Nutrient supply management system, and nutrient supply management method

Abstract

To provide a nutrient supply management system capable of maximizing the amount of carbon dioxide absorbed and stored in the atmosphere by both blue and green carbon.SOLUTION: The nutrient supply management system includes an arithmetic unit that executes calculations related to nutrient salt supply management for marine and terrestrial ecosystems. The arithmetic unit includes a supplyable nutrient salt amount estimation unit that calculates the amount of supplyable nutrient salt based on the emissions of nutrient salts from point and non-point sources in the target area. The arithmetic unit also includes a decarbonization promotion effect evaluation unit that evaluates the effect of marine and terrestrial ecosystems on the supply of nutrient salts. The arithmetic unit also includes a nutrient salt proper distribution unit that sets allocations of nutrient salt supply to marine and terrestrial ecosystems based on the effect of promoting decarbonization.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a nutrient supply management system and a nutrient supply management method.

Background Art

[0002] As a carbon negative technology for promoting decarbonization, the development of direct air capture (abbreviated as DAC) technology for directly recovering carbon dioxide in the atmosphere from the air is underway. In DAC technology, as natural-based technologies, green carbon by terrestrial ecosystems such as forests and blue carbon by marine ecosystems are being considered. A common promoting factor that can be artificially controlled and managed for both blue carbon and green carbon is the concentration of nutrients such as nitrogen and phosphorus in coastal areas and forest areas. For example, focusing on blue carbon, a method has been proposed to supply water containing eluted components such as nutrients according to the state of seaweeds growing in the ocean (see Patent Document 1). In addition, a method has been disclosed to promote the growth of phytoplankton by spraying nutrients to promote the absorption of carbon dioxide (see Patent Document 2). These methods artificially increase the supply amount of nutrients to the ocean. And they increase the amount of carbon dioxide absorption and storage by marine ecosystems such as seaweeds and phytoplankton. Therefore, these methods can be expected to promote blue carbon.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the methods described in Patent Document 1 and Patent Document 2 mentioned above, the evaluation criterion for setting the appropriate supply amount of nutrients is to maximize the absorption and storage amount of carbon dioxide in blue carbon. Therefore, it is difficult to maximize the absorption and storage amount of atmospheric carbon dioxide by both blue carbon and green carbon, which is a natural-based DAC other than blue carbon.

[0005] In order to solve the above-mentioned problems, the present invention provides a nutrient supply management system and a nutrient supply management method capable of maximizing the absorption and storage amount of atmospheric carbon dioxide by both blue carbon and green carbon.

[0006] Also, the above object and other objects of the present invention, as well as the novel features of the present invention, will be clarified by the description in this specification and the attached drawings.

Means for Solving the Problems

[0007] The nutrient supply management system of the present invention includes an arithmetic unit that executes arithmetic operations related to the supply management of nutrients supplied to marine ecosystems and terrestrial ecosystems. The arithmetic unit includes a supplyable nutrient amount estimation unit that calculates the amount of supplyable nutrients based on the discharge amounts of nutrients from point sources and non-point sources in the target area. The arithmetic unit also includes a decarbonization promotion effect evaluation unit that evaluates the decarbonization promotion effects of marine ecosystems and terrestrial ecosystems with respect to the supply amount of nutrients. Furthermore, the arithmetic unit includes a nutrient appropriate distribution unit that sets the distribution of the nutrient supply amount to marine ecosystems and terrestrial ecosystems based on the decarbonization promotion effect.

[0008] Also, the nutrient supply management method of the present invention calculates the amount of supplyable nutrients based on the discharge amounts of nutrients from point sources and non-point sources in the target area. Then, the nutrient supply management method evaluates the decarbonization promotion effects of marine ecosystems and terrestrial ecosystems with respect to the supply amount of nutrients, and sets the distribution of the nutrient supply amount to marine ecosystems and terrestrial ecosystems based on the decarbonization promotion effect.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a nutrient supply management system and a nutrient supply management method capable of maximizing the absorption and storage amount of carbon dioxide in the atmosphere by both blue carbon and green carbon.

[0010] In addition, problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

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Figure 7

Embodiments for Carrying Out the Invention

[0012] Hereinafter, an example of a nutrient supply management system and a nutrient supply management method according to an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following examples. In each of the drawings described below, common members are denoted by the same reference numerals. In the drawings used in this specification, the same or corresponding components are denoted by the same reference numerals, and repeated description of these components may be omitted.

[0013] 〈1. Outline of the Present Invention〉 In recent years, in response to carbon dioxide emissions associated with socio-economic activities, decarbonization by direct air capture (DAC) technology that directly captures carbon dioxide from the air has been under consideration. Generally, in DAC technology, industrial-based technologies using absorbents and the like are in the lead. On the other hand, green carbon, which is DAC by terrestrial ecosystems and blue carbon, which is DAC by marine ecosystems, which are nature-based technologies, may be able to keep costs relatively low compared to industrial-based technologies. Furthermore, green carbon and blue carbon can secondarily improve the environment other than global warming. For this reason, nature-based technologies are highly anticipated.

