Multi-interface adaptive catchment method in karst mountainous area

Abstract

The present application relates to the field of hydraulic engineering, in particular to a kind of karst mountainous area multi-interface adaptability water collection method, comprising: in the heterogeneous permeable interface, embedding water collection medium layer and tension sensing array, collecting transient matric potential data;Compare matric potential data with medium air intake value to determine water conduction state, and adjust fluid driving unit pressure accordingly;When determining as gas resistance critical state, adjust fluid driving unit to switch to intermittent pulse mode to restore interface liquid phase continuity;Calculate flow resistance index and periodically generate hydraulic shock pulse, the present application establishes the physical association of matric potential and air intake value, adjusts mode at gas-liquid phase change critical point, effectively avoids gas resistance effect and advantage flow bypass, maintains liquid phase conduction, by making pumping frequency match medium capillary recharge rate, improve the adaptation ability of system to permeability heterogeneity, guarantee the engineering robustness of water conservancy water collection network under complex geological conditions.

Description

Technical Field

[0001] This invention relates to a multi-interface adaptive water collection method for karst mountainous areas, belonging to the field of water conservancy engineering technology. Background Technology

[0002] The hydrogeological structure of karst mountainous areas is currently highly complex, with its surface karst zones exhibiting a high degree of heterogeneity, leading to rapid infiltration of rainfall. In the field of water conservancy engineering, rigid surface interception or micro-topographical runoff collection methods are commonly used to intercept surface runoff by constructing storage spaces. This constitutes the main technical approach in this field. However, traditional agricultural water conservancy and watershed management projects often struggle to simultaneously control surface runoff and intercept groundwater leakage, resulting in low water resource regulation efficiency and difficulty in meeting the long-term water storage and seepage prevention needs of regional water conservancy facilities. Karst multi-interface media, composed of soil, gravel, and weathered rock, exhibits a multi-scale pore distribution pattern. During active negative pressure suction at this interface, maintaining the continuity of water conduction within the porous media is crucial. If the negative pressure gradient exceeds the air intake value of the media, air intrusion into the large pores creates an air resistance effect, causing the liquid phase conduction chain to break, and water to leak vertically along karst fissures.

[0003] The industry typically enhances water interception capacity by simply increasing the negative pressure gradient. However, increasing negative pressure accelerates the dehydration process inside the medium, causing the gas phase intrusion critical point to be reached prematurely. Furthermore, continuous directional flow fields easily induce directional particle migration, resulting in physical blockage at the interface. Laying large-area impermeable materials has drawbacks such as high construction costs, damage to the ecological environment, and inability to match the spatiotemporal uneven distribution of permeability. Existing monitoring methods and flow field control logic are difficult to adapt to karst conditions. For example, Chinese invention patent CN115979908B discloses an in-situ measurement and monitoring method for soil water supply rate. It guides irrigation by establishing a model of the relationship between matrix potential and water supply rate. The logical basis is a uniform farmland soil environment. However, the permeability in karst mountainous areas exhibits strong spatiotemporal heterogeneity, and static relationship models are prone to failure under complex geological constraints. Existing monitoring methods focus on quantifying water transport rates but fail to identify the critical state of gas-liquid phase transition in karst media driven by negative pressure, and cannot predict and block the interruption of liquid phase conduction caused by gas resistance effects.

[0004] Therefore, the technical problem to be solved by this invention is how to establish a multi-interface adaptive water collection method for karst mountainous areas that can identify the critical state of hydraulic continuity of the medium and adaptively reconstruct the interception flow field, so as to efficiently intercept vertical leakage water at the interface under the premise of ensuring the stability of the geological environment, thereby improving the rainwater interception and watershed water storage and allocation capacity of water conservancy projects. Summary of the Invention

[0005] To address the problems in the background art, the technical solution of the present invention is as follows: A multi-interface adaptive water collection method for karst mountainous areas, comprising the following steps: Step 101: Bury a water collection medium layer at the heterogeneous permeation interface and deploy a tension sensing array at the heterogeneous permeation interface. Step 102: Collect transient matrix potential data, which characterizes the water state at the heterogeneous permeation interface, fed back by the tension sensing array. Step 103: Compare the transient matrix potential data with the preset medium inlet value; when the transient matrix potential data is less than the medium inlet value, determine that the heterogeneous permeation interface is in a liquid phase conduction state; when the transient matrix potential data is greater than or equal to the medium inlet value, determine that it is in a critical state of gas resistance. Step 104: Adjust the output pressure value of the fluid drive unit according to the judgment result; when the gas resistance critical state is judged, adjust the fluid drive unit to enter the intermittent pulse mode, and cut off the negative pressure source to make the transient matrix potential data rise back to the preset liquid phase recovery range, so as to restore the liquid phase continuity inside the water collection medium layer. Step 105: Collect the real-time pressure and instantaneous flow rate of the water collection channel and calculate the flow resistance index. When the rate of change of the flow resistance index exceeds the preset resistance mutation threshold, adjust the fluid drive unit to generate hydraulic oscillation pulses, and destroy the particle blockage structure at the heterogeneous infiltration interface through positive pressure feedback.

