Information processing device, information processing method, and program

Abstract

This information processing device comprises: an acquiring unit that acquires the catchment area and slope for each of a plurality of divided regions included in a prescribed area, and acquires the population density or distance from an urban area; a calculating unit that calculates a topographic wetness index on the basis of the catchment area and the slope for each of the plurality of divided regions; and an extracting unit that extracts a candidate site for a water source from among a plurality of target regions included in the area on the basis of the topographic wetness index and the population density or the distance from an urban area.

Description

Information Processing Apparatus, Information Processing Method, and Program

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

[0002] In recent years, due to changes in the external environment such as climate change and population growth, water risks such as water shortages, water pollution, floods, and droughts have been increasing worldwide. In addition, there are concerns about the decline in the groundwater level in water sources due to factors such as a decrease in precipitation, an increase in evapotranspiration, land desertification, an increase in water usage, and an increase in the pumping volume of factories. When problems such as a significant decline in the groundwater level of a water source occur, it is necessary to quickly search for candidate sites for alternative water sources.

[0003] While a water source is required to be located near the outskirts of an urban area with a large water usage, from the perspective of water quality, it is required to be far from facilities that can be pollution sources. On the other hand, in the outskirts of an urban area, there are many water users and the characteristic of increasing water risks. Also, the water source is required not to be too far from the urban area. Conventionally, an information processing apparatus has been proposed that can easily identify important points in carrying out water resource conservation activities in each target area (see Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2022-117715

[0005] It is required to appropriately extract candidate sites for water sources.

[0006] An object of the present disclosure is to provide an information processing apparatus, an information processing method, and a program capable of appropriately extracting candidate sites for water sources.

[0007] To solve such problems, the information processing apparatus of the present disclosure includes an acquisition unit that acquires the catchment area and slope for each of a plurality of divided regions included in a predetermined area, and also acquires the population density or the distance from an urban area, a calculation unit that calculates a topographic wetness index for each of the plurality of divided regions based on the catchment area and slope, and an extraction unit that extracts candidate sites for water sources from among a plurality of target regions included in the area based on the topographic wetness index, the population density, or the distance from an urban area.

[0008] In this disclosure, it is preferable that the extraction unit extracts candidate sites based on the result of comparing the topographic moisture index with a predetermined threshold.

[0009] In this disclosure, it is preferable that the distance from urban areas includes either the straight-line distance or the travel distance according to the route.

[0010] In this disclosure, the target area is preferably a topographic watershed boundary of a predetermined size.

[0011] To solve the aforementioned problems, the information processing method disclosed herein is characterized by including obtaining the drainage area and gradient for each of several subdivided areas included in a predetermined area, along with the population density or distance from urban areas, calculating a topographic moisture index for each of the several subdivided areas based on the drainage area and gradient, and extracting candidate water source sites from among several target areas included in the area based on the topographic moisture index and the population density or distance from urban areas.

[0012] To solve these problems, the program of this disclosure is characterized by providing a computer with the following functions: an acquisition unit that acquires the drainage area and gradient for each of several divided areas included in a predetermined area, as well as the population density or distance from urban areas; a calculation unit that calculates a topographic moisture index for each of the several divided areas based on the drainage area and gradient; and an extraction unit that extracts candidate water source locations from among several target areas included in the area based on the topographic moisture index and the population density or distance from urban areas.

[0013] The information processing device, information processing method, and program related to this disclosure can appropriately extract candidate water source locations.

[0014] This figure shows the schematic configuration of the information processing system according to the embodiment of this disclosure. This figure shows the schematic configuration of the computer device. This figure shows topographic watershed boundary map data. This figure shows population density map data. This figure shows distance map data. This figure shows TWI map data. This is a two-dimensional histogram showing the relationship between the analysis results of the distributed water cycle model for area AR and the TWI values. This is a flowchart showing an example of the operation of the process for extracting candidate water source locations. This figure shows output map data.

[0015] <Embodiments> Below, an information processing device, information processing method, and program relating to one aspect of an embodiment will be described with reference to the figures. However, it should be noted that the technical scope of this disclosure is not limited to these embodiments, but extends to the disclosures described in the claims and their equivalents.

[0016] Figure 1 is a diagram showing a schematic configuration of an information processing system 1 according to an embodiment of the present disclosure.

