Dam monitoring method and system based on magnetotelluric method

Abstract

The invention relates to the technical field of dam monitoring, in particular to a dam monitoring method and system based on a magnetotelluric method.The method comprises the steps that firstly, a monitoring area of a dam and a target frequency value corresponding to the monitoring area are determined; a plurality of detection points located on the same straight line are arranged in the monitoring area, the middle point between every two adjacent detection points is a collection point, and then detection electrodes are embedded into the detection points; obtaining a horizontal electric field component under the target frequency value collected by the detection electrode through the detection host every first preset duration; obtaining a potential curve graph through the horizontal electric field component, obtaining a quasi-cross-section diagram based on the potential curve graph, and judging whether the underground of the monitoring area is abnormal or not based on the quasi-cross-section diagram; according to the technical scheme, manual inspection is not needed to find whether the dam has the geological anomaly or not, and whether the dam has the geological anomaly or not can be timely and accurately found through the supervisor on duty of the monitoring terminal.

Description

Technical Field

[0001] The present invention relates to the technical field of dam monitoring, and in particular to a dam monitoring method and system based on magnetotelluric method. Background Art

[0002] As an important part of water conservancy projects, dams have made extremely important contributions to human production and national economic development. With the increase in the number of days the dams are in operation, and the influence of factors such as construction quality and poor geological structure, the geological hazards of dams are becoming increasingly severe. If the geological conditions of the dams are abnormal (such as internal collapse, cracks, water seepage, pipe bursts, etc.), it will pose a great threat to the personal safety and property safety of people nearby.

[0003] In order to ensure the normal and safe use of the dam, it is necessary to conduct safety monitoring of the dam. The existing method of safety monitoring of the dam is mainly manual inspection, which is not only inefficient, but also relies on the experience of the inspectors. It cannot guarantee timely and accurate detection of geological anomalies in the dam, so the effect of safety monitoring is poor. Summary of the invention

[0004] The main purpose of the present invention is to provide a dam monitoring method and system based on magnetotelluric method, aiming to solve the problem that the existing manual inspection method of dams cannot guarantee timely and accurate detection of whether there are geological anomalies in the dams.

[0005] The technical solution proposed by the present invention is:

[0006] A dam monitoring method based on magnetotelluric method is applied to a dam monitoring system based on magnetotelluric method; the system comprises a detection host, detection electrodes and a monitoring terminal; the monitoring terminal and the detection electrodes are both communicatively connected to the detection host; the number of the detection electrodes is multiple; the method comprises:

[0007] Determine a monitoring area on the dam, wherein a plurality of detection points on the same straight line are arranged in the monitoring area, the plurality of detection points are equally spaced, the distance between adjacent detection points is a preset distance, and the number of detection points is consistent with the number of detection electrodes and corresponds one to one;

[0008] Determine a plurality of collection points based on the detection points in the monitoring area, wherein the midpoint between two adjacent detection points is a collection point;

[0009] Determine the target frequency value of the monitoring area by the detection host;

[0010] When all the detection electrodes are fully embedded in the corresponding detection points, the horizontal electric field components at the target frequency value collected by the detection electrodes are obtained by the detection host at a first preset time interval;

[0011] Obtaining a potential curve graph at a target frequency value based on a horizontal electric field component at a target frequency value by the detection host;

[0012] The detection host obtains a profile pseudo-section diagram based on the potential curve diagram, and determines whether an abnormality occurs underground in the monitoring area based on the profile pseudo-section diagram;

[0013] When an abnormality occurs underground in the monitoring area, an early warning message is generated by the detection host, and the early warning message is sent to the monitoring terminal, and the early warning message is displayed by the monitoring terminal.

