Distributed temperature measurement optical cable and long-distance dike leakage monitoring device and method

Abstract

The invention discloses a distributed temperature measurement optical cable and a long-distance dike leakage monitoring device and method. The monitoring device comprises an optical fiber temperature measurement host, a temperature measurement optical cable, a display, a voltage regulator, an off-grid single-phase inverter, a colloid storage battery and a single-crystal solar panel, the optical fiber temperature measurement host is connected with the temperature measurement optical cable and is connected with the display through a data line; the voltage regulator is connected with the colloid storage battery and the temperature measuring optical cable through cables; and the off-grid single-phase inverter is connected with the single-crystal solar panel and the colloid storage battery through electrical interfaces. The monitoring device is powered by solar energy, does not depend on mains supply, can operate in remote areas without mains supply access, is stable and reliable in operation by combining an active heating optical cable and distributed optical fiber temperature measurement technology and adopting a constant-power heating mode, and is suitable for field unattended embankment leakage monitoring far away from a power grid.

Description

Technical Field

[0001] The present invention belongs to the technical field of leakage monitoring, and in particular relates to a distributed temperature measuring optical cable, a long-distance embankment leakage monitoring device and a method. Background Art

[0002] Distributed fiber-optic temperature sensing technology has broad application prospects in levee leakage monitoring. This technology leverages the sensitivity of temperature-sensing optical fibers to changes in the surrounding soil temperature. When leaking water enters the levee structure, it exchanges heat with the surrounding soil and optical fibers, causing the temperature at the leak site to change, enabling leak point identification. Under active heating conditions, by comparing the temperature change curves before and after fiber heating, it is found that normal areas experience a rapid and large temperature rise, while areas with leaks experience a significantly slower (or almost no) temperature rise due to the heat exchange effect of the water flow. This creates an amplified, detectable abnormal temperature rise difference. By monitoring temperature changes along the optical fiber in real time, continuous monitoring of large areas of the levee can be achieved, accurately locating the leak and determining its severity.

[0003] Existing distributed fiber optic temperature sensing devices for implementing the aforementioned levee leakage monitoring mainly fall into two typical structures. One type of temperature-sensing optical fiber lacks active heating capabilities and can only monitor temperature, relying on passive changes in the temperature field around the optical fiber caused by leakage. This passive temperature sensing method is severely affected by ambient temperature fluctuations, especially in areas with large diurnal temperature differences or seasonal temperature fluctuations, where the weak temperature signal caused by leakage is easily masked by environmental noise. Alternatively, based on this structure, an independent heating cable is laid parallel to the temperature-sensing optical fiber. By energizing the heating cable to heat the surrounding soil, the temperature-sensing optical fiber monitors changes in the soil temperature field to achieve leakage monitoring. However, the physical separation of the heating cable and the temperature-sensing optical fiber results in a long and inefficient heat transfer path. Moreover, the optical fiber's perception of the heated temperature is attenuated by the thermal resistance of its own protective layer, making it difficult to effectively amplify the temperature rise gradient in the target area, limiting the accuracy of leak location. Another type, such as application number 201920010348.7, is titled "A Self-Heating Temperature-Sensing Optical Cable Structure Based on Copper Wire." The heating copper wire and the temperature-sensing optical fiber are arranged in parallel and integrated within the same optical cable sheath to form an integrated structure. The copper wire is heated by electricity, and the optical fiber forms a stable temperature field when heated, which is used to monitor changes in the soil temperature field caused by leakage. However, this existing structure only heats the copper wire, which is affected by the resistance of the heated copper wire, resulting in poor heating effects. It is unable to amplify the temperature rise gradient and accurately locate the leak. Furthermore, the heating power supply mostly relies on mains electricity, making long-distance monitoring in the field impossible. Summary of the Invention

[0004] The purpose of the present invention is to address the problems in existing embankment leakage monitoring, such as the inability of traditional point instruments to achieve large-scale continuous monitoring, the susceptibility of conventional distributed temperature sensing optical fibers to interference from ambient temperature fluctuations, the separation of the temperature measuring optical fiber and the heating cable, the poor heating effect, and the inability to achieve long-distance monitoring in the field. The present invention provides a distributed temperature measuring optical cable, a monitoring device and a method based on active solar heating, which can be used for long-term unmanned long-distance embankment leakage monitoring.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The structure of the distributed temperature measurement optical cable includes four-core optical fibers, a metal loose tube, a core wire, a heating copper wire, an inner insulation layer, an armor stress relief device and an outer insulation layer;

[0007] The four-core optical fiber is located in a metal loose tube, and gel material is filled between the four-core optical fiber and the metal loose tube. The metal loose tube is twisted and wrapped with a heating copper wire, and the heating copper wire is wrapped with an inner insulation layer. The inner insulation layer is twisted and wrapped with copper wire and steel wire. The cross-twisted copper wire and steel wire constitute an armored stress relief device, and the armored stress relief device is wrapped with an outer insulation layer.

