A method for identifying soil carbon sequestration potential target areas based on geochemical combination anomalies

Abstract

The application provides a soil carbon sequestration potential target area identification method based on geochemical combination anomaly, first applies the theory and method of identifying the prospecting target area based on element combination anomaly in the exploration geochemistry field to the soil carbon sequestration potential area identification, breaks through the technical limitation of traditional soil carbon sequestration potential evaluation and target area identification; meanwhile, the application concept of combining organic carbon sequestration combination and inorganic carbon sequestration combination is proposed, various geochemical index factors influencing the soil organic carbon and inorganic carbon fixation process are systematically included into the corresponding combination system, and the accurate characterization and comprehensive consideration of the soil carbon sequestration driving factors are realized; on this basis, through geochemical multi-index anomaly analysis, the organic carbon sequestration potential target area, the inorganic carbon sequestration potential target area and the mixed carbon sequestration potential area are accurately identified, and a three-dimensional decision-making framework of the organic target area-inorganic target area-mixed target area is constructed, and scientific, accurate and operable technical reference and decision-making support are provided.

Description

Technical Field

[0001] This invention relates to the fields of environmental geochemistry and soil carbon sequestration technology, and in particular to a method for identifying soil carbon sequestration potential target areas based on geochemical assemblage anomalies. Background Technology

[0002] As one of the world's largest terrestrial carbon pools, soil carbon pools play a crucial role in participating in the global carbon cycle and addressing global climate change. It is estimated that a 4% increase in soil carbon storage within a one-meter depth globally could offset current global net carbon dioxide emissions. Under the "dual-carbon" strategy, accurately assessing soil carbon sequestration potential levels, mapping target areas for soil carbon sequestration potential by region and level, and developing an inventory of the carbon sequestration potential of arable land in black soil regions are core prerequisites for achieving integrated use and conservation of black soil and enhancing its carbon neutrality function.

[0003] Currently, mainstream methods for assessing soil carbon sequestration potential include the maximum value method, saturation value method, historical data comparison method, weighted method, and assessment methods based on remote sensing inversion and machine learning. Most of these methods estimate carbon sequestration potential based on homogenized environmental parameters such as climate, vegetation, and soil type. By establishing a high-order mapping relationship between environmental variables and soil organic carbon storage, they spatially homogenize the complex biogeochemical processes within the soil. However, they neglect the property gradient changes and carbon content differences within soil units, resulting in an inability to accurately capture the spatial heterogeneity of soil carbon content and hindering the precise estimation of carbon sequestration potential.

[0004] Furthermore, traditional spatial maps of soil carbon storage can only identify current high-value areas of soil carbon content and the current status of soil carbon storage. They cannot effectively predict future high-value areas of soil carbon sequestration potential, nor can they reveal the dynamic evolution mechanism of soil carbon sequestration potential at the mechanistic level, thus limiting their practical application in predicting the spatiotemporal evolution of soil carbon sequestration potential. Finally, current research on soil carbon sequestration potential suffers from a significant imbalance in understanding carbon forms. The vast majority of studies focus on the carbon sequestration potential of soil organic carbon, neglecting the enormous carbon sequestration potential contained in soil inorganic carbon, resulting in an incomplete and unobjective overall assessment of soil carbon sequestration potential.

[0005] In summary, current research on soil carbon sequestration potential relies heavily on model assumptions and black-box estimations. This approach not only makes it impossible to accurately identify spatial targets with the highest carbon sequestration potential and those requiring priority intervention, but also makes it difficult to design scientific, reasonable, and targeted differentiated response strategies for target areas dominated by different carbon sequestration mechanisms. This restricts the efficient exploitation of the carbon sequestration potential of cultivated land in the black soil region and the enhancement of its carbon neutrality function. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a method for identifying soil carbon sequestration potential target areas based on geochemical assemblage anomalies. This method aims to solve the technical problem that existing technologies, by neglecting the gradient changes in soil unit properties and spatial differences in carbon content, are unable to accurately capture the spatial differentiation characteristics of carbon content. At the same time, existing technologies are also unable to accurately identify spatial target points with the highest carbon sequestration potential and the most priority for intervention, and are even less able to design differentiated carbon sequestration management strategies for target areas dominated by different carbon sequestration mechanisms.

[0007] To achieve the above objectives, the technical solution of this invention is as follows: In a first aspect, the present invention provides a method for identifying soil carbon sequestration potential target areas based on geochemical assemblage anomalies, the method comprising: Multiple surface soil samples were collected from the study area, and the geochemical parameters related to organic carbon sequestration and inorganic carbon sequestration were analyzed and tested for each sample to obtain the set of organic carbon sequestration parameters and the set of inorganic carbon sequestration parameters for each sample. The lower limit of the single index anomaly for each geochemical index in the organic carbon fixation parameter set and the inorganic carbon fixation parameter set is determined respectively. Based on the test values ​​of each index for each sample and the corresponding lower limit of the single index anomaly, a single index geochemical anomaly map for each geochemical index is drawn. Based on the organic carbon fixation parameter set and the inorganic carbon fixation parameter set respectively, the geochemical parameter combination value of each sample is calculated using the multi-index contrast accumulation method; spatial interpolation is performed on the geochemical parameter combination value of each sample, and a combination anomaly map is drawn based on the lower limit of the anomaly of the combination values ​​of all interpolated samples and the single-index geochemical anomaly map; the combination anomaly map includes an organic carbon fixation combination anomaly map and an inorganic carbon fixation combination anomaly map. The carbon sequestration potential comprehensive index of each anomalous area in the organic carbon sequestration combination anomaly map and the inorganic carbon sequestration combination anomaly map is calculated respectively. Based on the carbon sequestration potential comprehensive index and the geological background information of the study area, the carbon sequestration potential of each anomalous area is rated to obtain the carbon sequestration potential rating result. The organic carbon fixation combination anomaly map is overlaid with the inorganic carbon fixation combination anomaly map to generate a comprehensive carbon fixation anomaly map. Based on the comprehensive carbon fixation anomaly map and the carbon fixation potential rating results, the potential target areas for organic carbon fixation, inorganic carbon fixation, and mixed carbon fixation are identified and divided.

