JP6795901B2 - Risk assessment device in the event of a disaster and risk assessment program in the event of a disaster - Google Patents

Description

The present invention relates to a risk assessment device at the time of a disaster and a risk assessment program at the time of a disaster.

It can be said that it is an important disaster countermeasure to prepare a regional risk map in order to take measures in the event of a disaster such as an earthquake or fire. In creating such a regional risk map, it is necessary to evaluate the risk of each region and set evacuation routes.

For example, Patent Document 1 below discloses a route simulation device that performs a simulation for evaluating the safety of a road between arbitrary points in the event of a disaster or the like. Further, Patent Document 2 below discloses a method for evaluating a fire risk of a building.

Most of the "regional risk maps" are for natural disasters, but this specification includes fires.

As mentioned above, the regional risk map is an important source of information for disaster countermeasures, but in the past, the risk evaluation criteria and expression methods were not uniform, and the information was not always easy to understand.

JP-A-2007-40907 Japanese Unexamined Patent Publication No. 2005-275732

An object of the present invention is to provide a risk assessment device at the time of a disaster and a risk assessment program at the time of a disaster, in which evaluation criteria and expression methods are unified and easy to understand and use.

In order to achieve the above object, one embodiment of the present invention is a risk assessment device at the time of a disaster, and the evaluation target area is divided into a plurality of evaluation areas, and each evaluation area is divided into building attributes. The number of buildings collapsed is calculated from the collapse rate calculation means that calculates the probability of building collapse at the time of a disaster based on the probability of building collapse and the number of buildings in the evaluation area, and per unit area based on the area of the evaluation area. A collapse number calculation means for calculating the number of collapsed buildings, and a collapse risk ranking calculation means for calculating the risk rank for building collapse in the evaluation area in the evaluation target area based on the number of building collapses per unit area. For each evaluation area, a fire spreadable area setting means for setting a fire spreadable area as a fire spreadable area due to a fire of an arbitrarily selected building based on the building attributes and the positional relationship between the buildings, and the fire spreadable area. For each, a burnout evaluation value is calculated for each evaluation area based on the number of fires calculation means for calculating the number of fires at the time of a disaster based on the attributes of the building, the number of fires, and the evaluation area in the area where the fire can spread. , A burnout evaluation value calculation means for calculating a burnout evaluation value per unit area based on the area of the evaluation area, and a fire risk ranking of the evaluation area in the evaluation target area based on the burnout evaluation value per unit area. It is characterized by including a fire risk ranking calculation means for calculating the above, and a comprehensive risk calculation means for calculating the total risk of the evaluation area based on the risk ranking related to the collapse of the building and the risk ranking related to the fire. And.

The evaluation area is preferably the total floor area of the buildings in the fire spreadable area.

Further, it is preferable that the collapse rate calculation means calculates the probability of building collapse at the time of a disaster based on the height of the building.

Further, the collapse rate calculation means determines that the structure of the building is wooden when the height of the building is equal to or less than a predetermined reference value, and when the height exceeds the reference value, the structure of the building is non-wooden. It is preferable to calculate the probability of building collapse from the structure of each building and the maximum seismic intensity.

In addition, the fire spreadable area setting means estimates the fire resistance classification of the building based on the height and structure of the building, and uses the predetermined fire spread limit distance for each estimated fire resistance classification to determine the attributes of the building and the mutual building. It is preferable to set the fire spreadable area from the positional relationship.

Further, it is preferable that the burnout evaluation value calculation means calculates the burnout evaluation value by multiplying the number of fires and the evaluation area of the fire spreadable area.

Further, another embodiment of the present invention is a risk assessment program at the time of a disaster, in which a computer divides an evaluation target area into a plurality of evaluation areas, and each evaluation area is based on the attributes of a building. The number of buildings collapsed is calculated from the collapse rate calculation means for calculating the probability of building collapse at the time of a disaster, the probability of building collapse and the number of buildings in the evaluation area, and the number of buildings collapsed per unit area based on the area of the evaluation area. A collapse number calculating means for calculating a number, a collapse risk ranking calculating means for calculating a risk ranking regarding a building collapse in the evaluation area in the evaluation target area based on the number of building collapses per unit area, and for each evaluation area. A fire spreadable area setting means for setting a fire spreadable area as a fire spreadable area due to a fire of an arbitrarily selected building based on the building attributes and the positional relationship between the buildings, and the building attribute for each fire spreadable area. Based on the number of fires calculating means for calculating the number of fires at the time of a disaster based on the above, the number of fires and the evaluation area in the area where the fire can spread, a burnout evaluation value is calculated for each evaluation area, and the area of the evaluation area is calculated. Burning evaluation value calculating means for calculating the burning evaluation value per unit area based on the fire risk ranking calculation for calculating the fire risk ranking of the evaluation area in the evaluation target area based on the burning evaluation value per unit area. It is characterized in that it functions as a means, a total risk calculating means for calculating the total risk of the evaluation area based on the risk ranking regarding the collapse of the building and the risk ranking regarding the fire.