[0008] Compared with the traditional heating optical cable structure, the copper wire twisted around the metal loose tube heats up faster, the heat inside the optical cable is more evenly distributed, the positioning effect is better after the optical fiber temperature rises, and the location of the embankment leakage risk can be located more accurately.

[0009] The temperature sensing optical fiber of the temperature measuring optical cable is a loose tube armored temperature sensing optical fiber. The temperature sensing optical fiber cannot be affected by force but can only be affected by temperature, so the selection of "loose tube armored" temperature optical fiber can meet this requirement.

[0010] Furthermore, a core wire is twisted and wound between the metal loose tube and the heating copper wire, the heating copper wire is wound outside the core wire, the heating copper wire and the core wire are connected to the voltage regulator through a cable interface, and the colloidal battery energizes the heating copper wire and the core wire through the voltage regulator.

[0011] The core wire is a metal alloy wire with a positive temperature coefficient of resistance. It is made of copper alloy and is evenly wrapped around the outer circumference of the metal loose tube, further increasing the heating speed and making the internal heating of the optical cable more uniform. In addition, the heating can be conducted over a longer distance with the same power.

[0012] A long-distance embankment leakage monitoring device includes an optical fiber temperature measurement host, a temperature measurement optical cable, a display, a voltage regulator, an off-grid single-phase inverter, a colloidal battery, and a monocrystalline solar panel;

[0013] The temperature measuring optical cable is connected to the optical fiber temperature measuring host, and the optical fiber temperature measuring host is connected to the display via a data cable;

[0014] The voltage regulator is connected to the gel battery and the temperature measuring optical cable through a cable;

[0015] The off-grid single-phase inverter is connected to the monocrystalline solar panel and the gel battery through an electrical interface.

[0016] The fiber optic temperature measurement host is equipped with a high-precision temperature demodulation unit, capable of achieving a temperature resolution of less than 0.1°C, improving leak detection accuracy. The fiber optic temperature measurement host utilizes an embedded system architecture, offering low power consumption and high reliability, making it suitable for long-term unattended operation.

[0017] The installation angle of monocrystalline solar panels can be dynamically adjusted based on the local solar altitude to improve photovoltaic power conversion efficiency. Using photovoltaic conversion technology, monocrystalline solar panels convert solar energy into direct current (DC) electricity, which is stored in GEL batteries or converted into alternating current (AC) via an off-grid single-phase inverter, providing a stable power source for system operation. GEL batteries, serving as energy storage units, store the electricity generated by the solar panels, providing backup power during periods of low sunlight or at night, ensuring continuous system operation. GEL batteries feature overcharge protection and temperature control to prevent performance degradation caused by high temperatures or excessive discharge.

[0018] Two GEL batteries are available, each with a balancing charging voltage range of 14.4-15.0V. The GEL battery voltage regulation stability is ±0.1V. The off-grid single-phase inverter has a rated output power of 3000W and a peak power of 6000W. The maximum output power of the monocrystalline solar panel is 1600W. For typical dike monitoring, heating monitoring is performed twice a day, and the battery charge is sufficient for four to five heating tests. Even in rainy weather, the solar panel can provide sufficient power.

[0019] The system adopts a modular design. The optical fiber temperature measurement host, temperature measurement optical cable, display, voltage regulator, off-grid single-phase inverter, colloidal battery and monocrystalline solar panel can be disassembled and maintained independently.

[0020] Furthermore, the heating copper wire is connected to a voltage regulator through a cable interface, and the colloidal battery energizes the heating copper wire through the voltage regulator.

[0021] The heating copper wire is a heating copper resistance wire, which is a material with good heating performance. The heating copper wire realizes a constant power heating mode through a voltage regulator.

[0022] Furthermore, a core wire is twisted and wound between the metal loose tube and the heating copper wire, the heating copper wire is wound outside the core wire, the heating copper wire and the core wire are connected to the voltage regulator through a cable interface, and the colloidal battery energizes the heating copper wire and the core wire through the voltage regulator.