[0008] In some embodiments, the geochemical parameters related to organic carbon fixation include at least soil organic carbon content, active iron and aluminum oxide content, clay content, available phosphorus content, and available nitrogen content; the geochemical parameters related to inorganic carbon fixation include at least soil inorganic carbon content, pH value, electrical conductivity, calcium carbonate content, and exchangeable calcium and magnesium ion content.

[0009] In some embodiments, determining the lower limit of anomalies for each geochemical index in the organic carbon fixation parameter set and the inorganic carbon fixation parameter set includes: performing a normality test on the test data of each geochemical index; for data that follows a normal distribution or a log-normal distribution, using the mean plus 2 times the standard deviation as the lower limit of anomalies for the corresponding geochemical index.

[0010] In some embodiments, the formula for calculating the combined values ​​of the geochemical parameters is as follows: In the formula, The combined values ​​of geochemical parameters for each sample; This represents the number of geochemical indicators in the corresponding combination; For the first Test values ​​of several geochemical indicators; For the first The arithmetic mean of the geochemical indicators across all samples.

[0011] In some embodiments, the formula for calculating the comprehensive carbon sequestration potential index is as follows: In the formula, A comprehensive index of carbon sequestration potential; This is the arithmetic mean of all sample combination values ​​within the abnormal region; This represents the lower limit of abnormal combined values. This represents the area of ​​the abnormal region.

[0012] In some embodiments, the carbon sequestration potential rating for each anomalous area includes: classifying the anomalous area according to the relative magnitude of its comprehensive carbon sequestration potential index, dividing the comprehensive carbon sequestration potential index into high, medium, and low levels from high to low; when the comprehensive carbon sequestration potential index is at the high level and, combined with the geological background information, is determined to be an advantageous area, the carbon sequestration potential rating result is determined to be a Class A anomalous area; the Class A anomalous area indicates high carbon sequestration potential and prospects; when the comprehensive carbon sequestration potential index is at the medium level and, combined with the geological background information, is determined to be an area suitable for intervention, the carbon sequestration potential rating result is determined to be a Class B anomalous area; the Class B anomalous area indicates high carbon sequestration potential and prospects after precision agricultural management and intervention; when the comprehensive carbon sequestration potential index is at the low level, the carbon sequestration potential rating result is determined to be a Class C anomalous area; the Class C anomalous area indicates a potential area with general or no practical significance in carbon sequestration potential.

[0013] In some embodiments, the method further includes: performing anomaly verification on the organic carbon sequestration potential target area, the inorganic carbon sequestration potential target area and the mixed carbon sequestration potential target area respectively, and conducting soil critical zone profile sampling tests and analyses in the anomaly area to confirm the carbon sequestration potential.

[0014] This invention provides a method for identifying soil carbon sequestration potential target areas based on geochemical assemblage anomalies. For the first time, it crosses boundaries between the theoretical methods of identifying mineral exploration target areas based on elemental assemblage anomalies in the field of exploration geochemistry and applies them to the identification of soil carbon sequestration potential areas, breaking through the technical limitations of traditional soil carbon sequestration potential evaluation and target area identification. Simultaneously, it proposes an inventive concept combining organic and inorganic carbon sequestration assemblages, systematically incorporating various geochemical indicators affecting soil organic and inorganic carbon fixation processes into corresponding combination systems, achieving accurate characterization and comprehensive consideration of soil carbon sequestration driving factors. Based on this, through geochemical multi-indicator anomaly analysis, it accurately identifies organic, inorganic, and mixed carbon sequestration potential target areas, and constructs a three-dimensional decision-making framework of organic-inorganic-mixed target areas. This provides scientific, accurate, and operable technical reference and decision support for the subsequent optimization of soil conservation and utilization patterns and the improvement of soil carbon neutrality function, promoting a technological leap in soil carbon sequestration potential evaluation from single indicators to a comprehensive system, and from qualitative description to quantitative identification. It has significant technological innovation value and practical application significance. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating the method for identifying soil carbon sequestration potential target areas based on geochemical assemblage anomalies provided in this embodiment of the invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In the following description, references to "some embodiments" refer to a subset of all possible embodiments; however, it is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. Unless otherwise defined, all technical and scientific terms used in the embodiments of the invention have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of the invention pertain. The terminology used in the embodiments of the invention is for the purpose of describing the embodiments of the invention only and is not intended to limit the invention.

[0018] The following describes an exemplary application of the soil carbon sequestration potential target area identification device based on geochemical assemblages anomalies according to embodiments of the present invention. This device can be implemented as a terminal or a server. In one implementation, the device can be implemented as a terminal such as a laptop, tablet, desktop computer, or mobile device. In another implementation, it can also be implemented as a server. The server can be an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms. The terminal and server can be directly or indirectly connected via wired or wireless communication, which is not limited in the embodiments of the present invention. The following describes an exemplary application of the soil carbon sequestration potential target area identification device as a server.

[0019] This invention provides a method for identifying soil carbon sequestration potential target areas based on geochemical assemblage anomalies. (See also...) Figure 1 , Figure 1 This is a flowchart illustrating a method for identifying soil carbon sequestration potential target areas based on geochemical assemblage anomalies provided in an embodiment of the present invention. Figure 1 The steps shown are explained.

