Method and system for quantitatively analyzing three-dimensional resistivity tomography imaging result

Abstract

The invention provides a method and system for quantitatively analyzing a three-dimensional resistivity tomography result, and the method comprises the steps: obtaining a three-dimensional distribution diagram of moisture content, carrying out the sectioning at a fixed interval in a manner of being vertical to an X axis and a Y axis, and correspondingly obtaining a section set containing m YZ sections and a section set containing n XZ sections; when the water content of the soil is changed due to water infiltration, drawing an isoline based on a preset water content threshold value so as to define the position of a wetting front; respectively meshing the XZ profile set and the YZ profile set, and calculating the moisture infiltration coverage degree in each grid in combination with the wetting front position; determining the matrix inflow seepage depth of each section in the XZ section set and the YZ section set, and then calculating the priority flow fraction of each section in the XZ section set and the YZ section set; and analyzing the value of the priority flow fraction to determine the difference of the infiltration mode, and quantifying the difference of matrix inflow and infiltration depth. According to the method, the problem that the infiltration mode and the spatial heterogeneity index are not judged by using the resistivity tomography method is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field, in particular, to a method and system for quantitatively analyzing three-dimensional resistivity tomography results. BACKGROUND

[0002] In the field of eco-hydrology, three-dimensional resistivity tomography technology can effectively obtain underground resistivity distribution data due to its non-invasive and high-resolution advantages, and has become an important means for detecting underground soil water content. Since the existing resistivity tomography can only qualitatively describe the distribution and change of soil moisture, it cannot directly quantify the differences in water infiltration process.

[0003] Patent document CN111722292A discloses a three-dimensional resistivity tomography method and system. The three-dimensional resistivity tomography method includes using at least two exploration methods to explore the region containing geological anomaly bodies respectively to obtain two-dimensional resistivity data of the corresponding detection plane; unifying the coordinate systems of the resistivity data points obtained by all exploration methods, extracting data points with the same coordinates; using principal component analysis to fuse the resistivity data of the same position; and performing three-dimensional coordinate conversion on the fused resistivity data to form a three-dimensional model.

[0004] However, patent document CN111722292A only stops at simple visual presentation of data, and cannot effectively analyze and characterize the key characteristics of water infiltration path, rate and mode, which seriously restricts the in-depth application and value of the technology in hydrological process research.

[0005] Therefore, there is an urgent need in the market for a method and system for quantitatively analyzing three-dimensional resistivity tomography results that can comprehensively and accurately analyze and characterize. SUMMARY

[0006] In view of the defects in the prior art, the purpose of the present application is to provide a method and system for quantitatively analyzing three-dimensional resistivity tomography results.

[0007] According to the method for quantitatively analyzing three-dimensional resistivity tomography results provided by the present application, the following steps are included:

[0008] Step S1: obtaining a three-dimensional distribution map of water content;

[0009] Step S2: cutting the three-dimensional map of water content at a fixed interval perpendicular to the X-axis to obtain a profile collection containing m YZ profiles, and cutting at a fixed interval perpendicular to the Y-axis to obtain a profile collection containing n XZ profiles;

[0010] Step S3: When the water infiltration causes the change of soil water content, the contour line is drawn based on the preset water content threshold to define the position of the wetting front, and the wetting front and the surrounding soil water distribution state are visually expressed in different regional colors;

[0011] Step S4: The XZ profile set and the YZ profile set are respectively gridded, and the water infiltration coverage in each grid is calculated in combination with the position of the wetting front;

[0012] Step S5: The matrix flow infiltration depth of each profile in the XZ profile set is determined, and the matrix flow infiltration depth of each profile in the YZ profile set is determined;

[0013] Step S6: According to the matrix flow infiltration depth and the water infiltration coverage in each grid, the preferential flow fraction of each profile in the XZ profile set and the YZ profile set is calculated;

[0014] Step S7: The value of the preferential flow fraction is analyzed to analyze the difference of the infiltration mode identified by the electrical resistivity tomography method, and the heterogeneity of the infiltration in space is quantified according to the matrix flow infiltration depth and the preferential flow fraction.