[0006] Preferably, the process of determining the preset medium intake value in step 103 includes the following sub-steps: Step 1031, injecting test gas into the heterogeneous permeation interface and collecting the moisture characteristic curve at the test interface; Step 1032, obtaining the inflection point pressure value corresponding to the decrease in water content on the moisture characteristic curve, and determining the inflection point pressure value as the medium intake value.

[0007] Preferably, the cutoff time of the intermittent pulse mode in step 104 is based on the recovery slope of the transient matrix potential data. Confirmed, rising slope The calculation logic is as follows: ,in, The matrix potential value at the initial moment of negative pressure adjustment. This marks the start of negative pressure regulation. This represents the matrix potential value at the time of detection after negative pressure adjustment. The time to be tested.

[0008] Preferably, in step 104, the slope of the rise is... When the pressure drops to the preset saturation equilibrium threshold of 0.05 kPa / min to 0.15 kPa / min, the fluid drive unit is adjusted to restore the target pressure value mapped by the transient matrix potential data.

[0009] Preferably, the process of deploying the tension sensor array in step 101 includes the following sub-steps: step 1011, deploying multiple tension meter nodes along the horizontal direction at the heterogeneous permeation interface; step 1012, each tension meter node is connected to the water collection medium layer through a manifold.

[0010] Preferably, the triggering logic for generating the hydraulic oscillation pulse in step 105 is as follows: when the rate of change of the flow resistance index within a preset 10-minute window exceeds the preset resistance mutation threshold, the fluid drive unit is adjusted to switch to the reverse rotation state.

[0011] Preferably, the peak pressure of the hydraulic oscillation pulse is set to 1.2 to 1.5 times the rated pressure of the fluid drive unit under negative pressure suction.

[0012] Preferably, the water collection medium layer is composed of graded filter material filled in the fissures of the heterogeneous permeable interface, and the particle size distribution range of the graded filter material is 0.075 mm to 2.0 mm.

[0013] Preferably, before step 102, the method further includes: collecting the penetrating raindrop kinetic energy parameters below the vegetation canopy; when the penetrating raindrop kinetic energy parameters are greater than a preset threshold and the current vertical infiltration flux has not reached the infiltration threshold, adjusting the dredging valve of the surface diversion channel to open, and guiding the surface runoff into the main water collection network.

[0014] Preferably, the process of adjusting the output pressure value in step 104 further includes: adjusting the operating frequency of the fluid drive unit to fluctuate between 20Hz and 50Hz based on the spatiotemporal deviation of the permeability of the heterogeneous permeation interface, so that the negative pressure suction rate matches the capillary replenishment rate of the medium.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. In multi-interface adaptive water collection in karst mountainous areas, by establishing a dynamic physical correlation between the transient matrix potential at the interface between soil and surface karst and the air intake value of the medium, the negative pressure source is forcibly cut off at the critical front of the gas-liquid phase transition in the water transport channel. This maintains the physical continuity of liquid phase conduction within the porous medium, avoids the large pore air resistance phenomenon and the generation of dominant flow bypass due to continuous suction, and ensures that the lateral hydraulic gradient in the strongly heterogeneous interface continues to effectively intercept the infiltrated water. This solves the problem of interception failure caused by gas-liquid instability during ecological water conservancy seepage prevention and active water collection in karst mountainous areas, thereby improving the water production efficiency and water storage stability of underground water collection facilities.

[0016] 2. By utilizing intermittent pulse control logic based on the slope of matrix potential recovery, the pumping rhythm of the water collection system is physically synchronized with the capillary charging and discharging cycle of the medium. During the period when pumping is shut off, the soil capillary force and natural infiltration gravity potential energy are used to promote the recovery of the interface saturation state. This transforms the macroscopic continuous irrigation and drainage into a breathing water collection mode that is micro-compliant with the geological medium replenishment rate. This reduces the overall operating energy consumption of the system while improving the ability of the water collection nodes to adapt to the spatiotemporal heterogeneity of interface water permeability.

[0017] 3. The integrated flow resistance monitoring and transient positive pressure backflushing mechanism of the lateral negative pressure confluence node, by acquiring the flow resistance index in real time and periodically outputting hydraulic oscillation pulses, destroys the fine particle bridging and siltation structure formed at the interface during the directional suction process from a fluid dynamics perspective, maintains the long-term physical connectivity of the water collection channel, avoids the decay of the permeability performance of karst mixed media under long-term stress, ensures the robustness of the groundwater resource interception network, effectively extends the service life of the groundwater pipe network and reduces the frequency of maintenance in the later stages of the project. Attached Figure Description

[0018] Figure 1 This is a flowchart of the steps of the multi-interface adaptive water collection method for karst mountainous areas according to the present invention; Figure 2 This is a logical architecture diagram of the multi-interface perception and action mapping of the water collection system of the present invention.