[0023] A long-distance embankment leakage monitoring method comprising:

[0024] A buried trench is excavated at the foot of the backslope of the levee, and the tail end of the temperature measuring optical cable is reserved outside the buried trench. The four-core optical fiber at the tail end of the temperature measuring optical cable is connected to the pigtail, and the head end of the temperature measuring optical cable is laid from one end of the buried trench along the length of the trench bottom to the other end of the buried trench, and then backfilled with soil; then the cable is continued to be laid along the surface of the backfill soil back to one end of the buried trench, and in this way, it is laid in layers in a vertical "S" shape along the elevation direction of the slope foot; the four-core optical fiber at the head end of the temperature measuring optical cable is connected to the optical fiber temperature measuring host, and the heating copper wire and core wire are connected to the voltage regulator. The heating copper wire and core wire are heated by the voltage regulator. The temperature rise amplitude and speed around the temperature measuring optical cable caused by levee leakage are reduced, and the temperature data is obtained through the optical fiber temperature measuring host and transmitted and processed to realize leakage monitoring.

[0025] Furthermore, the temperature measurement optical cable is laid at a depth of 0.5 to 2 meters from the slope foot surface. The laying depth should be set according to the leakage risk area of ​​the embankment to improve monitoring sensitivity.

[0026] Furthermore, the vertical spacing between the temperature measuring optical cables on each layer is 30 to 50 cm to ensure full coverage of the monitoring range of the leakage location.

[0027] Specifically: a 0.5m wide and 1.3m deep burial trench is excavated at the foot of the back slope of the embankment, the tail end of the temperature measuring optical cable is reserved outside the burial trench and connected to the pigtail, and the head end of the temperature measuring optical cable is laid from one end of the burial trench along the length of the trench bottom to the other end of the burial trench; then 50cm deep soil is backfilled and compacted, and the head end of the temperature measuring optical cable is laid back to one end of the burial trench along the surface of the backfill soil, and 50cm of soil is continued to be backfilled and compacted. This operation is repeated, and a total of three layers of temperature measuring optical cable are laid. After the last layer of temperature measuring optical cable is laid, 30cm of soil is backfilled and compacted to be flush with the ground, and the head end of the temperature measuring optical cable is led out.

[0028] The beneficial effects of the present invention are:

[0029] The temperature measuring optical cable of the present invention uses a circumferentially arranged heating copper wire to actively heat the optical cable, which enhances the temperature sensing sensitivity of the optical cable, can realize the fusion innovation of large-scale normalized monitoring and local refined positioning detection, and can realize long-distance embankment leakage positioning.

[0030] The monitoring device described in the present invention is powered by solar energy and does not rely on mains electricity. It can operate in remote areas without mains electricity access. It combines active heating optical cables and distributed optical fiber temperature measurement technology, adopts a constant power heating method, and operates stably and reliably. It is suitable for unmanned embankment leakage monitoring in the field far away from the power grid.

[0031] The monitoring method described in the present invention adopts an "S"-shaped arrangement of temperature measuring optical cables, which increases the measurement range of the vertical section and can realize real-time monitoring of temperature changes inside the embankment, thereby effectively identifying leakage areas and fully improving the recognition accuracy and recognition range of embankment monitoring for leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural diagram of the monitoring device;

[0033] Figure 2 This is a schematic diagram of the vertical layout of the temperature measurement optical cable;

[0034] Figure 3 It is the structural diagram of the temperature measurement optical cable;

[0035] Figure 4 The embankment model and layout diagram for the model test of the embodiment;

[0036] Figure 5 Graph showing temperature rise changes of the novel optical cable and the traditional optical cable under different voltages in the embodiment;

[0037] Figure 6 This is a leakage location diagram of a simulated leakage channel for monitoring a new optical cable in an embodiment;

[0038] Among them: 1 fiber optic temperature measurement host, 2 temperature measurement optical cable, 3 display, 4 voltage regulator, 5 off-grid single-phase inverter, 6 colloidal battery, 7 single crystal solar panel, 8 embankment, 21 four-core optical fiber, 22 metal loose tube, 23 core wire, 24 heating copper wire, 25 inner insulation layer, 26 armor stress relief device, 27 outer insulation layer. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the method of the present invention is further described in detail below with reference to the accompanying drawings and specific implementation cases. The specific implementation cases described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] Example 1:

