Hazardous water body transient electromagnetic probing device and probing method

Abstract

The invention discloses a harmful water body transient electromagnetic probing device and probing method.The probing device comprises a probing tube arranged in a drill hole, a probing tube concentric shaft capable of synchronously moving along with the probing tube is arranged in the probing tube in the axial direction, a direction pointing coil is arranged on the probing tube concentric shaft, and a rotating exciting coil is arranged outside the direction pointing coil; the center of the direction pointing coil and the center of the rotating exciting coil are positioned in the same geometric center; the plane where the direction pointing coil is located and the axis of the probe concentric shaft are located in the same plane, and the plane where the rotating excitation coil is located and the axis of the probe concentric shaft are located in the same plane; and when the rotary excitation coil synchronously rotates along with the probe tube, the direction pointing coil is always in a vertical state under the action of self gravity. According to the method, three-dimensional space exploration is carried out on the harmful water body only by using the Z component, the technical problem of low X component and Y component anomaly positioning precision in existing three-component measurement is effectively solved, and the distinguishing capability of the water body anomaly region is improved through waveform compression.

Description

Technical Field

[0001] The invention belongs to the technical field of geophysical detection, and in particular relates to a transient electromagnetic detection device and a detection method for hazardous water bodies. Background Art

[0002] Coal mine water damage is the second largest cause of disasters after gas. Before coal mine tunnel excavation or during mining, the prevention and control of water damage accidents has always been an important part of coal mine safety production work. In the prevention and control of underground coal mine water damage and advanced exploration work, the in-hole transient electromagnetic method is a more commonly used method. The in-hole transient electromagnetic method has been widely recognized by the industry for its advantages such as non-destructive, fast, efficient and large detection radius.

[0003] In the existing borehole transient electromagnetic exploration, a set of loops coaxial with the borehole is generally used as the transmitting coil to excite the electromagnetic field, and another set of loops coaxial with the borehole or three sets of loops perpendicular to each other are used to receive the signal. The receiving coil starts to collect data after the transmitting coil is powered off. When only a loop in one direction is used to receive the signal, only the magnetic field intensity in one direction can be collected, which is a single-component measurement. When three sets of loops perpendicular to each other are used to receive the signal, the characteristics of the magnetic field are fully reflected, which is a three-component measurement.

[0004] The single-component measuring instrument has the advantages of simple structure and short data interpretation and processing flow. Its disadvantage is that it can only interpret the borehole depth and radial distance from the borehole where the anomaly is located, and cannot achieve accurate spatial positioning, that is, it cannot determine the orientation of the anomaly. The three-component instrument has a relatively complex structure and many measuring components. Its advantage is that it can completely characterize the spatial form of the magnetic field. The disadvantage is that since the transmitting direction of the transmitting coil is single, among the three groups of receiving coils that are perpendicular to each other, only the receiving coils with the same posture as the transmitting coil can collect reliable signals (vertical components). The other two groups of components (horizontal components) for judging the orientation of the anomaly have weak signal amplitudes, so the signal-to-noise ratio is low, and there is a large error in using the horizontal component to complete positioning. If the location of the abnormal body beside the borehole is achieved through the joint use of multiple boreholes, the workload in the actual construction process will increase significantly and the exploration efficiency will be reduced. In addition, the spacing between the measuring points in the hole of the existing exploration device is generally 3m to 5m. Generally, reliable signal mutations must be observed at 3 to 5 consecutive measuring points to confirm that the abnormality is caused. That is, in the point measurement mode, only abnormal bodies with a scale of more than 10m can be detected, which seriously affects the resolution capability of transient electromagnetic in the hole. Summary of the invention

[0005] In view of the defects and shortcomings in the prior art, the present invention provides a transient electromagnetic detection device and detection method for hazardous water bodies to solve the technical problems in the prior art that the horizontal component measurement in the three-component measurement mode used for transient electromagnetic detection is difficult and the abnormal three-dimensional spatial positioning cannot be accurately achieved.

[0006] To achieve the above object, the present invention adopts the following technical scheme:

[0007] A transient electromagnetic detection device for hazardous water bodies, including a probe tube placed in a borehole, wherein a probe tube concentric axis is axially arranged in the probe tube, a direction pointing coil is arranged on the probe tube concentric axis, a rotation excitation coil is arranged outside the direction pointing coil, and the center of the direction pointing coil and the center of the rotation excitation coil are located at the same geometric center; the plane where the direction pointing coil is located and the axis of the probe tube concentric axis are located in the same plane, and the plane where the rotation excitation coil is located and the axis of the probe tube concentric axis are located in the same plane; when the rotation excitation coil rotates synchronously with the probe tube, the direction pointing coil is always in a vertical state under the action of its own gravity.