[0019] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0021] A multi-interface adaptive water collection method for karst mountainous areas includes the following steps: Step 101: Bury a water collection medium layer at the heterogeneous permeation interface and deploy a tension sensing array at the heterogeneous permeation interface. Step 102: Collect transient matrix potential data, which characterizes the water state at the heterogeneous permeation interface, fed back by the tension sensing array. Step 103: Compare the transient matrix potential data with the preset medium inlet value; when the transient matrix potential data is less than the medium inlet value, determine that the heterogeneous permeation interface is in a liquid phase conduction state; when the transient matrix potential data is greater than or equal to the medium inlet value, determine that it is in a critical state of gas resistance. Step 104: Adjust the output pressure value of the fluid drive unit according to the judgment result; when the gas resistance critical state is judged, adjust the fluid drive unit to enter the intermittent pulse mode, and cut off the negative pressure source to make the transient matrix potential data rise back to the preset liquid phase recovery range, so as to restore the liquid phase continuity inside the water collection medium layer. Step 105: Collect the real-time pressure and instantaneous flow rate of the water collection channel and calculate the flow resistance index. When the rate of change of the flow resistance index exceeds the preset resistance mutation threshold, adjust the fluid drive unit to generate hydraulic oscillation pulses, and destroy the particle blockage structure at the heterogeneous infiltration interface through positive pressure feedback.

[0022] Preferably, the process of determining the preset medium intake value in step 103 includes the following sub-steps: Step 1031, injecting test gas into the heterogeneous permeation interface and collecting the moisture characteristic curve at the test interface; Step 1032, obtaining the inflection point pressure value corresponding to the decrease in water content on the moisture characteristic curve, and determining the inflection point pressure value as the medium intake value.

[0023] Preferably, the cutoff time of the intermittent pulse mode in step 104 is based on the recovery slope of the transient matrix potential data. Confirmed, rising slope The calculation logic is as follows: ,in, The matrix potential value at the initial moment of negative pressure adjustment. This marks the start of negative pressure regulation. This represents the matrix potential value at the time of detection after negative pressure adjustment. The time to be tested.

[0024] Preferably, in step 104, the slope of the rise is... When the pressure drops to the preset saturation equilibrium threshold of 0.05 kPa / min to 0.15 kPa / min, the fluid drive unit is adjusted to restore the target pressure value mapped by the transient matrix potential data.

[0025] Preferably, the process of deploying the tension sensor array in step 101 includes the following sub-steps: step 1011, deploying multiple tension meter nodes along the horizontal direction at the heterogeneous permeation interface; step 1012, each tension meter node is connected to the water collection medium layer through a manifold.

[0026] Preferably, the triggering logic for generating the hydraulic oscillation pulse in step 105 is as follows: when the rate of change of the flow resistance index within a preset 10-minute window exceeds the preset resistance mutation threshold, the fluid drive unit is adjusted to switch to the reverse rotation state.

[0027] Preferably, the peak pressure of the hydraulic oscillation pulse is set to 1.2 to 1.5 times the rated pressure of the fluid drive unit under negative pressure suction.

[0028] Preferably, the water collection medium layer is composed of graded filter material filled in the fissures of the heterogeneous permeable interface, and the particle size distribution range of the graded filter material is 0.075 mm to 2.0 mm.

[0029] Preferably, before step 102, the method further includes: collecting the penetrating raindrop kinetic energy parameters below the vegetation canopy; when the penetrating raindrop kinetic energy parameters are greater than a preset threshold and the current vertical infiltration flux has not reached the infiltration threshold, adjusting the dredging valve of the surface diversion channel to open, and guiding the surface runoff into the main water collection network.

[0030] Preferably, the process of adjusting the output pressure value in step 104 further includes: adjusting the operating frequency of the fluid drive unit to fluctuate between 20Hz and 50Hz based on the spatiotemporal deviation of the permeability of the heterogeneous permeation interface, so that the negative pressure suction rate matches the capillary replenishment rate of the medium.

