Rainwater drainage simulation device, rainwater drainage simulation method, and rainwater drainage simulation program

Abstract

To provide a rainwater drainage simulation device, a rainwater drainage simulation method, and a rainwater drainage simulation program that make it possible to perform a rainwater drainage simulation that more accurately reflects the actual situation on a site.SOLUTION: A rainwater drainage simulation device simulates a rainwater drainage capacity of a simulation area including a building and an exterior area. The rainwater drainage simulation device sets an amount of rainfall falling in the simulation area, calculates a first amount of rainwater falling on the building, calculates a second amount of rainwater flowing into the simulation area through trees, calculates a third amount of rainwater falling on a road surface of the exterior area, calculates an amount of rainwater flowing into a rainwater drainage facility arranged in the simulation area using the first amount of rainwater, the second amount of rainwater, and the third amount of rainwater, and calculates a temporal change in the amount of rainwater in the rainwater drainage facility.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a storm water drainage simulation device, a storm water drainage simulation method, and a storm water drainage simulation program. [Background technology]

[0002] There is a known technology for simulating the rainwater drainage capacity within a building site as a measure against flood damage caused by heavy rain or typhoons. For example, Patent Document 1 discloses a flood simulation device that calculates the time change in water level in a simulation target area based on drainage ditch information indicating the position and cross-sectional area of ​​the drainage ditch in the simulation target area, the slope of the drainage ditch, and a set water volume. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-96271 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the field of storm water drainage simulation, there is still room for improvement in terms of setting simulation conditions that more accurately reflect actual site conditions. [Means for solving the problem]

[0005] A rainwater drainage simulation device that solves the above problem is a rainwater drainage simulation device that includes a control unit that simulates the rainwater drainage capacity of a simulation area including a building and an exterior area, in which the control unit sets the amount of rainfall that falls in the simulation area, calculates a first amount of rainwater that falls on the building using building information, calculates a second amount of rainwater that flows into the simulation area via trees using planting information, calculates a third amount of rainwater that falls on the road surface of the exterior area using road surface information, calculates the amount of rainwater that flows into a rainwater drainage facility located in the simulation area using the first, second, and third rainwater amounts, and calculates the change in the amount of rainwater in the rainwater drainage facility over time. Effect of the Invention

[0006] According to the present invention, it is possible to perform a storm water drainage simulation that more accurately reflects the actual conditions on a site. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an explanatory diagram of the configuration of a storm water drainage simulation device according to an embodiment. [Diagram 2] FIG. 2 is an explanatory diagram of a hardware configuration of the embodiment. [Diagram 3] FIG. 3 is an explanatory diagram of a processing procedure according to the embodiment. [Figure 4] FIG. 4 is a schematic diagram of a simulation domain according to an embodiment. [Diagram 5] FIG. 5 is a schematic diagram showing a state in which a simulation domain in the embodiment is divided into meshes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An embodiment of a storm water drainage simulation device, a storm water drainage simulation method, and a storm water drainage simulation program will be described with reference to Fig. 1 to Fig. 5. In this embodiment, a storm water drainage simulation is performed in a simulation area that reflects the state of a building and its surrounding exterior structure, thereby supporting the evaluation of the storm water drainage capacity within a site.

[0009] [Overall configuration] As shown in Fig. 1, the storm water drainage simulation device 1 includes a user terminal 10 and a server 20. The user terminal 10 is a computer terminal used by a user. The server 20 is a computer system that performs a storm water drainage simulation. The user terminal 10 and the server 20 are connected to each other via a network line.

[0010] The user terminal 10, for example, accepts input of various information for the storm water drainage simulation from a user and transmits the input information to the server 20. In addition, the user terminal 10 displays, for example, a simulation result of the storm water drainage simulation.

[0011] The server 20 includes a control unit 30. The control unit 30 executes each process in the storm water drainage simulation. The control unit 30 executes a storm water drainage simulation program to function as a simulation area creation unit 31, a rainfall setting unit 32, a first storm water volume calculation unit 33, a second storm water volume calculation unit 34, a third storm water volume calculation unit 35, a storm water inflow simulation unit 36, a fourth storm water volume calculation unit 37, and a determination unit 38. Each unit of the control unit 30 will be described in detail later.

[0012] The server 20 includes a storage unit 40. The storage unit 40 stores a storm water drainage simulation program and various information. The storage unit 40 includes a BIM information storage unit 41 and a judgment criteria storage unit 42 as a database for storing various information for performing a storm water drainage simulation. Details of each unit of the storage unit 40 will be described later.

[0013] [Hardware configuration] 2, a hardware configuration of an information processing device H10 constituting the user terminal 10 and the server 20 will be described. The information processing device H10 includes a communication device H11, an input device H12, a display device H13, a storage device H14, and a processor H15. Note that this hardware configuration is an example, and it may be realized by other hardware.

[0014] The communication device H11 is an interface that executes data transmission and reception by establishing a communication path with other devices, and is, for example, a network interface or a wireless interface.

[0015] The input device H12 is a device such as a mouse or a keyboard that accepts input of various information. The display device H13 is a display or the like that displays various information. The storage device H14 is a storage device that stores data and various programs for executing various functions of the user terminal 10 and the server 20. Examples of the storage device H14 include a ROM, a RAM, and a hard disk.

[0016] The processor H15 uses the programs and data stored in the storage device H14 to control each process in the user terminal 10 and the server 20. Examples of the processor H15 include a CPU and an MPU. The processor H15 executes various processes for each process by expanding a program stored in a ROM or the like into a RAM.