[0008] The present invention also has the following technical features:

[0009] Specifically, the rotation excitation coil is fixedly mounted on the coaxial axis of the probe tube, and the direction pointing coil is connected to the coaxial axis of the probe tube by means of a mounting ring sleeved on the coaxial axis of the probe tube.

[0010] Furthermore, the direction-pointing coil and the rotation excitation coil are both rectangular coils, and the length of the rotation excitation coil is greater than the length of the direction-pointing coil, and the width of the rotation excitation coil is greater than the width of the direction-pointing coil.

[0011] Furthermore, the direction pointing coil and the rotation excitation coil are both circular coils, and the diameter of the rotation excitation coil is larger than the diameter of the direction pointing coil.

[0012] Furthermore, the probe tube is a non-magnetic probe tube, and a groove for arranging the rotating excitation coil is provided in the probe tube, and the surface of the groove is coated with an insulating layer.

[0013] The present invention also protects a method for detecting hazardous water bodies, which is implemented by the above-mentioned hazardous water body transient electromagnetic detection device, and comprises the following steps:

[0014] Step 1, pushing the detection device to the bottom of the hole at a set rotation speed until the bottom of the borehole is pushed. During the pushing process, starting from the set detection starting point, a detection point is obtained for each unit length of the push. At each detection point, the voltage of multiple measurement angles at different detection times is collected by means of the detection device, and the multiple measurement angles are equally spaced along the circumference of the borehole;

[0015] Step 2, calculating the apparent resistivity of the voltages at multiple measurement angles collected at each detection point at different detection times, and obtaining a two-dimensional apparent resistivity curve of each detection point at different detection times; any point on the two-dimensional apparent resistivity curve has the measurement angle as the abscissa and the apparent resistivity as the ordinate;

[0016] Step 3: With the set interpolation step length as the interval, all the obtained two-dimensional apparent resistivity curves are interpolated at equal intervals, and the interpolation calculation is performed using the cubic spline interpolation method to obtain the interpolated curve of each detection point;

[0017] Step 4, using the method of replacing differentiation with difference to find the first and second order derivative zero-crossing points and the second second order derivative zero-crossing points of the interpolated curve, using the first and second order derivative zero-crossing points and the second second order derivative zero-crossing points as control points, performing waveform compression on the interpolated curve of each detection point to obtain a waveform compression curve of each detection point;

[0018] Step 5: Determine the abnormal area of ​​hazardous water body detection based on the waveform compression curve.

[0019] Preferably, in step 4, waveform compression is performed on the two-dimensional apparent resistivity curve based on the following formula:

[0020]

[0021] in,

[0022]

[0023] In the formula,

[0024] k is the order of the interpolation points in the interpolation data sequence;

[0025] Newps(k)* is the apparent resistivity value of the waveform compression after interpolation, in Ω·m;

[0026] newps(k) is the interpolated apparent resistivity value, in Ω·m;

[0027] degree(k) is the measurement angle in degrees, ranging from 0 to 180°;

[0028] T1 is the zero-crossing point of the first and second order derivatives, in degrees;

[0029] T2 is the second second-order derivative zero-crossing point, in degrees;

[0030] det is the standard deviation of the interpolated apparent resistivity value at the same detection point;

[0031] psstd is the maximum or minimum value of apparent resistivity on the apparent resistivity curve; the unit is Ω·m.

[0032] Preferably, the rotation speed in step 1 is 20 to 40 s / cycle, and the unit length is 1 m or 2 m.

[0033] Preferably, the interpolation step size set in step 4 is 1° to 2°.

[0034] Preferably, the step 5 specifically includes the following sub-steps:

[0035] Step 5.1, dividing the line segment between the first second-order derivative zero-crossing point and the second second-order derivative zero-crossing point into four equal parts, and obtaining a first segmentation point, a second segmentation point, and a third segmentation point arranged in sequence on the line segment between the first second-order derivative zero-crossing point and the second second-order derivative zero-crossing point;

[0036] Step 5.2: Take the point on the waveform compression curve whose horizontal coordinate is the same as the horizontal coordinate of the first dividing point as the first endpoint, take the point on the waveform compression curve whose horizontal coordinate is the same as the horizontal coordinate of the third dividing point as the second endpoint, and determine the area between the first endpoint and the second endpoint on the waveform compression curve as the abnormal area for hazardous water body detection.