[0031] Example 1: In a karst mountain water conservation project with an average annual rainfall exceeding 1200 mm, a horizontal interception trench is excavated at the interface between the gravel-clay overburden layer and the karst zone. A water-collecting medium layer composed of quartz sand with a particle size of 2 mm to 5 mm is laid in the horizontal interception trench, and a tension sensor array is buried at the contact surface between the water-collecting medium layer and the gravel-clay. When the rainfall intensity reaches 50 mm / h, water in the gravel-clay layer flows vertically down along the soil-karst interface. Due to the difficulty of adapting the surface interception surface to the spatiotemporal heterogeneity of karst medium permeability, deep leakage of rainfall runoff occurs before effective confluence is formed, resulting in the water production efficiency of the regional water storage facility being lower than the design expectation. Transient matrix potential data is collected by the tension sensor array buried at the interface. According to Darcy's law, the transient matrix potential data is converted into vertical permeability flux, and the vertical permeability flux is compared with the preset critical infiltration threshold of the dominant fractures in the karst. When vertical permeability flux is detected, the vertical permeability flux is detected. When the direct permeation flux exceeds the threshold, the suction valve of the lateral negative pressure confluence node is opened, establishing a lateral hydraulic gradient at the interface to change the seepage direction from vertical to horizontal. This allows water to flow into the main water collection network along the lateral hydraulic gradient. Transient matrix potential data drives flow field reconstruction, and a single monitoring signal is used to perform dynamic correlation between vertical leakage determination and lateral suction intensity. This achieves interface water interception without additional geological exploration. When performing the aforementioned dynamic correlation of suction intensity, the main control chip performs time-domain first-order differential operation on the transient matrix potential data sequence to extract its slope to characterize the spatiotemporal deviation characteristics of permeability at heterogeneous interfaces. The absolute value of this slope is linearly projected into a control frequency band of 20Hz to 50Hz through an internally fixed proportional-integral mapping algorithm, and the corresponding pulse width modulation control signal is output to drive the frequency converter, so that the negative pressure output speed of the fluid drive unit and the real-time solution of the medium moisture state form a closed-loop control chain.

[0032] To address the gas resistance effect induced by continuous negative pressure suction in heterogeneous porous media, the slope of the matrix potential recovery around the lateral negative pressure confluence node was monitored during suction. , The calculation formula is as follows: ,in, For the rising slope, The matrix potential value at the initial moment of negative pressure adjustment. This marks the start of negative pressure regulation. The matrix potential value at the time of detection. The time to be detected is when the absolute value of the transient matrix potential data reaches the medium inlet value. When the absolute value is 0.85 to 0.92 times, close the suction valve and utilize the continuous infiltration of rainfall and soil capillary force to restore the continuity of the interfacial liquid phase, and adjust the medium air intake value. The measured air ingress value is the initial air ingress value of the porous medium, and the slope of the matrix potential recovery is given. When the pressure drops to the saturation equilibrium threshold of 0.05 kPa / min to 0.15 kPa / min, it is determined that the medium has returned to a saturated and interconnected state and the pumping is restarted. The pressure and flow data of the water collection channel are collected by the differential pressure transmitter and the flow resistance index is calculated. When the rate of change of the flow resistance index exceeds the preset resistance mutation threshold, the bidirectional variable frequency pump is controlled to reverse and output hydraulic oscillation pulses with a duration of 2s to 5s. Through positive pressure feedback, the particle bridging structure at the interface is destroyed. This process reconstructs the surface interception method into a flow field control method that actively intercepts the flow in the shallow soil, avoids interception failure caused by gas-liquid instability, increases the groundwater resource capture under complex geological conditions, and maintains the physical connectivity of the water collection network under rainfall and drought cycle conditions.

[0033] Example 2: In a karst multi-interface moisture transport simulation test chamber containing a layer of gravelly clay and a layer of strongly weathered limestone, three sets of rainfall intensities with gradients were set. Verification of the multi-interface adaptive water collection method in karst mountainous areas in suppressing air resistance effect and improving interfacial water collection efficiency The test chamber was filled with a typical karst profile medium with a height of 1.5m. The porosity of the upper gravel and clay layer was 0.42, and the lower simulated surface karst layer had interconnected dominant fractures. The test data came from a tensiometer array, electromagnetic flowmeter, and differential pressure transmitter embedded in the heterogeneous permeable interface. The sampling period was used to determine the flow field state. The setting follows the Nyquist sampling criterion and the system energy consumption balance relationship, when the first derivative of the interface matrix potential... In the range of 0.5 kPa / min to 2.0 kPa / min, the inflection point of the gas-liquid phase transition is captured. The time was set to 10s. To simulate the electromagnetic noise of the field monitoring environment, Gaussian white noise with a signal-to-noise ratio of 20dB was superimposed on the 4mA to 20mA current signal returned by the sensor, and a smoothing operator with a sliding window length of 5 sampling points was used for filtering.