[0014] Preferably, after all the detection electrodes are embedded in the corresponding detection points, obtaining the horizontal electric field components at the target frequency value collected by the detection electrodes through the detection host every first preset time period includes:

[0015] Let the harmonic factor be e -iωt , to obtain the frequency domain electromagnetic field equations:

[0016]

[0017]

[0018] Where, E is the electric field strength of the monitoring area, H is the magnetic field strength of the monitoring area; J s represents the field source term, μ0 is the magnetic permeability in vacuum, i is the imaginary unit, ω is the circular frequency, and σ is the conductivity of the monitoring area;

[0019] Calculate the curl on both sides of formula (1) and substitute formula (2) to obtain the second-order vector Helmholtz equation satisfied by the electric field in the monitoring area:

[0020]

[0021] Let the field source term be 0 and apply the first-type boundary condition on the boundary to obtain formula (5), where the first-type boundary condition is as shown in formula (4):

[0022]

[0023] nE=nE0, (5)

[0024] Where n is the external normal vector of the boundary grid, and E0 is the electric field response of the one-dimensional medium on the boundary.

[0025] Preferably, determining the target frequency value of the monitoring area by the detection host includes:

[0026] Determine the maximum detection depth based on the altitude of the dam by the detection host;

[0027] The detection host determines a target frequency value of the monitoring area based on the maximum detection depth.

[0028] Preferably, obtaining a profile pseudo-section diagram based on the potential curve diagram by the detection host, and judging whether an abnormality occurs underground in the monitoring area based on the profile pseudo-section diagram, comprises:

[0029] The detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the profile pseudo-section diagram, uses the apparent depth as the ordinate of the profile pseudo-section diagram, and uses the positions of each collection point distributed along the extension direction of the detection point as the upper abscissa of the profile pseudo-section diagram to obtain the profile pseudo-section diagram;

[0030] Determine by the detection host whether there is an area in the cross-sectional pseudo-section diagram with a potential greater than a first preset value;

[0031] If so, the detection host determines that an abnormality occurs underground in the monitoring area;

[0032] The detection host marks the area in the cross-sectional pseudo-section image where the potential is greater than the first preset value as a high potential area.

[0033] Preferably, the detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the cross-sectional pseudo-section diagram, uses the apparent depth as the ordinate of the cross-sectional pseudo-section diagram, and uses the positions of each collection point distributed along the extension direction of the detection point as the upper abscissa of the cross-sectional pseudo-section diagram to obtain the cross-sectional pseudo-section diagram, and then also includes:

[0034] Determine by the detection host whether there is an area in the cross-sectional pseudo-section diagram with a potential less than a second preset value, wherein the second preset value is less than the first preset value;

[0035] If so, the detection host determines that an abnormality occurs underground in the monitoring area;

[0036] The detection host marks the area in the cross-sectional pseudo-section image where the potential is less than the second preset value as a low potential area.

[0037] Preferably, the detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the cross-sectional pseudo-section diagram, uses the apparent depth as the ordinate of the cross-sectional pseudo-section diagram, and uses the positions of each collection point distributed along the extension direction of the detection point as the upper abscissa of the cross-sectional pseudo-section diagram to obtain the cross-sectional pseudo-section diagram, and then also includes:

[0038] Determining whether a first condition is satisfied by the detection host, wherein the first condition is: there is no region in the cross-sectional pseudo-section diagram where the potential is greater than a first preset value, and there is no region where the potential is less than a second preset value;

[0039] If so, the detection host determines that there is no abnormality underground in the monitoring area.

[0040] Preferably, the detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the cross-sectional pseudo-section diagram, uses the apparent depth as the ordinate of the cross-sectional pseudo-section diagram, and uses the positions of each collection point distributed along the extension direction of the detection point as the upper abscissa of the cross-sectional pseudo-section diagram to obtain the cross-sectional pseudo-section diagram, and then also includes:

[0041] Marking, by the detection host, an area in the cross-sectional pseudo-section image whose potential is greater than a third preset value and less than the first preset value as a first target area, wherein the third preset value is less than the first preset value, and the third preset value is greater than the second preset value;

[0042] The detection host determines whether a second condition is satisfied, wherein the second condition is that the area of ​​the same first target region in the cross-sectional pseudo-cross-sectional image generated within the past second preset time length gradually increases with the passage of time, wherein the second preset time length is greater than the first preset time length;

[0043] If so, determining through the detection host that an abnormality occurs underground in the monitoring area;

[0044] If not, the detection host determines that there is no abnormality underground in the monitoring area.