[0017] The processor H15 is not limited to a processor that performs software processing for all the processes it executes. For example, the processor H15 may include a dedicated hardware circuit (e.g., an application specific integrated circuit (ASIC)) that performs hardware processing for at least a part of the processes it executes. That is, the processor H15 may be configured as follows:

[0018] [1] One or more processors that operate according to a computer program (software). [2] One or more dedicated hardware circuits that perform at least some of the various processes [3] Circuits that include combinations of these The processor includes a CPU and memory, such as RAM and ROM. The memory stores program codes or instructions configured to cause the CPU to execute processes. Memory, i.e., computer-readable media, includes any available media that can be accessed by a general-purpose or special-purpose computer.

[0019] Simulation Domain The simulation domain 101 will be described with reference to FIGS. 4, a simulation domain 101 is placed in a virtual modeling space 100. The simulation domain 101 is a three-dimensional model that reflects the state of a site on which a building 102 is placed. This three-dimensional model is generated using BIM (Building Information Modeling), as described later.

[0020] An outer edge 101E of the simulation domain 101 represents the boundary line of the site on which the building 102 is located. In other words, the simulation domain 101 includes the entire site on which the building 102 is located. Outside the simulation domain 101 in the modeling space 100, a sewer main 120 located outside the site is located.

[0021] The simulation area 101 includes a building 102 and an exterior area 103. The exterior area 103 is the area around the building 102 within the site, and is the area other than the building 102 in the simulation area 101. The exterior area 103 includes a paved area 104 and a planted area 105. In FIG. 4, the building 102 is hatched, and the outlines of the paved area 104 and the planted area 105 that constitute the exterior area 103 are indicated by thick lines.

[0022] The paved area 104 is a portion of the exterior area 103 where the road surface is paved with hardscape such as concrete, asphalt, stone, gravel, resin material, etc. The paved area 104 includes a plurality of layers including, for example, a surface layer, a roadbed, and a roadbed.

[0023] The planting area 105 is a portion in the exterior area 103 where plantings including trees 106 and soil are provided. In addition to the trees 106, the planting area 105 may also be provided with softscapes such as grass and flowers.

[0024] A rainwater infiltration facility 107 is provided in the ground of the paved area 104. The rainwater infiltration facility 107 gradually infiltrates collected rainwater into the ground. As an example, the rainwater infiltration facility 107 includes a plurality of infiltration inlets 108 and a plurality of infiltration pipes 109 connecting them. The infiltration inlets 108 collect rainwater flowing on the surrounding ground surface. The infiltration pipes 109 connect two infiltration inlets 108 underground. The infiltration pipes 109 are set to have an arbitrary gradient so that a difference in height occurs between the end of one infiltration inlet 108 side and the end of the other infiltration inlet 108 side. The rainwater infiltration facility 107 arranged in the simulation area 101 may be a facility arranged on the ground, such as a rain garden having a structure that temporarily stores rainwater that falls on the ground and gradually infiltrates it into the ground.

[0025] The rainwater infiltration facility 107 is connected to a sewer main pipe 120. For example, a drain pipe 110 is disposed underground in the paved area 104, connecting the infiltration basin 108 and the sewer main pipe 120. When the amount of rainwater in the rainwater infiltration facility 107 becomes greater than the infiltration capacity of the rainwater infiltration facility 107, the rainwater in the rainwater infiltration facility 107 is drained through the drain pipe 110 to the sewer main pipe 120. In FIG. 4, the drain pipe 110 is indicated by an arrow.

[0026] A rainwater storage facility 111 is provided in the paved area 104. The rainwater storage facility 111 temporarily stores collected rainwater. As an example, the rainwater storage facility 111 is a rainwater storage tank buried underground. Rainwater collected in a drainage ditch 112 arranged in the paved area 104 is supplied to the rainwater storage facility 111. The rainwater storage facility 111 arranged in the simulation area 101 may be a water source including a pond or a biotope, a rainwater storage tank, or a rainwater inlet.

[0027] An overflow pipe 113 connecting the rainwater storage facility 111 and the sewer main pipe 120 may be provided underground in the paved area 104. When the amount of rainwater in the rainwater storage facility 111 exceeds the storage capacity of the rainwater storage facility 111, the rainwater in the rainwater storage facility 111 is drained into the sewer main pipe 120 through the overflow pipe 113. Note that the overflow pipe 113 is indicated by an arrow in FIG. 4. The rainwater storage facility 111 may also have a pipe for gradually draining the stored rainwater into the sewer main pipe 120.

[0028] Rainwater that falls on the building 102 is discharged to the rainwater infiltration facility 107 and the rainwater storage facility 111. For example, as shown by arrows in FIG. 4, rainwater that falls on the roof, exterior wall, or balcony of the building 102 flows into the rainwater infiltration facility 107 and the rainwater storage facility 111 via a roof drain or underground piping. The rainwater infiltration facility 107 and the rainwater storage facility 111 may be disposed in an underground portion directly below the building 102. In other words, rainwater that falls on the building 102 or the exterior area 103 may be discharged to the rainwater infiltration facility 107 and the rainwater storage facility 111 disposed directly below the building 102.

[0029] As shown in Fig. 5, the simulation domain 101 is configured as a mesh model divided into a plurality of meshes 101M. Each mesh 101M is configured as a polyhedron such as a tetrahedron or a hexahedron having vertices, edges (sides), and faces. Fig. 5 shows an enlarged view of a state in which a building 102, a paved area 104 in which a rainwater infiltration facility 107 is arranged, and a planted area 105 in which trees 106 are arranged, configured as meshes 101M. For example, the size of one mesh 101M is preferably configured so that one side is between 10 cm and 5 m.

[0030] [Storage] Returning to FIG. 1, each component of the storage unit 40 will be described. 1, the BIM information storage unit 41 stores BIM information of each component (object) placed in the modeling space 100 and the location (coordinates) of each object in the modeling space 100. The BIM information is data in which attribute information is added to a three-dimensional model.