[0034] In simulated rainfall intensity Under a working condition of 50 mm / h, due to the strong heterogeneity of permeability at the karst interface, water infiltrates vertically along the fissures of the surface karst rock. At this time, the initial matrix potential at the interface is... Maintained at -12.5 kPa; the sample group of this invention is based on the measured medium intake value. Driven flow field control, when suction pressure causes transient matrix potential data It dropped to the range of -38.4 kPa to -41.6 kPa, meaning the value was in the range of... When the absolute value is between 0.85 and 0.92 times, the fluid drive unit cuts off the negative pressure source, restoring the interfacial liquid phase continuity by utilizing continuous rainfall infiltration and soil capillary force. In contrast, the control group used a continuous constant negative pressure suction mode. When the suction time reached 15.6 min, the interfacial matrix potential dropped to -49.5 kPa due to pore emptying, causing the water collection flow rate to drop sharply from 1.35 L / min to 0.08 L / min, resulting in air resistance cutoff. In the intermittent pulse mode, the slope of matrix potential recovery was monitored in the sample group of this invention. Within 2.8 minutes, the pressure decreased from 2.45 kPa / min to 0.12 kPa / min. This slope was lower than the saturation equilibrium threshold of 0.15 kPa / min. After the liquid phase was determined to be restored, the pumping was restarted by the fluid drive unit to keep the water collection flow rate stable in the range of 1.15 L / min to 1.28 L / min.

[0035] By setting The water collection efficiency at the interface is calculated using a three-stage gradient of 20 mm / h, 50 mm / h, and 80 mm / h. It exhibits nonlinear variation characteristics; when When increasing from 20mm / h to 50mm / h The percentage increased from 81.6% to 90.8%, demonstrating the system's ability to intercept infiltration loads; when When further increased to 80 mm / h, The growth trend has leveled off and stabilized at around 93.1%, indicating that the water collection efficiency is limited by the saturated permeability coefficient of the water collection medium layer. Compared with the lateral hydraulic conduction limit; in the parameter boundary test, the out-of-range control group sets the pulse shut-off threshold to That is, -47.5 kPa. The results show that gas-liquid two-phase flow occurred in the water collection channel, and the flow resistance index increased from 1.08 to 5.12, proving that anchoring the operating parameters at -47.5 kPa... Non-obviousness within the proportional window; the experiment directly demonstrates that the method solves the gas-liquid instability problem in the karst water collection process through physical quantitative mapping, and achieves groundwater resource capture under geological constraints by changing the water collection method from surface interception to active flow field regulation.

[0036] Example 3: This example combines Figures 1 to 2 This paper describes a multi-interface adaptive water collection method for karst mountainous areas, such as... Figure 1 As shown, the multi-interface adaptive water collection method in karst mountainous areas sequentially includes step 101, embedding a water collection medium layer at the interface and deploying a tension sensing array, proceeding to step 102, collecting transient matrix potential data fed back by the tension sensing array, then proceeding to step 103, comparing the matrix potential data with the air intake value to determine the conduction state, then executing step 104, adjusting the driving unit pressure and pulse mode according to the determination result, and finally calculating the resistance index in step 105, generating an oscillating pulse when its rate of change exceeds the preset resistance mutation threshold.

[0037] like Figure 2 As shown, the system's processing architecture encompasses the karst heterogeneous infiltration interface and the vegetation canopy, which serve as signal sources. The karst heterogeneous infiltration interface is associated with three logical nodes: acquiring transient matrix potential data, determining the critical state of air resistance, and disrupting the particle blockage structure of the interface. The internal node for restoring the liquid phase continuity of the water collection medium points its output direction to the node for determining the critical state of air resistance and the fluid drive unit, respectively. The vegetation canopy at the bottom is associated with the node for guiding surface runoff into the water collection network. Finally, the nodes for restoring the liquid phase continuity of the water collection medium, disrupting the particle blockage structure of the interface, matching the capillary recharge rate of the medium, and guiding surface runoff into the water collection network converge and unify, pointing to the fluid drive unit to achieve action mapping.