[0015] Preferably, the step S2 comprises:

[0016] The fixed interval d is perpendicular to the X axis x The YZ profile set (x1, x2, …, xm) is obtained by slicing, as follows: m (m-1)×d

[0017] = Length x

[0018] The fixed interval d is perpendicular to the Y axis y The XZ profile set (y1, y2, …, yn) is obtained by slicing, as follows: n (n-1)×d

[0019] = Width y

[0020] Wherein, Length and Width represent the length and width of the three-dimensional cuboid region distribution result of the water content obtained by the ERT experiment, respectively.

[0021] Preferably, in the step S3, the region with water content greater than or equal to the threshold value is assigned a non-white color, and the region with water content less than the threshold value is assigned a white color;

[0022] The step S4 comprises:

[0023] ​​Step S4.1: Each profile in the YZ profile set is divided into k grids from top to bottom, and the moisture infiltration coverage of each grid, i.e. the percentage of the total area occupied by non-white color, is calculated. The formula is as follows:

[0024]

[0025] In the formula, MIC represents the moisture infiltration coverage of the i-th grid of the profile of the YZ profile set, j the moisture infiltration coverage of the i-th grid of the profile of the YZ profile set, represents the moisture infiltration area of the i-th grid of the profile of the YZ profile set, j represents the moisture infiltration area of the i-th grid of the profile of the YZ profile set, YZ represents the area of the YZ profile, and k is a constant.

[0026] Step S4.2: All profiles in the XZ profile set are divided into k grids from top to bottom, and the moisture infiltration coverage of each grid, i.e. the percentage of the total area occupied by non-white color, is calculated. The formula is as follows:

[0027]

[0028] In the formula, MIC represents the moisture infiltration coverage of the i-th grid of the profile of the XZ profile set, j the moisture infiltration coverage of the i-th grid of the profile of the XZ profile set, represents the moisture infiltration area of the i-th grid of the profile of the XZ profile set, j represents the moisture infiltration area of the i-th grid of the profile of the XZ profile set, XZ is the area of the XZ profile.

[0029] Preferably, the matrix infiltration depth of each profile in the XZ and YZ profile set is calculated according to the following formula:

[0030]

[0031] In the formula, i xj-ithreshold represents the i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the x j profile, i yj-ithreshold represents the i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the y j profile, z represents the depth of the three-dimensional cuboid region distribution of water content obtained by the ERT experiment, and k is a constant.

[0032] Preferably, the preferential flow fraction, i.e. the percentage of the total infiltration area below the matrix infiltration depth, is calculated according to the following formula:

[0033]

[0034] In the formula, PF frrepresenting the priority flow fraction i xj-ithreshold representing x j The i value corresponding to the grid where the first moisture infiltration coverage MIC of the profile is less than 80%, i yj-ithreshold representing y j The i value corresponding to the grid where the first moisture infiltration coverage MIC of the profile is less than 80%, k is a constant, representing x in the YZ profile aggregate j The moisture infiltration area of the i-th rectangle of the profile (1≤j≤m), representing y in the XZ profile aggregate j The moisture infiltration area of the i-th rectangle of the profile (1≤j≤n).

[0035] According to the application, a system for quantitatively analyzing the results of three-dimensional resistivity tomography is provided, comprising:

[0036] Module M1: obtaining a three-dimensional distribution map of water content;

[0037] Module M2: vertically cutting the three-dimensional map of water content at a fixed interval along the X axis, and correspondingly obtaining a profile aggregate containing m YZ profiles, and cutting at a fixed interval along the Y axis, and correspondingly obtaining a profile aggregate containing n XZ profiles;

[0038] Module M3: when moisture infiltration causes changes in soil water content, drawing an isogram based on a preset water content threshold to define the position of the wetting front, and visualizing the distribution of moisture around the wetting front in different regions with different colors;