According to the present invention, it is possible to provide a risk assessment in the event of a disaster that is easy to understand and use.

It is a functional block diagram of the example of the risk evaluation device at the time of the occurrence of a disaster concerning the embodiment. It is a figure which shows the graph which shows the relationship between the maximum seismic intensity and the total destruction rate of a building. It is explanatory drawing of the fire spreadable area set by the fire spreadable area setting part which concerns on embodiment. It is a figure which shows the example of the processing when the fire spread possible area straddles different evaluation areas. It is a figure which shows the flow of the operation example of the risk evaluation apparatus at the time of a disaster which concerns on embodiment.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

FIG. 1 shows a functional block diagram of an example of a risk assessment device when a disaster occurs according to an embodiment. In FIG. 1, the risk evaluation device in the event of a disaster includes a collapse rate calculation unit 10, a collapse number calculation unit 12, a collapse risk ranking calculation unit 14, a fire spreadable area setting unit 16, a fire number calculation unit 18, and a burnout evaluation value. It includes a calculation unit 20, a fire risk ranking calculation unit 22, a total risk calculation unit 24, a display control unit 26, a communication unit 28, a storage unit 30, and a CPU 32. The risk assessment device in the event of a disaster is equipped with a CPU 32, ROM, RAM, non-volatile memory, I / O, a communication interface, etc., and is configured as a computer that controls the entire device and performs various calculations. Is realized, for example, by the CPU 32 and a program that controls the processing operation of the CPU 32.

The collapse rate calculation unit 10 divides the designated evaluation target area into a plurality of evaluation areas, and calculates the probability of building collapse at the time of a disaster for each evaluation area based on the attributes of the building. Here, the probability of building collapse at the time of a disaster is the probability of building collapse assuming the occurrence of a disaster. In addition, the evaluation target area is an area for estimating the distribution of the degree of risk in the event of a disaster, and can be, for example, an administrative division such as a municipality or a special ward in Tokyo. The evaluation target area is specified by the user by inputting information that exists on a map or the like by an appropriate input means (pointing device such as a mouse, keyboard, touch panel, etc.) or that specifies the described administrative division. be able to. In this case, it is preferable that the display control unit 26 displays the image of the map on an appropriate screen and inputs the information for designating the administrative division to the map on the screen. Alternatively, the information for designating the administrative division or the information itself for the designated administrative division may be received from another computer or the like via the communication unit 28. The information on administrative divisions includes information on towns and streets within the administrative divisions. The map data on which the administrative divisions are described, the information on the administrative divisions, and the like may be stored in the storage unit 30 in advance, or may be acquired from another appropriate server or the like via the communication unit 28 and stored in the storage unit 30. You may memorize it in. The collapse rate calculation unit 10 reads out these data and information from the storage unit 30 as needed and uses them.

The disaster refers to an earthquake and a fire caused by an earthquake, and the degree of risk refers to the degree of danger based on a certain evaluation standard described later. Further, the evaluation area is the minimum range (area) for evaluating the degree of risk, and the collapse rate calculation unit 10 may divide the evaluation target area into a plurality of areas and set an evaluation area for each town chome. it can. By making the evaluation area about the size of a town chome, avoid unnecessary detours when deciding an evacuation route, etc. based on the risk level evaluated by the risk level evaluation device in the event of a disaster according to the embodiment. Can be done. The set evaluation area is also stored in the storage unit 30. In addition, the user may specify a town chome as an evaluation area on a map on which administrative divisions are described, and store this in the storage unit 30.