[0037] Compared with the prior art, the present invention has the following technical features:

[0038] (1) The device of the present invention realizes three-dimensional spatial exploration of hazardous water bodies near the borehole using only the Z component by arranging a direction pointing coil that is always in a vertical state under the action of its own gravity in the probe tube and a rotating excitation coil that can rotate around the direction pointing coil, thereby solving the technical problem of low abnormal positioning accuracy of the X component and the Y component in the existing three-component measurement.

[0039] (2) The detection method provided by the present invention can obtain transient electromagnetic detection data of multiple measurement directions at the same detection depth in the borehole with the help of a transient electromagnetic detection device for hazardous water bodies, and then obtain a two-dimensional apparent resistivity curve. The waveform of the obtained two-dimensional apparent resistivity curve is then compressed, and the zero point of the second-order derivative of the curve is taken as the base point. The data within the zero point is enhanced, and the data outside the zero point is accelerated to decay, which greatly improves the resolution ability of abnormal areas of hazardous water bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention;

[0041] Figure 2 It is a partial structural schematic diagram of the device of the present invention;

[0042] Figure 3 is a schematic diagram of the detection coverage of the rotating excitation coil in the XOY plane in Example 1;

[0043] Figure 4is a voltage curve diagram obtained at a certain detection point in Example 1, wherein each curve corresponds to a detection moment;

[0044] Figure 5 is an apparent resistivity curve diagram of a certain detection point at a certain detection time in Example 1;

[0045] Figure 6 is a comparison diagram of apparent resistivity curves before and after waveform compression in Example 1;

[0046] Figure 7 It is a comparison diagram of abnormal areas before and after waveform compression in Example 1, wherein the light-colored area is the abnormal area before waveform compression, and the dark-colored area is the abnormal area after waveform compression.

[0047] Markings in the accompanying drawings:

[0048] 1-probe concentric axis, 2-direction pointing to the coil, 3-rotating excitation coil, 4-mounting ring. DETAILED DESCRIPTION

[0049] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0050] The terms "upper", "lower", "front", "back", "top", "bottom", etc. used in the present invention to indicate directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. "Inside" and "outside" refer to the inside and outside of the contour of the corresponding components, and the above terms should not be understood as limitations on the present invention.

[0051] In the present invention, unless otherwise specified, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] Example 1

[0053] Following the above technical solutions, such as Figure 1 and Figure 2As shown, this embodiment discloses a transient electromagnetic detection device for hazardous water bodies, including a probe tube placed in a borehole, wherein a probe tube concentric axis 1 capable of synchronously moving with the probe tube is axially arranged in the probe tube. In this embodiment, the probe tube concentric axis 1 is axially penetrated in the probe tube, and both ends of the probe tube concentric axis 1 are connected to the probe tube by means of connecting pieces; a direction pointing coil 2 is arranged on the probe tube concentric axis 1, and a rotating excitation coil 3 is arranged outside the direction pointing coil 2, and the center of the direction pointing coil 2 and the center of the rotating excitation coil 3 are located at the same geometric center; the plane where the direction pointing coil 2 is located is located in the same plane as the axis of the probe tube concentric axis 1, and the plane where the rotating excitation coil 3 is located is located in the same plane as the axis of the probe tube concentric axis 1; when the rotating excitation coil 3 rotates synchronously with the probe tube, the direction pointing coil 2 is always in a vertical state under the action of its own gravity.

[0054] The rotating excitation coil 3 is used as a transmitting coil and a receiving coil, and the direction pointing coil 2 is used as a receiving coil. After the power supply is terminated, the rotating excitation coil 3 can be switched to a signal receiving mode and used as a receiving coil.