[0039] Module M4: meshing the XZ profile aggregate and the YZ profile aggregate respectively, and calculating the moisture infiltration coverage in each grid in combination with the position of the wetting front;

[0040] Module M5: determining the matrix flow infiltration depth of each profile in the XZ profile aggregate, and determining the matrix flow infiltration depth of each profile in the YZ profile aggregate;

[0041] Module M6: calculating the priority flow fraction of each profile in the XZ profile aggregate and the YZ profile aggregate according to the matrix flow infiltration depth and the moisture infiltration coverage in each grid;

[0042] Module M7: analyzing the value of the priority flow fraction to analyze the differences in the infiltration mode identified by resistivity tomography, and quantifying the spatial heterogeneity of infiltration according to the matrix flow infiltration depth and the priority flow fraction.

[0043] Preferably, the module M2 comprises:

[0044] Vertically cutting along the X axis at a fixed interval d xThe sectioning obtains a set of YZ profile collections with m profiles, as follows:

[0045] (m-1) x d x = Length

[0046] fixed interval d y The sectioning obtains a set of XZ profile collections with n profiles, as follows:

[0047] (n-1) x d y = Width

[0048] where Length and Width represent the length and width of the three-dimensional cuboid area distribution of water content obtained by the ERT experiment, respectively.

[0049] Preferably, in the module M3, the area with water content greater than or equal to the threshold value is assigned a non-white color, and the area with water content less than the threshold value is assigned a white color.

[0050] The module M4 comprises:

[0051] Module M4.1: Each profile in the YZ profile collection is divided into k grids from top to bottom, and the percentage of non-white color occupying the total area in each grid, i.e. the water infiltration coverage, is calculated, as follows:

[0052]

[0053] In the formula, represents the water infiltration coverage of the ith rectangular of the profile of x j in the YZ profile collection, represents the water infiltration area of the ith rectangular of the profile of x j in the YZ profile collection, S YZ represents the area of the YZ profile, and k is a constant;

[0054] Module M4.2: All profiles in the XZ profile collection are divided into k grids from top to bottom, and the percentage of non-white color occupying the total area in each grid, i.e. the water infiltration coverage, is calculated, as follows:

[0055]

[0056] In the formula, represents the water infiltration coverage of the ith rectangular of the profile of y j in the XZ profile collection, represents the water infiltration area of the ith rectangular of the profile of y j in the XZ profile collection, S XZ is the area of the XZ profile.

[0057] Preferably, the matrix flow depth of each profile in the XZ and YZ profile combination set is calculated as follows:

[0058]

[0059] In the formula, i xj-ithreshold represents x j The i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the profile, i yj-ithreshold represents y j The i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the profile, z represents the depth of the three-dimensional cuboid area distribution result of the moisture content obtained by the ERT experiment, and k is a constant.

[0060] Preferably, the preferential flow fraction, i.e., the percentage of the infiltration area below the matrix flow depth in the total infiltration area, is calculated as follows:

[0061]

[0062] In the formula, PF fr represents the preferential flow fraction, i xj-ithreshold represents x j The i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the profile, i yj-ithreshold represents y j The i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the profile, k is a constant, represents the moisture infiltration area of the i-th rectangle in the profile of x j in the YZ profile combination set, represents the moisture infiltration area of the i-th rectangle in the profile of y j in the XZ profile combination set.

[0063] Compared with the prior art, the present application has the following beneficial effects:

[0064] 1. The present application calculates the infiltration analysis index of the resistivity tomography method evolved from the dyeing tracer index by processing the results of the resistivity tomography method in a flow, thereby solving the problem that the results of the resistivity tomography method have no quantitative index for analysis.