[0020] S110: Multiple surface soil samples were collected from the study area, and the geochemical parameters related to organic carbon sequestration and inorganic carbon sequestration were analyzed and tested for each sample to obtain the set of organic carbon sequestration parameters and the set of inorganic carbon sequestration parameters for each sample.

[0021] Here, surface soil samples refer to soil samples collected from the surface layer of the soil in the study area. They are used to analyze and test geochemical parameters related to carbon sequestration and serve as a carrier for obtaining basic data on soil carbon sequestration. Collection must adhere to the principles of random sampling and uniform distribution to ensure the representativeness of the samples and to cover different soil types and geomorphic units within the study area.

[0022] Here, the geochemical parameters related to organic carbon sequestration refer to geochemical indicators that characterize the soil's organic carbon sequestration capacity, organic carbon accumulation, and transformation characteristics. These mainly include soil components and physicochemical parameters related to organic carbon. Examples include soil organic carbon content, active iron and aluminum oxide content, humus content, available phosphorus content, and available nitrogen content. Among these, soil organic carbon content is the most crucial geochemical parameter related to organic carbon sequestration.

[0023] Here, inorganic carbon sequestration-related geochemical parameters refer to geochemical indicators that characterize the soil's inorganic carbon sequestration capacity and the accumulation and transformation of inorganic carbon (such as carbonates). These mainly include soil components and physicochemical parameters related to carbonates and minerals. Examples include soil inorganic carbon content, calcium carbonate content, bicarbonate concentration, soil pH, cation exchange capacity, electrical conductivity, silica-alumina ratio, and exchangeable calcium and magnesium ion content.

[0024] Here, the organic carbon sequestration parameter set refers to the dataset formed by organizing the test values ​​of organic carbon sequestration-related geochemical parameters of all surface soil samples in the study area according to the sample number. It contains the specific values ​​of all organic carbon sequestration-related indicators corresponding to each sample and serves as the basic data for subsequent organic carbon sequestration anomaly analysis and combined value calculation.

[0025] Here, the inorganic carbon sequestration parameter set is defined logically in the same way as the organic carbon sequestration parameter set. It refers to the dataset formed by organizing the test values ​​of inorganic carbon sequestration-related geochemical parameters of all surface soil samples in the study area according to the sample number. It contains the specific values ​​of all inorganic carbon sequestration-related indicators corresponding to each sample and serves as the basic data for subsequent inorganic carbon sequestration anomaly analysis and combined value calculation.

[0026] In this invention, multiple surface soil samples are first collected in the study area according to scientific sampling principles, such as grid sampling and stratified sampling, to ensure that the samples cover different soil types and geomorphic units in the study area. Subsequently, the relevant geochemical indicators of organic carbon fixation and inorganic carbon fixation are analyzed and tested for each collected sample, and finally the organic carbon fixation parameter set and inorganic carbon fixation parameter set corresponding to each sample are compiled.

[0027] S120, determine the lower limit of single-index anomaly for each geochemical index in the organic carbon fixation parameter set and the inorganic carbon fixation parameter set respectively, and draw a single-index geochemical anomaly map for each geochemical index based on the test values ​​of each index of each sample and the corresponding lower limit of single-index anomaly.

[0028] Here, the lower limit of anomaly for a single indicator refers to the upper limit of the normal background value of a certain geochemical indicator within the study area, that is, the highest value of the indicator normally distributed in the soil of the study area. When the measured value of the indicator in a sample is higher than this lower limit, the sample is judged to have an anomaly in that indicator. The method for determining the lower limit of anomaly can be geostatistical (such as the Kriging method), iterative method, 95th percentile method, etc., and the specific method can be selected according to the data distribution characteristics of the study area.

[0029] Here, a single-index geochemical anomaly map refers to a graphic created through spatial visualization, based on the spatial coordinates of the study area, combined with the spatial location of each surface soil sample, and the comparison between the measured values ​​of each geochemical index of that sample and the corresponding lower limit of the single-index anomaly. It is used to visually present the anomaly distribution range and anomaly intensity (the difference between the measured value and the lower limit of the anomaly) of a single geochemical index within the study area. Each geochemical index corresponds to one single-index geochemical anomaly map, such as the organic carbon single-index anomaly map and the calcium carbonate single-index anomaly map.

[0030] In this invention, firstly, for the organic carbon fixation parameter set and inorganic carbon fixation parameter set obtained in S110, the lower limit of the single index anomaly for each geochemical index is calculated to clarify the criteria for distinguishing between normal background and anomaly; then, the test values ​​of each index of each sample are compared with the corresponding lower limit of the single index anomaly to determine whether the sample has an anomaly in that index; finally, combined with the spatial coordinates of the sample, a single index geochemical anomaly map of each index is drawn using spatial visualization technology to intuitively present the spatial distribution of anomalies of a single index.

[0031] S130, based on the organic carbon fixation parameter set and the inorganic carbon fixation parameter set respectively, the geochemical parameter combination value of each sample is calculated using the multi-index contrast accumulation method; spatial interpolation is performed on the geochemical parameter combination value of each sample, and a combination anomaly map is drawn based on the lower limit of the anomaly of the combination values ​​of all interpolated samples; the combination anomaly map includes an organic carbon fixation combination anomaly map and an inorganic carbon fixation combination anomaly map.

[0032] Here, the multi-index contrast value accumulation method refers to a comprehensive evaluation method for calculating the combined geochemical parameter values ​​of soil samples. First, the contrast value of each index is calculated, which is the ratio of the sample test value to the arithmetic mean of the index in all samples. If the test value is lower than the anomaly limit, the contrast value is set to 1 to avoid negative influence. Then, the contrast values ​​of all relevant indices of the same sample are accumulated to obtain the combined geochemical parameter values ​​of the sample, thereby comprehensively characterizing the intensity of carbon sequestration-related geochemical anomalies of the sample.