[0031] For example, the BIM information storage unit 41 stores BIM information of the building 102. In the BIM information of the building 102, attribute information such as the material of the components and surface properties such as surface friction according to the material is added to three-dimensional models of the roof, gutters, balconies, exterior walls, and roof drains and pipes that constitute the storm water drainage system of the building 102. The three-dimensional shape information of each part of the building 102, the arrangement within the simulation area 101, and the attribute information of each part of the building 102 stored in the BIM information storage unit 41 are examples of building information.

[0032] For example, the BIM information storage unit 41 stores the BIM information of the pavement area 104. In the BIM information of the pavement area 104, the three-dimensional model of each layer constituting the pavement area 104 is given attribute information such as the material constituting each layer, the permeability coefficient and saturated permeability coefficient according to the material, the permeability of the soil located deeper than the roadbed, and the construction conditions. In addition, the three-dimensional model of the surface layer constituting the road surface of the pavement area 104 is given attribute information such as surface properties such as surface friction according to the material constituting the surface layer. For example, in the BIM information of the pavement area 104, the values ​​of the permeability coefficient and the like are set to be different between the case where the material paving the road surface is a permeable or water-pumping block and the case where the material paving the road surface is a non-permeable block. The three-dimensional shape information of the pavement area 104 stored in the BIM information storage unit 41, the arrangement in the simulation 101 area, and the attribute information of the pavement area 104 are examples of road surface information.

[0033] Furthermore, an example of the construction conditions of the paved area 104 is the rolling conditions when performing paving work on the paved area 104. For example, in the BIM information of the paved area 104, part of the attribute information assigned to the three-dimensional model constituting the paved area 104 may be stored as a function with parameters of the rolling conditions as variables. For example, the permeability coefficient as the attribute information assigned to the three-dimensional model constituting the paved area 104 takes a value according to the parameters of the rolling conditions input by the user.

[0034] For example, the BIM information storage unit 41 stores BIM information of the planting area 105. In the BIM information of the planting area 105, attribute information such as the soil quality, the infiltration coefficient and saturated hydraulic conductivity corresponding to the soil quality, and surface properties such as the surface friction of the road surface is added to a three-dimensional model of the soil of the planting area 105. The three-dimensional shape information of the soil of the planting area 105, its arrangement within the simulation 101 area, and the attribute information of the soil of the planting area 105 stored in the BIM information storage unit 41 are examples of road surface information.

[0035] In the BIM information of the planting area 105, the type (tree species) of the tree 106 and attribute information such as the crown projection area, the crown interception ratio, and the amount of evaporation according to the tree species are added to the three-dimensional model of the tree 106. The three-dimensional shape information such as the size of the tree 106 stored in the BIM information storage unit 41, the arrangement within the simulation 101 area, and the attribute information of the tree 106 are examples of planting information.

[0036] The crown projection area refers to the area of ​​the crown projection surface when the crown is projected directly upward from the ground surface. The crown interception ratio refers to the ratio of the amount of rainwater that falls within the crown projection surface of the tree 106 that is blocked from reaching the ground surface by the crown. The crown interception ratio is set to a value between 0.05 and 0.5 depending on the type of tree 106. The evaporation amount refers to the amount of rainwater that is intercepted by the tree 106 and that evaporates from the tree 106 per unit time. The crown interception ratio is a value obtained by subtracting the sum of the crown throughfall and stem flow rate from the amount of rainfall within the crown projection surface of the tree 106, and dividing the result by the amount of rainfall within the crown projection surface of the tree 106. The crown throughfall refers to the total amount of direct rainfall that reaches the ground surface directly by passing through the gaps between the branches and leaves, and drip rainfall that drips to the ground surface after being captured by the branches and leaves. The stem flow rate refers to the amount of rainfall that flows down to the ground surface along the surface of the trunk.

[0037] The three-dimensional model of the tree 106 may be provided with growth prediction information including prediction data of a change over time in the size of the tree 106 accompanying growth as attribute information. The three-dimensional model of the tree 106 may be provided with pruning plan information including prediction data of a change over time in the size of the tree 106 accompanying pruning as attribute information. The size of the tree 106 here includes, for example, the crown projection area, the height (thickness) of the crown, the number and size of the branches and leaves that make up the crown, the thickness and height of the trunk, and the like. In this case, the attribute information that depends on the size of the tree 106 may be stored as a function with the value of the prediction data as a variable. For example, the crown projection area is calculated according to the value of the prediction data corresponding to the date and time input by the user.

[0038] For example, the BIM information storage unit 41 stores BIM information of the rainwater drainage facilities arranged in the simulation area 101. The rainwater drainage facilities include, for example, rainwater storage and infiltration facilities, water collection facilities for collecting rainwater in the rainwater storage and infiltration facilities, and discharge facilities for discharging rainwater from the rainwater storage and infiltration facilities to the sewer main pipe 120. The rainwater storage and infiltration facilities are, for example, the rainwater infiltration facilities 107 and the rainwater storage facilities 111. The rainwater storage and infiltration facilities may be facilities such as rain gardens that temporarily store collected rainwater and gradually infiltrate the stored rainwater into the ground. The water collection facilities are, for example, drainage ditches 112, gratings, manholes, and pipes connecting these to the rainwater storage and infiltration facilities. The discharge facilities are, for example, pipes such as the drain pipe 110 and the overflow pipe 113 that connect the rainwater storage and infiltration facilities to the sewer main pipe 120.