In general, the susceptibility of a building to collapse during an earthquake, that is, the probability of building collapse, depends on the structure of the building, which is an attribute of the building. The structure in this case means whether it is wooden or not (wooden or non-wooden). Determining the wooden or non-wooden structure of each building existing in a certain evaluation area is extremely complicated and impractical. Therefore, the collapse rate calculation unit 10 according to the present embodiment estimates the structure of the building from the height as an attribute of the building. That is, if the building is below the predetermined standard height, it is estimated to be wooden, and if the building exceeds the standard height, it is estimated to be non-wooden. The reference height can be set according to the actual situation of each evaluation target area, and can be, for example, 11 to 14 m. As a result of investigations by the inventors of the present application in Yokohama City, Kawasaki City, etc., the above standard value is estimated to be 13 m, but the present invention is not limited to this. In addition to the above reference height, it is preferable to use the area of the building (projected area on the ground surface (horizontal projected area)) as the reference area. That is, the estimation accuracy of the structure of the building can be improved by estimating that the case of the reference height or less and the reference area or less is made of wood and the other cases are made of non-wooden. The reference area can be 80 to 100 m ² . From the above survey results, the reference area is estimated to be 90 m ² , but it is not limited to this. The height and area of the building can be calculated from, for example, an aerial photograph. Information such as the height and area of the building, and the values of the reference height and the reference area are also stored in the storage unit 30. Further, the storage unit 30 may store information on the structure of the building estimated by the collapse rate calculation unit 10. Further, it is preferable to store the position information of each building, that is, the position (coordinates) on the map on which the administrative division is described, in the storage unit 30.

The collapse rate calculation unit 10 reads the height or height and area of each building from the storage unit 30, estimates the structure of each building based on these values, and calculates the probability of building collapse. The probability of building collapse can be calculated from the results of a preliminary survey of the total collapse rate of buildings for each evaluation area and for each maximum seismic intensity of an earthquake. The investigation result of such a total destruction rate is stored in the storage unit 30 in advance.

FIG. 2 shows a graph showing the relationship between the maximum seismic intensity and the total destruction rate of the building. The graph of FIG. 2 is an example of the investigation result of the total destruction rate performed for each evaluation area stored in the storage unit 30, and is read out and used by the collapse rate calculation unit 10. In FIG. 2, the horizontal axis is the maximum seismic intensity and the vertical axis is the total destruction rate. The total destruction rate is used as the probability of building collapse. In addition, the maximum seismic intensity is the maximum of the ground surface considering the amplification factor by the ground when a seismic motion of 30 cm / s (Cain) is applied to the engineering foundation using the surface ground data of the Earthquake Hazard Station (J-SHIS). It is a numerical value obtained as a seismic intensity. The collapse rate calculation unit 10 calculates the probability of building collapse based on FIG. 2 based on the estimated structure of each building.

The collapse number calculation unit 12 calculates the number of building collapses from the probability of building collapse calculated by the collapse rate calculation unit 10 and the number of buildings in the evaluation area, and calculates the number of building collapses per unit area based on the area of the evaluation area. To do. This calculation is performed based on the following equation (1).

As shown in the formula (1), the number of buildings in the evaluation area is the structure of the building, that is, the number of buildings for each wooden and non-wooden structure. The numerical value of the number of buildings in this evaluation area may be stored in the storage unit 30 in advance, or may be acquired from another appropriate server or the like via the communication unit 28 and stored in the storage unit 30. You may leave it. Further, since the area of each town chome is known in advance, the area of the evaluation area is stored in the storage unit 30. In this embodiment, the area of each town chome excluding parks, green spaces, and rivers is used as the area of the evaluation area. The collapse number calculation unit 12 reads out the probability of building collapse, the numerical value of the number of buildings, and the area of the evaluation area from the storage unit 30 and uses it. The calculated number of building collapses and the number of building collapses per unit area are stored in the storage unit 30.

The collapse risk ranking calculation unit 14 reads out the number of building collapses per unit area calculated by the collapse number calculation unit 12 from the storage unit 30, and based on this numerical value, the collapse risk ranking regarding the building collapse in the evaluation area in the evaluation target area. Is calculated. Here, the risk ranking refers to the ranking of the number of collapsed buildings per unit area of the evaluation area in the evaluation target area. The higher the value of the number of collapsed buildings per unit area, the higher the ranking. The risk ranking calculated by the collapse risk ranking calculation unit 14 is stored in the storage unit 30.

