Soil organic carbon content estimation method, equipment, storage medium and program product

Abstract

The present invention provides a soil organic carbon content estimation method, device, storage medium and program product. The method comprises: obtaining a soil reflectance spectrum; obtaining a characteristic spectral band corresponding to soil organic carbon according to the soil reflectance spectrum, wherein the characteristic spectral band is determined based on the spectral characteristics of soil organic carbon and the absorption characteristics of the soil reflectance spectrum; inputting the characteristic spectral band into a preset soil organic carbon content estimation model to obtain the estimated soil organic carbon content. Compared with the traditional estimation model that uses the entire visible near-infrared band for soil organic carbon content estimation, the embodiment of the present invention obtains the characteristic spectral band corresponding to soil organic carbon from the soil reflectance spectrum for soil organic carbon content estimation, thereby solving the spectral data redundancy problem existing in the existing organic carbon content estimation research based on soil reflectance spectrum, reducing the complexity of the model and improving the estimation accuracy of the organic carbon content estimation model based on the soil reflectance spectrum.

Description

Technical Field

[0001] The present invention relates to the technical field of soil organic carbon content monitoring, and in particular to a soil organic carbon content estimation method, equipment, storage medium and program product. Background Art

[0002] Soil is the second largest carbon pool in terrestrial ecosystems. Most of the carbon in soil is stored in the form of organic carbon. Soil organic carbon content is an important basic data for global carbon cycle research. Soil organic carbon content is also an important indicator of soil fertility. Timely understanding of soil organic carbon content is crucial to ensure agricultural production. Therefore, conducting research on soil organic carbon content estimation has important scientific and practical significance.

[0003] The conventional soil organic carbon content survey method is to measure the soil organic carbon content by collecting soil samples in the field and conducting laboratory chemical analysis. The soil organic carbon content survey method based on limited sampling points is difficult to provide accurate surface information. For large-scale soil organic carbon content survey needs, the conventional soil organic carbon content survey method is time-consuming, labor-intensive and costly.

[0004] Remote sensing has the characteristics of large observation range, high frequency, and few restrictions on surface conditions. It can obtain periodic observation data of large-scale areas. Hyperspectral remote sensing integrates imaging technology and spectral technology, and can obtain continuous spectral curves of the target object while imaging. By analyzing the spectral information of the object, the physical and chemical property information of the object can be obtained. Hyperspectral remote sensing provides a technical approach for quantitatively obtaining the physical and chemical properties of large-scale areas.

[0005] The research on soil organic carbon (organic matter) content estimation based on reflectance spectra has gone through the development from indoor measurement spectra of soil samples, field in-situ measurement spectra of soil, to hyperspectral remote sensing images. With the increasing abundance of hyperspectral data and the development of multivariate regression modeling algorithms, the research on soil organic carbon content estimation based on reflectance spectra has become a hot topic in the field of hyperspectral remote sensing.

[0006] At present, the research on soil organic carbon content estimation based on reflectance spectra has not fully considered the spectral characteristics of soil organic carbon, and has not selected the soil reflectance spectrum band. The entire visible and near-infrared bands are used for soil organic carbon content estimation, which increases the complexity of the model, reduces the estimation accuracy of the model, and limits the application of reflectance spectra in soil organic carbon content estimation. Summary of the invention

[0007] The present invention provides a soil organic carbon content estimation method, device, storage medium and program product, which are used to solve the problems of spectral data redundancy in organic carbon content estimation research based on soil reflectance spectrum in the prior art, resulting in a complex soil organic carbon content estimation model and low estimation accuracy obtained by the soil organic carbon content estimation model, thereby reducing the complexity of the model and improving the estimation accuracy of the organic carbon content estimation model based on soil reflectance spectrum.

[0008] The present invention provides a method for estimating soil organic carbon content, comprising:

[0009] Obtain soil reflectance spectrum;

[0010] Acquire a characteristic spectral band corresponding to soil organic carbon according to the soil reflectance spectrum, wherein the characteristic spectral band is determined based on the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum;

[0011] The characteristic spectral band is input into a preset soil organic carbon content estimation model to obtain the estimated soil organic carbon content.