[0039] For example, in the BIM information of the infiltration inlet 108 and the infiltration pipe 109, the material of the infiltration inlet 108 and the infiltration pipe 109, the infiltration capacity (infiltration coefficient) corresponding to the material, the roughness coefficient of the infiltration pipe 109, etc. are given as attribute information. In the BIM information of the water collection facility, the material of the water collection facility, the roughness coefficient of the piping corresponding to the material, and the water collection capacity per unit time are given as attribute information. In the BIM information of the drainage facility, the material of the drainage facility, the roughness coefficient of the piping corresponding to the material, etc. are given as attribute information.

[0040] The rainwater infiltration facility 107 is placed at a predetermined distance (e.g., 30 cm) from other underground buried objects. Therefore, it is preferable that the BIM information storage unit 41 includes, for example, BIM information of drainage facilities other than the rainwater drainage facility, such as piping for draining sewage from the building 102, and information on their locations (coordinates). The BIM information storage unit 41 also stores BIM information of sewers located outside the simulation area 101, such as the sewer main 120.

[0041] The judgment criteria storage unit 42 stores judgment criteria for judging whether the storm water drainage plan for the simulation area 101 can handle the simulated amount of rainfall based on the simulation results. The storm water drainage plan refers to a plan for how to drain the rainwater that has fallen on the site. For example, the storm water drainage plan refers to a plan for appropriately draining the rainwater that has fallen on the simulation area 101 to the sewer main 120, such as the layout, number, size, infiltration capacity, and storage capacity of rainwater storage and infiltration facilities, as well as a plan for a rainwater flow path composed of the slope of the road surface and roof, piping, etc.

[0042] For example, the judgment criterion storage unit 42 may store, as the judgment criterion, the amount of watershed countermeasures required in the simulation domain 101. The amount of watershed countermeasures may be, for example, the storage volume (m 3 / ha), or the infiltration intensity (mm / hr) of the rainwater infiltration facilities 107 in the simulation area 101. The infiltration intensity refers to the sum of the volumes of rainwater infiltrating from each rainwater infiltration facility 107 per unit time divided by the catchment area (the entire area of ​​the simulation area 101).

[0043] For example, the judgment criterion storage unit 42 may store the permissible discharge amount (m 3 / s) may be stored. The allowable discharge amount refers to the amount of rainwater that can be discharged from the simulation area 101 to the external sewer main 120 per unit time. The allowable discharge amount is set according to the area of ​​the simulation area 101.

[0044] For example, the judgment criterion storage unit 42 may store an upper limit value of the flow rate of rainwater for each part in the storm water drainage facility as the judgment criterion. For example, the judgment criterion storage unit 42 may store an upper limit value of the water level of the rain water storage facility 111 (including a pond, a biotope, etc.) as the judgment criterion. The judgment criterion stored in the judgment criterion storage unit 42 may be stored in the BIM information storage unit 41 as attribute information added to the BIM information of the storm water drainage facility.

[0045] [Rainwater drainage simulation] The storm water drainage simulation method will be described with reference to Fig. 3. The storm water drainage simulation includes processes of steps S1 to S8. The processes of steps S1 to S8 are executed by each part of the control unit 30.

[0046] [Step S1] First, the simulation domain creation unit 31 creates a simulation domain 101 in the modeling space 100 based on the BIM information stored in the BIM information storage unit 41. Then, the simulation domain creation unit 31 divides the simulation domain 101 into a plurality of meshes 101M (step S1).

[0047] It should be noted that the three-dimensional information of the simulation domain 101, which has been divided into meshes 101M in advance, may be directly stored in the storage unit 40, so that the simulation domain creation unit 31 that performs the process of step S1 may be omitted.

[0048] [Step S2] Next, the rainfall setting unit 32 sets the amount of rainfall per given time falling in the simulation area 101 (step S2). The amount of rainfall may be input by the user from the user terminal 10, or an arbitrary value stored in the storage unit 40 may be set.

[0049] The amount of rainfall is, for example, the maximum amount of rainfall per hour expected in a site reproduced as the simulation domain 101. Alternatively, the amount of rainfall may be the maximum amount of rainfall per 10 minutes expected in a site reproduced as the simulation domain 101. Alternatively, the amount of rainfall may be the average value of the maximum amount of rainfall per hour expected in a site reproduced as the simulation domain 101 and a value obtained by converting the maximum amount of rainfall per 10 minutes into an amount of rainfall per hour.

[0050] [Step S3] Next, the first rainwater amount calculation unit 33 uses the building information to calculate a first amount of rainwater falling on the building 102 per unit time in accordance with the set value of the amount of rainfall (step S3).

[0051] As an example, the first rainwater amount calculation unit 33 calculates the first amount of rainwater falling per unit time on each mesh 101M constituting the roof of the building 102. As an example, the first rainwater amount calculation unit 33 calculates the first amount of rainwater falling per unit time on each mesh 101M constituting the outer wall of the building 102.

[0052] [Step S4] Next, the second rainwater amount calculation unit 34 uses the planting information to calculate the second amount of rainwater flowing into the simulation domain 101 via the trees 106 per unit time in accordance with the set value of the amount of rainfall (step S4).

[0053] For example, the second rainwater volume calculation unit 34 uses the crown projection area and the crown interception ratio of the trees 106 placed in the exterior area 103 to calculate the second rainwater volume that reaches the exterior area 103 from the rain that falls on the crown projection surface of each tree 106 per unit time.

[0054] The second rainwater amount varies with the size of the crown of the tree 106. For example, the larger the crown, the larger the crown projection area. Therefore, it is preferable that the second rainwater amount calculation unit 34 calculates the second rainwater amount using the crown projection area corrected using the growth prediction information and pruning plan information. For example, the user may input an arbitrary simulation date and time, and the second rainwater amount calculation unit 34 may calculate the second rainwater amount corrected according to the crown projection area at the simulation date and time using the growth prediction information and pruning plan information.

