Information processing device, information processing method, and program

Abstract

The present invention provides an information processing device, an information processing method, and a program that make it possible to appropriately understand the landslide disaster risk level of an area for observation, on the basis of an observed ground deformation amount. This information processing device comprises: a survey information acquisition unit that acquires survey information including a plurality of elevation data sets with respect to different time periods in an observation target area; a ground deformation amount calculation unit that calculates ground deformation amounts at observation points in the observation target area on the basis of differences in elevation data between different time periods; and a risk level evaluation unit that compares the ground deformation amounts with a deformation threshold, evaluates the landslide disaster risk level at the observation points, and outputs a signal that includes information on the landslide disaster risk level.

Description

Information processing device, information processing method, and program

[0001] The present disclosure relates to an information processing device, an information processing method, and a program.

[0002] There is a demand to monitor changes in topography and reduce the risk of disasters, etc. Information on ground movement can also be used to prevent landslides.

[0003] According to Patent Document 1, the state determination device includes a ground surface information acquisition means, an area setting means, a sensor information processing means, a state determination means, and an output means. The ground surface information acquisition means acquires ground surface displacement using a measurement image acquired from a ground surface measurement device. The area setting means sets, for each predetermined area, the amount of sensor information processing used in the process of acquiring sensor information from the sensor information acquisition device based on the ground surface displacement. The sensor information processing means processes the sensor information based on the amount of sensor information processing corresponding to the set area. The state determination means determines the state of the structure using the processed sensor information. The output means outputs the determined state of the structure.

[0004] According to Patent Document 2, a soil quality determination device includes a frequency characteristic calculation means, a soil quality storage means, and a soil quality determination means. The frequency characteristic calculation means calculates frequency characteristics representing frequency characteristics of vibrations of the target soil based on vibration data obtained by measuring vibrations of the target soil using a vibration sensor. The soil quality storage means stores soil quality models representing the relationship between moisture content and frequency characteristics for multiple densities of multiple soil types. The soil quality determination means uses the soil quality models to estimate the soil type and density of the target soil based on the moisture content, which is the amount of moisture contained in the target soil measured by a moisture meter that measures the amount of moisture contained in the soil, and the calculated frequency characteristics.

[0005] According to Patent Document 3, the disaster prediction system includes a soil moisture content acquisition means, a surface moisture content acquisition means, and an estimation means. The soil moisture content acquisition means acquires the soil moisture content at a specific point. The surface moisture content acquisition means acquires the surface moisture content within a certain range including the specific point. The estimation means estimates the soil moisture content at any point within the certain range or a parameter representing the soil characteristics at any point within the certain range based on the soil moisture content at the specific point and the surface moisture content within the certain range.

[0006] International Publication No. 2023 / 100309 International Publication No. 2016 / 136213 Japanese Patent Application Laid-Open No. 2021-009150

[0007] However, it is difficult to appropriately evaluate the risk of landslides from information on ground deformation.

[0008] In view of the above-mentioned problems, an object of the present disclosure is to provide an information processing device and the like for appropriately grasping the risk of landslides in an observation target area from the amount of ground deformation observed.

[0009] The information processing device according to the present disclosure includes a measurement information acquisition unit, a ground deformation calculation unit, and a risk assessment unit. The measurement information acquisition unit acquires measurement information including multiple pieces of elevation information for different time periods in an observation target area. The ground deformation calculation unit calculates the amount of ground deformation from the difference in elevation information for different time periods at an observation point in the observation target area. The risk assessment unit compares the amount of ground deformation with a deformation threshold, assesses the landslide risk at the observation point, and outputs a signal including information on the landslide risk.

[0010] The information processing method according to the present disclosure causes a computer to perform the following processes: The computer acquires measurement information including multiple pieces of elevation information for different time periods in an observation target area; The computer calculates the amount of ground deformation from the difference in the elevation information for different time periods at an observation point in the observation target area; The computer compares the amount of ground deformation with a deformation threshold, evaluates the landslide risk level at the observation point, and outputs a signal including information on the landslide risk level.

[0011] A program according to the present disclosure causes a computer to execute the following information processing method. The computer acquires measurement information including multiple pieces of elevation information for different time periods in an observation target area. The computer calculates the amount of ground deformation from the difference in the elevation information for different time periods at an observation point in the observation target area. The computer compares the amount of ground deformation with a deformation threshold, evaluates the landslide risk level at the observation point, and outputs a signal including information on the landslide risk level.

[0012] According to the present disclosure, it is possible to provide an information processing device, an information processing method, and a program for appropriately grasping the risk of landslides in an observation target area from the observed amount of ground deformation.

[0013] FIG. 1 is a first block diagram of an information processing device according to the present disclosure. FIG. 2 is a first flowchart of an information processing method according to the present disclosure. FIG. 3 is a diagram illustrating an example of a transition in ground deformation amount according to the present disclosure. FIG. 4 is a fourth block diagram of an information processing device according to the present disclosure. FIG. 5 is a fourth flowchart of an information processing method according to the present disclosure. FIG. 6 is a block diagram illustrating an example of a hardware configuration of a computer.

[0014] The present disclosure will be described below through embodiments, but the disclosure according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means for solving the problems. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and repeated explanations are omitted as necessary.

[0015] <First Embodiment> The first embodiment will be described below. Fig. 1 is a block diagram of an information processing device 10 according to the present disclosure. The information processing device 10 is used to estimate the risk of landslides in an observation target area. The information processing device 10 is, for example, a computer or a server. The information processing device 10 mainly includes a measurement information acquisition unit 111, a ground deformation amount calculation unit 112, and a risk assessment unit 113.

[0016] The measurement information acquisition unit 111 acquires measurement information including multiple pieces of elevation information for different periods of time for an observation target area. The measurement information is, for example, a SAR image. The SAR image is an image obtained by statistically processing data (SAR data) measured by a synthetic aperture radar (SAR) mounted on an air vehicle. The air vehicle is, for example, an artificial satellite, an aircraft, or a drone. The air vehicle in the present disclosure is preferably an artificial satellite equipped with a synthetic aperture radar. This artificial satellite is also referred to as a radar satellite or a SAR satellite.