[0038] Example 4: At a typical karst depression water collection and storage project site, the system operates in a habitat with an upper layer of red clay 1.2m to 1.8m thick and a lower layer with heterogeneous dissolution fissures. When encountering infiltration impacts with rainfall exceeding 40mm / h, the soil matrix potential rises from -200kPa to -15kPa within 30 minutes. Water undergoes uncontrolled vertical leakage through the soil-lime interface into deeper fissures. Because the static impermeable layer cannot sense the seepage vector change at the interface, it is difficult to establish hydraulic interception in the initial stage of leakage. To determine the decision-making criteria required for system operation, an interface hydraulic characteristic calibration program is established after the water collection medium layer is laid. By injecting tracer gas into the soil-lime interface at a constant rate of 0.05L / min, the real-time change process of the interface matrix potential is recorded simultaneously using a tension sensor array. When the interface matrix potential drops to the inflection point of the moisture characteristic curve, i.e., when the water content changes abruptly with decreasing pressure, the corresponding matrix potential measurement value is determined as the medium gas inlet value. The measured value was -42.5 kPa. Based on this physical benchmark, the preset lower limit of the liquid phase recovery range was set to -21.3 kPa, and the upper limit was set to -5.0 kPa, which is close to the saturation state. At the same time, the vertical seepage flux calculation logic integrated into the controller adopts a modified van Grüncheten model, using the soil saturation permeability coefficient input offline. The system converts the electrical signal fed back from the tension sensor array into real-time seepage velocity by comparing the measured matrix potential gradient with the actual flow rate. To successfully implement this gas displacement calibration at the open-connected surface karst interface, the system pre-injects a thermosensitive gelling agent into the calibration section via a bypass pipeline. This utilizes rheological phase change to establish a temporary, equivalent, closed, pressurized boundary within the surrounding large pore space, blocking the dominant leakage channels of the test gas. This creates a stable, measurable gas-liquid displacement phase within the macroscopic volume. After the characteristic curve is acquired, the sealing boundary is completely degraded using an acid-base flushing solution, restoring the original water-conducting background of the medium. During the lateral negative pressure suction phase, the system dynamically assesses the physical connectivity and flow resistance index by monitoring the pressure and flow rate signals of the water collection channel. The calculation formula is as follows: ,in, The flow resistance index, The pressure difference between the inlet and outlet of the suction pump. The instantaneous flow rate of the water collection channel, when monitored When the rate of change within 10 seconds exceeds the 15% resistance mutation threshold, it is determined that fine particle bridging and blockage have occurred at the interface. The fluid drive unit then switches to hydraulic oscillation mode and destroys the blockage structure by outputting positive pressure pulses with peak pressure of 150kPa to 200kPa. At this time, the 2mm to 5mm particle size distribution in the water collection medium layer forms an interface capillary isolation with the gravel and clay layer. With the help of pulse negative pressure regulation, the pore water at the interface is controlled to move horizontally and no longer leaks into the deep fissures.

[0039] Example 5: In construction areas where the thickness of the karst red clay layer and the proportion of crushed stone components vary, a pressure plate testing device is used to collect moisture characteristic curves of the medium at different depths. The controller determines the shape parameters in the van Grucherten model based on the least squares fitting operator. With pressure parameters In the target soil layer with a crushed stone content of 15% to 30%, the shape parameters The calibration values ​​are selected within the range of 1.25 to 1.48, pressure parameters. The calibration value was selected at 0.015. Up to 0.028 Within this scope, the static physical properties of the geological medium are transformed into a digital lookup table that the controller can access. This allows the system to obtain the corresponding vertical permeability flux based on transient matrix potential data under habitats with varying permeability heterogeneity. Well-known facts in porous media physics indicate that soil hydraulic conductivity is not a constant and decreases non-linearly with increasing matrix suction. Darcy's law of permeability, combined with the van Grochetten water characteristic model, characterizes the non-constant seepage process. Based on the objective correlation between matrix potential and unsaturated permeability, a closed-loop mechanism is constructed to convert transient physical quantities into quantifiable execution thresholds. Based on the hydraulic conductivity characteristics of porous media, the controller periodically calls the digital lookup table to perform data conversion calculations, resulting in the vertical permeability flux. The calculation formula is set as follows ,in, Characterizing the vertical seepage velocity at the interface, The tension sensing array is used to acquire transient matrix potential data in real time. The soil saturated permeability coefficient was pre-calibrated using a field double-ring infiltration test. and The common characterization is achieved by matching the output medium physical parameters through a digital lookup table. The intermediate parameter actually calculated by this formula structure is the unsaturated hydraulic conductivity under a specific suction state. To obtain the true vertical seepage velocity, the main control program retrieves the readings of two tension meters arranged on the same vertical line at different depths and calculates the difference. This difference is then divided by the absolute elevation difference between the two probes to dynamically extract the head gradient factor. Finally, the conductivity variable output by the above formula is multiplied by the head gradient factor, thereby deriving the vertical seepage flux with velocity dimensions within the closed-loop system of the physical formula. To address the loss of fine particles at the interface and the drift of physical properties caused by long-term vertical scouring of water flow, the system's main control program has a built-in time-based reconstruction procedure. When the cumulative seepage flow through the heterogeneous seepage interface exceeds a set threshold, the controller triggers a baseline update command. The system then overwrites the shape parameters by combining the newly extracted surrounding soil sample measurement data. With pressure parameters Initial settings maintain the boundaries of the mapping operation.