[0045] Preferably, the detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the cross-sectional pseudo-section diagram, uses the apparent depth as the ordinate of the cross-sectional pseudo-section diagram, and uses the positions of each collection point distributed along the extension direction of the detection point as the upper abscissa of the cross-sectional pseudo-section diagram to obtain the cross-sectional pseudo-section diagram, and then also includes:

[0046] By means of the detection host, an area in the cross-sectional pseudo-section image whose potential is less than a fourth preset value and greater than a second preset value is marked as a second target area, wherein the fourth preset value is greater than the second preset value, and the fourth preset value is less than the third preset value;

[0047] Determining whether a third condition is satisfied by the detection host, wherein the third condition is: the area of ​​the same second target region in the cross-sectional pseudo-cross-sectional image generated within the past second preset time period gradually increases with the passage of time;

[0048] If so, determining through the detection host that an abnormality occurs underground in the monitoring area;

[0049] If not, the detection host determines that there is no abnormality underground in the monitoring area.

[0050] Preferably, the detecting host marks a region in the cross-sectional pseudo-section image whose potential is greater than a third preset value and less than the first preset value as a first target region, and then further comprises:

[0051] Determine whether a fourth condition is satisfied by the detection host, wherein the fourth condition is: the number of first target areas in the cross-sectional pseudo-section image is greater than a preset number;

[0052] If so, determining through the detection host that an abnormality occurs underground in the monitoring area;

[0053] If not, the detection host determines that there is no abnormality underground in the monitoring area.

[0054] The present invention also proposes a dam monitoring system based on magnetotelluric method, which applies a dam monitoring method based on magnetotelluric method; the system includes a detection host, detection electrodes and a monitoring terminal; the monitoring terminal and the detection electrodes are both communicatively connected to the detection host; the number of the detection electrodes is multiple.

[0055] Through the above technical solution, the following beneficial effects can be achieved:

[0056] A dam monitoring method based on magnetotelluric method proposed in the present invention can timely and accurately detect whether there is geological anomaly in the dam; first determine the monitoring area of ​​the dam and the target frequency value corresponding to the monitoring area; a plurality of detection points in the same straight line are set in the monitoring area, and the midpoint between two adjacent detection points is the collection point, and then the detection electrode is embedded in the detection point; the horizontal electric field component at the target frequency value collected by the detection electrode is obtained by the detection host every first preset time period; then the potential curve diagram is obtained through the horizontal electric field component, and the profile pseudo-section diagram is obtained based on the potential curve diagram, and it is judged whether there is an abnormality underground in the monitoring area based on the profile pseudo-section diagram; the technical solution no longer requires manual inspection to detect whether there is geological anomaly in the dam, and the management personnel can timely and accurately detect whether there is geological anomaly in the dam by on-duty monitoring terminals, which greatly improves the effect of safety monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0058] Figure 1 This is a flowchart of the steps of the first embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention. DETAILED DESCRIPTION

[0059] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0060] The present invention provides a dam monitoring method and system based on magnetotelluric method.

[0061] As attached Figure 1 As shown, in a first embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention, the dam monitoring method based on magnetotelluric method is applied to a dam monitoring system based on magnetotelluric method; the system includes a detection host, detection electrodes and a monitoring terminal; the monitoring terminal and the detection electrodes are both communicatively connected to the detection host; the number of the detection electrodes is multiple; this embodiment includes the following steps:

[0062] Step S110: Determine a monitoring area on the dam, wherein a plurality of detection points on the same straight line are arranged in the monitoring area, the plurality of detection points are equally spaced, the distance between adjacent detection points is a preset distance, the number of detection points is consistent with the number of detection electrodes, and corresponds one to one.