[0012] According to a soil organic carbon content estimation method provided by the present invention, before the step of obtaining the soil reflectance spectrum, the method further includes:

[0013] Obtain soil reflectance spectra and soil organic carbon content;

[0014] extracting absorption characteristics of the soil reflectance spectrum according to the soil reflectance spectrum;

[0015] Determining a characteristic spectral band corresponding to soil organic carbon in the soil reflectance spectrum according to the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum;

[0016] A soil organic carbon content estimation model is established based on the characteristic spectral band and the soil organic carbon content.

[0017] According to a soil organic carbon content estimation method provided by the present invention, establishing a soil organic carbon content estimation model based on the characteristic spectral band and the soil organic carbon content includes:

[0018] Based on the characteristic spectral bands and the soil organic carbon content, a soil organic carbon content estimation model is established using a partial least squares regression algorithm.

[0019] According to a soil organic carbon content estimation method provided by the present invention, the step of determining the characteristic spectral band corresponding to the soil organic carbon in the soil reflectance spectrum according to the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum comprises:

[0020] Based on the difference in soil reflectance spectra before and after the organic carbon is extracted in the soil component sequential extraction experiment and the absorption characteristics of the soil reflectance spectrum, the characteristic spectral band corresponding to the soil organic carbon in the soil reflectance spectrum is determined.

[0021] According to a soil organic carbon content estimation method provided by the present invention, the step of obtaining the soil reflectance spectrum further includes:

[0022] The noise in the soil reflectance spectrum is removed.

[0023] According to a soil organic carbon content estimation method provided by the present invention, the absorption characteristics of the soil reflectance spectrum are extracted by any one of the spectral feature extraction algorithms including the spectral derivative method, the spectral difference method, and the spectral envelope removal method.

[0024] According to a soil organic carbon content estimation method provided by the present invention, the soil reflectance spectrum includes a soil reflectance spectrum measured by a ground object spectrometer, or a soil reflectance spectrum extracted based on a hyperspectral remote sensing image.

[0025] The present invention also provides a soil organic carbon content estimation device, comprising:

[0026] A first acquisition module is used to acquire a soil reflectance spectrum;

[0027] A second acquisition module, configured to acquire a characteristic spectral band corresponding to soil organic carbon according to the soil reflectance spectrum, wherein the characteristic spectral band is determined based on a spectral feature of the soil organic carbon and an absorption feature of the soil reflectance spectrum;

[0028] The organic carbon content estimation module is used to input the characteristic spectral band into a preset soil organic carbon content estimation model to obtain the estimated soil organic carbon content.

[0029] Preferably, the soil organic carbon content estimation device further comprises:

[0030] The third acquisition module is used to obtain soil reflectance spectrum and soil organic carbon content;

[0031] An absorption feature extraction module, used for extracting the absorption feature of the soil reflectance spectrum according to the soil reflectance spectrum;

[0032] A characteristic spectrum band determination module is used to determine the characteristic spectrum band corresponding to the soil organic carbon in the soil reflectance spectrum according to the spectrum characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum;

[0033] A model building module is used to establish a soil organic carbon content estimation model based on the characteristic spectral band and the soil organic carbon content.

[0034] Preferably, the model building module further includes:

[0035] The partial least squares regression algorithm model module is used to establish a soil organic carbon content estimation model using a partial least squares regression algorithm based on the characteristic spectral band and the soil organic carbon content.

[0036] Preferably, the characteristic spectral band determination module is used to determine the characteristic spectral band corresponding to soil organic carbon in the soil reflectance spectrum based on the difference in soil reflectance spectra before and after organic carbon is extracted in a soil component sequential extraction experiment, and the absorption characteristics of the soil reflectance spectrum.

[0037] Preferably, the characteristic spectrum band determination module further includes:

[0038] The noise removal module is used to remove noise in the soil reflectance spectrum.

