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CN-121977988-A - Research device and method for water penetration rate of in-situ rock-soil interface of stony desertification area

CN121977988ACN 121977988 ACN121977988 ACN 121977988ACN-121977988-A

Abstract

The invention relates to the technical field of hydrologic process monitoring and soil moisture migration research in a stony desertification region, and discloses a research device and a method for the moisture permeation rate of an in-situ rock-soil interface in the stony desertification region, wherein a water inlet device comprises a water tank, a rotor flowmeter and a connecting pipeline, and the water tank is arranged at a position higher than the rotor flowmeter; the invention provides a controllable rock surface flow generating device, which is characterized in that the controllable rock surface flow generating device is realized under the condition of a complex rock-soil interface, a reliable technical platform is provided for in-situ moisture permeability measurement, and the technical bottlenecks that the existing device cannot simulate rock surface confluence and is difficult to adapt to a heterogeneous interface are overcome.

Inventors

  • YANG CHENXI
  • PENG XUDONG
  • Dai quanhou
  • WANG TIELIN
  • AN DI

Assignees

  • 贵州大学

Dates

Publication Date
20260505
Application Date
20260228

Claims (10)

  1. 1. A research device for the water penetration rate of an in-situ rock-soil interface in a stony desertification region, which is characterized by comprising: The water inlet device comprises a water tank (11), a rotameter (9) and a connecting pipeline, wherein the water tank (11) is arranged at a position higher than the rotameter (9) so as to form gravity-driven siphon water supply; The water outlet device (3) comprises a water inlet, an internal steady flow cavity and a plurality of water outlet small holes (8) which are uniformly distributed along the length direction, wherein the water inlet is arranged at the lower part of the steady flow cavity and is connected with the connecting pipeline, and the water outlet small holes (8) are arranged at the upper part of the steady flow cavity so that water body can synchronously and uniformly overflow from each water outlet small hole (8) after water level lifting and water pressure homogenization are completed in the steady flow cavity; the bracket (4) is used for fixing the water outlet device (3) at the upper part of the exposed rock surface, so that the water outlet small holes (8) are closely distributed on the rock surface to form continuous and stable rock surface flow on the rock surface; the length of the water outlet device (3) is adapted according to the actual length of the exposed rock face, and the height of the support (4) is adapted according to the actual height of the exposed rock face.
  2. 2. The research device for the in-situ rock-soil interface water penetration rate of the stony desertification area according to claim 1, wherein the length of the water outlet device (3) is set to be 0.5-2.0 m, and the diameter of the water outlet small hole (8) is set to be 10mm.
  3. 3. The research device for the in-situ rock-soil interface water penetration rate of the stony desertification area according to claim 1, wherein the support (4) comprises a support rod (13) and a fixer (12), and the height of the support rod (13) is set to be 0.5 m-1.2 m.
  4. 4. The research device for the in-situ rock-soil interface water penetration rate of the stony desertification area according to claim 1, wherein the connecting pipeline comprises a connecting hose (10) and a water inlet hose (6), the water tank (11) is connected with the water inlet of the rotameter (9) through the connecting hose (10), and the water outlet of the rotameter (9) is connected with the water inlet through the water inlet hose (6).
  5. 5. The study device of the water permeation rate of the in-situ rock-soil interface of the stony desertification area according to claim 4, wherein the water outlet device (3) comprises a sectional water outlet hose (7) and a three-way joint (5), the three-way joint (5) is arranged at the middle position of the water outlet hose (7), and the water outlet hose (7) is connected with the water inlet hose (6) through the three-way joint (5).
  6. 6. A method for researching the water permeability of an in-situ rock-soil interface in a stony desertification region, which adopts the research device for researching the water permeability of the in-situ rock-soil interface in the stony desertification region according to any one of claims 1 to 5, and is characterized by comprising the following steps: the water supply system is established and is formed with steady flow of the rock surface, namely the water outlet device (3) is closely arranged on the rock surface with exposed rock, the water tank (11) is arranged at a position higher than the rotameter (9), a stable siphon water supply system is formed by utilizing gravity, and continuous and stable rock surface flow is formed on the rock surface with exposed rock after water flows through the rotameter (9) and the water outlet device (3); controlling rock surface flow through the rotameter (9), performing infiltration test from a preset minimum flow, increasing the flow step by step, observing the water migration condition of the rock surface flow after entering the rock-soil interface soil under each flow grade, judging that the super-osmotic flow does not occur if the soil surface does not form continuous and stable surface runoff, continuing to increase the flow, judging that the super-osmotic flow occurs if the soil surface forms continuous and stable surface runoff, and recording the critical flow; Measuring the following parameters, namely measuring the effective catchment area A RS of the exposed rock face, the critical flow Q, the equivalent rainfall intensity R, the runoff loss coefficient R LC , the expansion width W of the rock face flow on the soil surface after entering a rock-soil interface and the advancing distance L; Calculating the equivalent infiltration intensity of the rock face, namely when the super-infiltration production flow occurs in the soil at the rock-soil interface, considering that the input intensity of the rock face flow reaches the infiltration capacity of the soil at the rock-soil interface at the moment, the equivalent infiltration intensity R I of the rock face, Wherein R I represents the water input intensity over the effective catchment area of the unit rock face; the rock-soil interface water penetration rate is calculated by calculating the rock-soil interface water penetration rate I according to the following formula: , wherein, Is the equivalent infiltration strength of the rock face 。
  7. 7. The method for studying the water permeability of an in-situ rock-soil interface of a stony desertification area according to claim 6, wherein the same infiltration time is maintained under each stage of flow condition in the step of graded infiltration test and the step of super-infiltration product flow judgment, and the infiltration time is set to be 3min.
  8. 8. The method for studying the water permeability of an in-situ rock-soil interface of a stony desertification area according to claim 6, wherein in the step of parameter measurement, the effective catchment area A RS is calculated according to the geometric dimension of the exposed rock face, and the expansion width W and the advancing distance L are obtained through in-situ measurement.
  9. 9. The method for researching water permeability of in-situ rock-soil interface in stony desertification area as claimed in claim 6, further comprising determining surface runoff forming condition by taking water permeability I of said rock-soil interface as determination index when When the water quantity of the rock surface flow entering the soil surface is smaller than the infiltration capacity of the soil, no surface runoff is formed, when When the water quantity of the rock surface flow entering the soil surface exceeds the infiltration capacity of the soil, the surface runoff is formed, and the flow generation mechanism is super-infiltration flow.
  10. 10. The method for researching water permeability of in-situ rock-soil interface in stony desertification area according to claim 6, wherein under the condition that runoff loss coefficient R Lc =0, the calculation formula of water permeability I of rock-soil interface is simplified to 。