[0017] The SAR image data acquired by the measurement information acquisition unit 111 can also be referred to as SAR data. The multiple SAR images are images obtained by observing the same area during multiple different periods. In this disclosure, unless otherwise specified, measurement information is assumed to be acquired from the SAR images.

[0018] The measurement information does not have to be an SAR image. The measurement information may be selected by a user of the information processing device 10 as long as it is data including elevation information. The measurement information acquisition unit 111 may acquire, for example, information acquired by a surveying operation as the measurement information.

[0019] The ground deformation amount calculation unit 112 extracts elevation information for each observation point in the observation target area from the measurement information acquired by the measurement information acquisition unit 111. The ground deformation amount calculation unit 112 calculates the amount of ground deformation from the difference in elevation information for different periods at the observation points in the observation target area.

[0020] The ground deformation amount in this disclosure refers to the amount of elevation change at the same point in survey information from different time periods. The ground deformation amount calculation unit 112 uses well-known technology to calculate corrected survey information at the position of corresponding images in SAR images from multiple time periods as elevation information. The ground deformation amount calculation unit 112 acquires the elevation information for each calculated observation point for each time period and calculates the amount of ground deformation as the amount of elevation change.

[0021] Note that the corresponding positions in the multiple SAR images may be, for example, a single pixel in the image data. In this case, the pixel in the SAR image corresponds to the resolution of the SAR image. The corresponding positions in the multiple SAR images may also be statistically processed data of multiple adjacent pixels.

[0022] The risk assessment unit 113 compares the amount of ground deformation calculated by the ground deformation calculation unit 112 with a preset deformation threshold for each observation point. Based on the comparison result, the risk assessment unit 113 assesses the landslide risk indicating the risk of a landslide at each observation point. This enables the user of the information processing device 10 to take measures such as evacuating nearby residents, moving items, or inspecting and reinforcing facilities before a landslide actually occurs.

[0023] The risk assessment unit 113 outputs a signal including information on the landslide risk. The information processing device 10 is connected to a presentation device. The presentation device presents the landslide risk at the observation point based on the signal supplied from the risk assessment unit 113.

[0024] The risk assessment unit 113 may output a signal including information for visually presenting the landslide risk. The risk assessment unit 113 may include, in the output signal, information in the form of a table showing the landslide risk at each observation point, or a diagram in which the risk is depicted as height on a planar map. The risk assessment unit 113 may also set a display threshold for the landslide risk. In this case, the risk assessment unit 113 may include, in the output signal, a map in which points exceeding the display threshold are colored or a list of observation points that exceed the display threshold. The risk assessment unit 113 may also include, in the output signal, information for a presentation device to present the landslide risk using voice, an alarm sound, or vibration.

[0025] Next, processing executed by the information processing device 10 will be described with reference to Fig. 2. Fig. 2 is a flowchart of an information processing method according to the present disclosure.

[0026] First, in step S11, the measurement information acquisition unit 111 acquires measurement information including multiple pieces of elevation information for the observation target area over different time periods. The measurement information acquisition unit 111 supplies the acquired measurement information to the ground deformation calculation unit 112. The measurement information acquisition unit 111 may acquire, as the measurement information, data on multiple SAR images obtained by surveying the ground surface of the observation target area from above over multiple different time periods using a synthetic aperture radar. Alternatively, the measurement information acquisition unit 111 may acquire measurement information accumulated through surveying work by accessing an external database.

[0027] Next, in step S12, the ground deformation calculation unit 112 compares the measurement information obtained during the first period with the measurement information obtained during a second period that follows the first period, and calculates the amount of elevation change, i.e., the amount of ground deformation, for each corresponding observation point. The ground deformation calculation unit 112 supplies data on the calculated amount of ground deformation to the risk assessment unit 113.

[0028] Next, in step S13, the risk assessment unit 113 assesses the landslide risk for each observation point in the observation target area based on the amount of ground deformation received from the ground deformation calculation unit 112. Specifically, the risk assessment unit 113 assesses that there is a landslide risk, for example, when the magnitude of the ground deformation for each observation point is greater than a preset threshold. In this case, the risk assessment unit 113 evaluates the landslide risk using two values. The risk assessment unit 113 may also evaluate the landslide risk using multiple levels. Furthermore, the risk assessment unit 113 outputs a signal including information on the assessed landslide risk to a presentation device connected to the information processing device 10.

[0029] Using the above-described method, the information processing device 10 evaluates the landslide risk for each observation point included in the acquired measurement information. This allows a user of the information processing device 10 to appropriately grasp the landslide risk for the entire observation area included in the measurement information, based on the landslide risk for each observation point.

[0030] The information processing device 10 may include a processor and a storage device (not shown). The storage device of the information processing device 10 may include a storage device including a nonvolatile memory such as a flash memory or a solid-state drive (SSD). In this case, the storage device stores a computer program (hereinafter simply referred to as a program) for executing the above-described method. The processor loads the computer program from the storage device into a buffer memory such as a dynamic random access memory (DRAM) and executes the program.

[0031] Each component of the information processing device 10 may be implemented using dedicated hardware. Furthermore, some or all of the components may be implemented using general-purpose or dedicated circuits, processors, or a combination thereof. These may be implemented using a single chip or multiple chips connected via a bus. Some or all of the components of each device may be implemented using a combination of the above-mentioned circuits and programs. The processor may be a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an FPGA (Field-Programmable Gate Array), or the like. Furthermore, at least some of the processing performed by the information processing device 10 may be provided as Software as a Service (SaaS). The description of the components described herein may also be applied to other devices or systems described below in this disclosure.

[0032] As described above, according to the present embodiment, it is possible to provide an information processing device, an information processing method, and a program for appropriately grasping the risk of landslides in an observation target area from the observed amount of ground deformation.

[0033] <Embodiment 2> Next, embodiment 2 will be described. Fig. 3 is a schematic diagram of the configuration of a surveying system 1 according to the present disclosure. The surveying system 1 acquires SAR images of an observation target area A10 and evaluates the landslide risk of the observation target area A10. The surveying system 1 mainly includes a radar satellite 11, an antenna 12, a receiving device 13, a recording device 14, a display device 15, and an information processing device 20.