[0065] 2. The present application solves the problem that there is no index for distinguishing the infiltration mode and spatial heterogeneity when the resistivity tomography method is used by using the infiltration quantitative analysis index of the resistivity tomography method. BRIEF DESCRIPTION OF DRAWINGS

[0066] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the attached drawings:

[0067] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the attached drawings:Figure 1 The working method flowchart of the present application is shown in the figure;

[0068] Figure 2 The figure shows the conversion of resistivity to water content in the present application;

[0069] Figure 3 The figure shows the profile of the three-dimensional water content profile in the present application;

[0070] Figure 4 The figure shows the conversion of the profile water content to the profile gridding in the present application. DETAILED DESCRIPTION

[0071] The present application will be described in detail below with specific examples. The following examples will help those skilled in the art to further understand the present application, but in no way limit the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of changes and improvements can be made. These are within the scope of the present application.

[0072] Since the existing resistivity tomography can only qualitatively describe the distribution and change of soil moisture, it cannot directly quantify the differences in water infiltration process. The dye tracer index is a quantitative index for dye tracer experiment to quantify the differences in water infiltration process. According to the similarity of the profile of resistivity tomography and the profile of dye tracer experiment, the dye tracer index is evolved into an index for quantitative analysis of resistivity tomography, and the quantitative index is combined with image analysis to avoid the limitations of traditional method of image recognition and inference.

[0073] Example 1

[0074] According to the method for quantitatively analyzing three-dimensional resistivity tomography results provided by the present application, as shown in Figure 1 , the method comprises:

[0075] Step S1: Obtain a three-dimensional distribution map of water content. Since resistivity tomography measures resistivity, establishing a quantitative relationship between resistivity and soil volume water content is a necessary prerequisite for obtaining a three-dimensional distribution of water content, as shown in Figure 2 , the Archie formula is commonly used at present to establish this relationship:

[0076] ρ = aφ -m S -n ρ w

[0077] In the formula, ρ represents resistivity, φ represents porosity, S represents saturation, and ρ w represents pore water resistivity; a, m and n represent constants.

[0078] Substituting S = θ / Φ into the above equation, where θ represents the soil volumetric water content, we obtain:

[0079] ρ=aφ n-m θ -n ρ w

[0080] The three-dimensional distribution of moisture content is obtained from the above formula.

[0081] Step S2: As Figure 3 and Figure 4 As shown, the 3D map of moisture content is cut at fixed intervals perpendicular to the X-axis, resulting in a set of m YZ profiles (x1, x2, x3... x...). m , where x j The profile is located on the x-axis. j The YZ section at point (1≤j≤m) is also cut perpendicular to the Y-axis at fixed intervals, resulting in a set of n XZ sections (y1, y2, y3……y n , where y j The profile is located on the Y-axis. j The XZ section at point 1≤j≤n). Specifically, perpendicular to the X-axis at fixed intervals d. x After sectioning, a set of m YZ cross-sections is obtained, as shown in the following formula:

[0082] (m-1)×d x =Length

[0083] Perpendicular to the Y-axis at a fixed interval d y After cutting, a set of n XZ cross-sections is obtained, as shown in the following formula:

[0084] (n-1)×d y =Width

[0085] Wherein, Length and Width represent the length and width of the three-dimensional cuboid region distribution of water content obtained from the ERT experiment, respectively.

[0086] Step S3: When water infiltration causes changes in soil moisture content, contour lines are drawn based on a preset moisture content threshold to define the location of the wetting front. Areas with moisture content greater than or equal to the threshold are then assigned a non-white color (usually black or blue), while areas with moisture content less than the threshold are assigned white, thus visually representing the wetting front and the surrounding soil moisture distribution.