The fire spreadable area setting unit 16 sets, for each of the evaluation areas, a fire spreadable area as an area where the fire may spread due to a fire of an arbitrarily selected building based on the building attributes and the positional relationship between the buildings. In this embodiment, a fire in a building is caused by the collapse of the building due to an earthquake. Here, the attribute of the building is a fireproof classification of the building, and there are types of fireproof, semi-fireproof, and fireproof. The positional relationship between the buildings is the distance between the outer walls of the building. For buildings, the fire spread limit distance is set for each of the fireproof, semi-fireproof, and fireproof categories. The fire spread limit distance is a distance for determining the limit of fire spread to adjacent buildings when a certain building catches fire, and the fire spread limit set for each building farther than the fire spread limit distance, that is, the adjacent buildings. If there is no overlap in the area within the distance range, it is judged that the fire will not spread. This fire spread limit distance is the longest when the fire resistance classification is fire prevention, for example, in the case of a building having a horizontal projected area of 50 m ² , it is about 4 to 6 m from the outer wall of the building. Further, in the case of semi-fire resistance, the fire spread limit distance is shorter than in the case of fire prevention. For example, in the case of a building having a horizontal projected area of 50 m ² , it is about 2 to 3 m from the outer wall of the building. In the case of fire resistance, there is no fire and there is no danger of fire spreading, so the fire spread limit distance is set to 0 m. The information on the fire spread limit distance is stored in the storage unit 30 in advance.

The fireproof classification of each building is determined by the fire spreadable area setting unit 16 from the building structure (wooden or non-wooden) and the height (number of floors) of the building, which are the attributes of the building. As the structure of the building, the information of the structure estimated by the collapse rate calculation unit 10 is read from the storage unit 30 and used. Further, the height of the building is also read from the storage unit 30 and used. Examples of the method by which the fire spreadable area setting unit 16 determines the fire resistance classification of each building from the structure (wooden or non-wooden) of the building and the height of the building are shown in Table 1 below. In the example of Table 1, the fireproof classification of wooden buildings is fireproof, non-wooden buildings with 3 floors or less are semi-fireproof, and non-wooden buildings with 4 floors or more are fireproof. However, the method for determining the fireproof classification of each building is not limited to the method shown in Table 1.

The number of floors of the building (the number of floors above ground) is determined from the height of the building based on a predetermined standard. For example, a method such as increasing the number of floors by 1 for every 4.5 m in height can be mentioned. In this case, a building with a height of less than 9 m shall be a one-story building, and a building with a height of less than 13.5 m shall be a two-story building. The number of floors may be determined by the fire spreadable area setting unit 16 or the collapse rate calculation unit 10. The determined number of floors of the building is stored in the storage unit 30. The number of floors of each building may be investigated in advance and stored in the storage unit 30. The fire spreadable area setting unit 16 reads out the number of floors of the building from the storage unit 30 and uses it.

Next, the fire spreadable area setting unit 16 sets an area within the range of the fire spread limit distance from the fire spread limit distance of each building in the evaluation area, and sets an area within the range of the fire spread limit distance of adjacent buildings. If there is an overlap, it is determined that a fire spreads between the adjacent buildings. The relationship between adjacent buildings that are determined to cause fire spread is hereinafter referred to as the fire spread relationship. Such a determination of the fire spread relationship is performed for all the buildings in the evaluation area, a group of buildings having a fire spread relationship is created, and the area where the buildings in this group exist is set as the fire spread possible area. In the area where fire can spread, if any building in this area catches fire, the fire spreads to all the buildings in the area. However, since the fire does not spread to buildings whose fireproof classification is fireproof, it is excluded from the fire spreadable area. In addition, isolated buildings (buildings that do not overlap in the area within the above fire spread limit distance with adjacent buildings), etc., do not have the possibility of fire spreading to other buildings even if a fire breaks out. Treat as forming a fire spreadable area only. The fire spreadable area set by the fire spreadable area setting unit 16 is also stored in the storage unit 30.

Further, the fire spreadable area setting unit 16 also calculates the evaluation area used by the burnout evaluation value calculation unit 20 described later for calculating the burnout evaluation value. This evaluation area is an area that is exposed to the risk of fire when a fire breaks out in the evaluation area. For example, the total floor area of buildings in the fire spreadable area existing in the evaluation area should be used. Can be done. Further, the area may be the area where the fire can spread. The floor area of the building can be obtained, for example, as the product of the horizontally projected area of each building stored in the storage unit 30 and the number of floors of the building. Further, the area of the fire spreadable area is the area within the range of the fire spread limit distance around the building included in the fire spreadable area (the area within the range of the fire spread limit distance), and the overlap of the areas within the fire spread limit distance. Is the area excluding. The evaluation area and the area of the fire spreadable area are also stored in the storage unit 30.