[0033] Here, the combined geochemical parameter value refers to the numerical value calculated by the multi-index cumulative method, which comprehensively reflects the overall anomaly intensity of geochemical indicators related to organic or inorganic carbon sequestration in a single soil sample. It is the core comprehensive parameter characterizing the sample's carbon sequestration potential. The higher the combined value, the more significant the carbon sequestration-related geochemical anomaly of the sample, and the stronger its potential carbon sequestration capacity.

[0034] Here, spatial interpolation refers to using geostatistical methods, such as Kriging interpolation and inverse distance weighted interpolation, to extrapolate the combined values ​​of geochemical parameters from surface soil samples collected within the study area, thereby transforming discrete sample data into continuous spatial distribution data and providing a basis for drawing combined anomaly maps.

[0035] Here, a composite anomaly map refers to a spatial visualization drawn based on a combination of geochemical parameters obtained through spatial interpolation, combined with the lower limit of anomalies for all interpolated sample combinations, and the corresponding single-index geochemical anomaly map. It is used to present the distribution characteristics of composite anomalies of geochemical indicators related to organic or inorganic carbon sequestration within the study area, and is divided into two categories: organic carbon sequestration composite anomaly maps and inorganic carbon sequestration composite anomaly maps. Compared with single-index anomaly maps, composite anomaly maps can more comprehensively and holistically reflect the spatial distribution of regional carbon sequestration potential.

[0036] Here, the organic carbon sequestration composite anomaly map is a type of composite anomaly map. It is drawn based on the geochemical parameter combination values ​​calculated from the organic carbon sequestration parameter set, after spatial interpolation, and combined with the lower limit of the anomaly of the interpolated composite values ​​and the anomaly map of the organic carbon sequestration-related single index. It is used to intuitively present the spatial distribution, anomaly range and anomaly intensity of the organic carbon sequestration-related geochemical composite anomaly in the study area.

[0037] Here, the inorganic carbon fixation assemblage anomaly map is drawn based on the geochemical parameter combination values ​​calculated from the inorganic carbon fixation parameter set. After spatial interpolation, it is combined with the lower limit of the anomaly of the interpolated combination values ​​and the anomaly map of inorganic carbon fixation-related single indicators. It is used to intuitively present the spatial distribution, anomaly range and anomaly intensity of inorganic carbon fixation-related geochemical assemblage anomalies in the study area.

[0038] In this invention, firstly, for both organic and inorganic carbon fixation parameter sets, the geochemical parameter combination value of each sample is calculated using a multi-index contrast accumulation method to comprehensively characterize the intensity of carbon fixation-related anomalies in a single sample. Subsequently, spatial interpolation is used to transform the discrete sample combination values ​​into continuous spatial distribution data, compensating for the limitations of sample collection. Finally, the lower limit of anomalies for all sample combination values ​​after interpolation is calculated, and combined with the single-index geochemical anomaly map drawn by S120, organic carbon fixation combination anomaly maps and inorganic carbon fixation combination anomaly maps are drawn respectively, intuitively presenting the spatial distribution of the comprehensive anomalies of organic and inorganic carbon fixation in the study area.

[0039] S140, calculate the comprehensive carbon sequestration potential index of each anomalous area in the organic carbon sequestration anomaly map and the inorganic carbon sequestration anomaly map respectively, and perform carbon sequestration potential rating for each anomalous area based on the comprehensive carbon sequestration potential index and the geological background information of the study area to obtain the carbon sequestration potential rating result.

[0040] Here, an anomalous region refers to a spatial area in a composite anomaly map (organic or inorganic) where the combined values ​​of geochemical parameters are higher than the lower limit of the interpolated composite value anomaly. It is a preliminary area with potential carbon sequestration capacity. Each anomalous region can be divided into different anomalous blocks based on spatial continuity and anomaly intensity. For example, in an organic carbon sequestration composite anomaly map, if the combined values ​​of a continuous area are all higher than the lower limit of the anomaly, this area is the organic carbon sequestration composite anomaly region.

[0041] Here, the comprehensive carbon sequestration potential index is a comprehensive indicator used to quantitatively evaluate the carbon sequestration potential of each anomalous area. It is calculated by comprehensively weighting factors such as the combined anomalous intensity, anomalous area area, anomalous continuity, and the number of individual indicator anomalous elements. The higher the comprehensive index, the stronger the carbon sequestration potential of the anomalous area.

[0042] Here, geological background information refers to basic information related to soil carbon sequestration within the study area, such as geology, geomorphology, soil type, lithology, hydrogeology, and climate conditions. It serves as an important auxiliary basis for rating the carbon sequestration potential of anomaly areas, reflecting the stability, sustainability, and development feasibility of their carbon sequestration potential. For example, soil type (black soil), lithology (carbonate rock), and climate (humidity) all fall under geological background information.

[0043] Here, the carbon sequestration potential rating refers to the classification of the carbon sequestration potential of each anomaly area based on its comprehensive carbon sequestration potential index and the geological background information of the study area. In practical applications, the specific number of levels and classification criteria can be adjusted according to research needs to clarify the differences in carbon sequestration potential among different anomalies and provide a basis for target area identification. For example, anomalies with a comprehensive index ≥ 8.0 and a superior geological background are rated as having high carbon sequestration potential; anomalies with a comprehensive index between 4.0 and 8.0 and a moderate geological background are rated as having medium carbon sequestration potential; and anomalies with a comprehensive index < 4.0 and a poor geological background are rated as having low carbon sequestration potential.