[0087] Step S4: Mesh the XZ and YZ profile sets respectively, and calculate the water infiltration coverage in each grid based on the location of the wetting front. Step S4 includes:

[0088] Step S4.1: Each profile in the YZ profile set is divided into k (k generally takes 50-200) grids from top to bottom, and the percentage of black color occupying the total area in each grid, i.e. moisture infiltration coverage, is calculated, with the formula as follows:

[0089]

[0090] In the formula, MIC is the moisture infiltration coverage of the i-th grid of the profile of x in the YZ profile set; MIA is the moisture infiltration area of the i-th grid of the profile of x in the YZ profile set; S is the area of the YZ profile; and k is a constant, generally taking a value of 50-200. YZ(xj,i) j YZ(xj,i) j YZ

[0091] Step S4.2: All profiles in the XZ profile set are divided into k grids from top to bottom, and the percentage of black color occupying the total area in each grid, i.e. moisture infiltration coverage, is calculated, with the formula as follows:

[0092]

[0093] In the formula, MIC is the moisture infiltration coverage of the i-th grid of the profile of y in the XZ profile set; MIA is the moisture infiltration area of the i-th grid of the profile of y in the XZ profile set; and S is the area of the XZ profile. XZ(yj,i) j XZ(yj,i) j XZ

[0094] Step S5: The matrix infiltration depth of each profile in the XZ and YZ profile sets is determined, with the calculation as follows:

[0095]

[0096] In the formula, i represents the i value corresponding to the first grid with a moisture infiltration coverage MIC less than 80% of the profile of x, i represents the i value corresponding to the first grid with a moisture infiltration coverage MIC less than 80% of the profile of y, and z represents the depth of the three-dimensional cuboid region distribution result of water content rate obtained by the ERT experiment. xj-ithreshold j yj-ithreshold j

[0097] ​​​​​​​​​​​​​​Step S6: calculating the preferential flow fraction (PF) of each profile of the XZ profile set and the YZ profile set according to the matrix flow infiltration depth and the water infiltration coverage in each grid fr , that is, the percentage of the infiltration area below the matrix flow infiltration depth in the total infiltration area, which is calculated as follows:

[0098]

[0099] Step S7: analyzing the value of the PF fr , that is, the difference of the infiltration mode identified by the electrical resistivity tomography method, quantifying the spatial heterogeneity of the infiltration according to the matrix flow infiltration depth and the preferential flow fraction.

[0100] The present application is based on the evolution of the dye tracer indicator, is suitable for quantifying the three-dimensional electrical resistivity tomography result, and has been applied in the Qilian Mountain area. The three-dimensional electrical resistivity tomography result is quantitatively analyzed to analyze the three-dimensional water migration characteristics of the slope surface in the Qilian Mountain area, which is helpful to clarify the slope hydrological process.

[0101] Example Two

[0102] The present application also provides a system for quantitatively analyzing the three-dimensional electrical resistivity tomography result, which can be realized by executing the flow steps of the method for quantitatively analyzing the three-dimensional electrical resistivity tomography result, that is, the method for quantitatively analyzing the three-dimensional electrical resistivity tomography result can be understood as the preferred embodiment of the system for quantitatively analyzing the three-dimensional electrical resistivity tomography result by those skilled in the art.

[0103] According to the present application, a system for quantitatively analyzing the three-dimensional electrical resistivity tomography result is provided, which comprises:

[0104] Module M1: obtaining the three-dimensional distribution map of the water content.

[0105] Module M2: vertically cutting the three-dimensional map of the water content at a fixed interval along the X axis, and correspondingly obtaining a profile set containing m YZ profiles, and cutting at a fixed interval along the Y axis, and correspondingly obtaining a profile set containing n XZ profiles. The module M2 comprises: vertically cutting along the X axis at a fixed interval d x to obtain a YZ profile set containing a group of m profiles, as follows:

[0106] (m-1)×d x = Length

[0107] cutting along the Y axis at a fixed interval d y to obtain an XZ profile set containing a group of n profiles, as follows:

[0108] (n-1)×dy = Width

[0109] where Length and Width represent the length and width of the three-dimensional cuboid area distribution of water content obtained by the ERT experiment, respectively.

[0110] Module M3: When the water infiltration causes the change of soil water content, the contour line is drawn based on the preset water content threshold to define the position of the wetting front, and the wetting front and the surrounding soil water distribution state are visually expressed in different regional colors. In the module M3, the area with water content greater than or equal to the threshold is assigned a non-white color, and the area with water content less than the threshold is assigned a white color.