[0034] The radar satellite 11 generates SAR data by irradiating microwaves onto the Earth's surface from its onboard synthetic aperture radar and receiving the reflected waves. The SAR data includes information about the position of the observation target area A10. The SAR data also includes information about the position of the radar satellite 11. The radar satellite 11 transmits the generated SAR data to an antenna 12. The antenna 12 receives the SAR data from the radar satellite 11 and supplies the received SAR data to a receiving device 13.

[0035] The receiving device 13 performs processing such as demodulation on the SAR data received from the antenna 12 and supplies the data to the recording device 14. The recording device 14 has a recording medium such as an SSD, a hard disk, or a magnetic tape. The recording device 14 sequentially records the SAR data received from the receiving device 13 in a readable manner. The recording device 14 may be cloud storage. The recording device 14 is communicably connected to the information processing device 20 and supplies predetermined SAR data to the information processing device 20 in response to a request from the information processing device 20. The display device 15 displays the data processed by the information processing device 20 as a landslide risk area.

[0036] Next, the information processing device 20 will be described with reference to Fig. 4. Fig. 4 is a block diagram of the information processing device 20. The information processing device 20 mainly includes a measurement information acquisition unit 111, a ground deformation amount calculation unit 112, a risk assessment unit 113, a reference information acquisition unit 114, a storage unit 115, an operation reception unit 116, and a display control unit 117.

[0037] The measurement information acquisition unit 111 of the information processing device 20 acquires multiple pieces of measurement information as measurement information. More specifically, the measurement information acquisition unit 111 acquires data on multiple SAR images measured over multiple time periods from the recording device 14. The ground deformation calculation unit 112 compares the SAR images from the multiple time periods and calculates the elevation of each observation point in the observation target area A10 over the multiple time periods using well-known techniques. The ground deformation calculation unit 112 calculates the amount of ground deformation from the difference in elevation information for the observation points in the observation target area A10 over different time periods.

[0038] The risk assessment unit 113 calculates the rate of change, which is the amount of change over time in the amount of ground deformation at at least one observation point, and compares the rate of change with a rate threshold to assess the risk of landslides. That is, in this case, the risk assessment unit 113 assesses areas where the magnitude of the rate of change in the amount of ground deformation is higher than a predetermined threshold as having a high risk of landslides. Areas where the magnitude of the rate of change is higher than the predetermined threshold are, for example, points where the elevation has suddenly decreased due to the outflow of sediment, or points where the elevation has suddenly increased due to the accumulation of sediment.

[0039] This allows a user of the information processing device 20 to identify points where the amount of ground movement changes suddenly as a sign of a landslide. At this time, the risk assessment unit 113 may assess the landslide risk by referring to the reference information received from the reference information acquisition unit 114. The risk assessment unit 113 supplies a signal including information on the assessed landslide risk to the display control unit 117.

[0040] The reference information acquisition unit 114 acquires reference information for assessing the risk of landslides. The information processing device 20 stores the reference information in the storage unit 115. The reference information acquisition unit 114 reads the reference information from the storage unit 115 and supplies the read reference information to the risk assessment unit 113.

[0041] The reference information is information used by the risk assessment unit 113 to assess the risk of landslides. The reference information is, for example, topographical information including at least one of the geology and topography of the observation target area A10. Note that, if the topographical information is included in the survey information, the reference information acquisition unit 114 may acquire the reference information from the survey information.

[0042] Here, the geological information includes information indicating the geology and distribution of strata in the observation target area A10, and is related to the stability of the ground. Specifically, the geological information indicates, for example, that the observation point includes a clay layer or a bedrock layer. Furthermore, the topographical information includes information indicating the location of cliffs and water sources, and is related to the likelihood of landslides occurring or the likelihood of damage spreading if a landslide occurs. Specifically, the topographical information indicates, for example, that the observation point is along a river or on a steep slope.

[0043] In this case, the risk assessment unit 113 sets a threshold for assessing the risk of a landslide disaster based on, for example, topographical information included in the reference information. For example, the risk assessment unit 113 assesses the risk of a landslide disaster by relatively lowering the threshold at an observation point with a specific topography.

[0044] More specifically, the risk assessment unit 113 may prepare a speed threshold for each type of terrain, such as flat land, riverside land, and sloping land, and set the speed threshold based on the terrain of the observation point. Alternatively, a coefficient may be set for each type of terrain, such as flat land, riverside land, and sloping land, and the speed threshold may be set by multiplying the coefficient by a threshold determined in advance based on the terrain of the observation point. This allows the information processing device 20 to assess the risk of landslides with high sensitivity in areas with terrain or geology that potentially require caution.

[0045] The risk assessment unit 113 may determine the speed threshold based on topographical information of the observation point. This allows the information processing device 20 to detect signs of ground movement in areas with potentially alarming topography or geology at an earlier stage. In addition, users of the information processing device 20 can work on predictive maintenance.

[0046] The storage unit 115 is a non-volatile memory such as a flash memory. The storage unit 115 stores at least reference information. The reference information is, for example, information about the geology of the observation target area A10. The reference information may also be information about a hazard map of the observation target area A10.

[0047] The operation reception unit 116 receives operations from a user who uses the information processing device 20. The operation reception unit 116 receives predetermined information from an information input device such as a keyboard or switch that allows the user to input various instructions. The display control unit 117 receives a signal including information on the landslide disaster risk level from the risk assessment unit 113. The display control unit 117 controls the presentation information on the landslide disaster risk level to be displayed on the display device 15.

[0048] Next, the process executed by the information processing device 20 will be described with reference to Fig. 5. Fig. 5 is a second flowchart of the information processing method according to the present disclosure.

[0049] First, in step S21, the measurement information acquisition unit 111 acquires measurement information including multiple pieces of elevation information for the observation target area A10 over different time periods. The measurement information acquisition unit 111 supplies the acquired measurement information to the ground deformation calculation unit 112. The measurement information acquisition unit 111 may acquire, as the measurement information, data on multiple SAR images obtained by surveying the ground surface of the observation target area A10 from above over multiple different time periods using a synthetic aperture radar. Alternatively, the measurement information acquisition unit 111 may acquire measurement information accumulated through surveying work by accessing an external database.

[0050] Next, in step S22, the ground deformation calculation unit 112 compares the measurement information obtained over multiple periods to calculate the elevation change, i.e., the ground deformation, for each corresponding observation point. The ground deformation calculation unit 112 then supplies data on the calculated ground deformation to the risk assessment unit 113.