[0041] like Figure 3As shown, the distributed temperature measurement optical cable 2 includes a quad-core optical fiber 21, a loose metal tube 22, a core wire 23, a heating copper wire 24, an inner insulation layer 25, an armored stress relief device 26, and an outer insulation layer 27. The quad-core optical fiber 21 is located in the loose metal tube 22, and a gel material is filled between the quad-core optical fiber 21 and the loose metal tube 22 to buffer external forces, secure the optical fiber, and protect the optical fiber. The loose metal tube 22 is twisted and wrapped with the core wire 23, which is twisted and wrapped with the heating copper wire 24. The heating copper wire 24 is wrapped with an inner insulation layer 25. The inner insulation layer 25 is twisted and wrapped with copper and steel wires. The copper and steel wires are cross-twisted to form the armored stress relief device 26, which is wrapped with an outer insulation layer 27.

[0042] Example 2:

[0043] like Figure 1 As shown, a long-distance dike leakage monitoring device includes an optical fiber temperature measurement host 1, a temperature measurement optical cable 2, a display 3, a voltage regulator 4, a colloidal battery 5, an off-grid single-phase inverter 6 and a monocrystalline solar panel 7.

[0044] One end of the temperature measurement optical cable 2 is connected to the pigtail, and the other end is connected to the optical fiber temperature measurement host.

[0045] The heating copper wire 24 and core wire 23 are connected to a voltage regulator 4 via a cable interface. The voltage regulator 4 is connected to a colloidal battery 6, which energizes the heating copper wire 24 and core wire 23 through the voltage regulator 4 to generate heat. The four-core optical fiber senses the ambient temperature in real time and transmits it to the optical fiber temperature measurement host 1. The heating copper wire uses a constant power heating mode, with the voltage regulator automatically controlling the power output to adapt to different soil heat conduction characteristics.

[0046] The display 3 is connected to the optical fiber temperature measurement host 2 via a data cable, and is used to display the real-time temperature distribution data after demodulation; the voltage regulator 4 is connected to the colloidal battery 6, the heating copper wire 24 and the core wire 23 temperature measurement optical cable via a cable, and is used to adjust the voltage to ensure that the power of the heating copper wire and the core wire 23 meets the working requirements and reduces energy consumption.

[0047] The off-grid single-phase inverter 5 is connected to the monocrystalline solar panel 7 and the colloidal battery 6 via an electrical interface, and converts the direct current generated by the monocrystalline solar panel 7 into alternating current.

[0048] The colloidal battery 6 is connected to the off-grid single-phase inverter 5 and the voltage regulator 4 via a power interface, and is used to store the electrical energy generated by the monocrystalline solar panel 7 and energize the heating copper wire 24 and the core wire 23 through the voltage regulator 4 .

[0049] The present invention designs the heating cable, i.e., the heating copper wire, and the temperature measuring optical cable into an integral structure. The heating copper wire is wrapped around the optical cable, and the heating copper wire is closely wrapped around the temperature-sensing optical fiber. Compared with the structure with application number 201920010348.7, the heating area of ​​the optical fiber is large and the heating is uniform. The temperature field formed by the heating of the optical fiber is also more stable. Compared with the method of synchronously arranging the heating copper wire along the optical fiber, the heating is faster and the effect is better.

[0050] Example 3:

[0051] like Figure 2 As shown, the installation method of the temperature measuring optical cable 2 is as follows:

[0052] At the backwater foot of the embankment 8, the temperature measuring optical cable 2 is laid in a vertical "S" shape along the slope foot elevation direction, with an optical fiber spacing of 30 to 50 cm to ensure full coverage of the leakage location monitoring range.

[0053] According to the leakage risk area of ​​the embankment, the laying depth of the temperature measuring optical cable 2 is set within the range of 0.5 to 2 m from the slope foot surface to improve the monitoring sensitivity.

[0054] Specific approach: excavate a 0.5m wide and 1.3m deep burial trench at the foot of the backwater slope of the embankment 8 to bury the temperature measuring optical cable 2. First, lay the bottom layer of temperature measuring optical cable 2, reserve the tail end of the temperature measuring optical cable 2 outside the burial trench, and lay the head end of the temperature measuring optical cable 2 from one end of the burial trench along the length direction of the burial trench to the other end of the burial trench, then backfill 50cm deep soil and compact it. In the same way, lay the head end of the temperature measuring optical cable 2 along the surface of the backfill soil to one end of the burial trench, and then backfill 50cm of soil and compact it. A total of 4 layers of temperature measuring optical cable 2 are laid. After the last layer of temperature measuring optical cable 2 is laid, backfill 30cm of soil and compact it flush with the ground, and lead out the head end of the temperature measuring optical cable 2, thus completing the laying of the temperature measuring optical cable.