[0111] Module M4: The XZ profile collection and YZ profile collection are respectively gridded, and the water infiltration coverage in each grid is calculated in combination with the position of the wetting front. The module M4 includes: module M4.1: each profile in the YZ profile collection is divided into k grids from top to bottom, and the percentage of non-white color occupying the total area in each grid, i.e. the water infiltration coverage, is calculated, the formula is as follows:

[0112]

[0113] wherein, represents the water infiltration coverage of the i-th rectangle of the profile of x j in the YZ profile collection, represents the water infiltration area of the i-th rectangle of the profile of x j in the YZ profile collection, S YZ represents the area of the YZ profile, and k is a constant. Module M4.2: all profiles in the XZ profile collection are divided into k grids from top to bottom, and the percentage of non-white color occupying the total area in each grid, i.e. the water infiltration coverage, is calculated, the formula is as follows:

[0114]

[0115] wherein, represents the water infiltration coverage of the i-th rectangle of the profile of y j in the XZ profile collection, represents the water infiltration area of the i-th rectangle of the profile of y j in the XZ profile collection, S XZ is the area of the XZ profile.

[0116] Module M5: The matrix flow infiltration depth of each profile in the XZ and YZ profile collection is determined, and the calculation formula is as follows:

[0117]

[0118] wherein, i xj-ithresholdrepresents x j represents the i-th grid in the profile where the first moisture infiltration coverage MIC is less than 80%, i yj-ithreshold represents y j represents the i-th grid in the profile where the first moisture infiltration coverage MIC is less than 80%, z represents the depth of the three-dimensional cuboid region distribution of the water content obtained by the ERT experiment, and k is a constant.

[0119] Module M6: calculating the preferential flow fraction of each profile in the XZ profile set and the YZ profile set according to the matrix flow depth and the moisture infiltration coverage in each grid. The preferential flow fraction is the percentage of the infiltration area below the matrix flow depth in the total infiltration area, and the calculation formula is as follows:

[0120]

[0121] In the formula, PF fr represents the preferential flow fraction, i xj-ithreshold represents x j represents the i-th grid in the profile where the first moisture infiltration coverage MIC is less than 80%, i yj-ithreshold represents y j represents the i-th grid in the profile where the first moisture infiltration coverage MIC is less than 80%, k is a constant, represents the moisture infiltration area of the i-th rectangle in the profile x j of the YZ profile set, represents the moisture infiltration area of the i-th rectangle in the profile y j of the XZ profile set.

[0122] Module M7: analyzing the value of the preferential flow fraction, i.e., the difference in the infiltration mode identified by the electrical resistivity tomography method, and quantifying the spatial heterogeneity of the infiltration according to the matrix flow depth and the preferential flow fraction.

[0123] Those skilled in the art know that, in addition to implementing the system provided by the present application and each device, module, unit thereof in the form of pure computer readable program code, the system provided by the present application and each device, module, unit thereof can also be implemented in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers and embedded microcontrollers, etc. by logically programming the method steps to achieve the same functions. Therefore, the system provided by the present application and each device, module, unit thereof can be considered as a hardware component, and the devices, modules, units included therein for implementing various functions can also be considered as structures within the hardware component; the devices, modules, units for implementing various functions can also be considered as both software modules implementing methods and structures within hardware components.

[0124] The specific embodiments of the present application are described above. It needs to be understood that the present application is not limited to the specific embodiments described above, and various changes or modifications can be made by those skilled in the art within the scope of the claims, which does not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be combined with each other at will without conflict.