[0051] Next, in step S23, the reference information acquisition unit 114 acquires reference information corresponding to the observation target area A10 from the storage unit 115. The reference information acquisition unit 114 supplies the acquired reference information to the risk assessment unit 113.

[0052] Next, in step S24, the risk assessment unit 113 calculates the rate of change, which is the amount of change over time in the amount of ground movement, as a time-series trend, based on the amount of ground movement received from the ground movement calculation unit 112.

[0053] Next, in step S25, the risk assessment unit 113 assesses the landslide risk at each observation point in the observation target area A10 by referring to the time-series trend of the rate of ground deformation and the reference information. Furthermore, the risk assessment unit 113 outputs a signal including information on the assessed landslide risk to the display control unit 117.

[0054] The risk assessment unit 113 may further calculate a fluctuation acceleration, which is the amount of change over time in the rate of fluctuation of the ground deformation amount, in step S24. In this case, in step S25, the risk assessment unit 113 evaluates the landslide risk based on the fluctuation acceleration calculated in step S24.

[0055] Next, a method for analyzing data or information handled by the information processing device 20 will be described with reference to Fig. 6. Fig. 6 is a diagram showing an example of the transition of the amount of ground deformation according to the present disclosure. This transition of the amount of ground deformation was observed at one observation point. In Fig. 6, the vertical axis shows the amount of ground deformation, and the horizontal axis shows the observation period.

[0056] The risk assessment unit 113 calculates the difference between the amount of ground movement between the two time periods in Fig. 6 as the movement speed. The risk assessment unit 113 assesses the risk of a landslide disaster as high if the magnitude of the calculated movement speed is higher than a threshold. In other words, the survey information acquisition unit 111 has already acquired information on the amount of ground movement between at least two time periods in step S21 in order to calculate the movement speed of the amount of ground movement.

[0057] Here, the risk assessment unit 113 considers the fluctuation speed to be the difference in the amount of ground deformation between adjacent periods. Specifically, the risk assessment unit 113 evaluates the landslide risk using, for example, a ground deformation speed threshold of 4 mm / cycle. Here, the speed threshold of 4 mm / cycle is calculated from the transition of ground deformation at past landslide occurrence points. The periods in which the magnitude of the fluctuation speed is equal to or greater than the speed threshold are the period from 20XX / a1 / b to 20XX / a1 / c and the period from 20XX / a2 / d to 20XX / a2 / e. Therefore, the risk assessment unit 113 evaluates the landslide risk of the observation point in question as high during these periods. This allows users of the information processing device 20 to determine that the rate of ground movement during the period from 20XX / a1 / b to a1 / c and the period from 20XX / a2 / d to a2 / e is a sign of a landslide, and to take pre-emptive measures such as inspection and reinforcement at the observation points in question.

[0058] Here, if the reference information acquisition unit 114 has already acquired topographical information at multiple measurement points as reference information, the risk assessment unit 113 may vary the speed threshold for the magnitude of the fluctuation speed based on the topographical information.

[0059] Specifically, the risk assessment unit 113 sets the speed threshold near a cliff to 0.625 times the speed threshold in flat ground, and the speed threshold for sandstone geology to 0.8 times the speed threshold for bedrock geology. In this case, if the reference information indicates that an observation point is near a cliff and has sandstone geology, the risk assessment unit 113 sets the speed threshold at that observation point to half the speed threshold at an observation point on flat ground with bedrock geology. This allows the information processing device 20 to assess the landslide risk according to the topographical information of the observation point.

[0060] In this way, the information processing device 20 calculates the rate of ground deformation from SAR images taken over multiple different time periods and evaluates the landslide risk of the observation target area A10 by taking reference information into account. This allows the information processing device 20 to evaluate the landslide risk of the observation target area A10 based on the amount of change over time. Therefore, this embodiment can provide an information processing device, information processing method, and program for appropriately determining the landslide risk of the observation target area from multiple SAR images.

[0061] The information processing device 20 may store multiple different types of reference information and use these multiple types of reference information to evaluate the landslide risk. Specifically, the information processing device 20 may use, for example, topographical information of the observation target area A10 and the amount of rainfall during the survey period in the observation target area A10 as reference information. This allows the information processing device 20 to appropriately evaluate the landslide risk after rainfall in terrain that is easily affected by rain, such as near rivers or on slopes. Alternatively, the information processing device 20 may select and use reference information that is appropriate for evaluating the landslide risk from multiple types of reference information, depending on the location of the observation target area A10.

[0062] As described above, according to the present embodiment, it is possible to provide an information processing device, an information processing method, and a program for appropriately grasping the risk of landslides in an observation target area from the observed amount of ground deformation.

[0063] <Third Embodiment> Next, a third embodiment will be described. Fig. 7 is a block diagram of an information processing device 30 according to the present disclosure. The information processing device 30 according to the present disclosure corresponds to the information processing device 20 described with reference to Figs. 3 and 4, and has a similar configuration. The information processing device 30 functions in place of the information processing device 20 in the configuration of the surveying system 1 according to the present disclosure. Other configurations of the surveying system 1 are the same as the configuration of the surveying system 1 described with reference to Fig. 3. Therefore, a description of the elements that make up the surveying system 1 and the information processing device 30 will be omitted to avoid redundancy.

[0064] In the third embodiment, the risk assessment unit 113 sets a plurality of statistical districts each covering a plurality of observation points in the observation target area A10. The risk assessment unit 113 may assess the landslide risk by comparing a district ground deformation amount, which is calculated as a statistical quantity of the ground deformation amounts at the plurality of observation points included in the statistical district, with a district threshold. In other words, in this case, the risk assessment unit 113 assesses the landslide risk of the statistical district based on the characteristics of the ground deformation amounts at the plurality of observation points included in the statistical district, rather than the ground deformation amount at a single observation point.

[0065] Specifically, the risk assessment unit 113 may assess the risk of landslide disasters based on the average, median, maximum, or minimum value of the amount of ground deformation at each observation point included in the statistical area. This allows the information processing device 30 to collectively check the characteristics of the amount of ground deformation within the statistical area, and to assess the risk of landslide disasters in a wide observation area with reduced processing load.