[0014] Blue carbon has advantages such as a large potential carbon dioxide recovery amount and a long carbon dioxide fixation period. For this reason, it is a technology area whose examination has been accelerating in recent years. It has been scientifically clarified that carbon dioxide recovery in blue carbon is carried out in marine ecosystems such as seaweed and kelp beds, mangrove forests, saline wetlands, and phytoplankton breeding areas. The carbon dioxide recovery in these blue carbons is at a stage where various findings are being accumulated. The carbon dioxide recovery in blue carbon is quantified by marine monitoring. And the carbon dioxide recovery in blue carbon is ultimately credited as a carbon offset and traded in the carbon dioxide emission rights market. On the other hand, green carbon also absorbs and fixes carbon dioxide by the photosynthesis of plants in afforestation and forest conservation. Efforts are also active everywhere in green carbon. Green carbon is also positioned as a powerful option for decarbonization, similar to the above-mentioned blue carbon.

[0015] Both blue carbon and green carbon are compatible measures. Also, the promoting factors common to blue carbon and green carbon and that can be artificially controlled and managed are the concentrations of nutrients such as nitrogen and phosphorus in coastal areas and forest areas. Point sources in terrestrial areas that are the main sources of nutrients include the discharged water from sewage treatment plants. Non-point sources in terrestrial areas that are the main sources of nutrients include surface runoff from agricultural fertilization. However, the amount of nutrients discharged from these point sources and non-point sources is limited. That is, the amount of nutrients supplied to marine ecosystems and terrestrial ecosystems is limited. Therefore, when artificially promoting these, it is necessary to consider the competition for the use of nutrients, which is a common influencing factor in both marine ecosystems and terrestrial ecosystems. And nutrients such as nitrogen and phosphorus are rate-limiting factors when maintaining and expanding seaweed beds and forests. Therefore, technologies for appropriately distributing and utilizing limited nutrient resources are required. Therefore, this technology targets blue carbon, which is carbon dioxide recovery by marine ecosystems, and green carbon, which is carbon dioxide recovery by terrestrial ecosystems, and manages the supply of nutrients to plants, which is the main body of the carbon dioxide recovery effects of both.

[0016] Under the constraint that the available amount of nutrient supply is limited, in order to maximize the absorption and storage amount of carbon dioxide in the atmosphere by both blue carbon and green carbon, it is necessary to quantitatively evaluate the absorption and storage amount of carbon dioxide of both. This evaluation requires, for example, scientific knowledge regarding the degree of plant growth promotion with respect to the nutrient concentration supplied to marine ecosystems and terrestrial ecosystems, and models formulated therefrom. In addition, it is necessary to use scientific knowledge regarding the absorption and storage amount of carbon dioxide for each type of plant such as seagrass, seaweed, and phytoplankton, and models formulated therefrom.

[0017] Therefore, this technology quantitatively evaluates the absorption and storage amount of carbon dioxide based on the above-mentioned knowledge and models. And rationally and objectively sets the distribution of the nutrient supply amount for the target areas of blue carbon and green carbon. That is, this technology relates to a nutrient supply management system for managing natural-based negative emission measures for absorbing and storing carbon dioxide in the atmosphere, and a nutrient supply management method.

[0018] In this technology, based on the nutrient discharge amounts from point sources and non-point sources in the target area, the amounts of nutrients that can be supplied to the marine ecosystem and the terrestrial ecosystem, which are the targets of negative emission measures, are calculated. Also, in each of the marine ecosystem and the terrestrial ecosystem, the effect of promoting carbon dioxide absorption and the effect of promoting storage with respect to the amount of nutrient supply are calculated. Thereby, the decarbonization promotion effect by the amount of carbon dioxide absorption and storage is quantitatively evaluated. Then, based on the evaluation results of the decarbonization promotion effect by the calculated absorption promotion effect and storage promotion effect, the distribution of the amount of nutrient supply to the marine ecosystem and the terrestrial ecosystem, which are the targets of the negative emission measures, is set.

[0019] Also, in this technology, based on scientific knowledge, established mathematical models, etc., the distribution of the amount of nutrient supply to the target area is appropriately set. Examples of scientific knowledge and established mathematical models include, for example, the degree of promoting the growth of plants with respect to the nutrient concentration supplied to the marine ecosystem and the terrestrial ecosystem. Also, it is the amount of carbon dioxide absorption and storage for each type of plant body such as seagrass, seaweed, and phytoplankton. Thereby, the amount of carbon dioxide absorption and storage in the atmosphere by both blue carbon and green carbon is maximized.

[0020] 〈2. Embodiments of Nutrient Supply Management System and Nutrient Supply Management Method〉 Hereinafter, embodiments of the nutrient supply management system and the nutrient supply management method will be described. In this embodiment, an example of promoting the absorption and storage of carbon dioxide by blue carbon in the marine ecosystem and green carbon in the terrestrial ecosystem, which are nature-based negative emission technologies, will be described. The nutrient supply management system is installed, for example, in water treatment facilities, sewage treatment facilities, wastewater treatment facilities that are nutrient supply sources, and these management facilities and administrative agencies.

[0021] The nutrient supply management system is composed of a known computing device. For example, the nutrient supply management system is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a storage, etc. The CPU reads out the program code of the software related to various processes of nutrient supply management control stored in the ROM (an example of a recording medium) and expands it in the RAM. Then, the CPU implements nutrient supply management control according to the expanded program. Note that the nutrient supply management system may be provided with other computing devices such as an MPU (Micro Processing Unit) instead of the CPU.