[0017] As shown in Figure 1, the information processing system 1 includes a computer device 100, a GIS (Geographic Information System) server 200, and an external server 300. The computer device 100, the GIS server 200, and the external server 300 are connected to each other via a network N so that they can communicate with one another. Network N is a wired network such as the Internet or an intranet. Network N may also be a wireless network such as a wireless LAN (Local Area Network).

[0018] Figure 2 shows a schematic configuration of the computer device 100.

[0019] Computer device 100 is an example of an information processing device. Computer device 100 may be a notebook PC, a tablet PC, or the like.

[0020] The computer device 100 includes a communication unit 101, an input unit 102, a display unit 103, a storage unit 104, and a processing unit 110, etc. The communication unit 101, input unit 102, display unit 103, storage unit 104, and processing unit 110 are interconnected via a CPU (Central Processing Unit) bus or the like.

[0021] The communication unit 101 has an antenna for transmitting and receiving wireless signals and a wireless communication interface circuit that conforms to a communication protocol such as a wireless LAN (Local Area Network), and communicates with the network N in accordance with a communication standard such as a wireless LAN. The communication unit 101 sends data received from an external server 300, etc. via the network N to the processing unit 110. The communication unit 101 also transmits data received from the processing unit 110 to a GIS server 200, etc. via the network N. The communication unit 101 may also have a wireless communication interface circuit that conforms to a communication standard such as LTE (Long Term Evolution) or 5G, and communicates with the network N via a base station. Alternatively, the communication unit 101 may also have a wired communication interface circuit that conforms to a communication protocol such as TCP / IP (Transmission Control Protocol / Internet Protocol), and communicates with the network N in accordance with a communication standard such as Ethernet (registered trademark). The communication unit 101 is an example of an output unit.

[0022] The input unit 102 has an input device such as a touch panel, keyboard, or mouse, and an interface circuit that acquires signals from the input device, and outputs an operation signal corresponding to the user's input operation.

[0023] The display unit 103 is an example of an output unit. The display unit 103 has a display including liquid crystal, organic EL (Electro-Luminescence), etc., and an interface circuit that outputs image data to the display, and displays an image on the display based on the image data.

[0024] The storage unit 104 includes memory devices such as RAM (Random Access Memory) and ROM (Read Only Memory), fixed disk devices such as hard disks, or portable storage devices such as flexible disks and optical disks.

[0025] Furthermore, the storage unit 104 stores various data such as computer programs, databases, and tables used for various processes of the computer device 100. Computer programs may be installed in the storage unit 104 from a computer-readable portable recording medium using a known setup program or the like. Examples of portable recording media include CD-ROMs (compact disc read-only memory) and DVD-ROMs (digital versatile disc read-only memory). Computer programs may also be stored on a recording medium owned by a predetermined server and installed via the network N.

[0026] In addition to the above, the memory unit 104 stores the water source extraction program P1, topographic watershed boundary map data 105, population density map data 106, distance map data 107, and TWI (Topographic Wetness Index) map data 108, etc. The water source extraction program P1 is an example of the program of this disclosure.

[0027] The processing unit 110 operates based on a computer program pre-stored in the storage unit 104. The processing unit 110 is, for example, a CPU. A DSP (digital signal processor), LSI (large scale integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), etc., may be used as the processing unit 110. The processing unit 110 is connected to the communication unit 101, input unit 102, display unit 103, and storage unit 104, etc., and controls each device. The processing unit 110 acquires various information necessary to extract candidate water source locations from the GIS server 200 and external server 300 via the communication unit 101.

[0028] The processing unit 110 reads the water source extraction program P1 stored in the storage unit 104 and operates according to the read water source extraction program P1. As a result, the processing unit 110 functions as an acquisition unit 111, a calculation unit 112, an extraction unit 113, and an output control unit 114. The acquisition unit 111 is an example of an acquisition unit.

[0029] The water source extraction program P1 stored in the memory unit 104 is software for determining which topographic watershed boundary to extract as a candidate water source from among multiple topographic watershed boundaries included in a predetermined area where water source exploration is desired.

[0030] The area includes forests, rivers, and other types of land, and the user of the computer device 100 determines the desired area for searching for water sources from the map. The user can arbitrarily determine the extent and size of the area.