[0063] Specifically, multiple monitoring areas can be set up on the same dam; in this embodiment, the preset distance is 5 meters; the detection electrode adopts the natural electromagnetic method of the earth for detection.

[0064] Step S120: determining a plurality of collection points based on the detection points in the monitoring area, wherein the midpoint between two adjacent detection points is a collection point.

[0065] Step S130: Determine the target frequency value of the monitoring area through the detection host.

[0066] Specifically, different detection frequencies can reflect the geological conditions at different underground depths, so the corresponding target frequency value needs to be determined according to the detection requirement depth of the monitoring area.

[0067] Step S140: After all the detection electrodes are embedded in the corresponding detection points, the horizontal electric field components at the target frequency value collected by the detection electrodes are obtained by the detection host every first preset time period (for example, 1 day).

[0068] Specifically, the detection electrodes collect the horizontal electric field component once every day.

[0069] Step S150: obtaining a potential curve graph at a target frequency value based on the horizontal electric field component at the target frequency value through the detection host.

[0070] Step S160: obtaining a pseudo-section diagram based on the potential curve diagram through the detection host, and judging whether there is an abnormality underground in the monitoring area based on the pseudo-section diagram.

[0071] Specifically, when the pseudo-section diagram shows an area with too high or too low potential, it is determined that an abnormality occurs underground in the monitoring area, and the area with too high or too low potential corresponds to the location of the geological anomaly. Conversely, when the pseudo-section diagram does not show an area with too high or too low potential, it is determined that no abnormality occurs underground in the monitoring area.

[0072] Step S170: When an abnormality occurs underground in the monitoring area, an early warning message is generated by the detection host, and the early warning message is sent to the monitoring terminal, and the early warning message is displayed by the monitoring terminal.

[0073] A dam monitoring method based on magnetotelluric method proposed in the present invention can timely and accurately detect whether there is geological anomaly in the dam; first determine the monitoring area of ​​the dam and the target frequency value corresponding to the monitoring area; a plurality of detection points in the same straight line are set in the monitoring area, and the midpoint between two adjacent detection points is the collection point, and then the detection electrode is embedded in the detection point; the horizontal electric field component at the target frequency value collected by the detection electrode is obtained by the detection host every first preset time period; then the potential curve diagram is obtained through the horizontal electric field component, and the profile pseudo-section diagram is obtained based on the potential curve diagram, and it is judged whether there is an abnormality underground in the monitoring area based on the profile pseudo-section diagram; the technical solution no longer requires manual inspection to detect whether there is geological anomaly in the dam, and the management personnel can timely and accurately detect whether there is geological anomaly in the dam by on-duty monitoring terminals, which greatly improves the effect of safety monitoring.

[0074] In a second embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention, based on the first embodiment, step S140 includes the following steps:

[0075] Step S210: Let the harmonic transformation factor be e -iωt , to obtain the frequency domain electromagnetic field equations:

[0076]

[0077] Where, E is the electric field strength of the monitoring area, H is the magnetic field strength of the monitoring area; J s represents the field source term, μ0 is the magnetic permeability in vacuum, i is the imaginary unit, ω is the circular frequency, and σ is the conductivity of the monitoring area.

[0078] Specifically, any electromagnetic problem satisfies Maxwell's equations, so the above-mentioned frequency domain electromagnetic field equations are obtained.

[0079] Step S220: Calculate the curl on both sides of formula (1), and substitute formula (2) into it to obtain the second-order vector Helmholtz equation satisfied by the electric field in the monitoring area:

[0080]

[0081] Specifically, in the practical application of frequency domain electromagnetic method, the observation frequency is generally less than 104 Hz, so the displacement current can be ignored.

[0082] Step S230: Set the field source term to 0 and apply the first type of boundary condition on the boundary to obtain formula (5), where the first type of boundary condition is as shown in formula (4):

[0083]

[0084] nE=nE0, (5)

[0085] Where n is the external normal vector of the boundary grid, and E0 is the electric field response of the one-dimensional medium on the boundary.