[0055] The detection device also includes an electromagnetic control system, which includes a power supply, a control module, a data acquisition and processing module, and a wireless communication module. The control module, the data acquisition and processing module, and the wireless communication module are all associated with the power supply module, and the data acquisition and processing module and the control module can communicate with the wireless communication module. The control module is preset with a program that can control the operation of the transient electromagnetic detection device for hazardous water bodies. After receiving the instruction of the control module, the data acquisition module can control the rotating excitation coil 3 to instantly emit current according to the designed emission logic. At the same time, the rotating excitation coil 3 and the direction pointing coil synchronously receive transient electromagnetic detection data. The received transient electromagnetic detection data is processed by the data acquisition module and then transmitted to the receiving device arranged outside the probe tube through the wireless communication module arranged in the probe tube.

[0056] As a preferred solution of this embodiment, the rotation excitation coil 3 is fixed on the probe concentric shaft 1, and the direction pointing coil 2 is connected to the probe concentric shaft 1 by means of a mounting ring 4 sleeved on the probe concentric shaft 1. The rotation excitation coil 3 can rotate around the direction pointing coil 2.

[0057] As a preferred solution of this embodiment, the direction pointing coil 2 and the rotation excitation coil 3 are both rectangular coils, and the length of the rotation excitation coil 3 is greater than the length of the direction pointing coil 2, and the width of the rotation excitation coil 3 is greater than the width of the direction pointing coil 2.

[0058] As a preferred solution of this embodiment, the direction pointing coil 2 and the rotation excitation coil 3 are both circular coils, and the diameter of the rotation excitation coil 3 is larger than the diameter of the direction pointing coil 2. The rotation excitation coil 3 and the direction pointing coil 2 may also be of other shapes, as long as the rotation excitation coil 3 can rotate around the direction pointing coil 2.

[0059] When using this detection device:

[0060] The detection device is pushed to the bottom of the hole at a set rotation speed, and starting from the set detection starting point, a detection point is obtained for each unit length of advancement. During the pushing process, the rotating excitation coil 3 rotates uniformly around the direction pointing coil 2 under the drive of the probe tube. During the uniform rotation process, the direction pointing coil 2 is always in a vertical state under the action of its own gravity. Therefore, at each detection point, the control module arranged in the probe tube controls the transmitting coil to emit transient electromagnetic excitation current. At the same time, the rotating excitation coil 3 and the direction pointing coil 2 synchronously receive transient electromagnetic detection data including voltage. The received transient electromagnetic detection data is processed by the data acquisition module and then transmitted to the receiving device arranged outside the probe tube through the wireless communication module.

[0061] The device of the present invention has a simple structure, avoids complicated coil winding methods, simplifies the four coils commonly used in the prior art into two coils, and the rotating excitation coil 3 can be used as a transmitting coil and a receiving coil at the same time. The same coil is used for transmission and reception, and the coupling performance is further improved.

[0062] Example 2

[0063] This embodiment provides a method for detecting hazardous water bodies, which is implemented by the hazardous water body transient electromagnetic detection device disclosed in Embodiment 1, and includes the following steps:

[0064] Step 1, pushing the detection device to the bottom of the hole at a set rotation speed until the bottom of the borehole is pushed. During the pushing process, starting from the set detection starting point, a detection point is obtained for each unit length of the push. At each detection point, the voltage of multiple measurement angles at different detection times is collected by means of the detection device, and the multiple measurement angles are equally spaced along the circumference of the borehole;

[0065] Preferably, the rotation speed is 20-40s / cycle, and the unit length is 1m or 2m.

[0066] The multiple voltage values ​​obtained at a certain detection point at each detection time eventually form a curve. Therefore, all the voltage values ​​obtained at each measurement point at different times eventually form multiple curves, as shown in the following figure. Figure 4 shown.

[0067] Step 2: Calculate the apparent resistivity of the voltages at different detection times for the multiple measurement angles collected at each detection point to obtain a two-dimensional apparent resistivity curve for each detection point at different detection times; any point on the two-dimensional apparent resistivity curve has the measurement angle as the abscissa and the apparent resistivity as the ordinate. The apparent resistivity curve of a detection point at a certain detection time is as follows: Figure 5 As shown;

[0068] Step 3: for the data at any measurement time point, the two-dimensional apparent resistivity curve is interpolated at equal intervals with the set data interval, and the interpolation calculation is performed using the cubic spline interpolation method to obtain the interpolated curve;

[0069] Step 4, using the method of replacing differentiation with difference to find the first and second order derivative zero-crossing points and the second second order derivative zero-crossing points of the interpolated curve, using the first and second order derivative zero-crossing points and the second second order derivative zero-crossing points as control points, performing waveform compression on the interpolated curve of each detection point to obtain a waveform compression curve of each detection point;

[0070] The number of second-order derivative zero-crossing points is even, in pairs, that is, one abnormal point will bring two second-order derivative zero-crossing points of apparent resistivity values ​​in the data, and a two-dimensional apparent resistivity curve is obtained after waveform compression.