[0031] Figure 3 shows the topographic watershed boundary map data 105. The topographic watershed boundary map data 105 is map data representing multiple topographic watershed boundaries included in a rectangular area AR determined on the map. Figure 3 displays multiple topographic watershed boundaries 001, 002, 003, ... which are finely divided within the area AR. 001, 002, 003, ... are identification information for identifying the topographic watershed boundaries. The multiple topographic watershed boundaries 001, 002, 003, ... differ in size and shape from one another. The size of the topographic watershed boundaries can be arbitrarily changed by settings and conditions.

[0032] The topographic watershed boundaries that are targeted as potential water source locations are watersheds that include aquifers rich in groundwater. A topographic watershed boundary is an area in the area AR (Area Search for Water Sources) that is divided into multiple watersheds. Topographic watershed boundaries are watersheds enclosed by ridges, and the size and shape of each topographic watershed boundary differ from one another. A topographic watershed boundary is an example of a target area. Groundwater accumulates when water flows from high places to low places and accumulates in flat areas with a gentle slope. An aquifer is a layer of permeable soil that is saturated with groundwater.

[0033] The topographic watershed boundary map data 105 is provided by the computer device 100 to the GIS server 200 by providing area AR information and various conditions. The GIS server 200 generates the topographic watershed boundary map data 105 by dividing the area AR into multiple topographic watershed boundaries using DEM (Digital Elevation Model) data. DEM data is topographic data of a digital elevation model that does not include the height of buildings or trees. The topographic watershed boundary map data 105 is acquired in advance by the computer device 100 from the GIS server 200 and then stored in the storage unit 104. However, the topographic watershed boundary map data 105 may also be downloaded from the GIS server 200 or the like each time the computer device 100 needs it and stored in the storage unit 104. The GIS server 200 may generate the topographic watershed boundary map data 105 using not only DEM data, but also DSM (Digital Surface Model) data and DTM (Digital Terrain Model) data.

[0034] Figure 4 shows the population density map data 106. The population density map data 106 is map data that displays population density information, showing the areas of the AR area where water source search is desired to be divided according to population density.

[0035] In the population density map data 106, population density is the number of people per unit area and is expressed as persons / ha, etc. The area AR displayed in the population density map data 106 is divided into multiple cells of a predetermined size and is divided into ranges on the map according to the population density. The population density map data 106 is published, for example, on the website of a government ministry, and can be obtained from an external server 300.

[0036] Population density map data 106 shows that the population density is highest in the suburbs of urban areas and lower in areas further away from urban areas. In this case, the population density areas are divided into urban areas 106a, which corresponds to the urban area with the highest population density; suburban areas 106b, which correspond to the suburbs of urban areas with a moderate population density; and suburban areas 106c, which correspond to the suburbs with the lowest population density. Here, an urban area refers to a densely populated area, a large town that is the center of politics, economy, and culture, for example, a continuous area with a population density of 4,000 or more people per square kilometer, or an area with a population of 50,000 or more people.

[0037] Figure 5 shows the distance map data 107. The distance map data 107 is map data that displays information on the distance from urban areas, showing the ranges of the AR area where water source search is desired, divided according to the distance from urban areas.

[0038] The distance map data 107 displays distance ranges divided according to the distance from the urban area within the area AR. When the urban center is used as the reference point, the distance from the urban area is the straight-line distance between the location of each point in the area AR and the location of the urban center. The distance map data 107 can be obtained from the external server 300 and stored in the storage unit 104. Alternatively, the computer device 100 may obtain the straight-line distance between each point in the area AR and the urban center from the external server 300 and generate the distance map data 107 using a predetermined program.

[0039] The distance map data 107, like the population density map data 106, divides the area AR into multiple cells of a predetermined size. The cells in the distance map data 107 are the same size as the cells in the population density map data 106. In the distance map data 107, the distance ranges are divided into a short-distance range 107a, which is less than a radius A km from the center of the urban area; a medium-distance range 107b, which is further out and between a radius A km and less than B km from the center of the urban area; and a long-distance range 107c, which is even further out and has a radius of B km or more from the center of the urban area.

[0040] FIG. 6 is a diagram showing TWI map data 108. The TWI map data 108 is map data showing TWI information in which a plurality of cells obtained by dividing an area AR where water source exploration is desired according to the value of TWI (Terrain Wetness Index) are displayed.

[0041] In the TWI map data 108, a plurality of cells divided according to the value of TWI (Terrain Wetness Index) in the area AR where water source exploration is desired are displayed. In the TWI map data 108, the area AR where water source exploration is desired is divided into cells of a predetermined size (for example, 1500 m square). The cells in the TWI map data 108 are the same size as the cells in the population density map data 106 and the distance map data 107. However, the respective cells of the TWI map data 108, the population density map data 106, and the distance map data 107 may have different sizes.