[0055] [Step S5] Next, the third rainwater amount calculation unit 35 uses the road surface information to calculate a third amount of rainwater falling on the road surface of the exterior structure area 103 per unit time in accordance with the set value of the amount of rainfall (step S5).

[0056] For example, the third rainwater amount calculation unit 35 calculates the third rainwater amount falling per unit time on each mesh 101M constituting the road surface of the external structure area 103. In addition, in step S5, in a portion of the mesh 101M constituting the road surface of the external structure area 103 that overlaps with a crown projection surface of the tree 106, the calculation is performed assuming that the rainwater is blocked by the tree 106.

[0057] [Step S6] The rainwater inflow simulation unit 36 ​​performs a rainwater inflow simulation to calculate the amount of rainwater inflowing into the rainwater drainage equipment arranged in the simulation area 101 using the first rainwater volume, the second rainwater volume, and the third rainwater volume (step S6).

[0058] The rainwater inflow simulation unit 36 ​​calculates the amount of rainwater that flows into the rainwater drainage facility for each time step having a predetermined interval. For example, in the rainwater inflow simulation, the amount of rainwater that falls on each mesh 101M of the simulation area 101 is calculated for each time step using the first rainwater amount, the second rainwater amount, and the third rainwater amount. In addition, the amount of rainwater that flows into each mesh 101M from the other adjacent meshes 101M and the amount of rainwater that flows out from each mesh 101M to the other adjacent meshes 101M are calculated for each time step. Then, the amount of rainwater that flows into the mesh 101M in which the water collection facility for the rainwater drainage facility is provided is calculated for each time step, thereby calculating the amount of rainwater that flows into the rainwater drainage facility arranged in the simulation area 101. That is, in each mesh 101M, at a certain time step t n-1 The state at the next time step t is calculated by adding the amount of rainfall and the amount of rainwater inflow and outflow between the neighboring mesh 101M as the time-dependent change at the time step interval Δt. n The rainwater inflow simulation unit 36 ​​performs the above-mentioned process for each time step during the period from the start to the end of the simulation.

[0059] Here, an example of the rainwater inflow simulation will be described with reference to Fig. 5. The rainwater inflow simulation unit 36 ​​executes the following calculation process for each time step. Note that the thick arrows shown in Fig. 5 indicate the time step t n-1 to the next time step t n 5 shows a schematic diagram of the rainwater flow path in the simulation domain 101. In FIG. 5, the rainwater flows from each mesh 101M toward the infiltration tank 108 located in the mesh 101M below the water.

[0060] Arrow A1 represents a rainwater flow path that flows from the roof or balcony of the building 102 through a roof drain into the infiltration tank 108. The rainwater inflow simulation unit 36 ​​determines the amount of rainwater that flows into the infiltration tank 108 for each time step in the rainwater flow path of arrow A1, using the first rainwater amount calculated in step S3.

[0061] In detail, the rainwater inflow simulation unit 36 ​​uses information such as the slope of the roof, the arrangement of the roof drains, the pipe diameter, and the slope, and calculates the rainwater inflow at a certain time step t n-1 to the next time step t n The amount of rainwater discharged from the roof drain to the infiltration inlet 108 during the period from the roof drain to the infiltration inlet 108 is calculated. For example, a relational expression or a table for calculating the amount of rainwater discharged from the roof drain to the infiltration inlet 108 according to the amount of rainwater flowing into the mesh 101M in which the roof drain is located for each time step may be assigned to the roof drain as attribute information.

[0062] The arrow A2 represents a rainwater flow path that flows along the exterior wall of the building 102 and flows into the mesh 101M adjacent to the building 102 in the exterior area 103. The rainwater inflow simulation unit 36 ​​calculates the rainwater inflow amount of the rainwater flow path of the arrow A2 at time step t n-1 From time step t n The amount of rainwater that flows into the building 102 and the adjacent mesh 101M from the exterior wall is determined during this period.

[0063] For example, the arrow A3 represents a rainwater flow path that flows into the mesh 101M that constitutes the simulation domain 101 (here, the planting domain 105) via the tree 106. The rainwater inflow simulation unit 36 ​​calculates the rainwater flow path of the arrow A3 at time step t n-1 From time step t n The amount of rainwater that flows from the tree 106 to the mesh 101M adjacent to the tree 106 during this period is determined.

[0064] Arrow A4 indicates a rainwater flow path between adjacent meshes 101M that make up the road surface of the exterior area 103, flowing from a mesh 101M with a high gradient (above water side) to a mesh 101M with a low gradient (below water side).

[0065] In this case, first, the rainwater inflow simulation unit 36 ​​calculates the time step t n-1 From time step t n For example, the rainwater inflow simulation unit 36 ​​calculates the amount of rainwater flowing into the mesh 101M on the water side during the time step t n-1 From time step t n The amount of rainfall that falls on mesh 101M on the water surface during the time step t n-1 From time step t n During the time period up to t, the amount of rainwater flowing into the mesh 101M above the water is calculated from the mesh 101M above the water, which includes the buildings 102, trees 106, and the road surface of the exterior area 103. The sum of these is n-1 From time step t n The amount of rainwater that flows into mesh 101M on the water surface during the time step t n-1 The amount of rainwater present in mesh 101M above the water at time step t n-1 From time step t n The amount of rainwater flowing into mesh 101M above the water is added up.

[0066] Next, the rainwater inflow simulation unit 36 ​​calculates the infiltration coefficient of the mesh 101M on the water surface at a time step t n-1 From time step t n The amount of rainwater that infiltrates into the ground from the water surface mesh 101M per unit time is calculated during the time step t n-1 From time step t n During the time step t n-1 From time step t n The amount of rainwater that can flow from mesh 101M above the water to mesh 101M below the water is calculated.