[0086] In a third embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention, based on the first embodiment, step S130 includes the following steps:

[0087] Step S310: Determine the maximum detection depth based on the altitude of the dam by the detection host.

[0088] Step S320: determining the target frequency value of the monitoring area based on the maximum detection depth through the detection host.

[0089] Specifically, when the detection frequency is higher, the corresponding detection depth is shallower; when the detection frequency is lower, the corresponding detection depth is deeper; therefore, the target frequency value of the monitoring area is determined based on the maximum detection depth of the monitoring area; in this embodiment, the target frequency value is 200Hz.

[0090] In a fourth embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention, based on the first embodiment, step S160 includes the following steps:

[0091] Step S410: The detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the profile pseudo-section diagram, uses the apparent depth as the vertical coordinate of the profile pseudo-section diagram, and uses the positions of each acquisition point distributed along the extension direction of the detection point as the upper horizontal coordinate of the profile pseudo-section diagram to obtain the profile pseudo-section diagram.

[0092] Step S420: Determine, by means of the detection host, whether there is an area in the cross-sectional pseudo-section image whose potential is greater than a first preset value.

[0093] Step S430: If yes, determine through the detection host whether an abnormality occurs underground in the monitoring area.

[0094] Step S440: The detection host marks the area in the cross-sectional pseudo-section image where the potential is greater than the first preset value as a high potential area.

[0095] Specifically, in this embodiment, the first preset value is 50mV. When the potential is greater than the first preset value, it indicates that the area is a geological anomaly area (high potential area), which may be a geological anomaly such as a cavity, an ant hole or an internal collapse.

[0096] In a fifth embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention, based on the fourth embodiment, step S410 further includes the following steps:

[0097] Step S510: Determine, by means of the detection host, whether there is an area in the cross-sectional pseudo-section image whose potential is less than a second preset value, wherein the second preset value is less than the first preset value.

[0098] Step S520: If yes, determine through the detection host whether an abnormality occurs underground in the monitoring area.

[0099] Step S530: The detection host marks the area in the cross-sectional pseudo-section image where the potential is less than the second preset value as a low potential area.

[0100] Specifically, in this embodiment, the second preset value is 10mV. When the potential is less than the second preset value, it indicates that the area is a geological anomaly area (low potential area), which may be a geological anomaly such as pipe gushing or water seepage.

[0101] In a sixth embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention, based on the fourth embodiment, step S410 further includes the following steps:

[0102] Step S610: Determine whether a first condition is satisfied by the detection host, wherein the first condition is: there is no area in the cross-sectional pseudo-section diagram whose potential is greater than a first preset value, and there is no area whose potential is less than a second preset value.

[0103] If yes, execute step S620: determine through the detection host that there is no abnormality underground in the monitoring area.

[0104] Specifically, if there is neither an area with a potential greater than the first preset value nor an area with a potential less than the second preset value in the pseudo-section diagram, it means that there is neither a high potential area nor a low potential area in the pseudo-section diagram, so it is determined that there is no abnormality underground in the monitoring area.

[0105] In the seventh embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention, based on the fifth embodiment, step S410 further includes the following steps:

[0106] Step S710: The detection host marks the area in the cross-sectional pseudo-section image whose potential is greater than a third preset value (for example, 40 mV) and less than the first preset value as a first target area, wherein the third preset value is less than the first preset value, and the third preset value is greater than the second preset value.

[0107] Specifically, the first target area here is a relatively high potential area that does not meet the abnormal standard, but still has certain risks and needs to be continuously observed.

[0108] Step S720: Determine whether the second condition is met by the detection host, wherein the second condition is that the area of ​​the same first target area in the pseudo-sectional view generated within the past second preset time period (for example, 3 days) gradually increases with the passage of time, wherein the second preset time period is greater than the first preset time period.

