DVD-RW, DVD + RW, and Blu-ray (registered). Includes magnetic disks such as (trademark), HD DVD (AOD), optical disks, magneto-optical disks, semiconductor memories, and other media capable of storing programs. Further, the program includes a program stored in the above-mentioned recording medium and distributed, and a program distributed by download through a network line such as the Internet. Further, the stored device includes a general-purpose or dedicated device in which the above program is implemented in a state in which it can be executed in the form of software, firmware, or the like. Furthermore, each process or function included in the program may be executed by computer-executable program software, or each part of the process may be performed by hardware such as a predetermined gate array (FPGA, ASIC), or the program software and hardware. It may be realized in a format in which a partial hardware module that realizes a part of the hardware is mixed.

Furthermore, according to the method for flood analysis of multiple reservoirs according to the sixth embodiment, flood analysis in which a plurality of reservoirs including an upper pond located on the upstream side and a lower pond located on the downstream side of the upper pond collapse in a chain reaction. It is a method of flood analysis of multiple reservoirs for performing the above, and the process of acquiring the information of the upper pond and the lower pond and the topographical data of the area to be analyzed by the flood analysis, and the map including the vicinity of the upper pond and the lower pond are displayed on the display unit. Based on the process of having the upper pond and the lower pond specify the location of the bank where water flows out at the time of flooding, the area corresponding to the lake surface of the lower pond, and the acquired upper pond information in the displayed state. The step of calculating the outflow amount of water flowing out from the bank breakage position of the upper pond and the inflow amount of the lower pond flowing into the lower pond are calculated based on the acquired topographical data among the calculated outflow amounts. It may include a step of calculating the water level of the lower pond and the amount of the lower pond outflow flowing downstream from the bank breakage position of the lower pond based on the acquired lower pond information from the calculated lower pond inflow. it can. This makes it easy to analyze the chain break. In particular, a more flexible flow rate calculation can be realized by designating the bank breakage position, calculating the outflow amount from this position, and calculating the inflow amount to the lower pond according to the topography.

Furthermore, according to the method for analyzing the flooding of multiple reservoirs according to the seventh aspect, in addition to the above, the step of designating the area corresponding to the lake surface of the lower pond has information on the height difference of the ground surface, and from the upper pond. It is possible to include an association between the ground surface layer for calculating the outflow indefinite flow and the lower pond layer having information on the full area of the lower pond.

Furthermore, according to the plurality reservoir flood analysis method according to the eighth embodiment, the addition to either the step of calculating the lower reservoir inflow, of the associated ground surface layer, the lower reservoir lake setting unit The step of calculating the amount of water flowing into the defined area corresponding to the surface of the lower pond by giving the amount of water flowing into the area corresponding to the surface of the lower pond as the amount of water flowing into the area corresponding to the surface of the lower pond in the lower pond layer is calculated. In the lower pond layer, the amount of water flowing out from the lower pond is calculated based on the amount of water stored in the lower pond, and the amount of water flowing out from the calculated lower pond is discharged from the pre-designated bank breakage position of the lower pond in the ground surface layer. It can be given as the amount of water to be calculated.

Furthermore, according to the method for analyzing the inundation of a plurality of reservoirs according to the ninth aspect, in addition to any of the above, as an algorithm for calculating the amount of runoff of the lower pond in the step of calculating the amount of runoff of the lower pond, a calculation algorithm before the collapse of the lower pond And the calculation algorithm after the Shimoike collapse, and the water level of the Shimoike from the initial water level to the total overflow head is the depth of the discharge part acquired as the information of the Shimoike using the calculation algorithm before the Shimoike collapse. After that, the calculation algorithm of the Shimoike outflow amount can be switched so as to use the calculation algorithm after the Shimoike collapse. This makes it possible to more accurately analyze the flooding after the chain break of the upper pond and the lower pond.

Furthermore, according to the plurality of reservoir flood analysis apparatus according to the tenth embodiment, the flood analysis in which a plurality of reservoirs including the upper pond located on the upstream side and the lower pond located on the downstream side of the upper pond collapse in a chain reaction. It is a multiple reservoir flood analysis device for performing flood analysis, and is a pond information input unit for acquiring information on the upper pond and information on the lower pond, and topographical information for acquiring the topographical data of the area subject to flood analysis. An input unit, a display unit that can display a map including the vicinity of the upper pond and the lower pond, and a bank breakage position designation unit for designating the bank breakage position where water flows out at the time of flooding for the upper pond and the lower pond, respectively. And, based on the lower pond lake surface setting unit for designating the area corresponding to the lake surface of the lower pond and the upper pond information input from the pond information input unit, the outflow amount of water flowing out from the bank breakage position of the upper pond. Outflow amount calculated by the upper pond outflow calculation unit and the upper pond outflow calculation unit, and the lower pond inflow amount that flows into the lower pond based on the topographical data acquired by the topography information input unit. The lower pond that calculates the amount of water stored in the lower pond based on the lower pond information input from the pond information input unit from the lower pond inflow calculation unit for calculating the above and the lower pond inflow calculated by the lower pond inflow calculation unit. A water storage amount calculation unit and a lower pond outflow amount calculation unit that calculates the amount of lower pond outflow flowing downstream from the bank breakage position of the lower pond can be provided. With the above configuration, it becomes possible to easily analyze the chain breakage. In particular, a more flexible flow rate calculation can be realized by designating the bank breakage position, calculating the outflow amount from this position, and calculating the inflow amount to the lower pond according to the topography.

Further, according to the plurality of reservoir flood analysis apparatus according to the eleventh embodiment, in addition to the above configuration, the levee position designation unit can be configured to be configurable on a mesh-shaped map displayed on the display unit.

Further, according to the plurality of reservoir flood analysis apparatus according to the twelfth aspect, in addition to any of the above configurations, the levee position designation portion designates the levee position at the position of the discharge portion of the upper pond. Can be configured to. With the above configuration, the bank breakage position designation unit can automatically specify the bank breakage position.