[0044] In this invention, firstly, based on the anomaly map of organic and inorganic carbon sequestration combination drawn by S130, their respective anomaly zones are delineated; then, the comprehensive index of carbon sequestration potential for each anomaly zone is calculated, taking into account factors such as anomaly intensity, anomaly area, and anomaly continuity, and combined with the geological background information of the study area, the carbon sequestration potential of each anomaly zone is rated, and the carbon sequestration potential rating results are obtained, and anomaly zones with high carbon sequestration potential are selected.

[0045] S150, the organic carbon fixation combination anomaly map is superimposed with the inorganic carbon fixation combination anomaly map to generate a comprehensive carbon fixation anomaly map, and based on the comprehensive carbon fixation anomaly map and the carbon fixation potential rating result, the organic carbon fixation potential target area, the inorganic carbon fixation potential target area and the mixed carbon fixation potential target area are identified and divided.

[0046] Here, the integrated carbon fixation map refers to the spatial overlay of the organic carbon fixation combination anomaly map and the inorganic carbon fixation combination anomaly map, which integrates the anomaly information of the two to form a comprehensive graphic that can simultaneously present the distribution of organic and inorganic carbon fixation combination anomalies in the study area, and can clearly reflect the spatial location and range of single anomaly areas and mixed anomaly areas.

[0047] Here, the target area for organic carbon sequestration potential refers to the anomaly area in the comprehensive carbon sequestration anomaly map where only the combination of organic carbon sequestration is significantly abnormal and the carbon sequestration potential rating is medium to high. Its carbon sequestration potential mainly comes from the accumulation and fixation of organic carbon, and it is suitable for carrying out regulation and development related to organic carbon sequestration, such as planting carbon-sequestering vegetation and increasing the application of organic fertilizers.

[0048] Here, the inorganic carbon sequestration potential target area refers to the anomaly area in the comprehensive carbon sequestration anomaly map where only the inorganic carbon sequestration combination is significantly abnormal and the carbon sequestration potential rating is medium to high. Its carbon sequestration potential mainly comes from the precipitation and fixation of inorganic carbon such as carbonates, and it is suitable for carrying out inorganic carbon sequestration-related regulation and development, such as soil carbonate improvement and pH regulation.

[0049] Here, the mixed carbon sequestration potential target area refers to the anomaly area in the comprehensive carbon sequestration anomaly map where both organic and inorganic carbon sequestration combination anomalies are significant and the carbon sequestration potential rating is medium to high. Its carbon sequestration potential comes from both organic carbon accumulation and inorganic carbon fixation, and it is the target area with the highest carbon sequestration potential and the greatest comprehensive development value.

[0050] This invention provides a method for identifying soil carbon sequestration potential target areas based on geochemical assemblage anomalies. For the first time, it crosses boundaries between the theoretical methods of identifying mineral exploration target areas based on elemental assemblage anomalies in the field of exploration geochemistry and applies them to the identification of soil carbon sequestration potential areas, breaking through the technical limitations of traditional soil carbon sequestration potential evaluation and target area identification. Simultaneously, it proposes an inventive concept combining organic and inorganic carbon sequestration assemblages, systematically incorporating various geochemical indicators affecting soil organic and inorganic carbon fixation processes into corresponding combination systems, achieving accurate characterization and comprehensive consideration of soil carbon sequestration driving factors. Based on this, through geochemical multi-indicator anomaly analysis, it accurately identifies organic, inorganic, and mixed carbon sequestration potential target areas, and constructs a three-dimensional decision-making framework of organic-inorganic-mixed target areas. This provides scientific, accurate, and operable technical reference and decision support for the subsequent optimization of soil conservation and utilization patterns and the improvement of soil carbon neutrality function, promoting a technological leap in soil carbon sequestration potential evaluation from single indicators to a comprehensive system, and from qualitative description to quantitative identification. It has significant technological innovation value and practical application significance.

[0051] In some embodiments, the geochemical parameters related to organic carbon fixation include at least soil organic carbon content, active iron and aluminum oxide content, clay content, available phosphorus content, and available nitrogen content; the geochemical parameters related to inorganic carbon fixation include at least soil inorganic carbon content, pH value, electrical conductivity, calcium carbonate content, and exchangeable calcium and magnesium ion content.

[0052] In some embodiments, the above-mentioned S120 can also be achieved by: performing a normality test on the test data of each geochemical indicator, and for data that follow a normal distribution or a log-normal distribution, using the mean + 2 times the standard deviation as the lower limit of the single-indicator anomaly of the corresponding geochemical indicator.

[0053] In some embodiments, the formula for calculating the combined values ​​of the geochemical parameters is as follows: ; In the formula, The combined values ​​of geochemical parameters for each sample; This represents the number of geochemical indicators in the corresponding combination; For the first Test values ​​of several geochemical indicators; For the first The arithmetic mean of the geochemical indicators across all samples.

[0054] In some embodiments, the formula for calculating the comprehensive carbon sequestration potential index is as follows: ; In the formula, A comprehensive index of carbon sequestration potential; This is the arithmetic mean of all sample combination values ​​within the abnormal region; This represents the lower limit of abnormal combined values. This represents the area of ​​the abnormal region.

[0055] In some embodiments, the carbon sequestration potential rating for each anomalous area includes: classifying the anomalous area according to the relative magnitude of its comprehensive carbon sequestration potential index, dividing the comprehensive carbon sequestration potential index into high, medium, and low levels from high to low; when the comprehensive carbon sequestration potential index is at the high level and, combined with the geological background information, is determined to be an advantageous area, the carbon sequestration potential rating result is determined to be a Class A anomalous area; the Class A anomalous area indicates high carbon sequestration potential and prospects; when the comprehensive carbon sequestration potential index is at the medium level and, combined with the geological background information, is determined to be an area suitable for intervention, the carbon sequestration potential rating result is determined to be a Class B anomalous area; the Class B anomalous area indicates high carbon sequestration potential and prospects after precision agricultural management and intervention; when the comprehensive carbon sequestration potential index is at the low level, the carbon sequestration potential rating result is determined to be a Class C anomalous area; the Class C anomalous area indicates a potential area with general or no practical significance in carbon sequestration potential.