[0109] Specifically, when the area of ​​the same first target area in the pseudo-section diagram generated within the past second preset time period (for example, 3 days) increases with the passage of time, it indicates that the relatively high potential area is increasing, and an early warning is needed and timely processing is required; therefore, it is determined that an abnormality occurs underground in the monitoring area.

[0110] If so, execute step S730: determine, through the detection host, whether an abnormality occurs underground in the monitoring area.

[0111] If not, execute step S740: determine through the detection host that there is no abnormality underground in the monitoring area.

[0112] In an eighth embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention, based on the seventh embodiment, step S410 further includes the following steps:

[0113] Step S810: The detection host marks the area in the cross-sectional pseudo-section image whose potential is less than a fourth preset value (for example, 20 mV) and greater than the second preset value as a second target area, wherein the fourth preset value is greater than the second preset value, and the fourth preset value is less than the third preset value.

[0114] Specifically, the second target area here is a relatively low potential area that does not meet the abnormal standard, but still has certain risks and requires continuous observation.

[0115] Step S820: Determine whether a third condition is satisfied by the detection host, wherein the third condition is that the area of ​​the same second target region in the pseudo-sectional view generated within the past second preset time period increases with the passage of time.

[0116] Specifically, when the area of ​​the same second target area in the pseudo-section diagram generated within the past second preset time period (for example, 3 days) increases with the passage of time, it means that the relatively low potential area is increasing, and an early warning and timely processing are required; therefore, it is determined that an abnormality occurs underground in the monitoring area.

[0117] If so, execute step S830: determine, through the detection host, whether an abnormality occurs underground in the monitoring area.

[0118] If not, execute step S840: determine through the detection host that there is no abnormality underground in the monitoring area.

[0119] In a ninth embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention, based on the seventh embodiment, step S710 further includes the following steps:

[0120] Step S910: Determine whether the fourth condition is satisfied through the detection host, wherein the fourth condition is: the number of first target areas in the cross-sectional pseudo-section image is greater than a preset number (3).

[0121] Specifically, when the number of the first target areas in the pseudo-section diagram is greater than 3, it means that although there is no abnormal high potential area, there are multiple relatively high potential areas underground that are easy to evolve into abnormal high potential areas. In this case, early warning is also needed, so it is determined that an abnormality occurs underground in the monitoring area.

[0122] If so, execute step S920: determine, through the detection host, whether an abnormality occurs underground in the monitoring area.

[0123] If not, execute step S930: determine through the detection host that there is no abnormality underground in the monitoring area.

[0124] In the tenth embodiment of a dam monitoring method based on magnetotelluric method proposed by the present invention, based on the seventh embodiment, step S710 further includes the following steps:

[0125] Step S1010: Determine whether the fifth condition is satisfied by the detection host, wherein the fifth condition is that the number of first target areas in the pseudo-sectional view generated within the past second preset time period gradually increases with the passage of time.

[0126] Specifically, when the number of first target areas in the pseudo-section diagram generated within the second preset time period in the past gradually increases with the passage of time, it means that although there is no high-potential area at present, the number of relatively high-potential areas that are easy to evolve into high-potential abnormal areas is gradually increasing. In this case, early warning is also needed to prevent the sudden appearance of multiple high-potential areas, so it is determined that an abnormality occurs underground in the monitoring area.

[0127] If so, execute step S1020: determine, through the detection host, whether an abnormality occurs underground in the monitoring area.

[0128] If not, execute step S1030: determine through the detection host that there is no abnormality underground in the monitoring area.

[0129] The present invention also proposes a dam monitoring system based on magnetotelluric method, which applies a dam monitoring method based on magnetotelluric method; the system includes a detection host, detection electrodes and a monitoring terminal; the monitoring terminal and the detection electrodes are both communicatively connected to the detection host; the number of the detection electrodes is multiple.