Furthermore, according to the plurality of reservoir flood analysis apparatus according to the thirteenth aspect, in addition to any of the above configurations, the levee breach position is designated as the initial value at the position of the discharge portion in the levee position designation section. In the state, the levee position can be manually adjusted. With the above configuration, it is possible to automatically specify the position of the breach at the position of the discharge part and then adjust it as needed, making it possible to make more flexible settings according to the condition of the lower pond. Become.

Furthermore, according to the plurality of reservoir flood analysis apparatus according to the fourteenth aspect, in addition to any of the above configurations, the display unit displays a hydrograph showing the time change of the outflow amount from the time of the breach of the upper pond. A hydrograph display area for display can be provided.

Furthermore, according to the plurality of reservoir flood analysis apparatus according to the fifteenth embodiment, in addition to any of the above configurations, the ground has information on the height difference of the ground surface and calculates the indefinite flow flowing out from the upper pond. A layer association unit for associating the surface layer with the lower pond layer having information on the full area of the lower pond can be provided.

Furthermore, according to the plurality of reservoir flood analysis apparatus according to the sixteenth aspect, in addition to any of the above configurations, the lower pond inflow calculation unit is among the ground surface layers associated with the layer association unit. The amount of water flowing into the area corresponding to the Shimoike lake surface defined by the Shimoike lake surface setting unit is given as the amount of water flowing into the area corresponding to the Shimoike lake surface in the Shimoike layer, and the Shimoike outflow amount calculation unit in the lower reservoir layers, based on the amount of water stored lower reservoir, calculates the amount of water flowing out of the lower reservoir, the amount of water out flow from the lower reservoir, which is the operation of the ground surface layer, which is specified in advance by bank breach position designator It can be configured to give as the amount of water flowing out from the bank breakage position of the lower pond.

Furthermore, based on the upper pond information input from the pond information input unit, the upper pond outflow calculation unit assumes that the upper pond will collapse at the analysis start time, and is designated by the bank breakage position designation unit. The algorithm for calculating the amount of water flowing out of the upper pond can be used as a model in which the amount of water specified by the following formula flows out, with the location of the bank breakage of the upper pond as the outflow point.

In the above equation, V _max is the total water storage amount [× 10 ⁶ m ³ ], A is the full water area [m ² ], h _b is the flood discharge height [m], and q _l (t) is the outflow amount of the lower pond at time t [ m ³ / s], V _l is the amount of water stored at the time of the Shimoike collapse [× 10 ⁶ m ³ ], H _l is the Shimoike bank height [m] , t is the time from the time when the Shimoike collapsed [sec], and t _l is the Shimoike collapse. The time [sec] and q _{l_in} are the amount of water [m ³ / s] that flowed into the _lower pond after the collapse of the _lower pond.

Furthermore, as an algorithm for calculating the outflow amount of the lower pond, the lower pond outflow calculation unit assumes that if the total overflow head is smaller than the depth of cut of the discharge part, it will flow downstream from the discharge part of the lower pond. The flow rate discharged to
Calculate with, and assume that the desired amount of water stored in the reservoir is at the bottom of the discharge section.
Can be calculated with.
(Q is the flow rate [m ³ / s], C is the flow rate coefficient, B is the flood discharge width [m], h _k is the total overflow head [m], and V _max is the total water storage amount [m ³ ])

Furthermore, the Reservoir Reservoir Calculation Unit assumes that the reservoir will collapse when the total overflow head exceeds the depth of the discharge section, and determines the water storage capacity of the Reservoir.
(A is the full area [m ² ], h _b is the flood discharge height [m])
As an algorithm for calculating the Shimoike outflow amount after the collapse, the Shimoike outflow calculation unit can be switched to calculate the time change of the outflow amount from the Shimoike outflow point to the downstream by the following equation.
(Q _l (t) is the amount of runoff of the lower pond at time t [m ³ / s], V _l is the amount of water stored at the time of the collapse of the lower pond [× 10 ⁶ m ³ ], H _l is the height of the bank of the lower pond [m] , and t is the collapse of the lower pond. Time from the time [sec], t _l is the time when the _lower pond collapsed [sec], q _{l_in} is the amount of water that flowed into the _lower pond after the collapse of the _lower pond [m ³ / s])

Furthermore, according to the plurality of reservoir flood analysis apparatus according 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 boundary condition on the downstream side is further provided. Can be done.

Furthermore, according to the plurality of reservoir flood analysis apparatus according to the eighteenth embodiment, in addition to any of the above configurations, the ground surface layer may be further provided with a rainfall 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 indefinite flow analysis.

Furthermore, a tide level calculation unit for calculating a tide level that fluctuates with time can be provided. With the above configuration, the water level under the condition of the downstream end of the ground surface layer can be changed over time according to the tide level.

Furthermore, according to the plurality of reservoir flood analysis apparatus according 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 pond into the lower pond into the water level of the lower pond is further provided. be able to.