3 (a) and 3 (b) show explanatory views of the fire spreadable area set by the fire spreadable area setting unit 16. In the example of FIG. 3A, buildings A1 and B1 whose fireproof categories are semi-fireproof, buildings B2 which are fireproof, and buildings C1 which are fireproof are drawn. In addition, the fire spread limit distance _DL is indicated by the broken line around each building. The area within the range of the broken line corresponds to the area within the range of the fire spread limit distance. Incidentally, spread limit distance D _L is the fire of the building C1 is so 0 m, the dashed line is not described.

Spread area setting unit 16 determines the overlap of fire limit distance D _L, go to group together building are overlapped area in the range of fire limit distance D _L. The grouping process is optionally selected buildings (e.g., buildings B1) to select the building area within the fire limit distance D _L overlap, then the selected building and fire spread limit distance D _L the process of selecting the building area in the range overlaps performed by executing until the building is no longer a region within the fire limit distance D _L overlap. The group created in this way is a group of buildings that can spread to all buildings if a fire breaks out in any building in the group. In the example of FIG. 3 (a), since the area within the range of fire limit distance D _L buildings B1 and B2 overlap, it was grouped in the range of overlapping spread limit distance D _L region (dashed Within the range) is set as one fire spreadable area. Also, building A1, since the area within the fire limit distance D _L between the adjacent buildings do not overlap, only possible fire area within the range of fire limit distance D _L building A1 as an isolated building Set the area. In addition, it is judged that the fire does not spread to the fireproof building C1 and is excluded from the fire spreadable area. As a result, as shown in FIG. 3B, a fire spreadable area A for the building A1 and a fire spreadable area B for the buildings B1 and B2 are set. As described above, the fire spreadable area B does not include the building C1. Further, spread region A shown in FIG. 3 (b), the area of B is, there in an area within the range of each area of the fire area, i.e. spread limit distance of surrounding buildings included in the fire area D _L It is the area excluding the overlap.

FIG. 4 shows an example of processing when the fire spreadable area straddles different evaluation areas (town chome, etc.). In the example of FIG. 4, there is a fire spreadable area A * B that straddles the evaluation areas of town chome A and town chome B. The fire spreadable area setting unit 16 identifies the buildings included in the town chome A among the buildings existing in the fire spreadable area A * B, and sets the total floor area of them as the evaluation area on the town chome A side, and sets the town chome B Identify the buildings included in, and use the total floor area of them as the evaluation area on the town chome B side. In addition, the area where the fire spreadable area A * B is included in the town chome A and the area included in the town chome B are calculated, and the evaluation area (the area of the fire spreadable area) is apportioned based on the ratio of the calculated area. May be good. The area of the fire spreadable area A * B and the evaluation area are read from the storage unit 30 and used. In addition, the position of the fire spreadable area A * B where the boundary line between the town chome A and the town chome B is located is determined as follows. That is, based on the position of the building included in the fire spreadable area A * B (coordinates on the map on which the administrative divisions are described), the range of the fire spreadable area A * B on the above map is determined, and on the same map. The position of the boundary line in the fire spreadable area A * B is determined from the boundary line between the town chome A and the town chome B in. The map data in which the location of each building and the administrative divisions are described is read from the storage unit 30 and used.

In FIG. 4, the boundary line Lb between the town chome A and the town chome B exists in the fire spreadable area A * B, the total floor area of the buildings belonging to the town chome A is 200 m ² , and the town chome B has. An example is shown in which the total floor area of the building to which it belongs is 300 m ² . In the example of FIG. 4, the fire spreadable area A * B straddles two evaluation areas, but the same processing is performed even when the fire spreadable area A * B straddles three or more evaluation areas. To.

The number of fires calculation unit 18 calculates the number of fires at the time of a disaster based on the attributes of the building for each fire spreadable area set by the fire spreadable area setting unit 16. Here, the attributes of the building are the uses of the building and are illustrated in Table 2 below, but are not limited thereto. In the example of Table 2, the fire rate (fire rate for each building use) is set according to the seismic intensity of the earthquake for each building use. The fire rate for each building use is determined in advance from conventional fire investigations and the like. The seismic intensity in Table 2 is the maximum seismic intensity on the ground surface shown in FIG. The information in Table 2 is also stored in the storage unit 30.

The number of fires calculation unit 18 reads the information in Table 2 from the storage unit 30, and calculates (estimated value) the number of fires at the time of an earthquake for each fire spreadable area based on the following equation (2).