[0042] The plurality of cells in the TWI map data 108 are displayed in colors (gray scale) according to the value of TWI. In this case, cells with a TWI value less than a predetermined threshold X and cells with a TWI value of X or more are displayed in different colors. For example, the square cell 108a with a TWI value less than the threshold X is displayed in colorless or light gray, and the cell 108b with a TWI value of X or more is displayed in dark gray or black.

[0043] TWI (Terrain Wetness Index) is an index that quantifies the ease of constant water accumulation and the ease of water pooling in the area AR based on the characteristics of the terrain. TWI is calculated for each cell based on the catchment area and slope of the cells obtained by dividing the area AR into a predetermined size. A cell is an example of a plurality of divided regions included in the area AR. The cells in the TWI map data 108 are smaller than the size of the smallest terrain catchment boundary in the terrain catchment boundary map data 105. However, the size of the cells in the TWI map data 108 may be larger than the size of the smallest terrain catchment boundary, and the size and shape of the cells in the TWI map data 108 may be the same as the terrain catchment boundary.

[0044] For the calculation of TWI, the catchment area and slope of the cells in the DEM data are used and calculated by the following formula (1). α: Watershed area [m ,

[0049] β: Slope [rad]

[0045] The watershed area α is the area of the land within the range corresponding to the cell, and is expressed in the unit [m ２ . Note that as the watershed area α increases, the cumulative flow rate of groundwater also increases. Therefore, the cumulative flow rate may be used instead of the watershed area. The slope β is the maximum value of the inclination angle of the land within the range corresponding to the cell, and is expressed in the unit [rad]. The slope β may be the average value of the inclination angles of the land within the range corresponding to the cell.

[0046] As can be seen from equation (1), the TWI increases as the watershed area α of the cell increases, and increases as the slope β of the cell decreases. Therefore, the TWI is calculated as a larger value for a terrain where the watershed area α of the cell is large and the slope β is small.

[0047] In the TWI map data 108, it is possible to extract candidate areas for water sources based on the comparison result between the TWI value of the cell and the threshold value X. In this case, it means that the cell 108a is not a catchment area rich in groundwater, while the cell 108b is a catchment area rich in groundwater. Such TWI map data 108 is stored in the storage unit 104 after being generated based on the TWI value by the calculation unit 112 (described later) of the computer device 百.

[0048] Figure 7 is a two-dimensional histogram showing the relationship between the analysis result by the distributed water circulation model for the area AR and the TWI value. The distributed water circulation model is, for example, a simulation model of GETFLOWS (registered trademark) that analyzes the flow of groundwater, and it is possible to analyze the flow of groundwater for each cell using DEM data.

[0049] In this two-dimensional histogram, the vertical axis represents the TWI value (0 to 20), and the horizontal axis represents the change in groundwater level per grid cell (-20 to 0 m). The change in groundwater level is the amount by which the groundwater level changes (decreases) over a given period. This two-dimensional histogram shows that the smaller the TWI, the more cells there are with large changes in groundwater level, and the larger the TWI, the more cells there are with small changes in groundwater level. In other words, cells with a large TWI mean that the change in groundwater level is small and that the catchment area is rich in groundwater.

[0050] Thus, TWI correlates with changes in groundwater levels. Cells with high TWI values ​​indicate smaller changes in groundwater levels, making them more susceptible to water accumulation and thus should be identified as potential sources of abundant groundwater. Therefore, it is possible to estimate topographic watershed boundaries that are potential sources of abundant groundwater based on cells with high TWI values.

[0051] Figure 8 is a flowchart showing an example of the operation of the process for extracting candidate water source locations in the computer device 100.

[0052] The following describes an example of the process for extracting candidate water source locations, referring to the flowchart shown in Figure 8. The operations described below are mainly performed in cooperation with various elements of the computer device 100, based on the water source extraction program P1 that is stored in the memory unit 104 of the computer device 100.

[0053] The acquisition unit 111 determines an area AR on the map to search for potential water source locations (step S101). The acquisition unit 111 receives an operation from the user via the input unit 102 and determines an area AR on the map corresponding to that operation (step S101).