1A to 1G are schematic views showing a flow in which a chain break occurs. It is a functional block diagram which shows the multiple reservoir flood analysis apparatus which concerns on Embodiment 1 of this invention. FIG. 3A is a schematic diagram showing a digital elevation model in which there is no known point of elevation value in the central mesh, and FIG. 3B is a schematic diagram showing a digital elevation model interpolated with respect to FIG. 3A by the elevation interpolation function. It is an image diagram which shows the state which specifies the analysis area which performs the flood analysis of multiple reservoirs on a map. It is an image diagram which shows the state which superposed on FIG. 4 and displayed the state which displayed the 10m mesh digital elevation model. It is an image diagram which shows the ground elevation model creation condition setting screen. It is an image figure which superposed and displayed the ground elevation model of the created 5m mesh on FIG. It is an image diagram which shows the state which superposed on FIG. 7 and displayed the 5m mesh digital elevation model. It is an image diagram which shows the ground elevation model creation condition setting screen. It is an image figure which superposed and displayed the mixed ground elevation model of 5m mesh and 10m mesh on FIG. It is an image diagram which superimposes on FIG. 10 and shows the state which the mesh size of a digital elevation model is distinguished and highlighted. It is a schematic plan view which shows the definition point of a staggered structural grid and an unknown variable. It is a schematic cross-sectional view which shows the case where a water flow overflows unevenness such as embankment. It is a schematic cross-sectional view which shows the case where the dominant cross section appears between meshes. It is a schematic plan view which shows the definition point of the traveling direction and the flow rate of a drainage channel. It is a schematic diagram which shows the state of associating the ground surface layer and the Shimoike layer. It is a schematic diagram which modeled a reservoir. It is a schematic diagram which shows the state of specifying the bank breakage position of the upper pond. It is a schematic diagram which shows how to specify the area of the lake surface of Shimoike. It is a schematic diagram which shows the state of designating the breach position of the lower pond.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments shown below are examples for embodying the technical idea of the present invention, and the present invention is not specified as the following. Further, the present specification does not specify the member shown in the claims as the member of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments are not intended to limit the scope of the present invention to the specific description unless otherwise specified, and are merely described. It's just an example. The size and positional relationship of the members shown in each drawing may be exaggerated to clarify the explanation. Further, in the following description, members having the same or the same quality are shown with the same name and reference numeral, and detailed description thereof will be omitted as appropriate. Further, each element constituting the present invention may be configured such that a plurality of elements are composed of the same member and the plurality of elements are combined with one member, or conversely, the function of one member is performed by the plurality of members. It can also be shared and realized.

The connection between the plurality of reservoir flood analyzers used in the embodiments of the present invention and the computers, printers, external storage devices and other peripheral devices connected thereto for operations, controls, displays, other processes, etc. is, for example. Serial or parallel connections such as IEEE 1394, RS-232x, RS-422, RS-423, RS-485, USB, or electrical or magnetic via networks such as 10BASE-T, 100BASE-TX, 1000BASE-T, etc. Communicate by connecting objectively and optically. The connection is not limited to a physical connection using a wire, and may be a wireless LAN such as IEEE802.1x, a wireless connection using Bluetooth (registered trademark), other radio waves such as NFC, infrared rays, optical communication, or the like. Further, a memory card, a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like can be used as a recording medium for exchanging data and saving settings. In the present specification, the term “multiple reservoir flood analysis device” is used to include not only the main body of the multiple reservoir flood analysis device but also a flood degree real-time prediction system in which peripheral devices such as a computer and an external storage device are combined with the device.
(Embodiment 1)

The plurality of reservoir flood analysis apparatus according to the first embodiment of the present invention performs a flood analysis in which a plurality of reservoirs including an upper pond located on the upstream side and a lower reservoir located on the downstream side of the upper pond are broken in a chain reaction. It is a device for. In this specification, the term "reservoir" is used to include dams, farm ponds and other agricultural reservoirs, regulating reservoirs, rivers, landslide dams, etc. In addition, the collapse of the upper pond is used to include the inflow of earth and sand from the collapse of the hillside.

First, the process in which the chain break occurs will be described with reference to FIGS. 1A to 1G. As shown in FIG. 1A, consider the case where the upper pond RS1 exists above the inclined surface and the lower pond RS2 exists below the upper pond RS1. Both the upper pond RS1 and the lower pond RS2 are held so that water does not overflow on the wall surface on the downstream side. Conversely, when the water level on the lake surface exceeds the height of the wall surface, water overflows, resulting in a so-called collapse state. In order for the upper pond RS1 and the lower pond RS2 to break in a chain, it is necessary that the upper pond RS1 first breaks and then the lower pond RS2 breaks. In the following example, the chain breakage of the upper pond RS1 and the lower pond RS2 will be described for explanation, but the present invention is not limited to the reservoir, but the water accumulated on the upper side such as rivers, waterways, landslide dams, and landslides on the hillside. It can also be applied when a liquid substance such as the above flows into a reservoir or the like accumulated on the lower side. In addition, the multiple reservoir flood analysis device and the multiple reservoir flood analysis program can be used for chain collapse and flood analysis when multiple reservoirs collapse at the same time.

First, considering the collapse of the upper pond RS1, as shown in FIG. 1B, the stored water flows out 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 flows downstream according to the hydrograph calculated using the Costa formula (details will be described later). The Costa formula is a regression formula that calculates the peak flow rate based on the dam height and water storage capacity, which are the dam factors, based on statistical data (see Non-Patent Document 2). However, the present invention does not limit the flow rate calculation method to the Costa method, and other methods such as the Florich method, the cost-effectiveness calculation method for land improvement projects, and arbitrary hydrographs can also be used.

Next, let us consider the collapse of Shimoike RS2. As shown in FIG. 1C, due to the collapse of the upper pond RS1, the water stored in the upper pond RS1 flows into the lower pond RS2. Here, the case where the lower pond RS2 is not full as shown in FIG. 1D and the case where the lower pond RS2 is full as shown in FIG. 1F are considered separately.

When the lower pond RS2 is not full, the water flowing in from the upper pond RS1 is stored in the lower pond RS2 as shown in FIG. 1D, and the water level of the lower pond RS2 rises with the passage of time. Then, when the water level of the lower pond RS2 exceeds the "discharge portion" formed on the wall surface of the lower pond RS2, the water level flows down from the discharge portion to the downstream side of the lower pond RS2 as shown in FIG. 1E. This outflow amount is smaller than that in the case of collapse, and the calculation is calculated from the HQ formula (details will be described later).

On the other hand, when the lower pond RS2 is full as shown in FIG. 1F, the lower pond RS2 collapses and a large amount of water flows out to the downstream side of the lower pond RS2 as shown in FIG. 1G. As the outflow amount in this case, a Costa type or the like is adopted.
(Multiple Reservoir Flood Analysis Device 100)

FIG. 2 shows a plurality of reservoir flood analysis apparatus according to the first embodiment of the present invention. The plurality of reservoir flood analysis device 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 plurality of reservoir flood analysis device 100 can be configured by installing a plurality of reservoir flood analysis programs on a general-purpose or dedicated computer in addition to being configured by dedicated hardware.
(Input unit 10)

The input unit 10 is an input interface for receiving data input from the outside, and functions as a data acquisition unit for acquiring necessary information by accessing an external database, for example, by communicating with an external device or the like. .. 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 pond database under the jurisdiction of the Ministry of Agriculture, Forestry and Fisheries. This makes it possible to perform flood analysis without individually inputting the specifications of the ponds in each area.