[0067] Furthermore, the rainwater inflow simulation unit 36 ​​performs corrections on the rainwater that can flow into the mesh 101M below the water in accordance with the gradient between the meshes 101M, the surface properties (surface friction) of each material, and the like. n-1 From time step t n The amount of rainwater flowing from the mesh 101M above the water to the mesh 101M below the water is determined. The rainwater inflow simulation unit 36 ​​may correct parameters such as the permeability coefficient and surface properties according to the construction conditions (e.g., compaction conditions) during road construction.

[0068] The rainwater inflow simulation unit 36 ​​performs the above process for each mesh 101M, and calculates the time step t n-1 From time step t n The rainwater inflow simulation unit 36 ​​calculates the amount of rainwater flowing into the mesh 101M in which the water collection facility to the rainwater drainage facility is installed during the time step t n-1 From time step t n The amount of rainwater flowing from the drainage facility to the storm water drainage facility during this period is calculated.

[0069] From the above, the rainwater inflow simulation unit 36 ​​calculates the amount of rainwater that flows directly from the building 102 into the rainwater drainage equipment arranged in the external structure area 103, as indicated by arrow A1. The rainwater inflow simulation unit 36 ​​also calculates the amount of rainwater that flows into the rainwater drainage equipment arranged in the external structure area 103 via the road surface of the external structure area 103, as indicated by arrows A2 to A4. The rainwater inflow simulation unit 36 ​​performs the above-mentioned process for each time step during the period from the start to the end of the simulation, thereby calculating the change over time for each time step in the amount of rainwater that flows into the rainwater drainage equipment.

[0070] [Step S7] The fourth rainwater amount calculation unit 37 calculates the change in the amount of rainwater in the stormwater drainage facility over time for each time step based on the change in the amount of rainwater flowing into the stormwater drainage facility over time for each time step calculated in step S6 (step S7). The change in the amount of rainwater in the stormwater drainage facility over time calculated by the fourth rainwater amount calculation unit 37 is displayed on the user terminal 10 in the form of, for example, animation or graph.

[0071] The fourth rainwater volume calculation unit 37 calculates the time-dependent change in the flow velocity of rainwater flowing through any cross section in the pipe constituting the rainwater drainage facility for each time step based on, for example, the time-dependent change in the amount of rainwater flowing into the rainwater drainage facility. The flow velocity of rainwater flowing through the pipe can be calculated, for example, by Manning's formula. The BIM information storage unit 41 stores, as attribute data, parameters required for calculating the flow rate and flow velocity using Manning's formula for each pipe. When calculating the flow rate and flow velocity of rainwater flowing through the rainwater infiltration facility 107, the calculation is performed assuming that a part of the rainwater flowing through the rainwater infiltration facility 107 infiltrates into the ground according to the infiltration capacity of the infiltration basin 108 and the infiltration pipe 109.

[0072] The fourth rainwater volume calculation unit 37 calculates the change over time of the volume of rainwater stored in the rainwater storage facility 111 constituting the rainwater drainage facility for each time step based on, for example, the change over time of the amount of rainwater flowing into the rainwater drainage facility. The fourth rainwater volume calculation unit 37 calculates the change over time of the volume of rainwater drained into the sewer main 120 through the rainwater drainage facility based on, for example, the change over time of the amount of rainwater flowing into the rainwater drainage facility.

[0073] [Step S8] The determination unit 38 determines whether the storm water drainage plan in the simulation area 101 can accommodate the rainfall setting value set in step S2 based on the change over time in the amount of rainwater in the storm water drainage facility calculated in step S7 (step S8). The determination result by the determination unit 38 is displayed on the user terminal 10.

[0074] For example, based on the result of step S7, when the upper limit of the flow rate of rainwater in the rainwater drainage facility is exceeded or when the upper limit of the water level of the rainwater storage facility 111 is exceeded, the determination unit 38 displays on the user terminal 10 that the rainwater drainage plan in the simulated state cannot cope with the situation. Also, for example, when a backflow occurs in which rainwater flows from the downstream side to the upstream side with respect to the water gradient set in the pipes constituting the rainwater drainage facility, the determination unit 38 displays on the user terminal 10 that the rainwater drainage plan in the simulated state cannot cope with the situation. At this time, the location where the abnormality occurred in the rainwater drainage facility is highlighted, for example, and displayed on the user terminal 10 so that the user can identify the location.

[0075] For example, based on the result of step S7, when the amount of rainwater discharged from the rainwater drainage facility to the sewer main 120 exceeds the allowable discharge amount, the determination unit 38 displays on the user terminal 10 a message that the simulated rainwater drainage plan cannot cope with the situation. The rainwater drainage simulation is completed by the processes of steps S1 to S8.

[0076] [Effects of the embodiment] (1) In the above embodiment, the first amount of rainwater falling on the building 102, the second amount of rainwater flowing into the simulation area 101 via the trees 106, and the third amount of rainwater falling directly on the road surface of the exterior area 103 are reflected in the rainwater drainage simulation. This makes it possible to perform a rainwater drainage simulation that more accurately reflects the actual conditions on the site.

[0077] (2) In step S4, the second rainwater amount calculation unit 34 can calculate the second rainwater amount using growth prediction information of the tree 106. In this case, the second rainwater amount can be calculated according to the growth state of the crown of the tree 106 at any simulation date and time.

[0078] (3) In step S4, the second rainwater amount calculation unit 34 can calculate the second rainwater amount by using pruning plan information for the tree 106. In this case, the second rainwater amount can be calculated according to the pruning state of the crown of the tree 106 at any simulation date and time.