[0022] The storage is an example of a recording medium composed of a non-volatile storage, etc. The storage stores various processing programs executed by the CPU, programs such as an OS, information related to the functions of the nutrient supply management system 100 necessary for the execution of the programs, and various data tables used by the computing unit for calculations. The storage is, for example, an HDD (Hard Disk Drive), an SSD (Solid State Drive), and a magnetic tape, etc.

[0023] [Functional Configuration of Nutrient Supply Management System] Fig. 1 shows the schematic configuration of the nutrient supply management system. The nutrient supply management system 100 shown in Fig. 1 includes a computing unit 300, a storage unit 200, and a display unit 800. The computing unit 300 controls the nutrient supply management system 100 overall. Also, the computing unit 300 includes a supplyable nutrient amount estimation unit 400, a decarbonization promotion effect evaluation unit 500, and a nutrient proper distribution unit 600 as its functional configurations. The storage unit 200 of the nutrient supply management system 100 is composed of, for example, the above storage and RAM. The storage unit 200 stores the attribute information DB 210. It also stores various data calculated by the arithmetic unit 300. Furthermore, the storage unit 200 stores a formulated mathematical model regarding the absorption and storage amount of carbon dioxide. For example, it stores a nutrient generation amount model, a point source and non-point source model, a model regarding the flow to the target sea area, a marine ecosystem model, a terrestrial ecosystem model, and the like.

[0024] The display unit 800 visualizes the execution conditions and results of the calculation process by the arithmetic unit 300. Furthermore, the calculation result in the nutrient supply management system 100 is output from the arithmetic unit 300 to the nutrient supply facilities 700 such as sewage treatment plants and wastewater treatment facilities, and is reflected in the nutrient supply management to the target marine ecosystem and terrestrial ecosystem.

[0025] [Functional Configuration of the Arithmetic Unit] Next, the functional configuration of the arithmetic unit 300 will be described. The available nutrient amount estimation unit 400 calculates the amount of nutrients that can be supplied to the marine ecosystem and the terrestrial ecosystem based on the discharge amounts of nutrients from point sources and non-point sources in the target area. Also, the available nutrient amount estimation unit 400 calculates the discharge amount of nutrients in the target area using the attribute information regarding point sources and non-point sources stored in the storage unit 200.

[0026] The decarbonization promotion effect evaluation unit 500 evaluates the decarbonization promotion effect on the marine ecosystem and the terrestrial ecosystem with respect to the supply amount of nutrients. That is, the decarbonization promotion effect evaluation unit 500 calculates the change in the amount of carbon dioxide absorbed and stored (hereinafter also referred to as absorption / storage) in the marine ecosystem and the terrestrial ecosystem under the condition of changing the supply amount of nutrients. Further, in this calculation, the amount of carbon dioxide absorbed / stored is calculated using the condition of changing the supply ratio of nutrients to the marine ecosystem and the terrestrial ecosystem. Then, the decarbonization promotion effect evaluation unit 500 calculates the amount of carbon dioxide absorbed / stored by the marine ecosystem, the amount of carbon dioxide absorbed / stored by the terrestrial ecosystem, and the total amount of carbon dioxide absorbed / stored by the marine ecosystem and the terrestrial ecosystem under each condition. Furthermore, the decarbonization promotion effect evaluation unit 500 compares the calculation results under each condition and evaluates the nutrient supply condition that can maximize the amount of carbon dioxide absorbed / stored. In addition, the decarbonization promotion effect evaluation unit 500 performs the calculation of the amount of carbon dioxide absorbed / stored under each of the above conditions using a formulated model. The formulated model uses, for example, a model (functionalized) of the change in the growth degree of the plant body with respect to the increase or decrease in the concentration of nutrients.

[0027] The nutrient optimal distribution unit 600 sets the distribution of the nutrient supply amount to the marine ecosystem and the terrestrial ecosystem based on the evaluation of the decarbonization promotion effect by the decarbonization promotion effect evaluation unit 500. The nutrient optimal distribution unit 600 sets the distribution amount of nutrients to the marine ecosystem and the terrestrial ecosystem with respect to the nutrient discharge amount in the target area calculated by the available nutrient amount estimation unit 400. The nutrient optimal distribution unit 600 sets the distribution amount of nutrients to the marine ecosystem and the terrestrial ecosystem using a mathematical model including information on the amount of carbon dioxide absorbed / stored by the marine ecosystem and the terrestrial ecosystem. For example, the nutrient optimal distribution unit 600 uses a mathematical model including at least one or more of an evaluation index of the amount of carbon dioxide absorbed / stored, an evaluation index of the biodiversity of the target area, and an evaluation index of the marine productivity of the target area.

[0028] Details of the processing content of each functional component of the arithmetic unit 300 will be described later. Also, various processes and arithmetic processes performed by each functional component of the arithmetic unit 300 are performed with reference to the attribute information DB210 in the storage unit 200. Further, the arithmetic unit 300 stores various processing results and calculation results in the storage unit 200.

[0029] [Storage Unit] The data configuration of the attribute information DB210 stored in the storage unit 200 is shown in FIG. 2. The attribute information DB210 shown in FIG. 2 stores data (attribute information) related to the areas targeted for nutrient supply and distribution by the nutrient supply management system 100. The attribute information DB210 stores various types of data (referred to as data attributes) according to the purpose.