The topographical information input unit 12 is a member for acquiring topographical data of the area to be flood-analyzed. As the terrain data input by the terrain information input unit 12, 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, and the like can be used. The multiple reservoir flood analysis device has a ground elevation model creation function that creates a ground elevation model from such topographical data. For example, basic map information (digital elevation model, which is mesh data of elevation) by the Geographical Survey Institute of the Ministry of Land, Infrastructure, Transport and Tourism is input from the topographical information input unit 12, a ground elevation model of the flood analysis target area is created, and displayed on the display unit 40. Can be made to.
(Operation unit 20)

The operation unit 20 is a member for performing various operations and settings for the plurality of reservoir flood analysis devices, and input devices such as a mouse, keyboard, and console can be used. The operation unit 20 realizes the functions of the levee position designation unit 21, the Shimoike lake surface setting unit 22, the layer association unit 23, and the rainfall amount setting unit 24.
(Levee breach position designation section 21)

The levee position designation unit 21 is a member for designating the levee position where water flows out when the levee is breached for one or more levee ponds. As a result, the user can manually specify the levee position via the levee position designation unit 21, or the plurality of reservoir flood analysis devices can automatically specify the levee position.

The levee position designation unit 21 can designate the levee position of one or more levee ponds at the position of the discharge portion of the levee pond. This makes it possible to automatically specify the bank breakage position. Alternatively, the levee position may be manually adjusted while the levee position of the lower pond is specified as the initial value at the position of the discharge portion. In this case, after automatically designating the position of the levee breach to the position of the discharge part, it is possible for the user to adjust it as needed, and it is possible to make more flexible settings according to the state of the lower pond. Become. The user specifies one levee position for one reservoir. In other words, it is not assumed because it is stochastically low to break two banks at the same time in one reservoir.
(Lake Shimoike surface setting section 22)

The Shimoike Lake surface setting unit 22 is a member for designating an area corresponding to the Shimoike lake surface.
(Layer association unit 23)

The layer association unit 23 has information on the height difference of the ground surface including the upper pond, and information on the ground surface layer, which is a two-dimensional indefinite flow layer that calculates the indefinite flow flowing out from the upper pond, and the full area of the lower pond. It is a member for associating with the Shimoike layer, which is a layer of the lake surface having. The layer association unit 23 causes the amount of water flowing into the area corresponding to the Shimoike lake surface defined by the Shimoike lake surface setting unit 22 in the ground surface layer to flow into the area corresponding to the Shimoike lake surface in the Shimoike layer. It is given as the amount of water, and in the lower pond layer, the amount of water flowing out from the lower pond is calculated based on information such as the amount of water stored in the lower pond, and the calculated amount of outflow from the lower pond is calculated in advance by the breach position designation part of the ground surface layer. It can be configured to give as the amount of water flowing out from the breach position 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 setting unit 24 makes it possible to calculate the flow caused by rainfall on the ground surface layer of the two-dimensional indefinite flow analysis. In addition, this rainfall can be changed over time. Therefore, not only the amount of water caused by the breach of the upper pond but also the amount of water caused by rainfall flows into the lower pond. By comparing the results of the analysis considering precipitation and the analysis not considering rainfall, it is possible to examine the effect of precipitation on the levee of the reservoir. Further, the actual rainfall may be used as the rainfall data. The acceptance or rejection of such rainfall data is arbitrary, and analysis can be performed without using the rainfall data. Rainfall data is acquired, for example, by the input unit 10 via a communication network. This makes it easy to update the latest information one by one.

The rainfall data includes the analysis rainfall of the predicted area, the short-term precipitation forecast, and the arbitrarily set rainfall. Here, the analyzed rainfall is the amount of rainfall actually rained within a predetermined time in the past from the current time. The short-term precipitation forecast is the amount of rainfall that is expected to fall within a predetermined time from the current time. In the present embodiment, this predetermined time is set to every hour. For example, the rainfall data distributed by the Meteorological Business Support Center is distributed by updating the analysis rainfall and short-term precipitation forecast every 30 minutes with the predicted rainfall up to 6 hours ahead in the range where the topographical data is divided by a 1 km mesh. Therefore, the input unit 10 sequentially acquires such data and sends it to the calculation unit 30. In addition, the weather data captured by the input unit 10 can be stored in the data storage unit 50.

The collection destination of the rainfall data is not particularly specified. For example, the rainfall data distributed by the Japan Meteorological Agency or the Meteorological Business Support Center may be used, or an original rainfall observation device or the like may be installed to directly collect the rainfall data. Further, the predetermined time is not limited to one hour, and may be a shorter time (for example, 30 minutes) or a longer time (for example, 2 hours).
(Data storage unit 50)

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

Here, the section is a unit in which the predicted area is divided into 5 m squares in a grid pattern. In the first embodiment, a range of 5 m square is further combined in 5 × 5 vertical and horizontal directions to form a 25 m square as one section. The 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 the terrain data of 5 m square, or may store the average value of the terrain data of 25 m square in advance.

The size per section is not specified above. If precise prediction results are required, one section may be smaller than 25 m. For example, one side can be set to 1 m, 2.5 m, 5 m, or any other size. Alternatively, if speeding up of arithmetic processing is prioritized, one section may be enlarged.