[0071] Preferably, the waveform compression of the two-dimensional apparent resistivity curve is performed based on the following formula:

[0072]

[0073] in,

[0074]

[0075] In the formula,

[0076] k is the order of the interpolation points in the interpolation data sequence;

[0077] Newps(k)* is the apparent resistivity value of the waveform compression after interpolation, in Ω·m;

[0078] newps(k) is the interpolated apparent resistivity value, in Ω·m;

[0079] degree(k) is the measurement angle in degrees, ranging from 0 to 180°;

[0080] T1 is the first and second order derivative zero crossing point (left zero crossing point), in degrees;

[0081] T2 is the second second-order derivative zero-crossing point (right zero-crossing point), in degrees;

[0082] det is the standard deviation of the interpolated apparent resistivity value at the same detection point;

[0083] psstd is the maximum or minimum value of apparent resistivity on the apparent resistivity curve; the unit is Ω·m.

[0084] Step 5: Determine the abnormal area of ​​hazardous water body detection based on the waveform compression curve.

[0085] It includes the following sub-steps:

[0086] Step 5.1, dividing the line segment between the first second-order derivative zero-crossing point and the second second-order derivative zero-crossing point into four equal parts, and obtaining a first segmentation point, a second segmentation point, and a third segmentation point arranged in sequence on the line segment between the first second-order derivative zero-crossing point and the second second-order derivative zero-crossing point;

[0087] Step 5.2: Take the point on the waveform compression curve whose horizontal coordinate is the same as the horizontal coordinate of the first dividing point as the first endpoint, take the point on the waveform compression curve whose horizontal coordinate is the same as the horizontal coordinate of the third dividing point as the second endpoint, and determine the area between the first endpoint and the second endpoint on the waveform compression curve as the abnormal area for hazardous water body detection.

[0088] pass Figure 6 It can be seen from the curve graphs before and after the waveform compression that after the waveform compression, the abnormal range in the curve (the convex part of the curve) is more prominent, it is easier to determine the abnormal distribution range, and the resolution is better.

[0089] In this embodiment, the final comparison diagram of abnormal areas in the detection area before and after waveform compression is as follows: Figure 7 As shown in the figure, the light-colored area is the abnormal area before waveform compression, and the dark-colored area is the abnormal area after waveform compression. Figure 7 It can be seen that after the waveform compression processing is performed using the method of the present invention, the range of the abnormal area is smaller, which greatly improves the ability to distinguish abnormal areas that endanger water bodies.

[0090] In summary, the method of the present invention uses a method of rotating and pushing the probe tube to the bottom of the hole for continuous measurement during the process of pushing the probe tube to the bottom of the hole, which makes up for the shortcoming of too sparse measuring points in the existing point measurement working mode; it can obtain transient electromagnetic detection data of multiple measuring directions at the same detection depth, and then obtain a two-dimensional apparent resistivity curve, and then perform waveform compression on the obtained two-dimensional apparent resistivity curve, take the zero-crossing point of the second-order derivative of the curve as the base point, enhance the data within the zero-crossing point, and accelerate the attenuation of the data outside the zero-crossing point, which greatly improves the resolution ability of abnormal areas that endanger water bodies.

[0091] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0092] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A transient electromagnetic detection device for hazardous water bodies, comprising a probe placed in a borehole, characterized in that: A probe tube concentric shaft (1) capable of synchronously moving with the probe tube is axially arranged inside the probe tube, a direction pointing coil (2) is arranged on the probe tube concentric shaft (1), a rotation excitation coil (3) is arranged outside the direction pointing coil (2), and the center of the direction pointing coil (2) and the center of the rotation excitation coil (3) are located at the same geometric center; the plane where the direction pointing coil (2) is located is located in the same plane as the axis of the probe tube concentric shaft (1), and the plane where the rotation excitation coil (3) is located is located in the same plane as the axis of the probe tube concentric shaft (1); when the rotation excitation coil (3) rotates synchronously with the probe tube, the direction pointing coil (2) is always in a vertical state under the action of its own gravity.