[0030] The attribute information DB210 is composed of data attributes such as geographical attribute information 211, nutrient point source information 212, nutrient non-point source information 213, target marine ecosystem monitoring information 214, target terrestrial ecosystem monitoring information 215, and basic map information 216. Also, the attribute information DB210 has a data attribute of system calculation result data 217. It is desirable that the information of these data attributes is stored in units of geographical divisions of the target area. Examples of geographical divisions include mesh units, administrative boundary units, and land cover type units. The information of these data attributes is organized and stored in data layers based on the geographical divisions in the basic map information 216. Further, each data layer is composed of a time series of periods required for calculations.

[0031] The geographical attribute information 211 includes information such as elevation and river positions related to the phenomenon of nutrient flow into the sea area. The geographical attribute information 211 includes, as land use information, agricultural land, vegetation areas, etc., as well as information on residential areas, industrial areas, commercial areas, etc. For example, the geographical attribute information 211 stores information such as the movement route of nutrients from the supply source to rivers and the sea, and the height (elevation) information for calculating the movement route of nutrients.

[0032] Nutrient point source information 212 includes information such as sewage treatment plants and wastewater treatment facilities. For example, the nutrient point source information 212 includes information such as the locations of sewage treatment plants and wastewater treatment facilities, and the amounts of nutrients that can be supplied from each facility. The nutrient point source information 212 includes information such as facilities where the locations where treated water containing nutrients is supplied to the target area is concentrated and the nutrient sources can be regarded as points. In addition, the nutrient point source information 212 has a pre-prepared nutrient generation amount model as attribute information necessary for calculating the amount of nutrients supplied from the point source. The nutrient generation amount model is composed of, for example, a mathematical model and its coefficients. This mathematical model and coefficients are stored as a dataset for each point source in the target area.

[0033] Nutrient non-point source information 213 includes information such as agricultural lands and vegetation areas containing nutrient salts such as nitrogen and phosphorus by fertilization. In addition, the nutrient non-point source information 213 includes information such as the amounts (concentrations) of nutrients contained in agricultural lands and vegetation areas, the amounts (concentrations) of nutrients sprayed on agricultural lands and vegetation areas, and the outflow amounts of nutrients from agricultural lands and vegetation areas. The nutrient non-point source information 213 includes information such as locations where the nutrient sources spread over a wide area. In addition, the nutrient non-point source information 213 has a pre-prepared nutrient generation amount model as attribute information necessary for calculating the amount of nutrients supplied from the non-point source. The nutrient generation amount model is composed of, for example, a mathematical model and its coefficients. This mathematical model and coefficients are stored as a dataset for each non-point source in the target area.

[0034] Target marine ecosystem monitoring information 214 includes information such as seawater quality, the types, areas of seaweed beds composed of seaweeds and seaweeds, the areas of mangrove forests, and water temperatures. For example, the target marine ecosystem monitoring information 214 includes information on nutrient concentrations when red tides, blue tides, etc. occur, and basic information for creating a nutrient supply plan. The target terrestrial ecosystem monitoring information 215 includes at least information such as the types and areas of vegetation related to green carbon. For example, the target terrestrial ecosystem monitoring information 215 includes information on farmland and vegetation areas, information on the plants that make up these, the cultivated varieties of farmland, tree species (such as conifers and broad-leaved trees), and tree ages. The above geographical attribute information 211, nutrient point source information 212, nutrient non-point source information 213, target marine ecosystem monitoring information 214, target terrestrial ecosystem monitoring information 215, and basic map information 216 are prepared in advance and stored in the data layers of the attribute information DB 210 respectively.

[0035] The system operation result data 217 is stored in the attribute information DB 210 as the operation results in the nutrient supply management system 100, either as geographically divided data or data without geographical division. The system operation result data 217 is stored in the attribute information DB 210 separately from the above-mentioned pre-prepared data layers.

[0036] [Processing content of the operation unit] Next, the processing contents of the available nutrient amount estimation unit 400, decarbonization promotion effect evaluation unit 500, and nutrient appropriate distribution unit 600 that make up the operation unit 300 will be described. Nutrients are the sources that maintain and expand the ecosystems of the sea areas and land areas in the target region and promote the absorption and storage of carbon dioxide from the atmosphere. Nutrients consisting of nitrogen, phosphorus, and silicon are essential elements for maintaining and growing organisms such as seagrass, seaweed, mangroves, and forests together with organic matter.

[0037] In the sea area, when nutrients are excessively present in seawater, a so-called eutrophic state occurs. And the nutrients in the eutrophic state cause phenomena such as red tides due to abnormal growth of phytoplankton and the like. However, if the nutrients are appropriately managed below a predetermined concentration range, the total amount of seagrass, seaweed, and mangroves will increase. And accordingly, in the marine ecosystem, the absorption amount of carbon dioxide in water accompanying photosynthesis and the like will increase. When the partial pressure of carbon dioxide in seawater becomes smaller than that in the atmosphere, the carbon dioxide in the atmosphere is absorbed by the seawater. In addition, in the terrestrial area, appropriate nutrients are applied to vegetation such as forests, leading to the maintenance and expansion of the vegetation volume. As a result, in the terrestrial ecosystem, the absorption and storage of carbon dioxide by photosynthesis are promoted. If such phenomena in the sea area (marine ecosystem) and the terrestrial area (terrestrial ecosystem) continue, it is expected that carbon dioxide in the atmosphere will be recovered and accumulated, mitigating global warming.