For example, detailed ground height data of 5m mesh (for example, basic map information by the Geographical Survey Institute of the Ministry of Land, Infrastructure, Transport and Tourism) and 2m mesh (for example, 2m mesh elevation data by the Japan Map Center) have been published and sold. Such ground elevation data may reflect drainage channels as surface undulations.
(Elevation interpolation function)

In addition, the multiple reservoir flood analysis device can also be provided with an elevation interpolation function for interpolating numerical data of elevation when creating a ground elevation model or the like. The above-mentioned base map information is published as latitude / longitude information, and when converted to plane rectangular coordinates due to the difference in projection method, it is not always the case that there is a known point of elevation value one by one in a 5m x 5m mesh. Absent. For example, in a 5m × 5m mesh, there may be two known points, or there may be no known points. Therefore, it is possible to provide a complementary function for interpolating the average value of the ground elevation values of the neighboring meshes as the estimated ground elevation values of the mesh having no known points for the mesh having no known points. For example, in the digital elevation model shown in FIG. 3A, when there is no known elevation value in the central mesh, the average value of the ground elevation values of the meshes (8 in this case) located around the unknown mesh is used for this mesh. Interpolate as an estimated ground elevation value. Here, the average value is calculated from the sum of the elevation values of the meshes around the unknown mesh. In the example of FIG. 3A, (4.0 + 4.5 + 5.2 + 3.9 + 5.3 + 4.2 + 4.9 + 5.4) / 8 = 4.7, so as shown in FIG. 3B, interpolation is performed for a mesh having no known point. Set the altitude of 4.7.

Further, in order to distinguish between the mesh in which the ground elevation is interpolated and the mesh in which there are known points in the mesh, both may be colored in different colors and displayed on the display unit. For example, by displaying a mesh with known points in blue and a mesh without known points in yellow, the user can visually grasp the credibility of the displayed ground elevation.
(Mixed ground elevation model creation function)

Furthermore, the multiple reservoir flood analysis device can also be provided with a function of creating a mixed ground elevation model in which numerical elevation models of different mesh sizes are mixed.

Of the above-mentioned digital elevation models, the accuracy of the 5m mesh digital elevation model is better than that of the 10m mesh digital elevation model, but it does not cover the whole of Japan. Especially in the mountainous areas, there are places where there is no elevation value of the 5m mesh digital elevation model. On the other hand, the 10m mesh digital elevation model covers the whole of Japan. Therefore, by using this 5m mesh digital elevation model where there is a 5m mesh digital elevation model and using the 10m mesh digital elevation model where there is no 5m mesh digital elevation model, while covering a wide range, A ground elevation model with the highest possible accuracy can be obtained.

Therefore, the multiple reservoir inundation analysis device according to the present embodiment takes in a plurality of numerical elevation models having 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. It has a creation function. In addition, as a ground elevation model setting means for setting conditions when creating a mixed ground elevation model, it has a ground elevation initialization function and an elevation interpolation function.

The ground elevation initialization function is a function for calculating after initializing the ground elevation. When this function is set to ON by the ground elevation model setting means, the already set ground elevation is initialized and the ground elevation data is read. The altitude interpolation function is a function for interpolating the blank of the altitude value described above. When this function is set to ON, the average value of the ground elevations of nearby meshes is automatically interpolated as the ground elevation for meshes with no known points.

When importing multiple ground elevation data with different mesh sizes, these ground elevation initialization functions and elevation interpolation functions are set. Here, an example of creating a mixed ground elevation model by mixing a 5 m mesh digital elevation model and a 10 m mesh digital elevation model will be described.
(When the mesh size of the ground elevation model to be created 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 reading a 10 m mesh digital elevation model, both the ground elevation initialization function and the elevation interpolation function are set to ON to create an elevation model. After that, when reading the 5 m mesh digital elevation model, both the ground elevation initialization function and the elevation interpolation function are set to OFF, and the elevation model is created. As a result, it is possible to create a ground elevation model in which a 10m mesh digital elevation model is placed where there is no 5m mesh digital elevation model.
(When the mesh size of the ground elevation model to be created is 10 m or more)

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

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

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

Here, a procedure for creating a mixed ground elevation model by mixing a 5 m mesh digital elevation model and a 10 m mesh digital elevation model will be described with reference to FIGS. 4 to 11. First, in FIG. 4, an analysis area for performing a plurality of reservoir flood analysis is designated with the map displayed on the display unit 40. In the example of FIG. 4, the analysis region ROI is designated by a square blue frame.

Next, the 10m mesh digital elevation model is read. In the example shown in FIG. 5, the locations where the 10 m mesh digital elevation model exists in the rectangular red frame are displayed together with the data file names on the map displayed on the display unit 40. Here, it can be seen that the analysis region ROI straddles two 10 m mesh digital 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 creation function is executed in this state, a 5 m mesh ground elevation model is created by the 10 m mesh digital elevation models MM10-1 and MM10-2 as shown in FIG. The area where the ground elevation model is created is highlighted and displayed in a manner that distinguishes it from others on the map. In the example of FIG. 7, the 5 m mesh ground elevation model M5M is colored and displayed.

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

In this state, in order to execute the model creation function again, the ground elevation model creation condition is set as shown in FIG. Here, both the ground elevation initialization function and the elevation interpolation function are set to OFF. When the mixed ground elevation model creation function is executed in this state, the 5m mesh is superimposed on the 10m mesh as shown in FIG. 10, and the 5m mesh digital elevation model and the 10m mesh digital elevation model with higher definition than FIG. 7 are displayed. A mixed mixed ground elevation model M5-10M is created.
(Highlight function by mesh)

Further, in this state, it may be provided with a function of highlighting so that the mesh size of the digital elevation model constituting the mixed ground elevation model can be distinguished. For example, as shown in FIG. 11, of 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. As a result, the user can visually grasp the accuracy of the elevation value in which region on the mixed ground elevation model.
(Display unit 40)

The display unit 40 is a member for displaying a map showing an upper pond or a lower pond, displaying a hydrograph, or confirming necessary settings and the like. As the display unit 40, for example, an LCD, an organic EL display, a CRT, or the like can be used. Further, by using a touch panel for the display unit, the operation unit and the display unit can be integrally configured.

The display unit 40 is provided with a hydrograph display area for displaying a hydrograph showing a time change of the outflow amount from the time of the breakage of the upper pond. A hydrograph is a diagram showing the relationship between time and flood water level or flood flow rate.
(Calculation unit 30)

When the water storage amount of the lower pond calculated by the lower pond water storage amount calculation unit reaches the condition that the pre-given lower pond collapses, the calculation unit 30 changes the lower pond outflow amount to the flow rate after the lower pond collapses. This makes it possible to analyze the flooding after the collapse of Shimoike.