2. The hazardous water transient electromagnetic detection device according to claim 1, characterized in that: The rotating excitation coil (3) is fixedly mounted on the probe tube concentric shaft (1), and the direction pointing coil (2) is connected to the probe tube concentric shaft (1) by means of a mounting ring (4) sleeved on the probe tube concentric shaft (1).

3. The hazardous water transient electromagnetic detection device according to claim 1, characterized in that: The direction-pointing coil (2) and the rotation excitation coil (3) are both rectangular coils, and the length of the rotation excitation coil (3) is greater than the length of the direction-pointing coil (2), and the width of the rotation excitation coil (3) is greater than the width of the direction-pointing coil (2).

4. The hazardous water transient electromagnetic detection device according to claim 1, characterized in that: The direction-pointing coil (2) and the rotation excitation coil (3) are both circular coils, and the diameter of the rotation excitation coil (3) is greater than the diameter of the direction-pointing coil (2).

5. A method for detecting hazardous water bodies, characterized in that: The method is implemented by a hazardous water transient electromagnetic detection device according to any one of claims 1 to 4, comprising the following steps: Step 1, pushing the hazardous water transient electromagnetic detection device to the bottom of the hole at a set rotation speed until the pushing ends at the bottom of the borehole. During the pushing process, starting from the set detection starting point, a detection point is obtained for each unit length of the push. At each detection point, the voltage of multiple measurement angles at different detection times is collected by using the hazardous water transient electromagnetic detection device, and the multiple measurement angles are equally spaced along the circumference of the borehole; Step 2, calculating the apparent resistivity of the transient electromagnetic detection data of multiple measurement angles collected at each detection point to obtain a two-dimensional apparent resistivity curve of each detection point; any point on the two-dimensional apparent resistivity curve has the measurement angle as the abscissa and the apparent resistivity as the ordinate; Step 3: Perform equal-interval interpolation on the two-dimensional apparent resistivity curve of each detection point with the set interpolation step length as the interval, and use the cubic spline interpolation method to perform interpolation calculation to obtain the interpolated curve of each detection point; Step 4, using the method of replacing differentiation with difference to find the first and second order derivative zero-crossing points and the second second order derivative zero-crossing points of the interpolated curve, using the first and second order derivative zero-crossing points and the second second order derivative zero-crossing points as control points, performing waveform compression on the interpolated curve of each detection point to obtain a waveform compression curve of each detection point; Step 5: Determine the abnormal area of ​​hazardous water body detection based on the waveform compression curve.

6. The method for detecting hazardous water bodies according to claim 5, characterized in that: In step 4, waveform compression is performed on the two-dimensional apparent resistivity curve based on the following formula: in, In the formula, k is the order of the interpolation points in the interpolation data sequence; Newps(k)* is the apparent resistivity value of the waveform compression after interpolation, in Ω·m; newps(k) is the interpolated apparent resistivity value, in Ω·m; degree(k) is the measurement angle in degrees, ranging from 0 to 180°; T1 is the zero-crossing point of the first and second order derivatives, in degrees; T2 is the second second-order derivative zero-crossing point, in degrees; det is the standard deviation of the interpolated apparent resistivity value at the same detection point; psstd is the maximum or minimum value of apparent resistivity on the apparent resistivity curve; the unit is Ω·m.

7. The method for detecting hazardous water bodies according to claim 5, characterized in that: The rotation speed in step 1 is 20 to 40 seconds per cycle, and the unit length is 1 meter or 2 meters.

8. The method for detecting hazardous water bodies according to claim 5, characterized in that: The interpolation step size set in step 4 is 1° to 2°.

9. The method for detecting hazardous water bodies according to claim 5, characterized in that: The step 5 specifically includes the following sub-steps: Step 5.1, dividing the line segment between the first second-order derivative zero-crossing point and the second second-order derivative zero-crossing point into four equal parts, and obtaining a first segmentation point, a second segmentation point, and a third segmentation point arranged in sequence on the line segment between the first second-order derivative zero-crossing point and the second second-order derivative zero-crossing point; Step 5.2: Take the point on the waveform compression curve whose horizontal coordinate is the same as the horizontal coordinate of the first dividing point as the first endpoint, take the point on the waveform compression curve whose horizontal coordinate is the same as the horizontal coordinate of the third dividing point as the second endpoint, and determine the area between the first endpoint and the second endpoint on the waveform compression curve as the abnormal area for hazardous water body detection.

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