[0040] When the system is in the static calibration condition after initial installation, the inherent resistance index benchmark of the water collection channel is obtained by pumping under a zero infiltration background through the fluid drive unit. The controller collects pressure difference and flow rate data of the suction pump at different speed levels and establishes a pumping characteristic fitting curve. It removes system background noise by subtracting pipeline flow resistance and local resistance losses. During subsequent water collection operations, the controller will calculate the flow resistance index in real time. Compared to the resistance index benchmark Dynamic comparison is performed, and when the instantaneous deviation of the ratio exceeds 15%, physical blockage induced by particle migration is determined to have occurred. Interference from differences in equipment installation location or fluctuations in pipeline length on the blockage determination logic is eliminated, ensuring that the water collection network maintains a seepage flow continuity state during long-term operation. In the aforementioned stripping process, the system, based on the total length of the water collection network and the internal parameters of the design pipe diameter recorded in the survey, substitutes the Darcy-Weisbach theoretical formula to output constant flow resistance benchmark data. Simultaneously, it collects digital feedback signals of the actual opening degree of various throttling valve cores in the pipeline network. The local resistance coefficient quantification value corresponding to the address matching in the experience base is used. The two resistance losses are superimposed and directly subtracted from the total pressure difference, so that the resistance identification focus is limited to the heterogeneous interface side. Based on the fluid mechanics pipeline resistance change identification principle, the low-frequency baseline drift caused by long-term operation wear or pipe wall scaling of the bidirectional variable frequency pump is removed. The controller performs a real-time online baseline calibration procedure according to the above comparison results, extracts the rate of change of the flow resistance index within a preset 10-minute sliding window, and sets a fixed sampling step size of 10 seconds to extract the real-time flow resistance index at the current moment. and the historical flow resistance benchmark 10 minutes prior. ; Calculate the real-time flow resistance index Compared with historical flow resistance benchmark Numerical difference; divide the numerical difference by the historical flow resistance benchmark. The corresponding percentage quantization parameter is output, and the generated percentage quantization parameter is determined as the rate of change of the flow resistance index in the control logic. When the rate of change exceeds the preset 15% resistance mutation threshold for three consecutive sampling periods, the controller outputs a reverse voltage signal to the bidirectional variable frequency pump drive circuit to generate a hydraulic oscillation pulse. The time domain differential conversion step eliminates the data floor noise introduced by the environmental slow change factors. The condition for triggering the positive pressure backwash physical action is limited to the high-frequency transient clogging event caused by particle bridging at the heterogeneous infiltration interface, ensuring the safety of the mechanical structure under extreme working conditions.

[0041] Example 6: In a large-scale karst surface-subsurface combined water storage project containing multiple water collection units, the system collects transient matrix potential data of different topographic locations through a distributed tension sensor array. The controller assigns spatial weighting coefficients based on the water collection contribution of each confluence node's micro-topography. ,in This refers to the ratio of the catchment area corresponding to the node to the total catchment area. When the weighted average vertical permeability flux is detected to be greater than the preset critical infiltration threshold of the dominant fractures in the surface karst, the electromagnetic control valves corresponding to each catchment node receive a coordinated scheduling command to adjust the lateral hydraulic gradient. This clustered management mode extends single-point monitoring to synchronous reconstruction of the regional seepage field, eliminating the catchment dead zone caused by local permeability heterogeneity. This allows water to be controlled and converged into the main catchment network during cross-interface transport. Since the underground heterogeneous karst funnel system cannot rely on topographic contour lines to delineate the projection section, the catchment network releases environmentally friendly salt tracers to specific nodes during the trial operation and commissioning phase and performs constant flow pumping measurements at the system edge. By measuring the time lag of the solute peak captured by the response node, the effective influence radius circle corresponding to the hydraulic connectivity is drawn by inverse inversion. The equivalent area square, which has been substantially verified by the water flow field, is brought into the weight allocation calculation pool.

[0042] When the system determines that the air resistance is critical and cuts off the negative pressure source, the shutdown duration of the fluid drive unit in intermittent pulse mode is determined. The controller adjusts the slope of the matrix potential recovery based on real-time data. A first-order exponential decay prediction model was constructed to simulate the capillary self-healing process of the interfacial liquid phase. Satisfies the calculation formula: ,in, The estimated shutdown duration, These are characteristic parameters of capillary conduction in the medium. This is the intake value for the medium. The target matrix potential value in the liquid phase recovery region. To cut off the initial matrix potential value at the moment of negative pressure during the shutdown period, the controller scans the sensor feedback and corrects the characteristic parameters with a sampling period of 30 seconds. The real-time deviation is monitored until the transient matrix potential data recovers to the upper limit of the preset liquid phase recovery range. The fluid drive unit then restarts pumping and outputs a hydraulic pulse to the interface to disturb the gas-liquid boundary layer. This process transforms static time-waiting into dynamic control based on physical response, resolving the nonlinear hysteresis contradiction in the gas-liquid phase transition process and maintaining liquid connectivity within the water-collecting medium layer. During this process, the capillary conduction characteristic parameters of the medium are invoked. The inverse of the natural relaxation rate, which essentially characterizes the hydraulic reperfusion of the soil matrix, is used to ensure the successful initial convergence of the exponential decay model. During the startup phase, the controller extracts the existing saturated permeability parameter of the medium and divides it by the calibrated porosity constant. Based on this, a quantitative value characterizing its intrinsic capillary adsorption capacity is calculated and assigned to it. Used as a pre-cooling start-up reference coordinate for the first sampling period.