Here, the total number of collapsed buildings is the number of collapsed buildings calculated by the collapse number calculation unit 12, and this numerical value is read from the storage unit 30 and used. The number of non-totally destroyed buildings is the number obtained by subtracting the total number of completely destroyed buildings from the number of all buildings in the area where fire can spread. The number of all buildings in the fire spreadable area is a value counted when the fire spreadable area setting unit 16 sets the fire spreadable area. The coefficient α multiplied by the number of completely destroyed buildings is the fire rate of completely destroyed buildings determined in advance by investigating, and is, for example, a value of 0.2 to 0.3. In addition, the initial fire extinguishing success rate uses the numerical value obtained by investigating in advance, but when the maximum seismic intensity of the ground surface is 7 or more, it is about 0.1 to 0.2, and when the maximum seismic intensity of the ground surface is 6 upper. It is about 0.2 to 0.4, and when the maximum seismic intensity of the ground surface is 6 lower or less, it is about 0.6 to 0.7. The number of buildings, the coefficient α, and the initial fire extinguishing success rate of all the buildings in the fire spreadable area are also stored in the storage unit 30 in advance, and the fire occurrence number calculation unit 18 reads and uses them. The number of fires calculated by the number of fires calculation unit 18 is stored in the storage unit 30.

The burnout evaluation value calculation unit 20 calculates a burnout evaluation value for each evaluation area based on the number of fires calculated by the fire number calculation unit 18 and the evaluation area in the fire spreadable area, and per unit area based on the area of the evaluation area. Calculate the burnout evaluation value of. The number of fires and the evaluation area are read out from the storage unit 30 by the burnout evaluation value calculation unit 20 and used. In addition, the burnout evaluation value is calculated as the product of the number of fires and the evaluation area for each fire spreadable area existing in the evaluation area. As a result, the larger the number of fires in the evaluation area, the larger the burnout evaluation value, and the greater the risk of fire. When the fire spreadable area spans a plurality of evaluation areas, the evaluation area calculated for each evaluation area is combined with the evaluation area of the fire spreadable area that does not straddle other evaluation areas in the evaluation area. Use to calculate the burnout rating. The area of the evaluation area is read from the storage unit 30 and used in the same manner as the collapse number calculation unit 12. The burnout evaluation value calculation unit 20 calculates the burnout evaluation value per unit area based on the following equation (3).

In the above equation (3), Σ means that the calculation of (number of fires) × (evaluation area) is performed for each fire spreadable area in the evaluation area, and the above calculation results are totaled for each evaluation area. The burnout evaluation value per unit area obtained by dividing this total value by the area of the evaluation area is stored in the storage unit 30.

The fire risk ranking calculation unit 22 reads the burnout evaluation value per unit area calculated by the burnout evaluation value calculation unit 20 from the storage unit 30, and based on this value, the fire risk rank of the evaluation area in the evaluation target area. Is calculated. The risk ranking is the same as in the case of the collapse risk ranking, and refers to the ranking of the burnout evaluation value per unit area of the evaluation area in the evaluation target area. The higher the burnout evaluation value per unit area, the higher the ranking. The risk ranking calculated by the fire risk ranking calculation unit 22 is stored in the storage unit 30.

The total risk calculation unit 24 reads from the storage unit 30 the risk ranking related to building collapse calculated by the collapse risk ranking calculation unit 14 and the fire risk ranking calculated by the fire risk ranking calculation unit 22. Calculate the total risk of the evaluation area based on the ranking of. The total risk level is determined by calculating the sum of the risk level ranking related to building collapse and the risk level ranking related to fire, and the numerical value of the sum is determined by the ranking (total ranking) in the evaluation target area according to a predetermined standard. The smaller the value of the sum, the higher the overall ranking. For example, in the case of an evaluation area where both ranks are first, the sum is 2, and in this case, the overall rank of the evaluation area in the evaluation target area is first. After that, the overall ranking goes down as the sum value increases.

As the above-mentioned predetermined standard, for example, the total degree of risk may be expressed on a 5-point scale based on the above-mentioned overall ranking. Table 3 shows an example of the total risk based on this 5-grade evaluation.

In the example of Table 3, the overall risk is up to the top 2% (0 <, ≦ 2), the total risk is over 5, 2% and up to 8% (2 <, ≦ 8), the total risk is over 4.8%. Up to 23% (8 <, ≦ 23) with a total risk of over 3, 23% up to 55% (23 <, ≦ 55) with a total risk of over 2,55% and up to 100% (55 <, ≦ 100) Is a total risk level of 1. The evaluation is not limited to 5 grades, and may be, for example, a 10 grade evaluation. In addition, the notch of evaluation is not limited to the above example, and can be appropriately determined based on the results of prior surveys and the like.