[0079] (4) In step S8, the determination unit 38 determines whether the storm water drainage plan in the simulation domain 101 can cope with the change over time in the amount of storm water in the storm water drainage facility, and outputs the result to the user terminal 10. In this way, the storm water drainage simulation device 1 can be used to evaluate the storm water drainage capacity of the simulation domain 101 in which the building 102 is arranged.

[0080] (5) In step S6, the rainwater inflow simulation unit 36 ​​can calculate the amount of rainwater flowing from the mesh 101M above the water to the mesh 101M below the water, depending on the type of material that constitutes the road surface of the external structure area 103. In this case, the difference in the amount of rainwater flowing into the rainwater drainage facility due to the type of material that constitutes the road surface of the external structure area 103 can be reflected in the rainwater drainage simulation.

[0081] (6) In step S6, the rainwater inflow simulation unit 36 ​​can calculate the amount of rainwater flowing from the mesh 101M above the water to the mesh 101M below the water, depending on the construction conditions of the road surface of the external structure area 103. In this case, the difference in the amount of rainwater flowing into the rainwater drainage facility due to the construction conditions of the road surface of the external structure area 103 can be reflected in the rainwater drainage simulation.

[0082] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0083] In step S4, the second rainwater volume calculation unit 34 may calculate the second rainwater volume using the crown projection area and the crown interception ratio determined for each type of tree 106, without relying on the growth prediction information or pruning plan information of the tree 106.

[0084] In step S4, when the crown projection surface of the tree 106 spans multiple meshes 101M, the meshes 101M overlapping with the crown projection surface may be configured to receive a second rainwater volume equivalent to the crown throughfall volume. Also, the meshes 101M overlapping with the trunks of the trees 106 may be configured to receive a second rainwater volume equivalent to the trunk flow volume.

[0085] The process of step S8 may be omitted. Even in this case, the user can evaluate the storm water drainage capacity of the simulation area 101 based on the change over time in the amount of storm water in the storm water drainage facility calculated in step S7.

[0086] In step S6, the rainwater inflow simulation unit 36 ​​may calculate the amount of rainwater flowing from above the water to the mesh 101M below the water, with a constant permeability coefficient and surface properties applied to the mesh 101M, regardless of the type of material constituting the road surface of the exterior area 103. In this case, the rainwater inflow simulation unit 36 ​​may calculate the amount of rainwater flowing from above the water to the mesh 101M below the water, depending on the gradient between the meshes 101M. In this case, the calculation process in step S6 can be simplified.

[0087] In step S6, the rainwater inflow simulation unit 36 ​​may calculate the amount of rainwater flowing from the above-water side to the mesh 101M below the water, regardless of the construction conditions of the road surface of the external structure area 103. In this case, the rainwater inflow simulation unit 36 ​​may calculate the amount of rainwater flowing from the above-water side to the mesh 101M below the water, depending on the gradient between the meshes 101M and the type of material that constitutes the road surface of the external structure area 103. In this case, the calculation process of step S6 can be simplified.

[0088] In step S6, in mesh 101M of the external structure area 103 where underground flow occurs, such as in green space, a calculation method may be used in which runoff occurs due to underground water paths connecting when the soil becomes saturated.

[0089] The cost of each component may be added as attribute information to the BIM information of each component of the simulation area 101. In this case, the costs of the paved area 104, the planted area 105, the storm water drainage facilities, etc. that constitute the external area 103 may be calculated based on the BIM information of the external area 103.

[0090] A simulation method in which the amount of rainfall changes over time at each time step may be used. In this case, the change in the amount of rainfall over time may be set in step S2. Furthermore, the processing of steps S3 to S5 may be performed for each time step so that the first rainwater amount, the second rainwater amount, and the third rainwater amount change over time.

[0091] The building information for calculating the first rainwater amount may be data other than the BIM information of the building 102. For example, an elevation including information on the position and slope of the roof may be used as the building information. The planting information for calculating the second rainwater amount may be data other than the BIM information of the trees 106. For example, a planting plan including information such as the type, position, and size of the trees 106 arranged on the site may be used as the planting information.

[0092] The road surface information for calculating the third rainwater amount may be data other than the BIM information of the paved area 104 and the planted area 105. For example, a pavement division map including information on the pavement condition of the exterior structure within the site, an elevation survey map including information on the site boundary and site boundary height, and a layout map including information on the layout (outer edge) of the building 102 within the site may be used as the road surface information.

[0093] In the rainwater drainage simulation, instead of forming the polyhedral mesh 101M, for example, a surface model that expresses a road surface or the like with curved surfaces may be divided into a plurality of meshes.

[0094] The server 20 may be a cloud server. Furthermore, the storm water drainage simulation device 1 is not limited to a configuration including the user terminal 10 and the server 20, and may be a single computer terminal.

[0095] [Note] According to the above embodiment and its modifications, the following technical ideas can be derived. [Appendix 1] A rainwater drainage simulation device including a control unit that simulates the rainwater drainage capacity of a simulation area including a building and an exterior area, The control unit: Setting the amount of rainfall falling in the simulation area; Calculating a first amount of rainwater falling on the building using the building information; Calculating a second amount of rainwater flowing into the simulation area through trees using planting information; Using the road surface information, a third amount of rainwater falling on the road surface of the exterior area is calculated; Calculating an inflow amount of rainwater into a rainwater drainage facility arranged in the simulation area using the first rainwater amount, the second rainwater amount, and the third rainwater amount; Calculating the change over time in the amount of rainwater in the rainwater drainage facility; Based on the change over time in the amount of rainwater in the rainwater drainage facility, a determination is made as to whether or not the rainwater drainage plan in the simulation area is capable of dealing with the set value of the amount of rainfall, and the determination is output. Stormwater drainage simulation device.