[0130] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0131] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A dam monitoring method based on magnetotelluric method, characterized in that: Applicable to a dam monitoring system based on magnetotelluric method; the system comprises a detection host, detection electrodes and a monitoring terminal; The monitoring terminal and the detection electrode are both communicatively connected to the detection host; The number of the detection electrodes is multiple; the method comprises: Determine a monitoring area on the dam, wherein a plurality of detection points on the same straight line are arranged in the monitoring area, the plurality of detection points are equally spaced, the distance between adjacent detection points is a preset distance, and the number of detection points is consistent with the number of detection electrodes and corresponds one to one; Determine a plurality of collection points based on the detection points in the monitoring area, wherein the midpoint between two adjacent detection points is a collection point; Determine the target frequency value of the monitoring area by the detection host; When all the detection electrodes are fully embedded in the corresponding detection points, the horizontal electric field components at the target frequency value collected by the detection electrodes are obtained by the detection host at a first preset time interval; Obtaining a potential curve graph at a target frequency value based on a horizontal electric field component at a target frequency value by the detection host; The detection host obtains a profile pseudo-section diagram based on the potential curve diagram, and determines whether an abnormality occurs underground in the monitoring area based on the profile pseudo-section diagram; When an abnormality occurs underground in the monitoring area, an early warning message is generated by the detection host, and the early warning message is sent to the monitoring terminal, and the early warning message is displayed by the monitoring terminal.

2. A dam monitoring method based on magnetotelluric method according to claim 1, characterized in that: After all the detection electrodes are embedded in the corresponding detection points, the horizontal electric field components at the target frequency value collected by the detection electrodes are obtained by the detection host at intervals of a first preset time, including: Let the harmonic factor be e -iωt , to obtain the frequency domain electromagnetic field equations: Where, E is the electric field strength of the monitoring area, H is the magnetic field strength of the monitoring area; J s represents the field source term, μ0 is the magnetic permeability in vacuum, i is the imaginary unit, ω is the circular frequency, and σ is the conductivity of the monitoring area; Calculate the curl on both sides of formula (1) and substitute formula (2) to obtain the second-order vector Helmholtz equation satisfied by the electric field in the monitoring area: Let the field source term be 0 and apply the first-type boundary condition on the boundary to obtain formula (5), where the first-type boundary condition is as shown in formula (4): nE=nE0, (5) Where n is the external normal vector of the boundary grid, and E0 is the electric field response of the one-dimensional medium on the boundary.

3. A dam monitoring method based on magnetotelluric method according to claim 1, characterized in that: The determining of the target frequency value of the monitoring area by the detection host includes: Determine the maximum detection depth based on the altitude of the dam by the detection host; The detection host determines a target frequency value of the monitoring area based on the maximum detection depth.

4. A dam monitoring method based on magnetotelluric method according to claim 1, characterized in that: The method of obtaining a profile pseudo-section diagram based on the potential curve diagram by the detection host, and judging whether an abnormality occurs underground in the monitoring area based on the profile pseudo-section diagram, includes: The detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the profile pseudo-section diagram, uses the apparent depth as the ordinate of the profile pseudo-section diagram, and uses the positions of each collection point distributed along the extension direction of the detection point as the upper abscissa of the profile pseudo-section diagram to obtain the profile pseudo-section diagram; Determine by the detection host whether there is an area in the cross-sectional pseudo-section diagram with a potential greater than a first preset value; If so, the detection host determines that an abnormality occurs underground in the monitoring area; The detection host marks the area in the cross-sectional pseudo-section image where the potential is greater than the first preset value as a high potential area.

5. A dam monitoring method based on magnetotelluric method according to claim 4, characterized in that: The detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the cross-sectional pseudo-section diagram, uses the apparent depth as the ordinate of the cross-sectional pseudo-section diagram, and uses the positions of each collection point distributed along the extension direction of the detection point as the upper abscissa of the cross-sectional pseudo-section diagram to obtain the cross-sectional pseudo-section diagram, and then also includes: Determine by the detection host whether there is an area in the cross-sectional pseudo-section diagram with a potential less than a second preset value, wherein the second preset value is less than the first preset value; If so, the detection host determines that an abnormality occurs underground in the monitoring area; The detection host marks the area in the cross-sectional pseudo-section image where the potential is less than the second preset value as a low potential area.