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A multi-interface adaptive water collection method for karst mountainous areas, characterized in that, Includes the following steps: Step 101: Bury a water collection medium layer at the heterogeneous permeation interface and deploy a tension sensing array at the heterogeneous permeation interface. Step 102: Collect transient matrix potential data, which characterizes the water state at the heterogeneous permeation interface, fed back by the tension sensing array. Step 103: Compare the transient matrix potential data with the preset medium inlet value; when the transient matrix potential data is less than the medium inlet value, determine that the heterogeneous permeation interface is in a liquid phase conduction state; when the transient matrix potential data is greater than or equal to the medium inlet value, determine that it is in a critical state of gas resistance. Step 104: Adjust the output pressure value of the fluid drive unit according to the judgment result; when the gas resistance critical state is judged, adjust the fluid drive unit to enter the intermittent pulse mode, and cut off the negative pressure source to make the transient matrix potential data rise back to the preset liquid phase recovery range, so as to restore the liquid phase continuity inside the water collection medium layer. Step 105: Collect the real-time pressure and instantaneous flow rate of the water collection channel and calculate the flow resistance index. When the rate of change of the flow resistance index exceeds the preset resistance mutation threshold, adjust the fluid drive unit to generate hydraulic oscillation pulses, and destroy the particle blockage structure at the heterogeneous infiltration interface through positive pressure feedback.

2. The multi-interface adaptive water collection method for karst mountainous areas according to claim 1, characterized in that, The process of determining the preset medium inlet gas value in step 103 includes the following sub-steps: Step 1031, inject test gas into the heterogeneous permeation interface and collect the moisture characteristic curve at the test interface. Step 1032: Obtain the inflection point pressure value corresponding to the decrease in water content on the moisture characteristic curve, and determine the inflection point pressure value as the medium intake value.

3. The multi-interface adaptive water collection method for karst mountainous areas according to claim 1, characterized in that, The cutoff time of the intermittent pulse mode in step 104 is based on the rise slope of the transient matrix potential data. Confirmed, rising slope The calculation logic is as follows: ,in, The matrix potential value at the initial moment of negative pressure adjustment. This marks the start of negative pressure regulation. This represents the matrix potential value at the time of detection after negative pressure adjustment. The time to be tested.

4. The multi-interface adaptive water collection method for karst mountainous areas according to claim 3, characterized in that, In step 104, the slope of the rise When the pressure drops to the preset saturation equilibrium threshold of 0.05 kPa / min to 0.15 kPa / min, the fluid drive unit is adjusted to restore the target pressure value mapped by the transient matrix potential data.

5. The multi-interface adaptive water collection method for karst mountainous areas according to claim 1, characterized in that, The process of deploying the tension sensor array in step 101 includes the following sub-steps: Step 1011, deploying multiple tension meter nodes along the horizontal direction at the heterogeneous permeation interface; Step 1012, connecting each tension meter node to the water collection medium layer through a manifold.

6. The multi-interface adaptive water collection method for karst mountainous areas according to claim 1, characterized in that, The triggering logic for generating hydraulic oscillation pulses in step 105 is as follows: when the rate of change of the flow resistance index within a preset 10-minute window exceeds the preset resistance mutation threshold, the fluid drive unit is adjusted to switch to the reverse rotation state.

7. A multi-interface adaptive water collection method for karst mountainous areas according to claim 6, characterized in that, The peak pressure of the hydraulic oscillation pulse is set to 1.2 to 1.5 times the rated pressure of the fluid drive unit under negative pressure suction.

8. The multi-interface adaptive water collection method for karst mountainous areas according to claim 1, characterized in that, The water collection medium layer is composed of graded filter material filled in the fissures of the heterogeneous permeable interface. The particle size distribution of the graded filter material ranges from 0.075 mm to 2.0 mm.

9. A multi-interface adaptive water collection method for karst mountainous areas according to claim 1, characterized in that, Before step 102, the process also includes: collecting the penetrating raindrop kinetic energy parameters below the vegetation canopy; when the penetrating raindrop kinetic energy parameters are greater than a preset threshold and the current vertical infiltration flux has not reached the infiltration threshold, adjusting the dredging valve of the surface diversion channel to open and guide the surface runoff into the main water collection network.

10. A multi-interface adaptive water collection method for karst mountainous areas according to claim 1, characterized in that, The process of adjusting the output pressure value in step 104 also includes: adjusting the operating frequency of the fluid drive unit to fluctuate between 20Hz and 50Hz based on the spatiotemporal deviation of the permeability of the heterogeneous permeation interface, so that the negative pressure suction rate matches the capillary replenishment rate of the medium.

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