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

The upper pond outflow 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.

The lower pond inflow calculation unit 32 calculates the amount of water flowing into the lower pond based on the topographical data acquired by the topographical information input unit 12 among the total outflow amount calculated by the upper pond outflow calculation unit 31. It is a member of.
(Shimoike calculation unit 33)

The lower pond calculation unit 33 is based on the lower pond inflow amount calculated by the lower pond inflow calculation unit 32 and the lower pond information input from the pond information input unit 11, and the water storage amount of this lower pond and the lower pond flowing downstream from this lower pond. It is a member for calculating the outflow amount. The lower pond calculation unit 33 is configured to switch the algorithm for calculating the flow rate between the time when the water depth of the lower pond reaches the depth of the discharge part and the time between the initial flooding and the total head of the overflow.

The lower pond calculation unit 33 realizes the functions of the lower pond water storage amount calculation unit 34 and the lower pond outflow amount calculation unit 36. The lower pond water storage amount calculation unit 34 is a member for calculating the water storage amount of the lower pond based on the lower pond information input from the pond information input unit 11 from the lower pond inflow amount calculated by the lower pond inflow amount calculation unit 32. is there. The lower pond outflow calculation unit 36 is a member for calculating the amount of lower pond runoff that flows downstream from this lower pond.
(Shimoike water level calculation unit 35)

Further, the lower pond water storage amount calculation unit 34 can also realize the function of the lower pond water level calculation unit 35 that calculates the water level of the lower pond. For example, the algorithm switching condition is the timing when the water level of the lower pond reaches the depth of the discharge part. Information on the depth of the discharge portion of the lower pond is acquired in advance by the pond information input unit 11. As a result, the algorithm for calculating the outflow amount of the lower pond can be switched between the time when the water level of the lower pond reaches the initial water level and the total head of the overflow (there is no breach during this period) and the time when the water discharge depth is reached.
(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 boundary condition on the downstream side that fluctuates with time. The downstream end water level may be calculated separately by the user and directly input as a numerical value, or may be calculated. In addition, at the place where the flooded water from the reservoir flows down to the sea surface, the inundation situation by the reservoir at high tide or low tide can be simulated by linking the time change with the tide level at the downstream end. Furthermore, by comparing the analysis results at high tide and low tide, it is possible to examine the effect of tide on the inundation situation. Alternatively, the downstream end water level can be set as the tide level. In this case, the tide level that changes with time is acquired and input. In this way, the downstream end water level input unit 37 can change the water level under the downstream end condition of the ground surface layer over time according to the tide level.
(Water level conversion unit 38)

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

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

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

The following two-dimensional, unsteady shallow water flow continuity equation and equation of motion are used as the basic equations for flooding on the ground surface.
[Continuous]
[Number 1]
[X-direction equation of motion]
[Number 2]
[Y-direction equation of motion]
[Number 3]

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

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

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

Here, the calculation method for special cases will be examined.
(Overflow of embankment, etc.)

First, as shown in FIG. 13, a case of overflowing unevenness such as embankment will be examined. When a band-shaped object such as an embankment or a road exists in this way, the equation of motion cannot be applied as it is. If the water levels on both sides of the strip-shaped object are lower than the height of the crown, the flow flux is set to zero. If this is not the case, the overflow flow flux is calculated by the overflow formula between Honma such as Equations 6 and 7.
[Number 6]
[Number 7]

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

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

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

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

In the above equation, h is the water depth, q is the unit width flow rate in the drainage channel, and is a positive value when the flow direction matches the direction of the coordinate axes, and a negative value when the flow direction is opposite. q _GROUND'is the amount of water that overflows, flows out, or flows into the drainage channel from the drainage channel onto the ground surface. H indicates the water level, and τ indicates the frictional resistance stress. Note that x and y indicated by subscripts indicate that they are equations for drainage channels running in the x and y directions, respectively. The frictional resistance term is expressed by the following equation.
[Number 15]
[Number 16]

In the above equation, R is the diameter depth and n is the Manning roughness coefficient. Further, the subscripts x and y indicate that the equations are for drainage channels running in the x and y directions, respectively.
(3) Reservoir setting 1) Upper pond

As mentioned above, it is assumed that the upper pond will collapse at the analysis start time when the analysis by the multiple reservoir flood analysis device is started. The amount of water according to the hydrograph calculated using the Costa formula flows out to 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 so that the total outflow amount becomes the water storage amount, that is, the number 19 is satisfied.
[Number 17]
[Number 18]
[Number 19]

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

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

The concept of the Shimoike model is shown in FIG. Here, the reservoir is modeled as a rectangular parallelepiped. In addition, a discharge section for discharging a part of the stored water is provided in a part of the downstream side of the reservoir. The discharge part is a flood discharge part such as a reservoir or an overflow part such as a river embankment. For example, a part of a concrete reservoir is formed in a notch shape, and when the water is almost full, the discharge part is passed through. It is configured so that the water in the part can flow down stably. As the shape of the discharge portion, polygonal or rectangular cuts such as a triangular weir or a square weir can be used. In the example of FIG. 17, a rectangular notch is adopted. Further, in the present specification, the cut height of the discharge portion is referred to as the depth of the discharge portion. When the water level of the reservoir exceeds the depth of the discharge part, it can be determined that the water overflows. When the total head of the overflow is smaller than the depth of the discharge part, it is assumed that the head flows downstream from the discharge part, and the head is discharged downstream from the HQ equation of several tens. Further, the initial water storage amount of the reservoir is set to several 21, and the water level is set to the lower end of the discharge portion.
[Number 20]
[Number 21]