[0039] Preferably, the absorption characteristics of the soil reflectance spectrum are extracted by any one of the spectral feature extraction algorithms including a spectral derivative method, a spectral difference method, and a spectral envelope removal method.

[0040] Preferably, the soil reflectance spectrum includes a soil reflectance spectrum measured by a ground object spectrometer, or a soil reflectance spectrum extracted based on a hyperspectral remote sensing image.

[0041] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of any of the above-mentioned methods for estimating soil organic carbon content are implemented.

[0042] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-described methods for estimating soil organic carbon content.

[0043] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the steps of any of the above-mentioned methods for estimating soil organic carbon content are implemented.

[0044] The soil organic carbon content estimation method, device, storage medium and program product provided by the present invention obtain a soil reflectance spectrum; and obtain a characteristic spectral band corresponding to soil organic carbon according to the soil reflectance spectrum. The characteristic spectral band is determined based on the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum. Thus, a characteristic spectral band corresponding to soil organic carbon with a smaller band range is obtained from the soil reflectance spectrum, and finally the characteristic spectral band is input into a preset soil organic carbon content estimation model to obtain the estimated soil organic carbon content. Compared with the traditional estimation model that uses the entire visible near-infrared band for soil organic carbon content estimation, the embodiment of the present invention obtains the characteristic spectral band corresponding to soil organic carbon from the soil reflectance spectrum for soil organic carbon content estimation, thereby solving the spectral data redundancy problem existing in the existing organic carbon content estimation research based on soil reflectance spectrum, reducing the complexity of the model and improving the estimation accuracy of the organic carbon content estimation model based on the soil reflectance spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 It is one of the flow diagrams of the soil organic carbon content estimation method provided by the present invention;

[0047] Figure 2 This is a schematic diagram of the soil organic carbon content estimation results based on the spectral range of 400-1000nm;

[0048] Figure 3 It is a schematic diagram of the soil organic carbon content estimation result obtained by estimating based on the characteristic spectral band of the present invention;

[0049] Figure 4 It is a schematic diagram of the soil reflectance spectrum of 400-1000nm measured in the laboratory obtained by the present invention;

[0050] Figure 5 It is a structural schematic diagram of the soil organic carbon content estimation device provided by the present invention;

[0051] Figure 6 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] The existing models use the entire visible-near infrared band for estimating soil organic carbon content, which increases the complexity of the model, reduces the estimation accuracy of the model, and limits the application of reflectance spectra in estimating soil organic carbon content.

[0054] The inventive concept of the embodiment of the present invention is to obtain the characteristic spectral bands corresponding to soil organic carbon from the soil reflectance spectrum for estimating the soil organic carbon content, thereby solving the problem of spectral data redundancy existing in the existing research on organic carbon content estimation based on soil reflectance spectrum, reducing the complexity of the model and improving the estimation accuracy of the organic carbon content estimation model based on the soil reflectance spectrum.

[0055] Combine the following Figure 1-Figure 6 The present invention describes a soil organic carbon content estimation method, device and electronic device.

[0056] Please refer to Figure 1 , Figure 1 A flow chart of a method for estimating soil organic carbon content provided by one embodiment of the present invention.

[0057] like Figure 1 A method for estimating soil organic carbon content is shown, including:

[0058] S100, obtaining soil reflectance spectrum;

[0059] The soil reflectance spectrum is obtained by an electronic device. The soil reflectance spectrum includes a soil reflectance spectrum measured indoors or outdoors using a ground object spectrometer. Specifically, the reflectance spectra of 73 soil samples can be measured using a PSR-3500 (Spectral Evolution Inc., Lawrence, MA, USA). The soil reflectance spectrum in the spectral range of 350-2500 nm wavelength range can be measured by the PSR-3500 spectrometer.

[0060] Of course, in some other embodiments, the soil reflectance spectrum may also be a soil reflectance spectrum extracted from a hyperspectral remote sensing image.