Claims

1. A method of quantitatively analyzing three-dimensional resistivity tomography results, characterized by, The method comprises the following steps: Step S1: obtaining a three-dimensional distribution map of water content; Step S2: cutting the three-dimensional map of water content at a fixed interval perpendicular to the X axis to obtain a profile collection containing m YZ profiles, and cutting the three-dimensional map of water content at a fixed interval perpendicular to the Y axis to obtain a profile collection containing n XZ profiles; Step S3: when the water infiltration causes the change of soil water content, an isogram is drawn based on a preset water content threshold to define the position of the wetting front, and the wetting front and the surrounding soil water distribution state are visually expressed in different regional colors; Step S4: the XZ profile collection and the YZ profile collection are respectively gridded, and the water infiltration coverage in each grid is calculated in combination with the position of the wetting front; Step S5: the matrix flow infiltration depth of each profile in the XZ profile collection is determined, and the matrix flow infiltration depth of each profile in the YZ profile collection is determined; Step S6: the preferential flow fraction of each profile in the XZ profile collection and the YZ profile collection is calculated according to the matrix flow infiltration depth and the water infiltration coverage in each grid; Step S7: the value of the preferential flow fraction is analyzed to analyze the difference of the infiltration mode identified by the electrical resistivity tomography method, and the heterogeneity of the infiltration in space is quantified according to the matrix flow infiltration depth and the preferential flow fraction.

2. The method of quantitatively analyzing three-dimensional resistivity tomography results according to claim 1, characterized by, The step S2 comprises: at a fixed interval d x The YZ profile set is obtained by cutting the profile, and the profile set has m profiles, as shown in the following formula: (m - 1) x d x = Length at a fixed interval d y The XZ profile set is obtained by cutting the profile, and the profile set has n profiles. (n-1) x d y = Width Wherein, Length and Width respectively represent the length and width of the three-dimensional cuboid region distribution result of the water content obtained by the ERT experiment.

3. The method of quantitative analysis of 3D resistivity tomography results according to claim 1, characterized in that, In the step S3, the region with water content greater than or equal to the threshold value is assigned a non-white color, and the region with water content less than the threshold value is assigned a white color; The step S4 comprises: Step S4.1: each profile in the YZ profile collection is divided into k grids from top to bottom, and the percentage of the total area occupied by the non-white color in each grid, i.e. the water infiltration coverage, is calculated, and the formula is as follows: wherein represents the moisture infiltration coverage of the i-th rectangle of the profile of the x j represents the moisture infiltration coverage of the i-th rectangle of the profile of the x j YZ represents the area of the YZ profile, and k is a constant.​​ Step S4.2: all the profiles in the XZ profile collection are divided into k grids from top to bottom, and the percentage of the total area occupied by the non-white color in each grid, i.e. the water infiltration coverage, is calculated, and the formula is as follows: wherein represents the moisture infiltration coverage of the i-th rectangle of the profile of the XZ profile aggregate, j represents the moisture infiltration area of the i-th rectangle of the profile of the XZ profile aggregate, j XZ is the area of the XZ profile.​​ 4. The method of quantitative analysis of 3D resistivity tomography results according to claim 1, characterized in that, The formula for calculating the matrix flow infiltration depth of each profile in the XZ and YZ profile collection is as follows: where i xj-ithreshold represents x j The i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the profile, i yj-ithreshold represents y j The i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the profile, z represents the depth of the three-dimensional cuboid region distribution result of the water content obtained by the ERT experiment, and k is a constant.

5. The method of quantitative analysis of 3D resistivity tomography results according to claim 1, characterized in that, The preferential flow fraction is the percentage of the infiltration area below the matrix flow infiltration depth to the total infiltration area, and the formula is as follows: wherein PF fr represents the priority flow fraction, i xj-ithreshold represents x j represents the i value of the grid corresponding to the first moisture infiltration coverage MIC less than 80% of the profile, i yj-ithreshold represents y j represents the i value of the grid corresponding to the first moisture infiltration coverage MIC less than 80% of the profile, k is a constant, represents the moisture infiltration area of the i-th rectangle of the profile of the x j section in the YZ profile combination, represents the moisture infiltration area of the i-th rectangle of the profile of the y j section in the XZ profile combination.