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

If the total head of the overflow exceeds the depth of cut of the discharge part, it is assumed that the reservoir will collapse 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, respectively. Here, the number 23 is set so that the total outflow of the upper pond becomes the amount of water stored, that is, the following number 24 is satisfied. In addition, since the inflow to the lower pond is expected even after the collapse of the lower pond, the inflow amount to the lower pond is made to flow out from the lower pond outflow point in addition to the Costa type when the outflow amount changes with time (Equation 23).
[Number 22]
[Number 23]
[Number 24]
[Number 25]

In the above equation, q _l (t) is the amount of water stored in the lower pond at time t [m ³ / s], V _l is the amount of water stored when the lower pond collapses [× 10 ⁶ m ³ ], and H _l is the height of the lower pond bank [m] , t. Is the time [sec] from the time when the Shimoike broke, t _l is the time when the Shimoike broke [sec], and q _{l_in} is the amount of water [m ³ / s] that flowed into the Shimoike after the Shimoike broke.
3. 3. Setting method

Next, the procedure of the setting method when performing the flood analysis at the time of chain breakage is described.
(1 Setting of Ueike collapse position)

First, the upper pond collapse position is set as shown in FIG.
(2 Setting of Lake Shimoike)

Next, as shown in FIG. 19, a mesh corresponding to the lake surface of the lower pond is set. The flood water on the mesh set by this is transferred from the ground surface model to the Shimoike reservoir model. If the water level is higher than the discharge part, it will flow out from the Shimoike collapse position to the ground surface model.
(3 Setting of Shimoike collapse position)

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

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

In the example described above, an example of flood analysis including chain breakage was described for two ponds, the upper pond and the lower pond. However, depending on the situation, there may be multiple lower ponds on the downstream side of the upper pond. In addition, there may be a difference in elevation between a plurality of lower ponds, and for example, three ponds such as an upper pond, an intermediate pond, and a lower pond may be arranged on a slope. In this way, the present invention can be applied even in a mode in which a plurality of lower ponds are connected.

By using the multiple reservoir flood analysis program of the present invention, a computer-readable recording medium and a storage device, a plurality of reservoir flood analysis methods, and a plurality of reservoir flood analysis devices, it is possible to perform flood analysis of a plurality of reservoirs. Inundation analysis can be performed in real time during actual rainfall, and flood patterns can be calculated and estimated in advance. Disaster prevention such as analysis of past inundation mechanisms, prediction of future inundation areas, damage prediction and evacuation route formulation It can be useful for such things.

100 ... Multiple reservoir inundation analyzer 10 ... Input unit 11 ... Pond information input unit 12 ... Topographic information input unit 20 ... Operation unit 21 ... Bank breakage position designation unit 22 ... Shimoike lake surface setting unit 23 ... Layer association unit 24 ... Rainfall setting Unit 30 ... Calculation unit 31 ... Upper pond outflow calculation unit 32 ... Shimoike inflow calculation unit 33 ... Shimoike calculation unit 34 ... Shimoike water storage amount calculation unit 35 ... Shimoike water level calculation unit 36 ... Shimoike outflow 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 ... Shimoike ROI ... Analysis area M5M ... 5m mesh Ground elevation model MM5-1 to MM5- 11 ... 5m mesh digital elevation model MM10-1, MM10-2 ... 10m mesh digital elevation model M5-10M ... mixed ground elevation model H10 ... 10m mesh digital elevation model area H5 ... 5m mesh digital elevation model created area

Claims (19)