[0055] Connect the four-core optical fiber 21 at the head end of the temperature-measuring optical cable 2 to the optical fiber temperature measurement host 1. Connect the heating copper wire 24 and core wire 23 to the voltage regulator 4. The length of the four-core optical fiber 21 represents the length of the monitoring section for leakage in the dike 8. The optical fiber temperature measurement host 1 measures the temperature of the four-core optical fiber 21 and core wire 23 in real time. The colloidal battery 5 and voltage regulator 4 heat the heating copper wire 24 and core wire 23 at a constant power. The measured temperature changes after heating can be used to determine whether a leak has occurred and locate the leak.

[0056] The previously commonly used layout method was to bury only one layer of optical fiber 80 cm from the soil surface and lay it in an S-shaped manner along the backwater slope. The improved design now is to lay a layer of optical fiber vertically every 30 cm to 50 cm, avoiding leakage and the problem of water not flowing through the fiber optic buried area and being unable to be identified.

[0057] Example 4:

[0058] In this embodiment, the temperature measuring optical cable described in Example 1 and the monitoring device described in Example 2 are arranged in the manner of Example 3 for verification testing.

[0059] The embankment model and layout of the model test are as follows: Figure 4 As shown, including the embankment model and the long-distance embankment leakage monitoring device, the specific plan of the model test is as follows:

[0060] The constructed levee was 50m long, 2m wide at the top, 2.5m high, and had a slope ratio of 1:2. Leakage channels were buried at 8m, 20m, 32m, and 44m (at 12m intervals) from the north side of the levee to conduct simulated leakage monitoring tests. A new optical cable (the temperature measurement optical cable 2 described in the present invention) and a traditional heating optical cable (the optical cable with application number 201920010348.7) were laid on the backwater side of the levee model according to Example 2, and the long-distance levee leakage monitoring device of the present invention was installed according to Example 1.

[0061] All leakage channels are closed. Temperature data are collected through the new optical cable and the traditional heating optical cable respectively. Figure 6 The temperature curve before heating is shown in FIG. 1 . Then, the voltage regulator 4 is used to heat the new optical cable and the traditional heating optical cable at voltages of 35V and 40V for 15 minutes respectively. The temperature rise changes of the two optical cables heated at different voltages obtained and processed by the optical fiber temperature measurement host 2 are shown in FIG. Figure 5 As shown in the figure, the temperature rise values ​​of the new optical cable under two voltages are higher than those of the traditional optical cable, indicating that its heating effect is better.

[0062] Open leakage channel 4 to simulate dike leakage. After stable leakage is formed, heat the new optical cable at 40V for 15 minutes according to the method proposed in the present invention. The optical fiber temperature measurement host obtains and processes the temperature data and temperature rise value of the new optical cable before and after heating. Figure 6 As shown in the figure, in the corresponding area of ​​the leakage channel, the leaking water takes away the heat of the optical cable. The temperature rise value of the new optical cable here is lower than that in other areas where no leakage occurs. Therefore, the location of the leakage can be located according to the temperature rise change.

[0063] The present invention has been verified through repeated model tests and has achieved satisfactory practical engineering application effects.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A distributed temperature measurement optical cable, characterized in that: It comprises a four-core optical fiber (21), a metal loose tube (22), a core wire (23), a heating copper wire (24), an inner insulating layer (25), an armored stress relief device (26) and an outer insulating layer (27); The four-core optical fiber (21) is located in a metal loose tube (22), and a gel material is filled between the four-core optical fiber (21) and the metal loose tube (22). The metal loose tube (22) is twisted and wound with a heating copper wire (24), and the heating copper wire (24) is wrapped with an inner insulating layer (25). The inner insulating layer (25) is twisted and wound with copper wire and steel wire. The cross-twisted copper wire and steel wire constitute an armored stress relief device (26), and the armored stress relief device (26) is wrapped with an outer insulating layer (27).

2. A distributed temperature measurement optical cable according to claim 1, characterized in that: A core wire (23) is twisted and wound between the metal loose tube (22) and the heating copper wire (24).