[0038] (Flowchart: Estimation of Nutrient Quantity) Next, the processing content of the available nutrient quantity estimation unit 400 that constitutes the arithmetic unit 300 will be described. The available nutrient quantity estimation unit 400 quantitatively estimates the generation amount of nutrients in the target area.

[0039] Fig. 3 shows a flowchart of an example of the processing of the available nutrient quantity estimation unit 400. First, in the regional attribute form information reading step, the available nutrient quantity estimation unit 400 reads the geographical attribute information 211 used in the arithmetic processing of the subsequent steps from the attribute information DB 210 (step S410). The data read here is stored in the internal memory (such as RAM) of the arithmetic device on which the nutrient supply management system 100 is implemented and is referred to in the subsequent steps.

[0040] Next, the available nutrient amount estimation unit 400 reads, as a nutrient generation amount model prepared in advance necessary for calculation, a mathematical model and its coefficients in the nutrient generation amount model reading step (step S420). The nutrient generation amount model here is a mathematical model based on an arithmetic expression for quantitatively evaluating the amount of nutrients generated in the target area on a predetermined time scale (for example, monthly, seasonally, or annually) using the geographical attribute information 211 stored in the attribute information DB 210. This model is roughly classified into a point source model and a non-point source model. The point source model targets locations where treated water containing nutrients is discharged toward the target sea area, such as sewage treatment plants, where the sources of nutrients can be regarded as points. The non-point source model targets areas where the sources of nutrients spread over a surface, such as when flowing out from fertilized farmland. In the above nutrient generation amount model, data sets of the mathematical model and coefficients for each type of point source and non-point source are stored as attribute information in the nutrient point source information 212 and the nutrient non-point source information 213. The nutrients targeted here are at least nitrogen and phosphorus, and in some cases, silicon and the like are also targeted.

[0041] The above point source model is defined, for example, in a sewage treatment plant or a wastewater treatment facility, which is a typical point source, by the arithmetic expression [nutrient generation amount = discharge water volume × nutrient concentration in the discharge water]. The discharge water volume and the nutrient concentration in the discharge water are basic data that are daily managed in sewage treatment plants or wastewater treatment facilities of specific enterprises and can be obtained as public information. Also, the above non-point source model quantitatively evaluates the amount of nutrients generated on the ground surface of the target area and is defined by the arithmetic expression [nutrient generation amount = source coverage area × nutrient generation amount per unit area]. In the non-point source model, the difference in the amount of nutrients generated due to land cover and land use can be set by the nutrient generation amount per unit area. Note that the definition of the mathematical model is not limited to these examples. The mathematical model may be an arithmetic expression that simply evaluates the nutrient mass balance according to the situation of the nutrient source and the available attribute data. For example, as an alternative to the point source model, for each type of sewage treatment method, using the designed effluent quality and the information on the treatment scale in the facility design, it may be defined by the arithmetic expression of [designed effluent quality × designed treatment scale]. Thus, it is also possible to simply calculate the nutrient generation amount without using the daily actual values.

[0042] Next, in the point source nutrient generation amount calculation step, the available nutrient amount estimation unit 400 calculates the nutrient generation amount at each point source based on the point source model read in the above-mentioned nutrient generation amount model reading step, targeting the point sources existing in the target area (step S430). Furthermore, in the non-point source nutrient generation amount calculation step in the same way, the available nutrient amount estimation unit 400 calculates the nutrient generation amount at each non-point source based on the non-point source model (step S440).

[0043] Next, in the nutrient generation amount calculation step, the available nutrient amount estimation unit 400 aggregates the calculated point source nutrient generation amount and non-point source nutrient generation amount in the point sources and non-point sources included in the target area (step S450). In the aggregation here, the total nutrient generation amount for each type of point source and non-point source and the temporal change over time are obtained.

[0044] Further, in the process of calculating the available nutrient amount, the available nutrient amount estimation unit 400 calculates the amount of nutrients actually supplied to the sea area or land area of the target region among the nutrient generation amounts (step S460). Specifically, it is calculated using a mathematical model including information on internal utilization at point source nutrient generation sources (for example, agricultural use of the effluent from a sewage treatment plant) and the flow to the target sea area from non-point source nutrient generation sources. The flow to the target sea area here refers to the process until the nutrients discharged from the generation source reach the target sea area. Nutrients decrease by retention, precipitation, and decomposition in the ground surface and rivers through which they pass during the process of reaching the target sea area. Therefore, in the process of calculating the available nutrient amount, an arithmetic expression capable of expressing the process of nutrient flow is used. As a typical flow model, an arithmetic model based on the arithmetic expression [nutrient flow amount = nutrient generation amount × exp(-attenuation coefficient × flow distance)] can be used. Representative numerical values of the attenuation coefficient are known from past findings for each type of flow path. Also, the flow distance can be calculated from the basic map information 216 stored in the basin attribute information DB200.

[0045] Finally, in the calculation result output step, the available nutrient amount estimation unit 400 outputs the calculation result in the above-described available nutrient amount calculation step to the system calculation result data 217 of the basin attribute information DB200 (step S470). Also, the available nutrient amount estimation unit 400 outputs to the display unit 800 and visualizes the result as needed. After the processing of the calculation result output step, the processing according to this flowchart is terminated.