[0061] S200, acquiring a characteristic spectral band corresponding to soil organic carbon according to the soil reflectance spectrum, wherein the characteristic spectral band is determined based on a spectral characteristic of the soil organic carbon and an absorption characteristic of the soil reflectance spectrum;

[0062] The electronic device first intercepts the 400-1000nm near-infrared spectrum from the 350-2500nm soil reflectance spectrum measured by the PSR-3500 spectrometer for soil organic carbon content estimation. The 400-1000nm soil sample reflectance spectrum measurement results are as follows: Figure 4 The electronic device then obtains the characteristic spectral band corresponding to soil organic carbon from the near-infrared spectrum of 400-1000nm for estimating the soil organic carbon content.

[0063] Specifically, the characteristic spectral band can be determined based on the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum.

[0064] Among them, the spectral characteristics of soil organic carbon can be obtained by analyzing the difference in soil reflectance spectra before and after the extraction of organic carbon in the soil component sequential extraction experiment. Since real soil is a mixture of many components, for example, the soil includes iron oxides, organic carbon (mass), clay minerals, water, etc. The components in the soil are extracted by chemical sequential extraction (Chemical Sequential Extraction), for example, first extracting soluble acids in the soil, then extracting manganese oxides in the soil, then extracting organic carbon in the soil, and finally extracting iron oxides in the soil. The spectral characteristics of soil organic carbon can be obtained by analyzing the difference in soil reflectance spectra before and after the sequential extraction of soil components. By analyzing the difference in soil reflectance spectra before and after the extraction of organic carbon in the soil component sequential extraction experiment, the influence of organic carbon on the soil reflectance spectrum is mainly in 400-1000nm, and the spectral range with the greatest influence is in 600-750nm.

[0065] The absorption characteristics of the soil reflectance spectrum are obtained by a spectral feature extraction algorithm. Furthermore, the present embodiment can extract the absorption characteristics of the soil reflectance spectrum by a spectral envelope removal method. The results of the absorption feature extraction of the soil sample reflectance spectrum by the spectral envelope removal method show that there are four main absorption peaks in the spectral range of 400-1000nm in the soil reflectance spectrum, namely, the absorption peak centered at 410nm, the absorption peak centered at 500nm, the absorption peak in the 600-750nm range, and the absorption peak centered at 900nm. Therefore, the absorption peak centered at 410nm, the absorption peak centered at 500nm, the absorption peak in the 600-750nm range, and the absorption peak centered at 900nm are used as alternative bands for the characteristic spectral band.

[0066] Based on the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum, the absorption peak centered at 500 nm and the absorption peak in the range of 600-750 nm are used as characteristic spectral bands corresponding to the soil organic carbon.

[0067] Specifically, the results of removing the reflectance spectrum envelope of 73 soil samples in this embodiment show that the specific spectral range of the absorption peak centered at 500nm is 450-525nm, and the specific spectral range of the absorption peak in the interval of 600-750nm is 610-715nm. Therefore, based on the absorption peak centered at 500nm and the absorption peak in the interval of 600-750nm as the characteristic spectral bands corresponding to soil organic carbon, the spectral interval of 450-525nm and the spectral interval of 610-715nm are selected from the spectral interval of 400-1000nm as the characteristic spectral bands corresponding to soil organic carbon.

[0068] S300, inputting the characteristic spectral band into a preset soil organic carbon content estimation model to obtain an estimated soil organic carbon content.

[0069] After obtaining the characteristic spectral band corresponding to soil organic carbon, the electronic device inputs the characteristic spectral band into a preset soil organic carbon content estimation model, thereby obtaining the estimated soil organic carbon content. Since the characteristic spectral band is a smaller spectral band obtained from the larger range of soil reflectance spectrum initially obtained in step S100, the smaller range of characteristic spectral bands is used for soil organic carbon content estimation, thereby solving the spectral data redundancy problem existing in the existing research on organic carbon content estimation based on soil reflectance spectrum, reducing the complexity of the model and improving the estimation accuracy of the organic carbon content estimation model based on soil reflectance spectrum.