The calculation result of the total risk of each evaluation area is stored in the storage unit 30, and is displayed on an appropriate screen by the display control unit 26. It is preferable to display the total risk level on a map image that displays the evaluation target area including the evaluation area. Examples of this display method include a method of expressing an image of an evaluation area (an image of a town street or the like) in a color corresponding to a calculated total risk level.

The display control unit 26 controls a liquid crystal display device and other appropriate display devices to display, for example, an image of a map on which administrative divisions are described, a display of the total risk level, and other images.

The communication unit 28 is configured by an appropriate interface, and is used by the CPU 32 to exchange data with an external server or the like via a wireless or wired communication line.

The storage unit 30 is composed of a non-volatile memory such as a hard disk device and a solid state drive (SSD), and stores the above-mentioned various information and information necessary for each process performed by the object recording device such as an operation program of the CPU 32. Let me. The storage unit 30 includes a digital versatile disk (DVD), a compact disk (CD), a magneto-optical disk (MO), a flexible disk (FD), a magnetic tape, an electrically erasable and rewritable read-only memory ( EEPROM), flash memory, etc. may be used. Further, the storage unit 30 includes a random access memory (RAM) that mainly functions as a work area of the CPU 32, and a read-only memory (ROM) that stores a control program such as a BIOS and other data used by the CPU 32. It is suitable.

FIG. 5 shows a flow of an operation example of the risk assessment device in the event of a disaster according to the embodiment. In FIG. 5, the collapse rate calculation unit 10 divides the evaluation target area (administrative divisions such as municipalities and special wards of Tokyo) designated by the user into a plurality of evaluation areas (town chome, etc.) for each evaluation area. In addition, the probability of building collapse (collapse rate) at the time of a disaster is calculated based on the attributes of the building (S1).

The collapse number calculation unit 12 calculates the number of building collapses from the probability of building collapse calculated by the collapse rate calculation unit 10 in S1 and the number of buildings in the evaluation area, and based on the calculated number of building collapses and the area of the evaluation area. The number of collapsed buildings per unit area is calculated by the above equation (1) (S2).

The collapse risk ranking calculation unit 14 is based on the number of building collapses per unit area calculated by the collapse number calculation unit 12 in S2, and is the risk ranking regarding building collapse in the evaluation area in the evaluation target area, that is, the unit of each evaluation area. The ranking of the number of collapsed buildings per area in the evaluation target area is calculated (S3).

Next, the fire spreadable area setting unit 16 sets, for each of the above evaluation areas, a fire spreadable area as a fire spreadable area due to the fire of an arbitrarily selected building based on the building attributes and the positional relationship between the buildings. (S4).

The number of fires calculation unit 18 calculates the number of fires at the time of a disaster by the above formula (2) based on the attributes of the building for each fire spreadable area set by the fire spreadable area setting unit 16 in S4 (S5).

The burnout evaluation value calculation unit 20 calculates the burnout evaluation value for each evaluation area based on the number of fires calculated by the fire number calculation unit 18 in S5 and the evaluation area in the fire spreadable area, and based on the area of the evaluation area. The burnout evaluation value per unit area is calculated by the above equation (3) (S6).

The fire risk ranking calculation unit 22 is based on the burnout evaluation value per unit area calculated by the burnout evaluation value calculation unit 20 in S6, and is the fire risk rank of the evaluation area in the evaluation target area, that is, the unit of each evaluation area. The ranking of the burnout evaluation value per area in the evaluation target area is calculated (S7).

Next, the comprehensive risk calculation unit 24 determines the risk ranking related to building collapse calculated by the collapse risk ranking calculation unit 14 in S3 and the fire risk ranking calculated by the fire risk ranking calculation unit 22 in S7. Based on this, the total risk of the evaluation area is calculated (S8).

The display control unit 26 displays the total risk calculated by the total risk calculation unit 24 in S8 on a map image displaying the evaluation target area including the evaluation area in colors or the like representing each risk (S9). ).

The program for executing each step of FIG. 5 described above can be stored in a recording medium, and the program may be provided by a communication means. In that case, for example, the program described above may be regarded as an invention of a "computer-readable recording medium on which a program is recorded" or an invention of a "data signal".