[0066] The risk assessment unit 113 may calculate the amount of ground deformation for a statistical district based on the difference between the amounts of ground deformation at multiple observation points included in the statistical district. Specifically, the risk assessment unit 113 assesses the landslide risk for a district based on the difference between the maximum and minimum amounts of ground deformation. Alternatively, the risk assessment unit 113 assesses the landslide risk for a district based on the variance or standard deviation of the amount of ground deformation at each observation point included in the statistical district. In this way, the information processing device 30 can detect localized ground deformation occurring at some of the multiple nearby observation points and assess the landslide risk.

[0067] The reference information acquired by the reference information acquisition unit 114 may be information about a hazard map for the observation target area A10. In this case, the risk assessment unit 113 sets statistical areas based on information about non-alert areas or alert areas on the hazard map. For example, the risk assessment unit 113 evaluates the risk level by collectively assessing non-alert areas where the possibility of a landslide is considered low. This reduces the processing load on the information processing device 30 for information processing.

[0068] Furthermore, the information processing device 30 may, for example, assess the risk level for all alert areas that are considered to be highly likely to experience a landslide disaster. This allows the information processing device 30 to assess the risk of a landslide disaster in the observation target area with high sensitivity.

[0069] The risk assessment unit 113 may subdivide the statistical district in stages. Specifically, for example, the risk assessment unit 113 designates the first statistical district as the first statistical district. The risk assessment unit 113 assesses the landslide risk of the first statistical district based on the first district ground deformation amount and the first district threshold value, which are the district ground deformation amount and the district threshold value in the first statistical district.

[0070] Next, the risk assessment unit 113 sets a plurality of second statistical districts by dividing the first statistical district when the magnitude of the first district ground deformation amount is greater than the first district threshold. The risk assessment unit 113 may set the second statistical districts by equally dividing the first statistical district into a predetermined number of districts. Alternatively, the risk assessment unit 113 may set the second statistical districts by equally dividing the first statistical district into a number based on the size of the first statistical district. Note that the risk assessment unit 113 may set the second statistical districts to be smaller the higher the landslide risk of the first statistical district.

[0071] Furthermore, the risk assessment unit 113 compares the second area ground movement amount calculated as a statistical quantity of ground movement amounts at observation points included in the second statistical area with the second area threshold value to update the landslide risk level of the second statistical area.

[0072] This allows the information processing device 30 to concentrate processing on areas at risk of landslides and to evaluate the degree of risk of landslides in detail over a wide observation area.

[0073] Furthermore, the risk assessment unit 113 may set the first zone threshold and the second zone threshold to be different from each other. The risk assessment unit 113 evaluates the landslide risk according to the range and characteristics of the statistical zone by varying the threshold according to the set statistical zone. This allows the information processing device 30 to gradually identify observation points with a higher landslide risk.

[0074] Next, the process executed by the information processing device 20 will be described with reference to Fig. 8. Fig. 8 is a third flowchart of the information processing method according to the present disclosure.

[0075] Steps S31 to S33 are the same procedures as steps S21 to S23 described with reference to Fig. 5, and therefore redundant description will be omitted. In step S33, the reference information acquisition unit 114 may acquire a hazard map as reference information.

[0076] In step S34, the risk assessment unit 113 refers to the reference information acquired from the reference information acquisition unit 114 and sets a plurality of statistical districts that include a plurality of observation points in the observation target area A10 within their ranges.

[0077] Next, in step S35, the risk assessment unit 113 calculates the amount of zonal ground movement by collecting the amounts of ground movement at multiple observation points included in the statistical area. Specifically, the risk assessment unit 113 calculates, for example, the largest amount of ground movement within the statistical area as the amount of zonal ground movement. The risk assessment unit 113 may determine the average or median of the amounts of ground movement within the statistical area as the amount of zonal ground movement. The risk assessment unit 113 may also determine the variance or deviation of the amounts of ground movement within the statistical area as the amount of zonal ground movement.

[0078] In step S36, the risk assessment unit 113 compares the zonal ground deformation amount with a preset zonal threshold value to assess the landslide risk. Specifically, the risk assessment unit 113 assesses, for example, observation points included in zonal ground deformation amounts lower than the zonal threshold value as being at risk of landslide. This allows the information processing device 30 to assess the landslide risk at all observation points included in a wide observation target area without increasing the processing load, even when the target area is a wide area.

[0079] Next, a method for analyzing data or information handled by the information processing device 20 will be described with reference to Fig. 9. Fig. 9 is a diagram showing an example of setting statistical areas according to the present disclosure.

[0080] The left image in the upper part of Fig. 9 is a reference SAR image P1 acquired during a reference period. The reference period is a period used as a reference when calculating the amount of ground deformation. The right image in the upper part of Fig. 9 is a survey SAR image P2 acquired during the surveying period. The ground deformation calculation unit 112 calculates the amount of ground deformation at each observation point included in the observation target area from the reference SAR image P1 and the survey SAR image P2.

[0081] Map D11 in the center of the middle row of Figure 9 is a map showing the amount of ground deformation. In map D11, the observation area is divided into grids that indicate each observation point, and the amount of ground deformation at each observation point is indicated by the color intensity of the grid. Here, the contours of the terrain shown by dotted lines in map D11 are added for explanatory purposes and do not need to be actually drawn.

[0082] The map D12 in the middle right of Figure 9 is a hazard map acquired by the reference information acquisition unit 114. The map D12 includes information on the non-alert area A11 and the alert area A12 set in the hazard map. The risk assessment unit 113 extracts the area of ​​the non-alert area A11 from the map D12. Furthermore, the risk assessment unit 113 sets an area including multiple observation points as a statistical area in the area corresponding to the non-alert area A11 on the map D11.

[0083] Map D13 in the lower part of Fig. 9 shows a map on which statistical districts have been set. Here, grids surrounded by thick lines indicate statistical districts. Here, the risk assessment unit 113 sets the statistical districts so that they include 2 x 2 observation points. Note that the size of the statistical districts set by the risk assessment unit 113 does not have to be 2 x 2. Specifically, the size of the statistical districts may be a size that includes 3 x 3 observation points.