[0070] The soil organic carbon content estimation method provided by the present invention obtains a soil reflectance spectrum; and obtains a characteristic spectral band corresponding to soil organic carbon according to the soil reflectance spectrum. The characteristic spectral band is determined based on the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum. Thus, a characteristic spectral band corresponding to soil organic carbon with a smaller band range is obtained from the soil reflectance spectrum, and finally the characteristic spectral band is input into a preset soil organic carbon content estimation model to obtain the estimated soil organic carbon content. Compared with the traditional estimation model that uses the entire visible near-infrared band for soil organic carbon content estimation, the embodiment of the present invention obtains the characteristic spectral band corresponding to soil organic carbon from the soil reflectance spectrum for soil organic carbon content estimation, thereby solving the spectral data redundancy problem existing in the existing organic carbon content estimation research based on the soil reflectance spectrum, reducing the complexity of the model and improving the estimation accuracy of the organic carbon content estimation model based on the soil reflectance spectrum.

[0071] As a preferred embodiment, before the step of obtaining the soil reflectance spectrum, the step further includes:

[0072] S001. Obtain soil reflectance spectrum and soil organic carbon content;

[0073] Soil reflectance spectra and soil organic carbon content were obtained by electronic equipment. Similarly, soil reflectance spectra can be measured by a soil reflectance spectra measured by a ground feature spectrometer or extracted from a hyperspectral remote sensing image. The ground feature spectrometer can measure the reflectance spectra of 73 soil samples using a PSR-3500 (Spectral Evolution Inc., Lawrence, MA, USA).

[0074] The soil organic carbon content can be determined by using potassium dichromate-sulfuric acid solution in accordance with the "Soil Organic Matter Determination Method" (GB 9834-88), or by using the combustion loss method (such as the muffle furnace combustion loss method) to measure the soil organic carbon content of the above 73 soil samples.

[0075] S002. Extracting absorption characteristics of a soil reflectance spectrum according to the soil reflectance spectrum;

[0076] Similar to the above step S200, the absorption characteristics of the soil reflectance spectrum can be extracted by using the spectral envelope removal (Continuum Removing, CR) method. The results of extracting the absorption characteristics of the soil sample reflectance spectrum by the spectral envelope removal method show that the soil reflectance spectrum has four main absorption peaks in the spectral range of 400-1000nm, namely, the absorption peak centered at 410nm, the absorption peak centered at 500nm, the absorption peak in the 600-750nm range, and the absorption peak centered at 900nm.

[0077] S003, determining a characteristic spectral band corresponding to soil organic carbon in the soil reflectance spectrum according to the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum;

[0078] The electronic device determines the characteristic spectral band corresponding to the soil organic carbon in the soil reflectance spectrum according to the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum. Specifically, in some embodiments, step S003 specifically includes: determining the characteristic spectral band corresponding to the soil organic carbon in the soil reflectance spectrum based on the difference in soil reflectance spectra before and after organic carbon is extracted in the soil component sequential extraction experiment and the absorption characteristics of the soil reflectance spectrum.

[0079] Similar to step S200, by analyzing the difference in soil reflectance spectra before and after the extraction of organic carbon in the soil component sequential extraction experiment, the influence of organic carbon on the soil reflectance spectrum is mainly in the range of 400-1000nm, and the spectral range with the greatest influence is in the range of 600-750nm. Based on the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum, the absorption peak centered at 500nm and the absorption peak in the range of 600-750nm are used as characteristic spectral bands corresponding to soil organic carbon. Specifically, the results of the envelope removal of the reflectance spectra of 73 soil samples in this embodiment show that the specific spectral range of the absorption peak centered at 500nm is 450-525nm, and the specific spectral range of the absorption peak in the range of 600-750nm is 610-715nm. Therefore, based on the absorption peak centered at 500nm and the absorption peak in the range of 600-750nm as the characteristic spectral bands corresponding to soil organic carbon, the spectral range of 450-525nm and the spectral range of 610-715nm are selected from the spectral range of 400-1000nm as the characteristic spectral bands corresponding to soil organic carbon.