3. A long-distance embankment leakage monitoring device, characterized in that: Based on the distributed temperature measurement optical cable described in claim 1, the monitoring device includes an optical fiber temperature measurement host (1), a distributed temperature measurement optical cable (2), a display (3), a voltage regulator (4), an off-grid single-phase inverter (5), a colloidal battery (6) and a single crystal solar panel (7); The temperature measuring optical cable (2) is connected to the optical fiber temperature measuring host (1), and the optical fiber temperature measuring host (1) is connected to the display (3) via a data cable; The voltage regulator (4) is connected to the gel battery (6) and the temperature measuring optical cable (2) via an electric cable; The off-grid single-phase inverter (5) is connected to the monocrystalline solar panel (7) and the colloidal storage battery (6).

4. The long-distance embankment leakage monitoring device according to claim 3, characterized in that: The temperature measuring optical cable (2) comprises a four-core optical fiber (21), a metal loose tube (22), a core wire (23), a heating copper wire (24), an inner insulating layer (25), an armor stress relief device (26) and an outer insulating layer (27); The four-core optical fiber (21) is located in a metal loose tube (22), and a gel material is filled between the four-core optical fiber (21) and the metal loose tube (22). The metal loose tube (22) is twisted and wound with a heating copper wire (24), and the heating copper wire (24) is wrapped with an inner insulating layer (25). The inner insulating layer (25) is twisted and wound with copper wire and steel wire. The cross-twisted copper wire and steel wire constitute an armored stress relief device (26), and the armored stress relief device (26) is wrapped with an outer insulating layer (27).

5. The long-distance embankment leakage monitoring device according to claim 4, characterized in that: The heating copper wire (24) is connected to the voltage regulator (4) through a cable interface, and the colloidal battery (6) energizes the heating copper wire (24) through the voltage regulator (4).

6. The long-distance embankment leakage monitoring device according to claim 5, characterized in that: A core wire (23) is twisted and wound between the metal loose tube (22) and the heating copper wire (24). The heating copper wire (24) is wound around the core wire (23). The heating copper wire (24) and the core wire (23) are connected to a voltage regulator (4) through a cable interface. The colloidal battery (6) energizes the heating copper wire (24) and the core wire (23) through the voltage regulator (4).

7. A long-distance embankment leakage monitoring method, characterized in that: The long-distance embankment leakage monitoring device according to any one of claims 3 to 6 comprises: A buried trench is excavated at the foot of the backslope of the levee, and the tail end of the temperature measuring optical cable is reserved outside the buried trench. The four-core optical fiber at the tail end of the temperature measuring optical cable is connected to the pigtail, and the head end of the temperature measuring optical cable is laid from one end of the buried trench along the length of the trench bottom to the other end of the buried trench, and then backfilled with soil; then the cable is continued to be laid along the surface of the backfill soil back to one end of the buried trench, and in this way, it is laid in layers in a vertical "S" shape along the elevation direction of the slope foot; the four-core optical fiber at the head end of the temperature measuring optical cable is connected to the optical fiber temperature measurement host, and the heating copper wire and core wire are connected to the voltage regulator. The heating copper wire and core wire are heated by the voltage regulator. The temperature rise amplitude and speed around the temperature measuring optical cable caused by levee leakage are reduced, and the temperature data is obtained through the optical fiber temperature measurement host and transmitted and processed to realize leakage monitoring.

8. A long distance embankment leakage monitoring method according to claim 7, characterized in that: The laying depth of the temperature measuring optical cable (2) is set within the range of 0.5 to 2 m from the slope foot surface.

9. The long-distance embankment leakage monitoring method according to claim 7, characterized in that: The vertical spacing between each layer of temperature measuring optical cables (2) is 30 to 50 cm.

10. The long-distance embankment leakage monitoring method according to claim 7, characterized in that: A 0.5m wide and 1.3m deep burial trench is excavated at the foot of the back slope of the embankment (8), and the tail end of the temperature measuring optical cable (2) is reserved outside the burial trench. The four-core optical fiber at the tail end of the temperature measuring optical cable is connected to the pigtail. The head end of the temperature measuring optical cable (2) is laid from one end of the burial trench along the length direction of the trench bottom to the other end of the burial trench, and then 50cm deep soil is backfilled and compacted; then the head end of the temperature measuring optical cable (2) is laid back to one end of the burial trench along the surface of the backfill soil, and 50cm of soil is backfilled and compacted. The operation is repeated, and a total of three layers of temperature measuring optical cables (2) are laid. After the last layer of temperature measuring optical cables (2) is laid, 30cm of soil is backfilled and compacted to be flush with the ground, and the head end of the temperature measuring optical cable (2) is led out.

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