[0084] The risk assessment unit 113 compiles statistics of the amount of ground deformation at multiple observation points included in each statistical district, and calculates it as a district ground deformation amount. Next, the risk assessment unit 113 compares the district ground deformation amount with a district threshold to assess the landslide risk for each statistical district. Here, the risk assessment unit 113 defines the maximum value of the magnitude of the amount of ground deformation at the observation points included in the statistical district as the district ground deformation amount. This allows the information processing device 30 to assess the landslide risk based on the regional characteristics of the amount of ground deformation in the statistical district. Furthermore, the information processing device 30 can assess the landslide risk for a wide observation area with reduced processing load.

[0085] At observation points where no statistical area, which is a square surrounded by thin lines, has been set, the risk assessment unit 113 assesses the risk of landslides for each observation point using the same procedure as in embodiment 1.

[0086] Here, the risk assessment unit 113 may set statistical areas of different sizes depending on the observation point in the observation target area A10. Specifically, the risk assessment unit 113 sets statistical areas of different sizes based on the designation status of the alert area and special alert area on the hazard map, for example.

[0087] In this case, the risk assessment unit 113 does not set a statistical area in an area designated as a special alert area on the hazard map. The risk assessment unit 113 also sets a statistical area of ​​2x2 observation points in an area designated as a alert area on the hazard map. Furthermore, the risk assessment unit 113 sets a statistical area of ​​3x3 observation points in an area not designated as a alert area on the hazard map. This allows the information processing device 30 to assess the risk of landslides with reduced load by performing processing that is more in line with the state of the observation target area.

[0088] The risk assessment unit 113 may also set statistical districts only when there is a zonal ground deformation amount, rather than fixing the statistical districts. Specifically, the risk assessment unit 113 may set, for example, a 3x3 statistical district centered on an observation point. Next, the risk assessment unit 113 calculates the zonal ground deformation amount in the statistical district. Furthermore, the risk assessment unit 113 evaluates the landslide risk of the observation point by comparing the zonal ground deformation amount with a zonal period threshold. This allows the information processing device 30 to evaluate the landslide risk of each observation point based on the characteristics of ground deformation within the district.

[0089] In this way, the information processing device 30 sets a statistical district including multiple observation points based on SAR images taken over multiple different time periods, taking into account reference information, and evaluates the landslide risk of the observation target area A10. This allows the information processing device 30 to evaluate the landslide risk based on the regional characteristics of ground deformation in the statistical district. Therefore, this embodiment can provide an information processing device, information processing method, and program for appropriately determining the landslide risk of the observation target area from multiple SAR images.

[0090] The information processing device 30 may store a plurality of different types of reference information and use these plurality of pieces of reference information to determine the landslide disaster risk. Alternatively, the information processing device 30 may select and use reference information that is suitable for determining the landslide disaster risk from the plurality of types of reference information as appropriate, depending on the position of the observation target area A10.

[0091] As described above, according to the present embodiment, it is possible to provide an information processing device, an information processing method, and a program for appropriately grasping the risk of landslides in an observation target area from the observed amount of ground deformation.

[0092] <Fourth Embodiment> Next, a fourth embodiment will be described. Fig. 10 is a block diagram of an information processing device 40 according to the present disclosure. The information processing device 40 according to the present disclosure corresponds to the information processing device 20 described with reference to Figs. 3 and 4, and has a similar configuration. The information processing device 40 functions in place of the information processing device 20 in the configuration of the surveying system 1 according to the present disclosure. Other configurations of the surveying system 1 are the same as the configuration of the surveying system 1 described with reference to Fig. 3. Therefore, a description of the elements that make up the surveying system 1 and the information processing device 40 will be omitted to avoid redundancy.

[0093] In the fourth embodiment, the risk assessment unit 113 calculates a rate of change, which is the amount of change over time in the amount of ground deformation at at least one observation point, and compares the rate of change with a rate threshold to assess the first risk. Furthermore, the risk assessment unit 113 sets a plurality of statistical districts that include a plurality of observation points in the observation target area A10, and assesses the second risk by comparing the calculated zonal ground deformation amounts, which are statistics of the amount of ground deformation at the plurality of observation points included in the statistical districts, with a zonal threshold. Furthermore, the risk assessment unit 113 assesses the risk of landslide disasters based on the first risk and the second risk.

[0094] According to this, the information processing device 40 can integrate the rate of ground deformation and regional characteristics to evaluate the risk of landslides in the observation area from multiple indicators, and estimate areas with a high risk of landslides.

[0095] The risk assessment unit 113 may, for example, assess the higher of the first and second risk levels as the landslide risk level. Alternatively, the risk assessment unit 113 may, for example, assess the landslide risk level as the average value of the first and second risk levels. Furthermore, the risk assessment unit 113 may, for example, input the first and second risk levels into a predetermined discriminant to assess the landslide risk level.

[0096] Next, the processing executed by the information processing device 20 will be described with reference to Fig. 11. Fig. 11 is a fourth flowchart of the information processing method according to the present disclosure.

[0097] Steps S41 to S44 are the same procedures as steps S21 to S24 described with reference to Fig. 5, and therefore will not be described again. In step S33, the reference information acquisition unit 114 may acquire a hazard map as reference information.

[0098] In step S45, the risk assessment unit 113 evaluates the landslide risk of each observation point in the observation target area A10 as a first risk level by referring to the rate of ground deformation and the reference information. That is, the risk assessment unit 113 calculates the rate of deformation for each observation point and evaluates the first risk level.

[0099] Steps S46 and S47 are the same procedures as steps S34 and S35 described with reference to FIG. 5, and therefore a duplicated description will be omitted.

[0100] In step S48, the risk assessment unit 113 compares the amount of zonal ground deformation with a predetermined zonal threshold value to assess the second risk level. Specifically, the risk assessment unit 113 assesses, for example, that an observation point included in a zonal ground deformation amount lower than the zonal threshold value has the second risk level.

[0101] Next, in step S49, the risk assessment unit 113 assesses the risk of a landslide disaster based on the first and second risk levels. Specifically, the risk assessment unit 113 assesses, for example, an observation point that has both the first and second risk levels as being at risk of a landslide disaster.