[0080] S004. Establishing a soil organic carbon content estimation model based on the characteristic spectral band and the soil organic carbon content.

[0081] On the basis of acquiring the characteristic spectral band, the electronic device establishes a soil organic carbon content estimation model based on the characteristic spectral band and the soil organic carbon content.

[0082] Specifically, in some embodiments, S004 specifically includes: based on the characteristic spectral band and the soil organic carbon content, using a partial least squares regression algorithm to establish a soil organic carbon content estimation model.

[0083] The soil organic carbon content estimation model was established by partial least squares regression (PLSR) using the extracted characteristic spectral bands (i.e., the spectral interval of 450-525nm and the spectral interval of 610-715nm) and the measured soil organic carbon content.

[0084] It is worth mentioning that in order to improve the estimation accuracy of the model and reduce the complexity of the model, the genetic algorithm (GA) can be used for band selection in PLSR modeling. The parameter settings of the GA algorithm include: population number: 20; maximum generation: 120; generation difference: 10%; mutation frequency: 10%; run the genetic algorithm 5 times, and select the bands used in the experiment with the highest estimation accuracy of organic carbon content.

[0085] The soil organic carbon estimation accuracy obtained by using the soil organic carbon content estimation method provided by the present invention is shown in Table 1.

[0086] Table 1 Estimation accuracy of soil organic carbon content

[0087] Soil reflectance spectrum RMSEP(%) <![CDATA[R 2 ]]> 400-1000nm 0.48 0.79 Characteristic spectral bands of organic carbon 0.46 0.81

[0088] Among them, 400-1000nm means all spectral bands from 400 to 1000nm;

[0089] The organic carbon characteristic spectral band refers to the spectral band included in the absorption peak centered at 500nm (i.e., 450-525nm) and the absorption peak in the 750nm interval (i.e., 610-715nm) proposed in the present invention; RMSEP (Root mean square error of prediction) is the root mean square error of prediction, which indicates the root mean square error of prediction of the organic carbon content estimation model in the organic carbon content estimation; R 2 (Coefficient of determination) is the determination coefficient of the soil organic carbon content estimation model. It can be seen that the root mean square error of the prediction obtained based on the soil organic carbon characteristic spectral band is 0.46, which is smaller than the root mean square error of the prediction obtained based on the 400-1000nm spectral band, which is 0.48. Therefore, the method provided by the present invention can achieve a higher accuracy soil organic carbon content estimation using fewer reflectance spectral bands.

[0090] The estimation accuracy of the soil organic carbon content estimation method of this embodiment is described below with reference to the accompanying drawings.

[0091] Figure 2 It is the soil organic carbon content estimation result obtained using all spectral bands from 400 to 1000 nm. Figure 3 This is the soil organic carbon content estimation result obtained by using the characteristic spectral band of soil organic carbon in this example. Figure 2 and Figure 3 RMSEP (Root mean square error of prediction) is the root mean square error of prediction, which indicates the root mean square error of prediction of organic carbon content estimation model in organic carbon content estimation; R 2 (Coefficient of determination) is the determination coefficient of the soil organic carbon content estimation model. Figure 2 and Figure 3 The horizontal axis Measured content represents the measured value, and the vertical axis Predicted content represents the predicted value.

[0092] From the estimation results of soil organic carbon content, it can be seen that Figure 3 Compared with the scatter plot in Figure 2 The scattered points in are generally closer to the diagonal line of y=x, which means Figure 3 The measured and predicted values ​​in are generally close to equal, while Figure 2 In other words, the method provided by the present invention can achieve a higher-precision estimation of soil organic carbon content using fewer reflectance spectral bands, thereby improving the estimation accuracy of the organic carbon content estimation model based on soil reflectance spectrum.

[0093] As a preferred embodiment, the step of obtaining the soil reflectance spectrum further includes:

[0094] The noise in the soil reflectance spectrum is removed.