[0046] (Flowchart: Carbon Dioxide Emission Reduction Promotion Effect Evaluation) Next, the processing content of the carbon dioxide emission reduction promotion effect evaluation unit 500 that constitutes the calculation unit 300 will be described. The carbon dioxide emission reduction promotion effect evaluation unit 500 quantitatively evaluates the carbon dioxide emission reduction promotion effect in blue carbon (marine ecosystem) and green carbon (terrestrial ecosystem). Specifically, the carbon dioxide emission reduction promotion effect evaluation unit 500 evaluates the promotion amount of carbon dioxide absorption and storage when the available amount of nutrients generated in the target region is supplied to the sea area and the land area.

[0047] Fig. 4 shows a flowchart of an example of the process of the decarbonization promotion effect evaluation unit 500. First, in the available nutrient amount reading step, the decarbonization promotion effect evaluation unit 500 reads the data of the available nutrient amount calculated by the available nutrient amount estimation unit 400 from the attribute information DB210 (step S510). The data read here is stored in the internal memory (such as RAM) of the arithmetic unit in which the nutrient supply management system 100 is implemented and is used for calculations in subsequent steps.

[0048] Next, in the nutrient allocation amount setting step, the decarbonization promotion effect evaluation unit 500 sets a plurality of candidates for the distribution of the amount of nutrients supplied to the sea area for promoting blue carbon and the amount of nutrients supplied to the land area for promoting green carbon (step S520). The setting of the distribution is, for example, mechanically applying a plurality of ratios (such as 1:1) prepared in advance for both. Alternatively, the user of the nutrient supply management system 100 inputs candidates for arbitrary distribution settings, and a plurality of input ratios are set.

[0049] Next, in the regional terrain information reading step, the decarbonization promotion effect evaluation unit 500 reads the terrain information of the target area, which is required for model calculation and result display in subsequent steps, from the regional attribute DB210 (step S530). The terrain information here is the attribute information constituting the regional attribute DB210 illustrated in Fig. 2, such as the geographical attribute information 211 and the basic map information 216.

[0050] Next, in the marine ecosystem model calculation step, the decarbonization promotion effect evaluation unit 500 calculates the amount of carbon dioxide absorption and storage in the marine ecosystem at the nutrient allocation amounts set in the above nutrient allocation amount setting step using a pre-prepared marine ecosystem model (step S540). The marine ecosystem model here takes as inputs the nutrient concentration and seawater temperature in the sea area, the area of seaweed beds (seagrass, seaweed) constituting the marine ecosystem, the carbon dioxide absorption and storage coefficient (carbon dioxide absorption and storage amount per unit area) for each type of marine ecosystem, etc. Then, the marine ecosystem model outputs the amount of carbon dioxide absorption and storage in the target sea area for a predetermined period (for example, one year).

[0051] As this model, mathematical models such as a detailed dynamic model based on scientific knowledge of marine ecosystems and a simple statistical model based on achievements in marine ecosystem monitoring can be applied. For example, in this mathematical model, an important operation target is the area of seaweed beds that are the main body of carbon dioxide absorption and storage. When accurately quantitatively evaluating the increase or decrease in the area of seaweed beds, an arithmetic expression for calculating the growth of seagrasses and seaweeds that make up the seaweed beds can be used based on information such as the above-mentioned nutrient amounts, nutrient concentrations, water temperature, etc. Also, as a mathematical model, an arithmetic expression regarding the growth of phytoplankton in which competition for the use of nutrients occurs can be used based on the above information. These arithmetic expressions can be defined using past knowledge in the marine field. On the other hand, in practical use, a mathematical model using a reasonably simplified arithmetic expression may be used without relying on a detailed mathematical model regarding growth.

[0052] Here, an example of a simplified mathematical model is illustrated in FIG. 5. A simplified mathematical model such as a function F that formulates the application of the seaweed bed cultivation area S with respect to the marine ecosystem nutrient concentration N shown in FIG. 5 can be applied to the marine ecosystem model calculation process. The seaweed bed cultivation area S is calculated based on the value estimated from the nutrient supply amount to the sea area or the marine ecosystem nutrient concentration N based on the monitoring performance value. Then, by multiplying this by the carbon dioxide absorption and storage coefficient, the carbon dioxide absorption and storage amount (blue carbon amount) in the target sea area can be calculated.

[0053] Next, in the same manner in the land ecosystem model calculation process, the decarbonization promotion effect evaluation unit 500 calculates the carbon dioxide absorption and storage amount of the land ecosystem at the nutrient supply amount set in the nutrient distribution amount setting process using a pre-prepared land ecosystem model (step S550). The land ecosystem model here refers to a mathematical model that takes as input the nutrient supply amount (i.e., fertilization amount) to forests growing on land, the type and area of vegetation, temperature, sunshine conditions, the carbon dioxide absorption and storage coefficient (carbon dioxide absorption and storage amount per unit area) for each type of vegetation, etc., and outputs the carbon dioxide absorption and storage amount in the target land area over a predetermined period (for example, one year).