[0054] The acquisition unit 111 acquires topographic watershed boundary map data 105 corresponding to the area AR from which water source extraction is desired (step S102). The acquisition unit 111 transmits information about the area AR and conditions such as the size of the smallest unit of the topographic watershed boundary to the GIS server 200 via the communication unit 101. The acquisition unit 111 acquires the topographic watershed boundary map data 105, in which the area AR has been divided into multiple topographic watershed boundaries, via the communication unit 101 and stores it in the storage unit 104.

[0055] Next, the acquisition unit 111 acquires the population density map data 106 for the area AR from an external server 300 or the like via the communication unit 101 (step S103). The acquisition unit 111 transmits the area AR information and a request signal for the population density map data 106 to the external server 300 via the communication unit 101. After acquiring the population density map data 106 for the area AR from the external server 300, the acquisition unit 111 stores it in the storage unit 104.

[0056] Next, the acquisition unit 111 acquires distance map data 107 for the area AR from an external server 300 or the like via the communication unit 101 (step S104). The acquisition unit 111 transmits area AR information and a request signal for distance map data 107 to the external server 300 via the communication unit 101. After acquiring the distance map data 107 for the area AR from the external server 300, the acquisition unit 111 stores it in the storage unit 104.

[0057] The acquisition unit 111 may arbitrarily change the order in which it acquires the topographic watershed boundary map data 105, the population density map data 106, and the distance map data 107, or it may acquire the topographic watershed boundary map data 105, the population density map data 106, and the distance map data 107 simultaneously.

[0058] Next, the calculation unit 112 calculates the TWI for each cell of the area AR from which water sources are to be extracted, and generates TWI map data 108 in which the calculated TWI values ​​are assigned to the cells (step S105). The acquisition unit 111 has previously acquired and stored the drainage area and gradient for each cell of the DEM data corresponding to the area AR from the external server 300. The calculation unit 112 calculates the TWI value for each cell based on the drainage area and gradient of the cells included in the area AR. The calculation unit 112 generates TWI map data 108 by dividing multiple cells using the calculated TWI values ​​and stores it in the storage unit 104.

[0059] Next, the extraction unit 113 specifies the population density range in the population density map data 106, the distance range in the distance map data 107, and the threshold X value for the cells in the TWI map data 108 (step S106). In response to the user's operation on the input unit 102, the extraction unit 113 specifies the population density range from which water sources are to be extracted (for example, the suburban range 106b) among the urban range 106a, suburban range 106b, and outlying range 106c in the population density map data 106. In response to the user's operation on the input unit 102, the extraction unit 113 specifies the distance range from which water sources are to be extracted (for example, the medium-distance range 107b) among the short-distance range 107a, medium-distance range 107b, and long-distance range 107c in the distance map data 107. In response to the user's operation on the input unit 102, the extraction unit 113 specifies the threshold X value to be compared with the TWI of the cells in the TWI map data 108.

[0060] Next, the extraction unit 113 overlays layers of TWI map data 108, population density map data 106, and distance map data 107 for the same area AR onto the topographic watershed boundary map data 105 acquired in step S102 (step S107). After overlaying the TWI map data 108 onto the topographic watershed boundary map data 105, the extraction unit 113 may overlay either the population density map data 106 or the distance map data 107.

[0061] Next, the extraction unit 113 determines, cell by cell, whether the locations of multiple topographic watershed boundaries included in the topographic watershed boundary map data 105 overlap with the locations of cells in the TWI map data 108 that are above a threshold X (step S108). If there are no topographic watershed boundaries that are spatially overlapping with cells above a threshold X (step S108: NO), the extraction unit 113 terminates the process because there are no topographic watershed boundaries that should be considered as candidate locations for water sources. On the other hand, if there are topographic watershed boundaries that are spatially overlapping with cells above a threshold X (step S108: YES), the extraction unit 113 proceeds to the next step, S109.

[0062] Next, the extraction unit 113 extracts, cell by cell, the topographic watershed boundaries that overlap with the population density range of the population density map data 106 and the distance range of the distance map data 107, from among the topographic watershed boundaries that overlap with cells whose TWI value is greater than or equal to the threshold X (step S109). That is, the extraction unit 113 extracts from among the multiple topographic watershed boundaries that overlap with cells whose TWI value is greater than or equal to the threshold X, multiple topographic watershed boundaries that are within the specified population density range and are included within the specified distance range as candidate locations for water sources.