[0095] Specifically, the electronic device can remove noise in the soil reflectance spectrum through the Savitzky-Golay (SG) filtering algorithm. When the soil reflectance spectrum is extracted from the hyperspectral remote sensing image, various noises are introduced due to the influence of natural light illumination conditions, ground terrain, mixed pixel problems, etc. during hyperspectral image imaging. This noise exists in the spectral domain and therefore needs to be removed.

[0096] Please note that, please refer to Figure 4 , Figure 4 The horizontal axis Wavelength represents the wavelength of the soil spectrum, and the vertical axis Reflectance represents the soil spectrum reflectance. Figure 4 The soil reflectance spectrum measured in the laboratory shown does not have obvious noise, and it is not necessary to remove noise from the soil reflectance spectrum.

[0097] The soil organic carbon content estimation device provided by the present invention is described below. The soil organic carbon content estimation device described below and the soil organic carbon content estimation method described above can be referenced to each other.

[0098] Please refer to Figure 5 The present invention also provides a soil organic carbon content estimation device, comprising:

[0099] A first acquisition module 201 is used to acquire a soil reflectance spectrum;

[0100] A second acquisition module 202 is used to acquire a characteristic spectral band corresponding to soil organic carbon according to the soil reflectance spectrum, wherein the characteristic spectral band is determined based on the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum;

[0101] The organic carbon content estimation module 203 is used to input the characteristic spectral band into a preset soil organic carbon content estimation model to obtain the estimated soil organic carbon content.

[0102] The soil organic carbon content estimation device of the embodiment of the present invention obtains a soil reflectance spectrum; and obtains a characteristic spectral band corresponding to soil organic carbon according to the soil reflectance spectrum. The characteristic spectral band is determined based on the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum. Thus, a characteristic spectral band corresponding to soil organic carbon with a smaller band range is obtained from the soil reflectance spectrum, and finally the characteristic spectral band is input into a preset soil organic carbon content estimation model to obtain the estimated soil organic carbon content. Compared with the traditional estimation model that uses the entire visible near-infrared band for soil organic carbon content estimation, the embodiment of the present invention obtains the characteristic spectral band corresponding to soil organic carbon from the soil reflectance spectrum for soil organic carbon content estimation, thereby solving the spectral data redundancy problem existing in the existing organic carbon content estimation research based on soil reflectance spectrum, reducing the complexity of the model and improving the estimation accuracy of the organic carbon content estimation model based on the soil reflectance spectrum.

[0103] As a preferred embodiment, the soil organic carbon content estimation device further includes:

[0104] The third acquisition module is used to obtain soil reflectance spectrum and soil organic carbon content;

[0105] An absorption feature extraction module, used for extracting the absorption feature of the soil reflectance spectrum according to the soil reflectance spectrum;

[0106] A characteristic spectrum band determination module is used to determine the characteristic spectrum band corresponding to the soil organic carbon in the soil reflectance spectrum according to the spectrum characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum;

[0107] A model building module is used to establish a soil organic carbon content estimation model based on the characteristic spectral band and the soil organic carbon content.

[0108] As a preferred embodiment, the model building module further includes:

[0109] The partial least squares regression algorithm model module is used to establish a soil organic carbon content estimation model using a partial least squares regression algorithm based on the characteristic spectral band and the soil organic carbon content.

[0110] As a preferred embodiment, the characteristic spectral band determination module is used to determine the characteristic spectral band corresponding to soil organic carbon in the soil reflectance spectrum based on the difference in soil reflectance spectra before and after organic carbon is extracted in the soil component sequential extraction experiment, and the absorption characteristics of the soil reflectance spectrum.

[0111] As a preferred embodiment, the characteristic spectrum band determination module further includes:

[0112] The noise removal module is used to remove noise in the soil reflectance spectrum.

[0113] As a preferred embodiment, the absorption characteristics of the soil reflectance spectrum are extracted by any one of the spectral feature extraction algorithms including a spectral derivative method, a spectral difference method, and a spectral envelope removal method.