[0056] Here, Grade A anomaly refers to the highest level of anomaly in the carbon sequestration potential rating. It is an anomaly area that simultaneously meets two conditions: the comprehensive carbon sequestration potential index is greater than or equal to the first threshold and the geological background information is judged to be an advantageous area. It has natural and stable high carbon sequestration potential, clear carbon sequestration prospects, and can achieve efficient carbon sequestration without complex artificial intervention. It is the carbon sequestration potential area with the greatest development value and application prospects.

[0057] Here, Class B anomaly refers to a medium-level anomaly in the carbon sequestration potential rating. It is an anomaly area that simultaneously meets two conditions: the comprehensive carbon sequestration potential index is between the second threshold and the first threshold, and the geological background information indicates that it is an area that can be intervened in.

[0058] Here, Class C anomaly refers to the lowest level of anomaly in the carbon sequestration potential rating. It is an anomaly area that only meets the condition that the comprehensive carbon sequestration potential index is less than or equal to the second threshold. Its core characteristics are that the carbon sequestration potential is average or weak and has no actual development value. Even with artificial intervention, the space for improving carbon sequestration capacity is limited, and it cannot provide effective support for the improvement of regional carbon sinks. It is usually not included in the scope of carbon sequestration potential target areas.

[0059] In this embodiment, the Jenks natural breakpoint method is used to classify the NAP values ​​of all anomaly areas into three levels: high-value areas (approximately the top 30%) are classified as Class A anomalies, medium-value areas (approximately the middle 40%) as Class B anomalies, and low-value areas (approximately the bottom 30%) as Class C anomalies. It should be noted that the above proportions are only an exemplary classification method. In practical applications, appropriate adjustments can be made based on the number of anomaly areas in the study area, the distribution characteristics of NAP values, and geological background information, such as soil type, geomorphic units, and land use patterns. For example, if the NAP value of an anomaly area is not in the top 30%, but it is located on a black soil plateau with good vegetation cover, its rating can be upgraded based on the actual geological background.

[0060] In this embodiment, by refining the rating criteria, clarifying the grade characteristics, and improving the judgment logic, the scientificity, operability, accuracy, and economy of the entire carbon sequestration potential target area identification method are improved, providing strong support for the subsequent precise development and hierarchical management of target areas, and demonstrating significant technological progress and practical application value.

[0061] In some embodiments, the method further includes: performing anomaly verification on the organic carbon sequestration potential target area, the inorganic carbon sequestration potential target area and the mixed carbon sequestration potential target area respectively, and conducting soil critical zone profile sampling tests and analyses in the anomaly area to confirm the carbon sequestration potential.

[0062] The following will describe an exemplary application of the embodiments of the present invention in a practical application scenario.

[0063] Soil carbon sequestration capacity, potential, and efficiency are limited by specific geochemical barriers. The spatial co-occurrence and anomalous combination patterns of these geochemical elements can directly indicate the dominant areas and mechanisms of carbon sequestration potential. This embodiment innovatively applies the methodology of delineating mineralized target areas based on elemental assemblages in exploration geochemistry to the spatial identification and mechanism analysis of black soil carbon sequestration potential, proposing the concept of combinations of functional geochemical parameters for organic / inorganic carbon sequestration. The specific technical methods are as follows: 1) Basic data survey of the study area: A systematic data collection and survey of the study area will be conducted. The surveyed data includes, but is not limited to: natural geography (topography, landforms, water system, climate, etc.), regional geology (strata, structure, lithology, etc.), mineral resource distribution, historical geochemical survey data, geophysical exploration data, and remote sensing image data.

[0064] 2) Sampling point layout and soil sample collection: According to the specifications for exploration geochemistry, the sampling density was determined to be 6.25 km². 2 / sample (1 sampling point per 2.5km×2.5km grid unit), after removing dead branches and fallen leaves from the surface, use the five-point sampling method to collect surface soil samples (0-30 cm). The number of duplicate samples should be 2%-3% of the total number of samples, evenly distributed in the work area. The samples should be systematically numbered and detailed information recorded.

[0065] 3) Sample processing and pretreatment: Place the collected soil samples in a ventilated place to air dry naturally or dry them at a low temperature below 40℃. After drying, the samples are ground and then passed through a 200-mesh sieve. The samples that pass through the sieve are thoroughly mixed and then packaged into sealed bags and stored in a dry, cool place for later use.

[0066] 4) Analysis of geochemical parameters related to organic carbon sequestration: A series of geochemical parameters related to the organic carbon sequestration mechanism were tested on the processed soil samples, including: soil organic carbon content, active iron and aluminum oxide content, total iron, aluminum and silicon content, clay content, soil aggregate classification composition, available phosphorus content and available nitrogen content.

[0067] 5) Analysis of inorganic carbon fixation related geochemical parameters: A series of geochemical parameters related to the inorganic carbon fixation mechanism were tested on the processed soil samples, including: soil inorganic carbon content, pH value, electrical conductivity, calcium carbonate content, exchangeable calcium and magnesium ion content, exchangeable sodium ion content, and exchangeable potassium ion content.

[0068] 6) Analytical testing quality control: Analytical quality is monitored through duplicate samples, parallel samples, and national first-class standard materials; the main monitoring is accuracy, precision, and detection limit to ensure that the analytical results of all test indicators are within the quality control requirements.