It is a multiple reservoir flood analysis program for performing flood analysis in which multiple reservoirs including the upper pond located on the upstream side and the lower pond located on the downstream side of the upper pond collapse in a chain.
A function to acquire information on the upper and lower ponds and topographical data of the area subject to flood analysis,
With the map including the vicinity of the upper pond and the lower pond displayed on the display, let the upper pond and the lower pond specify the location of the breach where water flows out at the time of the breach and the area corresponding to the lake surface of the lower pond. Function and
Based on the acquired information on the upper pond, a function to calculate the amount of water flowing out from the breach position of the upper pond, and
Of the calculated outflow amount, a function to calculate the inflow amount of the lower pond that flows into the lower pond based on the acquired topographical data,
To realize a function of calculating the water level of the lower pond and the amount of the lower pond outflow downstream from the breach position of the lower pond based on the acquired lower pond information from the calculated lower pond inflow amount. Multiple reservoir flood analysis program. The multiple reservoir flood analysis program according to claim 1, further
A ground surface layer that has information on the height difference of the ground surface and calculates the indefinite flow flowing out of the upper pond,
Multiple reservoir flood analysis program to realize a layer association function that associates with the Shimoike layer that has information on the full area of the Shimoike. The multiple reservoir flood analysis program according to claim 2.
The function of calculating the inflow of the lower pond is
The amount of water flowing into the area corresponding to the Shimoike lake surface defined by the Shimoike lake surface setting unit in the associated ground surface layer is determined.
In the Shimoike layer, it includes a function to give and calculate the amount of water flowing into the area corresponding to the Shimoike lake surface.
The function to calculate the amount of Shimoike outflow is
In the lower pond layer, the amount of water flowing out from the lower pond is calculated based on the amount of water stored in the lower pond.
A plurality of reservoir flood analysis programs including a function of giving and calculating the amount of water flowing out from the calculated lower pond as the amount of water flowing out from the breach position of the lower pond specified in advance on the ground surface layer. The multiple reservoir flood analysis program according to any one of claims 1 to 3.
The display unit is a multi-reservoir flood analysis program including a hydrograph display area for displaying a hydrograph showing the time change of the outflow amount from the time of the breach of the upper pond. A computer-readable recording medium or device that stores the program according to any one of claims 1 to 4. This is a multiple reservoir flood analysis method for performing a flood analysis in which multiple reservoirs including the upper pond located on the upstream side and the lower reservoir located on the downstream side of the upper pond collapse in a chain.
The process of acquiring information on the upper and lower ponds and the topographical data of the area subject to flood analysis,
With the map including the vicinity of the upper pond and the lower pond displayed on the display, let the upper pond and the lower pond specify the location of the breach where water flows out at the time of the breach and the area corresponding to the lake surface of the lower pond. Process and
Based on the acquired information on the upper pond, the process of calculating the amount of water flowing out from the breach position of the upper pond, and
Of the calculated outflow amount, the process of calculating the inflow amount of the lower pond that flows into the lower pond based on the acquired topographical data, and
Multiple reservoir flood analysis method including a step of calculating the water level of the lower pond and the amount of the lower pond outflow downstream from the breach position of the lower pond based on the acquired lower pond information from the calculated lower pond inflow. .. The method for analyzing flooding of a plurality of reservoirs according to claim 6.
The process of designating the area corresponding to the lake surface of the lower pond is
A ground surface layer that has information on the height difference of the ground surface and calculates the indefinite flow flowing out of the upper pond,
Multiple reservoir flood analysis methods, including associating with a Shimoike layer that has information on the full area of the Shimoike. The method for analyzing flooding of a plurality of reservoirs according to claim 7.
The step of calculating the inflow amount of the lower pond is
Among the associated ground surface layer, the amount of water flowing into the region corresponding to the lower reservoir lake defined by lower reservoir lake setting unit,
Within the Shimoike layer, it is given as the amount of water flowing into the area corresponding to the Shimoike lake surface and calculated.
The step of calculating the outflow amount of the lower pond is
In the lower pond layer, the amount of water flowing out from the lower pond is calculated based on the amount of water stored in the lower pond.
A method for analyzing flooding of a plurality of reservoirs, which is calculated by giving the calculated amount of water flowing out of the lower pond as the amount of water flowing out from a predetermined breach position of the lower pond on the ground surface layer. The method for analyzing flooding of a plurality of reservoirs according to any one of claims 6 to 8.
In the process of calculating the Shimoike outflow amount, as an algorithm for calculating the Shimoike outflow amount, there is a calculation algorithm before the Shimoike collapse and a calculation algorithm after the Shimoike collapse.
The water level of the lower pond is
From the initial water level to the total head of overflow, the calculation algorithm before the collapse of Shimoike is used.
A multiple reservoir flood analysis method that switches the calculation algorithm for the amount of runoff of the lower pond so that the calculation algorithm after the collapse of the lower pond is used after the depth of the discharge part acquired as the information of the lower pond is reached. It is a multiple reservoir flood analysis device for performing flood analysis in which multiple reservoirs including the upper pond located on the upstream side and the lower reservoir located on the downstream side of the upper pond collapse in a chain.
Pond information input section for acquiring information on the upper pond and information on the lower pond,
A topographical information input unit for acquiring topographical data of the area subject to flood analysis,
A display unit that can display a map including the vicinity of the upper and lower ponds,
A levee position designation part for designating the levee position where water flows out at the time of breach for the upper and lower ponds,
The Shimoike Lake surface setting section for designating the area corresponding to the Shimoike lake surface,
Based on the upper pond information input from the pond information input unit, the upper pond outflow amount calculation unit that calculates the outflow amount of water flowing out from the breach position of the upper pond,
Of the outflow amount calculated by the upper pond outflow calculation unit, the lower pond inflow calculation unit for calculating the inflow amount of the lower pond flowing into the lower pond based on the topographical data acquired by the topographic information input unit. ,
The lower pond water storage amount calculation unit that calculates the water storage amount of the lower pond based on the lower pond information input from the pond information input unit from the lower pond inflow amount calculated by the lower pond inflow amount calculation unit.
The Shimoike outflow calculation unit that calculates the Shimoike outflow amount that flows downstream from the breach position of the Shimoike,
Multiple reservoir flood analysis device equipped with. The plurality of reservoir flood analysis apparatus according to claim 10.
The levee position designation unit is a plurality of reservoir flood analysis device configured so as to be configurable on a mesh-shaped map displayed on the display unit. The plurality of reservoir flood analysis apparatus according to claim 11.
The levee position designation unit is a plurality of reservoir flood analysis apparatus configured to designate the levee position at the position of the discharge portion of the upper pond. The plurality of reservoir flood analysis apparatus according to claim 12.
A plurality of reservoir flood analysis devices configured so that the levee position can be manually adjusted while the levee position is designated as the initial value at the position of the discharge portion in the levee position designation unit. The plurality of reservoir flood analysis apparatus according to any one of claims 10 to 13.
The display unit is a plurality of reservoir flood analysis apparatus including a hydrograph display area for displaying a hydrograph showing a time change of the outflow amount from the time of the breach of the upper pond. The plurality of reservoir flood analysis apparatus according to claim 14, further
A ground surface layer that has information on the height difference of the ground surface and calculates the indefinite flow flowing out of the upper pond,
A multi-reservoir flood analysis device equipped with a layer association unit that associates with the Shimoike layer that has information on the full area of the Shimoike. The plurality of reservoir flood analysis apparatus according to claim 15.
The lower pond inflow calculation unit
Of the ground surface layers associated with the layer association unit, the amount of water flowing into the area corresponding to the Shimoike lake surface defined by the Shimoike lake surface setting unit is determined.
Within the Shimoike layer, give as the amount of water flowing into the area corresponding to the Shimoike lake surface.
The Shimoike outflow calculation unit
In the lower pond layer, the amount of water flowing out from the lower pond is calculated based on the amount of water stored in the lower pond.
A plurality of reservoir flood analysis devices configured to give the calculated amount of water flowing out of the lower pond as the amount of water flowing out from the bank breakage position of the lower pond designated in advance by the bank breakage position designation unit of the ground surface layer. The plurality of reservoir flood analysis apparatus according to any one of claims 10 to 16, further comprising.
A multi-reservoir flood analysis device equipped with a downstream end water level input unit for inputting the water level as a boundary condition on the downstream side. The plurality of reservoir flood analysis apparatus according to claim 15 or 16, further comprising.
A plurality of reservoir flood analysis devices provided with a rainfall setting unit for adding rainfall to the ground surface layer. The plurality of reservoir flood analysis apparatus according to any one of claims 10 to 18, further comprising.
A multi-reservoir flood analysis device equipped with a water level conversion unit that converts the flow rate flowing from the upper pond to the lower pond into the water level of the lower pond.