[0054] As this mathematical model, similar to the case of the sea area, a sophisticated dynamic model based on scientific knowledge of the terrestrial ecosystem or a simple statistical model based on the achievements in terrestrial ecosystem monitoring can be applied. The main targets of quantitative evaluation of the terrestrial ecosystem model are forest growth or forest area. For quantitatively evaluating these amounts, a mathematical model can use arithmetic expressions based on past knowledge regarding the growth of trees for each type of tree that makes up the forest. Specifically, for each type of tree that makes up the forest, an arithmetic expression regarding growth is used. Also, based on information such as the above-described fertilization amount, temperature, and solar radiation conditions, a model for calculating forest growth is used. By this model, forest growth and area are obtained, and by multiplying by the carbon dioxide absorption and storage coefficient for each type of vegetation, the amount of carbon dioxide absorption and storage (green carbon amount) in the target land area is calculated.

[0055] Next, in the decarbonization promotion effect calculation step, the decarbonization promotion effect evaluation unit 500 calculates and aggregates the total amount of carbon dioxide absorption and storage in the target sea area and the target land area, that is, the decarbonization promotion effect in the target region, for each setting condition (ratio, etc.) of the nutrient distribution amount (step S560). The total amount of carbon dioxide absorption and storage in the target sea area and the target land area uses those calculated in the above-described marine ecosystem model calculation step and terrestrial ecosystem model calculation step. Therefore, in this step, the total amount of all carbon dioxide absorption and storage amounts (green carbon amount and blue carbon amount) in the sea area and land area within the target region is calculated. Furthermore, in the calculation result output step, the decarbonization promotion effect evaluation unit 500 outputs the aggregated result of the decarbonization promotion effect to the attribute information DB210 of the storage unit 200 (step S570). Also, if necessary, the decarbonization promotion effect evaluation unit 500 outputs the aggregated result of the decarbonization promotion effect to the display unit 800 to visualize the result. After the processing of the calculation result output step, the processing by this flowchart ends.

[0056] [Flowchart: Optimal Nutrient Distribution] Next, the processing content of the nutrient appropriate distribution unit 600 that constitutes the arithmetic unit 300 will be described. The nutrient appropriate distribution unit 600 sets an appropriate distribution of nutrients between the sea area and the land area such that the decarbonization promotion effect in the target area is maximized.

[0057] Fig. 6 shows a flowchart of an example of the processing of the nutrient appropriate distribution unit 600. First, in the step of reading the decarbonization promotion effect evaluation result, the nutrient appropriate distribution unit 600 reads the total amount of carbon dioxide absorption and storage (blue carbon amount and green carbon amount) in the sea area and the land area under a plurality of nutrient distribution setting conditions (step S610). In this step, the nutrient appropriate distribution unit 600 reads the total amount of carbon dioxide absorption and storage for each nutrient distribution setting condition calculated by the decarbonization promotion effect evaluation unit 500 for each nutrient distribution setting condition.

[0058] Next, in the step of setting the appropriate nutrient distribution, the nutrient appropriate distribution unit 600 sets the nutrient distribution condition that maximizes the total amount of carbon dioxide absorption and storage between the sea area and the land area among the plurality of nutrient distribution setting conditions as the appropriate distribution condition (step S620). That is, the nutrient appropriate distribution unit 600 compares the total amount of carbon dioxide absorption and storage read in the step of reading the decarbonization promotion effect evaluation result for each distribution setting condition to obtain the nutrient distribution condition that maximizes the total amount of carbon dioxide absorption and storage.

[0059] Next, in the step of calculating the target value of the nutrient supply facility, the nutrient appropriate distribution unit 600 sets the operation management target value of the nutrient supply facility 700 such as a sewage treatment plant according to the set appropriate distribution conditions between the sea area and the land area (step S630). For example, in the case of a sewage treatment plant, the operation management target value is the quality of the treated sewage with the nutrient concentration of the set nutrient distribution setting condition. Specifically, the quality of the treated sewage is the value obtained by dividing the amount of nutrients supplied to the set sea area by the sewage discharge amount. It is preferable that the nutrient appropriate distribution unit 600 calculates the operation management target value for each type of nutrient such as nitrogen, phosphorus, and silicon. In addition, when there are multiple nutrient supply facilities 700 within a region, the nutrient appropriate distribution unit 600 allocates the nutrient supply amount according to the appropriate distribution conditions to each facility based on the actual performance of the nutrient supply amount of each facility. Further, the nutrient appropriate distribution unit 600 may allocate the nutrient supply amount according to the appropriate distribution conditions to each facility so that the total processing cost at each facility is minimized.

[0060] Also, as another embodiment, the nutrient appropriate distribution unit 600 may set appropriate distribution conditions using a mathematical model considering other effects related to nutrient supply. For example, the nutrient appropriate distribution unit 600 may evaluate effects on biodiversity, effects on marine productivity, and effects on the improvement of the urban environment and landscape due to forest expansion. Then, the nutrient appropriate distribution unit 600 may set appropriate distribution conditions so that the sum of the above-mentioned multiple effects, together with the amount of carbon dioxide absorption and storage, is maximized. Also, as indicators for evaluating the effect on biodiversity, the richness (Species richness) and evenness of individuals existing in ecosystems in sea areas or land areas, such as seagrass, seaweed, and forests, are representative. Also, the indicator for evaluating the effect on marine productivity indicates to what extent the marine ecosystem can be maintained. There are several indicators for marine productivity based on different viewpoints. For example, the amount of phytoplankton, chlorophyll concentration, and the harvestable amount of a predetermined marine product from the perspective of fisheries can be used as indicators.