6. A system for quantitative analysis of three-dimensional resistivity tomography results, characterized by The method comprises the following steps: Module M1: obtaining a three-dimensional distribution map of water content; Module M2: cutting the three-dimensional map of water content at a fixed interval perpendicular to the X axis to obtain a profile collection containing m YZ profiles, and cutting the three-dimensional map of water content at a fixed interval perpendicular to the Y axis to obtain a profile collection containing n XZ profiles; Module M3: when the water infiltration causes the change of soil water content, an isogram is drawn based on a preset water content threshold to define the position of the wetting front, and the wetting front and the surrounding soil water distribution state are visually expressed in different regional colors; Module M4: the XZ profile collection and the YZ profile collection are respectively gridded, and the water infiltration coverage in each grid is calculated in combination with the position of the wetting front; Module M5: determine the matrix infiltration depth of each profile in the XZ profile set and the matrix infiltration depth of each profile in the YZ profile set; Module M6: calculate the preferential flow fraction of each profile in the XZ profile set and the YZ profile set according to the matrix infiltration depth and the water infiltration coverage in each grid; Module M7: analyze the value of the preferential flow fraction to analyze the difference of the infiltration mode identified by electrical resistivity tomography, and quantify the spatial heterogeneity of the infiltration according to the matrix infiltration depth and the preferential flow fraction.

7. The system for quantitative analysis of three-dimensional resistivity tomography results according to claim 6, characterized in that, The module M2 includes: at a fixed interval d x The YZ profile set is obtained by cutting the profile, as follows: (m - 1) x d x = Length at a fixed interval d y The XZ profile set is obtained by cutting the profile, as follows: (n - 1) x d y = Width where Length and Width represent the length and width of the three-dimensional cuboid area distribution result of the water content obtained by the ERT experiment, respectively.

8. The system for quantitative analysis of 3D resistivity tomography results according to claim 6, characterized in that, In the module M3, the area with water content greater than or equal to the threshold value is assigned a non-white color, and the area with water content less than the threshold value is assigned a white color. The module M4 includes: Module M4.1: divide each profile in the YZ profile set into k grids from top to bottom, and calculate the percentage of the total area occupied by the non-white color in each grid, i.e., the water infiltration coverage, as follows: wherein S represents the area of the i-th rectangle of the profile of the YZ cross section j S represents the area of the i-th rectangle of the profile of the YZ cross section S represents the area of the i-th rectangle of the profile of the YZ cross section j S represents the area of the i-th rectangle of the profile of the YZ cross section YZ S represents the area of the i-th rectangle of the profile of the YZ cross section Module M4.2: divide all profiles in the XZ profile set into k grids from top to bottom, and calculate the percentage of the total area occupied by the non-white color in each grid, i.e., the water infiltration coverage, as follows: wherein represents the moisture infiltration coverage of the i-th rectangle of the profile of the XZ profile aggregate, j represents the moisture infiltration area of the i-th rectangle of the profile of the XZ profile aggregate, j XZ is the area of the XZ profile.​​ 9. The system for quantitative analysis of 3D resistivity tomography results according to claim 6, characterized in that, The matrix infiltration depth of each profile in the XZ and YZ profile set is calculated as follows: where i xj-ithreshold represents x j The i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the profile, i yj-ithreshold represents y j The i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the profile, z represents the depth of the three-dimensional cuboid region distribution result of the water content obtained by the ERT experiment, and k is a constant.

10. The system for quantitative analysis of 3D resistivity tomography results according to claim 6, characterized in that, The preferential flow fraction is the percentage of the infiltration area below the matrix infiltration depth to the total infiltration area, and the calculation formula is as follows: PF = (1 - P) / P fr where PF represents the priority flow fraction, i xj-ithreshold where x represents the x j where i represents the i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the profile, yj-ithreshold where y represents the y j where k is a constant, and i represents the i value corresponding to the grid with the first moisture infiltration coverage MIC less than 80% in the profile, where x represents the x j of the i-th rectangle of the profile in the XZ profile combination, where y represents the y j of the i-th rectangle of the profile in the XZ profile combination.

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