[0096] [Appendix 2] A rainwater drainage simulation device including a control unit that simulates the rainwater drainage capacity of a simulation area including a building and an exterior area, The control unit: Setting the amount of rainfall falling in the simulation area; Calculating a first amount of rainwater falling on the building using the building information; Calculating a second amount of rainwater flowing into the simulation area through trees using planting information; Using the road surface information, a third amount of rainwater falling on the road surface of the exterior area is calculated; Calculating an inflow amount of rainwater into a rainwater drainage facility arranged in the simulation area using the first rainwater amount, the second rainwater amount, and the third rainwater amount; Calculating the change over time in the amount of rainwater in the rainwater drainage facility; The amount of rainwater flowing into the rainwater drainage facility is calculated according to the type of material that constitutes the road surface. Stormwater drainage simulation device.

[0097] [Appendix 3] A rainwater drainage simulation device including a control unit that simulates the rainwater drainage capacity of a simulation area including a building and an exterior area, The control unit: Setting the amount of rainfall falling in the simulation area; Calculating a first amount of rainwater falling on the building using the building information; Calculating a second amount of rainwater flowing into the simulation area through trees using planting information; Using the road surface information, a third amount of rainwater falling on the road surface of the exterior area is calculated; Calculating an inflow amount of rainwater into a rainwater drainage facility arranged in the simulation area using the first rainwater amount, the second rainwater amount, and the third rainwater amount; Calculating the change over time in the amount of rainwater in the rainwater drainage facility; The amount of rainwater flowing into the rainwater drainage facility is calculated according to the construction conditions of the road surface. Stormwater drainage simulation device.

[0098] [Appendix 4] A rainwater drainage simulation device including a control unit that simulates the rainwater drainage capacity of a simulation area including a building and an exterior area, The control unit: Setting the amount of rainfall falling in the simulation area; Calculating a first amount of rainwater falling on the building using the building information; Calculating a second amount of rainwater flowing into the simulation area through trees using planting information; Using the road surface information, a third amount of rainwater falling on the road surface of the exterior area is calculated; Calculating an inflow amount of rainwater into a rainwater drainage facility arranged in the simulation area using the first rainwater amount, the second rainwater amount, and the third rainwater amount; Calculating the change over time in the amount of rainwater in the rainwater drainage facility; The second rainwater amount is calculated using tree pruning plan information as the planting information. Stormwater drainage simulation device. [Explanation of symbols]

[0099] A1 to A4...arrows, H10...information processing device, H11...communication device, H12...input device, H13...display device, H14...storage device, H15...processor, S1-S8...steps, 1...stormwater drainage simulation device, 10...user terminal, 20...server, 30...control unit, 31...simulation area creation unit, 32...rainfall setting unit, 33...first rainwater amount calculation unit, 34...second rainwater amount calculation unit, 35...third rainwater amount calculation unit, 36...rainwater inflow simulation unit, 37...fourth rainwater amount calculation unit Quantity calculation unit, 38...judgment unit, 40...memory unit, 41...BIM information memory unit, 42...judgment criterion memory unit, 100...modeling space, 101...simulation area, 101E...outer edge, 101M...mesh, 102...building, 103...exterior area, 104...paved area, 105...planted area, 106...trees, 107...stormwater infiltration facility, 108...infiltration tank, 109...infiltration pipe, 110...drainage pipe, 111...stormwater storage facility, 112...drainage ditch, 113...overflow pipe, 120...sewer main pipe.

Claims

1. A rainwater drainage simulation device including a control unit that simulates the rainwater drainage capacity of a simulation area including a building and an exterior area, The control unit: Setting the amount of rainfall falling in the simulation area; Calculating a first amount of rainwater falling on the building using the building information; Calculating a second amount of rainwater flowing into the simulation area through trees using planting information; Using the road surface information, a third amount of rainwater falling on the road surface of the exterior area is calculated; Calculating an inflow amount of rainwater into a rainwater drainage facility arranged in the simulation area using the first rainwater amount, the second rainwater amount, and the third rainwater amount; Calculate the change over time in the amount of rainwater in the rainwater drainage facility Stormwater drainage simulation device.

2. The second rainwater amount is calculated using growth prediction information of the tree as the planting information. The rainwater drainage simulation device according to claim 1.

3. A rainwater drainage simulation method for simulating a rainwater drainage capacity of a simulation area including a building and an exterior area by using a rainwater drainage simulation device having a control unit, The control unit: Setting the amount of rainfall falling in the simulation area; Calculating a first amount of rainwater falling on the building using the building information; Calculating a second amount of rainwater flowing into the simulation area through trees using planting information; Using the road surface information, a third amount of rainwater falling on the road surface of the exterior area is calculated; Calculating an inflow amount of rainwater into a rainwater drainage facility arranged in the simulation area using the first rainwater amount, the second rainwater amount, and the third rainwater amount; Calculate the change over time in the amount of rainwater in the rainwater drainage facility Stormwater drainage simulation method.

4. A rainwater drainage simulation program for simulating the rainwater drainage capacity of a simulation area including a building and an exterior area by using a rainwater drainage simulation device having a control unit, The control unit, Setting the amount of rainfall falling in the simulation area; Calculating a first amount of rainwater falling on the building using the building information; Calculating a second amount of rainwater flowing into the simulation area through trees using planting information; Using the road surface information, a third amount of rainwater falling on the road surface of the exterior area is calculated; Calculating an inflow amount of rainwater into a rainwater drainage facility arranged in the simulation area using the first rainwater amount, the second rainwater amount, and the third rainwater amount; The rainwater drainage system is provided with a function of calculating a change in the amount of rainwater over time. Stormwater drainage simulation program.

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