10 Collapse rate calculation unit, 12 Collapse number calculation unit, 14 Collapse risk ranking calculation unit, 16 Fire spreadable area setting unit, 18 Fire number calculation unit, 20 Burnout evaluation value calculation unit, 22 Fire risk ranking calculation unit, 24 Comprehensive Risk calculation unit, 26 display control unit, 28 communication unit, 30 storage unit, 32 CPU.

Claims (5)

The evaluation target area is divided into a plurality of evaluation areas, and for the buildings existing in the evaluation area, wooden or non-wooden structures as the building structure are estimated from the height of the building based on a predetermined reference height, and the evaluation area a collapse rate calculating means for calculating a probability of a building collapse in the event of a disaster based on, the structure of the building each,
A collapse number calculation means that calculates the number of building collapses from the probability of building collapse and the number of buildings in the evaluation area and calculates the number of building collapses per unit area based on the area of the evaluation area.
Based on the number of building collapses per unit area, a collapse risk ranking calculation means for calculating the risk ranking regarding building collapse in the evaluation area in the evaluation target area, and a collapse risk ranking calculation means.
For buildings existing in the evaluation area , the number of floors of the building is determined from the height of the building based on a predetermined criterion for determining the number of floors, and the fireproof classification of the building is determined based on the structure of the building and the number of floors of the building. From the fire spread limit distance set for each fire resistance category and the positional relationship between buildings, the area where there is a possibility of fire spread due to the fire of an arbitrarily selected building is set as the fire spread possible area, and the fire spread possible area setting is set for each evaluation area. Means and
For each of the fire spreadable areas, a fire number calculation means for calculating the number of fires at the time of a disaster based on the attributes of the building, and a fire number calculation means.
A burnout evaluation value calculation means that calculates a burnout evaluation value for each evaluation area based on the number of fires and the evaluation area in the fire spreadable area, and calculates the burnout evaluation value per unit area based on the area of the evaluation area. ,
A fire risk ranking calculation means for calculating a fire risk ranking in the evaluation area in the evaluation target area based on a burnout evaluation value per unit area.
Comprehensive risk calculation means for calculating the total risk of the evaluation area based on the risk ranking for building collapse and the risk ranking for fire.
A risk assessment device in the event of a disaster. The risk assessment device at the time of a disaster according to claim 1, wherein the evaluation area is the total floor area of buildings in the fire spreadable area. The risk assessment device at the time of a disaster according to claim 1 or 2, wherein the collapse rate calculating means calculates the probability of building collapse from the structure of the building and the maximum seismic intensity. The risk level at the time of a disaster according to any one of claims 1 to 3 , wherein the burnout evaluation value calculating means calculates a burnout evaluation value by multiplying the number of fires and the evaluation area of the fire spreadable area. Evaluation device. Computer,
The evaluation target area is divided into a plurality of evaluation areas, and for the buildings existing in the evaluation area, wooden or non-wooden structures as the building structure are estimated from the height of the building based on a predetermined reference height, and the evaluation area collapse rate calculating means for calculating a probability of a building collapse in the event of a disaster based on, the structure of the building each,
A collapse number calculation means that calculates the number of building collapses from the probability of building collapse and the number of buildings in the evaluation area, and calculates the number of building collapses per unit area based on the area of the evaluation area.
A collapse risk ranking calculation means for calculating a risk ranking regarding building collapse in the evaluation area in the evaluation target area based on the number of building collapses per unit area.
For buildings existing in the evaluation area , the number of floors of the building is determined from the height of the building based on a predetermined criterion for determining the number of floors, and the fireproof classification of the building is determined based on the structure of the building and the number of floors of the building. From the fire spread limit distance set for each fire resistance category and the positional relationship between buildings, the area where there is a possibility of fire spread due to the fire of an arbitrarily selected building is set as the fire spread possible area, and the fire spread possible area setting is set for each evaluation area. means,
A means for calculating the number of fires, which calculates the number of fires at the time of a disaster based on the attributes of the building for each of the fire spreadable areas.
A burnout evaluation value calculation means that calculates a burnout evaluation value for each evaluation area based on the number of fires and the evaluation area in the fire spreadable area, and calculates the burnout evaluation value per unit area based on the area of the evaluation area.
A fire risk ranking calculation means for calculating a fire risk ranking in the evaluation area in the evaluation target area based on a burnout evaluation value per unit area.
Comprehensive risk calculation means for calculating the total risk of the evaluation area based on the risk ranking related to building collapse and the risk ranking related to fire.
A risk assessment program in the event of a disaster that functions as a disaster.