[0069] 7) Descriptive Statistics: Descriptive statistical analysis was performed on the test data for each geochemical indicator, calculating the sample size, maximum value, minimum value, mean, median, and relative standard deviation for each indicator. The relative standard deviation (RSD) was calculated using the following formula: ; in, For the first Standard deviation of geochemical indicators For the first The arithmetic mean of several geochemical indicators.

[0070] 8) Normality Test and Data Transformation: Using statistical software such as SPSS, Origin, or R, perform a normality test on all geochemical index data. For indices that significantly deviate from a normal distribution, logarithmic transformation or Box-Cox power transformation methods are used to bring the transformed data closer to a normal distribution, thus meeting the requirements of subsequent statistical analysis.

[0071] 9) Drawing geochemical anomaly maps for single indicators: Using professional software such as R language, Geochem Studio, Surfer or ArcGIS, spatial grid interpolation is performed on each geochemical indicator to draw its geochemical spatial distribution contour map, so as to intuitively reveal the spatial differentiation pattern and enrichment trend of each indicator in the study area.

[0072] 10) Use Origin or Geochem Studio to perform multivariate statistical analysis on all geochemical indicators, including factor analysis, correlation analysis, and cluster analysis. By analyzing the intrinsic correlations and symbiotic combinations among the indicators, the correlations and causal relationships among the various geochemical indicators can be preliminarily determined.

[0073] 11) Functional grouping of geochemical indicators: Based on the analysis results of steps 9-10, and combined with the theoretical mechanisms of soil organic carbon sequestration and inorganic carbon sequestration, all measured geochemical indicators are divided into two major categories: combinations of organic carbon sequestration functional parameters and combinations of inorganic carbon sequestration functional parameters.

[0074] 12) Determination of the lower limit of anomalies for single indicators: For data following a normal or log-normal distribution, the lower limit of anomalies for each geochemical indicator is determined using the mean + 2 standard deviations, i.e.: ; in, For the first The lower limit of anomalies for several geochemical indicators, For the first The standard deviation of each geochemical indicator.

[0075] 13) Single-index anomaly map drawing: Using software such as Surfer, Geochem Studio or R language, draw single-element anomaly maps of each geochemical index, with the anomaly lower limit determined in step 12 as the starting value of the contour lines.

[0076] 14) Calculation of Combined Parameters using the Multi-Indicator Contrast Accumulation Method: This embodiment employs the multi-indicator contrast accumulation method to construct a combined geochemical parameter value M that comprehensively reflects carbon sequestration potential. For each sampling point, the parameter combination value M for its corresponding functional combination (organic or inorganic) is as follows: ; in, The combined values ​​of geochemical parameters for each sample, This represents the number of geochemical indicators within the assemblage. For the first Test results of several geochemical indicators.

[0077] 15) Combination Anomaly Mapping: Combination values ​​of geochemical parameters for each sample. Perform grid interpolation and use software such as Surfer, Geochem Studio, or R to plot its spatial distribution contour maps. The lower bound of the outer band of the combined anomaly is... The abnormal outer, middle, and inner zone limits are respectively taken as follows: , and (The anomaly threshold can be adjusted based on the background and actual situation of the study area, increasing or decreasing it); among which, For parameter combination values The arithmetic mean, For parameter combination values The standard deviation.

[0078] 16) Calculation of the Comprehensive Carbon Sequestration Potential Index: To quantitatively assess and compare the carbon sequestration potential of different anomaly zones, this embodiment defines the Comprehensive Carbon Sequestration Potential Index (NAP), which is calculated using the following formula: ; in, This is the arithmetic mean of the combined values ​​within the outlier region. This represents the lower bound of abnormal combined values. This represents the area of ​​the abnormal region.

[0079] 17) Combination Anomaly Rating and Ranking: Based on the actual geological background of the study area (including geomorphic units, soil types, parent material), land use patterns (cultivated land, forest land, grassland, etc.), and the calculated NAP values, organic carbon sequestration combination anomalies and inorganic carbon sequestration combination anomalies are ranked and rated respectively. Anomalies are divided into three levels: A, B, and C. Level A anomalies are defined as representing areas with significant carbon sequestration potential and prospects; Level B anomalies represent areas with significant carbon sequestration potential and prospects after precision agricultural management and intervention; and Level C anomalies represent areas with average or no practical carbon sequestration potential.

[0080] 18) Comprehensive Anomaly Map Drawing: Using geographic information system software, the organic carbon sequestration combination anomaly map and the inorganic carbon sequestration combination anomaly map are overlaid to draw a comprehensive carbon sequestration anomaly map. Different colors or different line types of contour lines are used in the map to delineate the boundaries of organic carbon sequestration potential anomalies, inorganic carbon sequestration potential anomalies, and the superposition anomalies of the two, so as to intuitively identify different types of potential areas.

[0081] 19) Delineation and naming of carbon sequestration potential target areas: Based on the analysis results of the comprehensive anomaly map and combined with the anomaly rating, three types of carbon sequestration potential target areas are delineated and named: organic carbon sequestration potential target areas, inorganic carbon sequestration potential target areas, and mixed carbon sequestration potential target areas.

[0082] 20) Anomaly Verification and Validation: Conduct field anomaly verification work in areas with high organic carbon sequestration potential, high inorganic carbon sequestration potential, and mixed carbon sequestration potential. Specifically, deploy vertical profiles of key soil zones within the anomaly target areas, conduct systematic stratified sampling, testing, and analysis, verify the authenticity of surface soil index anomalies, identify the vertical distribution and migration transformation patterns of carbon in the profiles, and ultimately confirm and quantify their actual carbon sequestration potential.