[0102] The risk assessment unit 113 may assess the landslide risk level into multiple levels. Specifically, for example, when the first risk level and the second risk level are low, the risk assessment unit 113 assesses the landslide risk level as level 0. In this case, the user of the information processing device 40 determines that the risk of a landslide is low. Next, when the second risk level is high and the first risk level is low, the risk assessment unit 113 assesses the risk as level 1. In this case, the user of the information processing device 40 determines that there is a risk of a landslide in the area but that immediate action is not required.

[0103] Furthermore, the risk assessment unit 113 assesses the risk as Level 2 when the first risk level is high and the second risk level is low. In this case, the user of the information processing device 40 warns those in the vicinity to be careful because there is a local risk of a landslide. Furthermore, the risk assessment unit 113 assesses the risk as Level 3 when both the first risk level and the second risk level are high. In this case, the user of the information processing device 40 warns those in the vicinity to be careful because there is a risk of a landslide and starts arranging for predictive maintenance.

[0104] This allows the user of the information processing device 40 to predetermine detailed responses according to the degree of danger, and immediately take appropriate measures according to the assessed degree of danger.

[0105] The information processing device 40 may further include an alarm transmission unit. The alarm transmission unit transmits a signal that causes the receiving device to sound an alarm when the risk assessment unit 113 determines that the landslide risk is at level 2 or level 3. The alarm transmission unit may output a signal to the display control unit 117 to notify the user of the information processing device 40.

[0106] In this way, the information processing device 40 calculates the rate of ground deformation from SAR images measured over multiple different time periods and evaluates the first risk level of the observation target area A10 by taking the reference information into account. The information processing device 40 also sets a statistical district including multiple observation points by taking the reference information into account and evaluates the second risk level of the observation target area A10. Furthermore, the information processing device 40 integrates the first risk level and the second risk level to evaluate the risk level of landslides.

[0107] This allows the information processing device 40 to determine the landslide risk level based on both the amount of change over time and the regional characteristics of the amount of ground change in the statistical district. Therefore, according to this embodiment, it is possible to provide an information processing device, information processing method, and program for appropriately understanding the landslide risk level of an observation target area from multiple SAR images.

[0108] The information processing device 40 may store a plurality of different types of reference information and use these plurality of pieces of reference information to evaluate the landslide risk. Alternatively, the information processing device 40 may select and use reference information that is suitable for evaluating the landslide risk from the plurality of types of reference information, depending on the position of the observation target area A10.

[0109] As described above, according to the present embodiment, it is possible to provide an information processing device, an information processing method, and a program for appropriately grasping the risk of landslides in an observation target area from the observed amount of ground deformation.

[0110] <Example of Hardware Configuration> Hereinafter, an example will be described in which each functional configuration of an information processing device according to the present disclosure is realized by a combination of hardware and software.

[0111] FIG. 12 is a block diagram illustrating an example of a hardware configuration of a computer. The information processing device of the present disclosure can realize the above-described functions by a computer 500 including the hardware configuration shown in the figure. The computer 500 may be a portable computer such as a smartphone or tablet terminal, or a stationary computer such as a PC. The computer 500 may be a dedicated computer designed to realize each device, or may be a general-purpose computer. The computer 500 can realize desired functions by installing a predetermined application.

[0112] The computer 500 has a bus 502, a processor 504, a memory 506, a storage device 508, an input / output interface (I / F) 510, and a network interface (I / F) 512. The bus 502 is a data transmission path for the processor 504, the memory 506, the storage device 508, the input / output interface 510, and the network interface 512 to transmit and receive data to and from each other. However, the method of connecting the processor 504 and the like to each other is not limited to bus connection.

[0113] The processor 504 is a processor such as a CPU, a GPU, an FPGA, etc. The memory 506 is a main storage device realized using a RAM (Random Access Memory) or the like.

[0114] The storage device 508 is an auxiliary storage device realized using a hard disk, an SSD, a memory card, a ROM (Read Only Memory), etc. The storage device 508 stores programs for realizing desired functions. The processor 504 reads the programs into the memory 506 and executes them to realize the respective functional components of each device.

[0115] The input / output interface 510 is an interface for connecting the computer 500 to input / output devices. For example, an input device such as a keyboard and an output device such as a display device are connected to the input / output interface 510. The network interface 512 is an interface for connecting the computer 500 to a network.

[0116] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0117] Each drawing is merely an example for describing one or more embodiments. Each drawing may not relate to only one particular embodiment, but may also relate to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0118] Some or all of the above embodiments can be described as, but are not limited to, the following supplementary notes. (Supplementary Note 1) An information processing device comprising: a survey information acquisition unit that acquires survey information including multiple pieces of elevation information for different time periods in an observation target area; a ground deformation amount calculation unit that calculates a ground deformation amount from a difference in the elevation information for the different time periods at an observation point in the observation target area; and a risk assessment unit that compares the ground deformation amount with a deformation amount threshold, evaluates a landslide risk for the observation point, and outputs a signal including information on the landslide risk. (Supplementary Note 2) The information processing device according to Supplementary Note 1, wherein the risk assessment unit calculates a deformation speed that is a time-dependent change in the ground deformation amount for at least one of the observation points, and evaluates a first risk by comparing the deformation speed with a speed threshold. (Supplementary Note 3) The information processing device according to Supplementary Note 2, wherein the survey information includes topography information including at least one of geology and topography, and the risk assessment unit determines the speed threshold based on the topography information for the observation point. (Supplementary Note 4) The information processing device according to any one of Supplementary Notes 1 to 3, wherein the risk assessment unit sets a plurality of first statistical districts each covering a plurality of the observation points in the observation target area, and assesses a second risk by comparing first district ground deformation amounts, calculated as statistics of the ground deformation amounts at the plurality of observation points included in the first statistical districts, with a first district threshold. (Supplementary Note 5) The information processing device according to Supplementary Note 4, wherein the risk assessment unit calculates the first district ground deformation amount based on a difference in the ground deformation amounts at the plurality of observation points included in the first statistical district. (Supplementary Note 6) The information processing device according to Supplementary Note 4 or 5, wherein the risk assessment unit acquires a hazard map and sets at least one first statistical district by referring to the hazard map. (Supplementary Note 7) The information processing device according to Supplementary Note 4 or 5, wherein the risk assessment unit, when assessing that there is the second risk, sets a plurality of second statistical districts in at least one of the first statistical districts, and updates the second risk by comparing second district ground deformation amounts calculated as statistics of the ground deformation amounts of the observation points included in the second statistical districts with a second district threshold. (Supplementary Note 8) The information processing device according to Supplementary Note 7, wherein the first district threshold and the second district threshold are different from each other.(Supplementary Note 9) The information processing device according to any one of Supplementary Notes 1 to 8, wherein the risk assessment unit calculates a rate of change which is an amount of change over time in the amount of ground deformation at at least one of the observation points, compares the rate of change with a rate threshold to assess a first level of risk, sets a plurality of first statistical districts which include a plurality of the observation points in the observation target area within their ranges, and assesses a second level of risk by comparing first district ground deformation amounts obtained by statistically calculating the amounts of ground deformation at the plurality of observation points included in the first statistical districts with a first district threshold, and assesses the landslide risk based on the first and second risk levels. (Supplementary Note 10) The information processing device according to Supplementary Note 9, wherein the risk assessment unit assesses the landslide risk into a plurality of stages. (Supplementary Note 11) An information processing method comprising: an acquisition step of acquiring measurement information including multiple pieces of elevation information for an observation target area over different time periods; a calculation step of calculating an amount of ground deformation from a difference in the elevation information for the different time periods at an observation point in the observation target area; and an evaluation step of comparing the amount of ground deformation with a deformation threshold, evaluating a landslide risk for the observation point, and outputting a signal including information on the landslide risk. (Supplementary Note 12) A program for causing a computer to execute: an acquisition procedure of acquiring measurement information including multiple pieces of elevation information for an observation target area over different time periods; a calculation procedure of calculating an amount of ground deformation from a difference in the elevation information for the different time periods at an observation point in the observation target area; and an evaluation procedure of comparing the amount of ground deformation with a deformation threshold, evaluating a landslide risk for the observation point, and outputting a signal including information on the landslide risk.