[0061] Finally, in the calculation result output step, the nutrient appropriate distribution unit 600 outputs the appropriate distribution conditions of nutrients and the target values at the nutrient supply facilities to the attribute information DB 210, the display unit 800, and the nutrient supply facilities 700 (step S640). After the processing of the calculation result output step, the processing according to this flowchart is terminated.

[0062] [Flowchart: Display] Next, the processing content of the display unit 800 constituting the nutrient supply management system 100 will be described. FIG. 7 shows a flowchart of an example of the processing of the display unit 800. First, when the nutrient supply management system 100 is activated, the display unit 800 displays the function menu of the system on the system screen in the system menu display step (step S810). At the same time, the display unit 800 displays the basic map information of the sea area and land area of the target area as a map in the target area map display step (step S820). Next, in the system menu execution result display step, the display unit 800 displays various calculation results by the above-described calculation unit 300 in the form of an overlay display on the map or a numerical table (step S830). Next, the display unit 800 determines whether the execution of the system has ended (step S840). If the execution of the system continues (No in step S840), these steps are repeated. If the execution of the system ends (Yes in step S840), the processing according to this flowchart ends.

[0063] By executing the above-described series of processes, it is possible to quantify and visualize the dynamics of nutrients, carbon dioxide absorption and storage, and their decarbonization promotion effects related to blue carbon and green carbon. Therefore, it is possible to maximize the amount of carbon dioxide absorbed and stored in the atmosphere by both blue carbon and green carbon. And it can be expected to contribute to the promotion of the social implementation of natural-based negative emission technologies by blue carbon and green carbon.

[0064] Note that the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and the present invention is not necessarily limited to the embodiments having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Further, it is possible to add the configuration of another embodiment to the configuration of one embodiment. Also, it is possible to delete a part of the configuration of each embodiment or add and replace other configurations.

Explanation of Reference Numerals

[0065] 100 Nutrient supply management system, 200 Memory unit, 210 Attribute information DB, 211 Geographic attribute information, 212 Nutrient point source information, 213 Nutrient non-point source information, 214 Target marine ecosystem monitoring information, 215 Target terrestrial ecosystem monitoring information, 216 Basic map information, 217 System operation result data, 300 Operation unit, 400 Estimation unit for available nutrient amount, 500 Decarbonization promotion effect evaluation unit, 600 Appropriate nutrient distribution unit, 700 Nutrient supply facility, 800 Display unit

Claims

1. It includes an arithmetic unit that executes arithmetic operations related to the supply management of nutrients supplied to marine ecosystems and terrestrial ecosystems. The arithmetic unit A supplyable nutrient amount estimation unit that calculates the amount of the supplyable nutrients based on the discharge amounts of the nutrients from point sources and non-point sources in the target area. A decarbonization promotion effect evaluation unit that evaluates the decarbonization promotion effects of marine ecosystems and terrestrial ecosystems with respect to the supply amount of the nutrients. Based on the decarbonization promotion effect, it includes a nutrient appropriate distribution unit that sets the distribution of the nutrient supply amounts to the marine ecosystem and the terrestrial ecosystem. A nutrient supply management system.

2. It includes a storage unit that stores a database. The supplyable nutrient amount estimation unit Calculates the discharge amount of the nutrients using the attribute information related to the point sources and non-point sources stored in the storage unit. The storage unit includes at least any one of information on sewage treatment plants and wastewater treatment facilities as the attribute information of the point sources, and includes at least any one of information on agricultural lands and vegetation areas as the attribute information of the non-point sources. The nutrient supply management system according to Claim 1.

3. The decarbonization promotion effect evaluation unit calculates the decarbonization promotion effect using a mathematical model that formulates the change in the growth degree with respect to the increase and decrease in the nutrient concentration of plants that absorb and store carbon dioxide. The nutrient supply management system according to Claim 1.

4. The nutrient appropriate distribution unit sets the distribution amounts of the nutrients to the marine ecosystem and the terrestrial ecosystem using a mathematical model of the absorption amount and storage amount of carbon dioxide by the marine ecosystem and the terrestrial ecosystem. The nutrient supply management system according to Claim 1.

5. The nutrient appropriate distribution unit uses the mathematical model including at least any one or more of an evaluation index of the absorption and storage amount of carbon dioxide, an evaluation index of the biodiversity of the target area, and an evaluation index of the marine productivity of the target area. The nutrient supply management system according to Claim 4.

6. The arithmetic unit Based on the distribution amounts of the nutrients to the marine ecosystem and the terrestrial ecosystem set by the nutrient appropriate distribution unit, sets the operation management target value of the discharge amount of the nutrients at the point sources. The nutrient supply management system according to Claim 1.

7. Based on the discharge amounts of the nutrients from point sources and non-point sources in the target area, calculates the amount of the supplyable nutrients. Evaluate the decarbonization promotion effect on the marine ecosystem and the terrestrial ecosystem with respect to the supply amount of the nutrient salts, Based on the decarbonization promotion effect, set the distribution of the nutrient salt supply amounts for the marine ecosystem and the terrestrial ecosystem Nutrient salt supply management method.

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