6. A dam monitoring method based on magnetotelluric method according to claim 4, characterized in that: The detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the cross-sectional pseudo-section diagram, uses the apparent depth as the ordinate of the cross-sectional pseudo-section diagram, and uses the positions of each collection point distributed along the extension direction of the detection point as the upper abscissa of the cross-sectional pseudo-section diagram to obtain the cross-sectional pseudo-section diagram, and then also includes: Determining whether a first condition is satisfied by the detection host, wherein the first condition is: there is no region in the cross-sectional pseudo-section diagram where the potential is greater than a first preset value, and there is no region where the potential is less than a second preset value; If so, the detection host determines that there is no abnormality underground in the monitoring area.

7. A dam monitoring method based on magnetotelluric method according to claim 5, characterized in that: The detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the cross-sectional pseudo-section diagram, uses the apparent depth as the ordinate of the cross-sectional pseudo-section diagram, and uses the positions of each collection point distributed along the extension direction of the detection point as the upper abscissa of the cross-sectional pseudo-section diagram to obtain the cross-sectional pseudo-section diagram, and then also includes: Marking, by the detection host, an area in the cross-sectional pseudo-section image whose potential is greater than a third preset value and less than the first preset value as a first target area, wherein the third preset value is less than the first preset value, and the third preset value is greater than the second preset value; The detection host determines whether a second condition is satisfied, wherein the second condition is that the area of ​​the same first target region in the cross-sectional pseudo-cross-sectional image generated within the past second preset time length gradually increases with the passage of time, wherein the second preset time length is greater than the first preset time length; If so, determining through the detection host that an abnormality occurs underground in the monitoring area; If not, the detection host determines that there is no abnormality underground in the monitoring area.

8. A dam monitoring method based on magnetotelluric method according to claim 7, characterized in that: The detection host uses the horizontal electric field component along the extension direction of the detection point as the section line of the cross-sectional pseudo-section diagram, uses the apparent depth as the ordinate of the cross-sectional pseudo-section diagram, and uses the positions of each collection point distributed along the extension direction of the detection point as the upper abscissa of the cross-sectional pseudo-section diagram to obtain the cross-sectional pseudo-section diagram, and then also includes: By means of the detection host, an area in the cross-sectional pseudo-section image whose potential is less than a fourth preset value and greater than a second preset value is marked as a second target area, wherein the fourth preset value is greater than the second preset value, and the fourth preset value is less than the third preset value; Determining whether a third condition is satisfied by the detection host, wherein the third condition is: the area of ​​the same second target region in the cross-sectional pseudo-cross-sectional image generated within the past second preset time period gradually increases with the passage of time; If so, determining through the detection host that an abnormality occurs underground in the monitoring area; If not, the detection host determines that there is no abnormality underground in the monitoring area.

9. A dam monitoring method based on magnetotelluric method according to claim 7, characterized in that: The detecting host marks the area in the cross-sectional pseudo-cross-sectional image where the potential is greater than the third preset value and less than the first preset value as the first target area, and then further comprises: Determine whether a fourth condition is satisfied by the detection host, wherein the fourth condition is: the number of first target areas in the cross-sectional pseudo-section image is greater than a preset number; If so, determining through the detection host that an abnormality occurs underground in the monitoring area; If not, the detection host determines that there is no abnormality underground in the monitoring area.

10. A dam monitoring system based on magnetotelluric method, characterized in that: A dam monitoring method based on magnetotelluric method as described in any one of claims 1 to 9 is applied; the system includes a detection host, detection electrodes and a monitoring terminal; the monitoring terminal and the detection electrodes are both communicatively connected to the detection host; and the number of the detection electrodes is multiple.

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