[0119] Some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 2 to 10 that are dependent on Supplementary Note 1 may also be dependent on Supplementary Notes 11 and 12 in the same dependency relationship as Supplementary Notes 2 to 10. Some or all of the elements described in any Supplementary Note may be applied to various hardware, software, recording means for recording software, systems, and methods.

[0120] This application claims priority based on Japanese Patent Application No. 2024-108156, filed on July 4, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0121] 1 Surveying system 10, 20, 30, 40 Information processing device 11 Radar satellite 12 Antenna 13 Receiving device 14 Recording device 15 Display device 111 Surveying information acquisition unit 112 Ground deformation calculation unit 113 Risk assessment unit 114 Reference information acquisition unit 115 Storage unit 116 Operation reception unit 117 Display control unit 500 Computer 502 Bus 504 Processor 506 Memory 508 Storage device 510 Input / output interface 512 Network interface A10 Observation target area A11 Non-warning area A12 Warning area D11, D12, D13 Map P1, P2 Image

Claims

1. An information processing device comprising: a measurement information acquisition unit that acquires measurement information including multiple pieces of elevation information for different periods in an observation area; a ground deformation calculation unit that calculates the amount of ground deformation from the difference in the elevation information for the different periods at an observation point in the observation area; and a risk assessment unit that compares the amount of ground deformation with a deformation threshold, evaluates the landslide risk level at the observation point, and outputs a signal including information on the landslide risk level.

2. The information processing device described in claim 1, wherein the risk assessment unit calculates a rate of change, which is the amount of change over time in the amount of ground movement at at least one of the observation points, and compares the rate of change with a rate threshold to assess the first risk level.

3. The information processing device according to claim 2, wherein the survey information includes topographical information including at least one of geology and topography, and the risk assessment unit determines the speed threshold based on the topographical information of the observation point.

4. An information processing device as described in any one of claims 1 to 3, wherein the risk assessment unit sets a plurality of first statistical districts that include a plurality of the observation points in the observation target area within their ranges, and evaluates the second risk by comparing the first district ground movement amount calculated as a statistical quantity of the ground movement amount at the plurality of observation points included in the first statistical districts with a first district threshold value.

5. The information processing device according to claim 4, wherein the risk assessment unit calculates the first area ground movement amount based on the difference in the ground movement amounts of the multiple observation points included in the first statistical area.

6. The information processing device according to claim 4 or 5, wherein the risk assessment unit acquires a hazard map and sets at least one of the first statistical areas by referring to the hazard map.

7. An information processing device as described in claim 4 or 5, wherein the risk assessment unit, when assessing that there is the second risk level, sets multiple second statistical areas in at least one of the first statistical areas, and updates the second risk level by comparing the second area ground movement amount calculated as a statistical amount of the ground movement amount at the observation point included in the second statistical area with a second area threshold value.

8. The information processing device according to claim 7, wherein the first area threshold and the second area threshold are different from each other.

9. An information processing device according to any one of claims 1 to 8, wherein the risk assessment unit calculates a rate of change, which is the amount of change over time, of the amount of ground movement at at least one of the observation points, compares the rate of change with a rate threshold to assess a first risk level, sets a plurality of first statistical districts that include a plurality of the observation points in the observation target area within their ranges, and assesses a second risk level by comparing a first district ground movement amount, which is a statistical calculation of the amount of ground movement at the plurality of observation points included in the first statistical districts, with a first district threshold, and assesses the landslide risk level based on the first risk level and the second risk level.

10. The information processing device according to claim 9, wherein the risk assessment unit assesses the risk of landslide disasters into a plurality of stages.

11. An information processing method comprising: an acquisition step in which a computer acquires survey information including multiple pieces of elevation information for different periods in an observation area; a calculation step in which a ground deformation amount is calculated from the difference in the elevation information for the different periods at an observation point in the observation area; and an evaluation step in which the ground deformation amount is compared with a deformation threshold to evaluate the landslide risk level at the observation point, and output a signal including information on the landslide risk level.

12. A program for causing a computer to execute the following steps: an acquisition procedure for acquiring survey information including multiple elevation information for different periods in an observation area; a calculation procedure for calculating the amount of ground movement from the difference in the elevation information for the different periods at an observation point in the observation area; and an evaluation procedure for comparing the amount of ground movement with a movement threshold, evaluating the landslide risk at the observation point, and outputting a signal including information on the landslide risk.

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