[0063] Next, the output control unit 114 displays the multiple topographic watershed boundaries extracted in step S109 as candidate water source locations on the display unit 103 (step S110), and terminates the process. The output control unit 114 generates output map data in which the multiple topographic watershed boundaries extracted as candidate water source locations are displayed, and outputs this to the display unit 103 for display.

[0064] Figure 9 shows the output map data 109. As shown in Figure 9, the map of the output map data 109 displays multiple topographic watershed boundaries as candidate water source locations (WS).

[0065] The output map data 109 displays only the topographic watershed boundaries that can serve as candidate water source locations (WS). Therefore, users can instantly recognize topographic watershed boundaries that could serve as candidate water source locations (WS) within that area of ​​AR. These candidate water source locations (WS) are watersheds rich in groundwater, where the TWI value is above threshold X, located in suburban areas with a moderate population density that require large amounts of water, and are in appropriate locations that are not too far from urban areas.

[0066] In this manner, the extraction unit 113 first extracts topographic watershed boundaries that overlap with cells whose TWI value is greater than or equal to the threshold X, and then extracts topographic watershed boundaries that overlap with the population density range of the population density map data 106 and the distance range of the distance map data 107. As a result, the computer device 100 can extract and provide to the user topographic watershed boundaries that are suitable candidates for water sources, taking into account both the population density range and the distance range from urban areas.

[0067] Furthermore, the extraction unit 113 may first extract topographic watershed boundaries that overlap with cells whose TWI value is greater than or equal to the threshold X, and then extract topographic watershed boundaries that overlap with either the population density range of the population density map data 106 or the distance range of the distance map data 107. In this case as well, the computer device 100 can extract topographic watershed boundaries that are suitable candidate water source locations WS considering the population density range or the distance range from urban areas, and provide them to the user.

[0068] As detailed above, the computer device 100 can extract a suitable topographic watershed boundary from among multiple topographic watershed boundaries included in area AR that will serve as a candidate site WS for a water source, based on the TWI value and the population density or distance from urban areas.

[0069] <Other Embodiments> The extraction unit 113 may arbitrarily change the value of the threshold X that it compares with the TWI value. By setting the threshold X to a larger value, the extraction unit 113 can narrow down the extraction to topographic watershed boundaries with smaller groundwater level changes. On the other hand, by setting the threshold X to a smaller value, the extraction unit 113 can extract multiple topographic watershed boundaries from a wider range. Furthermore, the extraction unit 113 may change the value of the threshold X according to the area AR, or it may change the threshold X according to the amount of groundwater level change.

[0070] Furthermore, although the extraction unit 113 is configured to specify a distance range based on the straight-line distance from the urban area, it may also be configured to specify a distance range based on the travel distance according to the route from the urban area. In this case, the computer device 100 can extract more realistic candidate water source locations WS that take into account the travel distance according to the route.

Claims

1. An information processing device comprising: an acquisition unit that acquires the drainage area and gradient for each of several divided regions included in a predetermined area, as well as the population density or distance from urban areas; a calculation unit that calculates a topographic moisture index for each of the several divided regions based on the drainage area and gradient; and an extraction unit that extracts candidate water source locations from among several target regions included in the area based on the topographic moisture index and the population density or distance from urban areas.

2. The information processing apparatus according to claim 1, wherein the extraction unit extracts candidate sites based on the result of comparing the terrain moisture index with a predetermined threshold.

3. The information processing apparatus according to claim 1, wherein the distance from the urban area includes the straight-line distance or the travel distance according to the route.

4. The information processing device according to any one of claims 1 to 3, wherein the target area is a topographic watershed boundary of a predetermined size.

5. An information processing method characterized by: obtaining the drainage area and gradient for each of several divided regions included in a predetermined area, as well as obtaining the population density or distance from urban areas; calculating a topographic moisture index for each of the several divided regions based on the drainage area and gradient; and extracting candidate water source locations from among several target regions included in the area based on the topographic moisture index and the population density or distance from urban areas.

6. A program characterized by causing a computer to function as follows: an acquisition unit that acquires the drainage area and gradient for each of several divided regions included in a predetermined area, and also acquires the population density or distance from urban areas; a calculation unit that calculates a topographic moisture index for each of the several divided regions based on the drainage area and gradient; and an extraction unit that extracts candidate water source locations from among several target regions included in the area based on the topographic moisture index and the population density or distance from urban areas.

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