[0083] This embodiment directly starts from the core geochemical parameters of the soil itself, such as its physicochemical properties and ionic composition, and accurately delineates the anomaly maps of organic carbon sequestration, inorganic carbon sequestration, and comprehensive carbon sequestration using a multi-index contrast accumulation method. This provides a clear and intuitive representation of the spatial distribution of areas with high carbon sequestration potential within the study area, clarifies the core reasons for these areas' high carbon sequestration potential, and precisely defines their dominant carbon sequestration pathways. This provides a targeted and operable spatial decision-making basis for precise soil carbon sequestration management. Its core scientific value lies in the fact that it systematically elucidates the spatial differentiation characteristics and intrinsic formation mechanism of soil carbon sequestration potential from a geochemical perspective for the first time. By considering both organic and inorganic carbon sequestration in a synergistic manner, it effectively promotes the understanding of soil carbon sequestration potential from traditional indirect estimation using models to a more scientific analysis of intrinsic mechanisms, further improving the technical system and theoretical understanding of soil carbon sequestration potential evaluation.

[0084] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of the present invention are included within the scope of protection of the present invention.

[0085] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of the invention, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the invention. The sequence numbers of the above-described embodiments of the invention are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0086] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. In the several embodiments provided by this invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not performed.

[0087] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for identifying soil carbon sequestration potential target areas based on geochemical assemblage anomalies, characterized in that, The method includes: Multiple surface soil samples were collected from the study area, and the geochemical parameters related to organic carbon sequestration and inorganic carbon sequestration were analyzed and tested for each sample to obtain the set of organic carbon sequestration parameters and the set of inorganic carbon sequestration parameters for each sample. The lower limit of the single index anomaly for each geochemical index in the organic carbon fixation parameter set and the inorganic carbon fixation parameter set is determined respectively. Based on the test values ​​of each index for each sample and the corresponding lower limit of the single index anomaly, a single index geochemical anomaly map for each geochemical index is drawn. Based on the organic carbon fixation parameter set and the inorganic carbon fixation parameter set respectively, the geochemical parameter combination value of each sample is calculated using the multi-index contrast accumulation method; spatial interpolation is performed on the geochemical parameter combination value of each sample, and a combination anomaly map is drawn based on the lower limit of the anomaly of the combination values ​​of all interpolated samples and the single-index geochemical anomaly map; the combination anomaly map includes an organic carbon fixation combination anomaly map and an inorganic carbon fixation combination anomaly map. The comprehensive carbon sequestration potential index of each anomalous area in the organic carbon sequestration anomaly map and the inorganic carbon sequestration anomaly map is calculated respectively. Based on the comprehensive carbon sequestration potential index and the geological background information of the study area, the carbon sequestration potential of each anomalous area is rated to obtain the carbon sequestration potential rating result. The formula for calculating the comprehensive carbon sequestration potential index is as follows: In the formula, A comprehensive index of carbon sequestration potential; This is the arithmetic mean of all sample combination values ​​within the abnormal region; This represents the lower limit of abnormal combined values. The area of ​​the abnormal region; The organic carbon fixation combination anomaly map is overlaid with the inorganic carbon fixation combination anomaly map to generate a comprehensive carbon fixation anomaly map. Based on the comprehensive carbon fixation anomaly map and the carbon fixation potential rating results, the potential target areas for organic carbon fixation, inorganic carbon fixation, and mixed carbon fixation are identified and divided.

2. The method according to claim 1, characterized in that, The relevant geochemical parameters for organic carbon sequestration include at least soil organic carbon content, active iron and aluminum oxide content, clay content, available phosphorus content, and available nitrogen content; The inorganic carbon fixation-related geochemical parameters include at least soil inorganic carbon content, pH value, electrical conductivity, calcium carbonate content, and exchangeable calcium and magnesium ion content.

3. The method according to claim 1, characterized in that, The determination of the lower limit of single-index anomaly for each geochemical index in the organic carbon fixation parameter set and the inorganic carbon fixation parameter set includes: For each geochemical indicator, a normality test was performed on the test data. For data that follow a normal or log-normal distribution, the mean plus two standard deviations was used as the lower limit of the single-indicator anomaly for the corresponding geochemical indicator.

4. The method according to claim 1, characterized in that, The formula for calculating the combined value of the geochemical parameters is as follows: ； In the formula, The combined values ​​of geochemical parameters for each sample; This represents the number of geochemical indicators in the corresponding combination; For the first Test values ​​of several geochemical indicators; For the first The arithmetic mean of the geochemical indicators across all samples.

5. The method according to claim 1, characterized in that, The carbon sequestration potential rating for each anomalous region includes: Based on the relative magnitude of the comprehensive carbon sequestration potential index of each anomalous area, the comprehensive carbon sequestration potential index is divided into high-level, medium-level and low-level from high to low. When the comprehensive carbon sequestration potential index is at a high level and is judged to be an advantageous area based on the geological background information, the carbon sequestration potential rating result is determined to be a Class A anomaly; the Class A anomaly indicates that it has high carbon sequestration potential and prospects. When the comprehensive carbon sequestration potential index is at the medium level and the geological background information indicates that the area is suitable for intervention, the carbon sequestration potential rating result is determined to be a Class B anomaly; the Class B anomaly indicates that after precision agricultural management and intervention, it has a high carbon sequestration potential and prospect. When the comprehensive index of carbon sequestration potential is at a low level, the carbon sequestration potential rating result is determined to be a Class C anomaly. The Class C anomaly indicates a potential area with general or no practical significance in terms of carbon sequestration potential.

6. The method according to claim 1, characterized in that, The method further includes: Anomaly detection was conducted on the organic carbon sequestration potential target area, the inorganic carbon sequestration potential target area, and the mixed carbon sequestration potential target area, respectively. Sampling and analysis of the key zone soil profile were carried out in the anomaly area to confirm the carbon sequestration potential.

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