[0114] Figure 6 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 6 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the soil organic carbon content estimation method, which includes: obtaining a soil reflectance spectrum and a soil organic carbon content; extracting the absorption characteristics of the soil reflectance spectrum according to the soil reflectance spectrum; determining the characteristic spectral band corresponding to the soil organic carbon in the soil reflectance spectrum according to the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum; and establishing a soil organic carbon content estimation model based on the characteristic spectral band and the soil organic carbon content.

[0115] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0116] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the soil organic carbon content estimation method provided by the above-mentioned methods, and the method includes: obtaining a soil reflectance spectrum and a soil organic carbon content; extracting the absorption characteristics of the soil reflectance spectrum according to the soil reflectance spectrum; determining the characteristic spectral band corresponding to the soil organic carbon in the soil reflectance spectrum according to the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum; and establishing a soil organic carbon content estimation model based on the characteristic spectral band and the soil organic carbon content.

[0117] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the soil organic carbon content estimation method provided by the above-mentioned methods, the method comprising: obtaining a soil reflectance spectrum and a soil organic carbon content; extracting the absorption characteristics of the soil reflectance spectrum according to the soil reflectance spectrum; determining a characteristic spectral band corresponding to the soil organic carbon in the soil reflectance spectrum according to the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum; and establishing a soil organic carbon content estimation model based on the characteristic spectral band and the soil organic carbon content.

[0118] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0119] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for estimating soil organic carbon content, characterized in that: include: Obtain soil reflectance spectrum; Acquire a characteristic spectral band corresponding to soil organic carbon according to the soil reflectance spectrum, wherein the characteristic spectral band is determined based on the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum; Inputting the characteristic spectral band into a preset soil organic carbon content estimation model to obtain an estimated soil organic carbon content; The step of obtaining the soil reflectance spectrum also includes: Obtain soil reflectance spectra and soil organic carbon content; extracting absorption characteristics of the soil reflectance spectrum according to the soil reflectance spectrum; Determining a characteristic spectral band corresponding to soil organic carbon in the soil reflectance spectrum according to the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum; Establishing a soil organic carbon content estimation model based on the characteristic spectral band and the soil organic carbon content; Establishing a soil organic carbon content estimation model based on the characteristic spectral band and the soil organic carbon content includes: Based on the characteristic spectral bands and the soil organic carbon content, a soil organic carbon content estimation model is established using a partial least squares regression algorithm; The step of determining the characteristic spectral band corresponding to the soil organic carbon in the soil reflectance spectrum according to the spectral characteristics of the soil organic carbon and the absorption characteristics of the soil reflectance spectrum comprises: Based on the difference in soil reflectance spectra before and after the extraction of organic carbon in the soil component sequential extraction experiment, and the absorption characteristics of the soil reflectance spectrum, determine the characteristic spectral band corresponding to the soil organic carbon in the soil reflectance spectrum; Among them, the influence of organic carbon on soil reflectance spectrum is between 400-1000nm, and the spectral range with the greatest influence is between 600-750nm. Combined with the absorption peak of the soil reflectance spectrum in the spectral range of 400-1000nm, the absorption peak centered at 500nm and the absorption peak in the range of 600-750nm are determined as the characteristic spectral bands corresponding to soil organic carbon.

2. The method for estimating soil organic carbon content according to claim 1, characterized in that: The step of obtaining the soil reflectance spectrum also includes: The noise in the soil reflectance spectrum is removed.

3. The method for estimating soil organic carbon content according to any one of claims 1 to 2, characterized in that: The absorption characteristics of the soil reflectance spectrum are extracted by using any one of the spectrum feature extraction algorithms including the spectrum derivative method, the spectrum difference method and the spectrum envelope removal method.

4. The method for estimating soil organic carbon content according to claim 1, characterized in that: The soil reflectance spectrum includes a soil reflectance spectrum measured by a ground object spectrometer, or a soil reflectance spectrum extracted based on a hyperspectral remote sensing image.

5. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the soil organic carbon content estimation method according to any one of claims 1 to 4 are implemented.

6. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the soil organic carbon content estimation method according to any one of claims 1 to 4 are implemented.

7. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the soil organic carbon content estimation method according to any one of claims 1 to 4 are implemented.

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