Description

Research device and method for water penetration rate of in-situ rock-soil interface of stony desertification area Technical Field The invention relates to the technical field of hydrologic process monitoring and soil moisture migration research in stony desertification areas, in particular to a research device and method for in-situ rock-soil interface moisture permeability rate in stony desertification areas. Background The karst stony desertification region is a typical representation of a southwest ecological fragile region in China, and the region has exposed large area of bedrock, extremely thin soil layer and even missing, and the soil is in direct contact with the bedrock to form a rock-soil interface with complex structure and clear boundary. The interface is affected by the rock surface shape, the fracture structure and the physical properties of the soil body, and the infiltration capacity of the interface is obviously higher than that of non-interface soil, so that the interface is an important channel for rapid infiltration and underground leakage of water in the process of rainfall and rock surface confluence. The method for accurately measuring the water penetration rate of the rock-soil interface has important scientific significance and practical value for revealing the hydrologic process of the stony desertification area, evaluating the underground leakage risk and guiding the ecological restoration engineering. The prior art has the following main defects: The conventional soil infiltration measuring method (such as a single-ring infiltration instrument and a double-ring infiltration instrument) is mainly suitable for continuous and flat soil layer conditions, and the working principle is that accumulated water is formed on the surface of homogeneous soil, and the infiltration rate is calculated by measuring the water level descending rate. However, the rock-soil interface structure of the stony desertification area is complex, the rock exposed surface and the soil are alternately distributed, the conventional method is difficult to stably arrange under the rock exposed condition, and the moisture permeability characteristic of the rock-soil interface under the in-situ condition can not be truly reflected. The conventional indoor simulation test carries out infiltration determination by manually preparing a rock-soil combined sample, but the indoor conditions are difficult to restore the complex rock surface morphology, crack development characteristics and in-situ soil structure in the field, the determination result has obvious deviation from the actual situation, and reliable data support cannot be provided for the hydrologic process research of the stony desertification area. The water input of the rock-soil interface mainly comes from rock surface confluence, but the prior art lacks a special device capable of stably generating controllable rock surface flow under the field in-situ condition, and cannot realize accurate regulation and control of the input intensity of the rock surface flow, so that quantitative determination of the infiltration capacity of the rock-soil interface lacks reliable hydraulic boundary conditions. In the prior art, the research on the water infiltration process of the rock-soil interface is stopped in a qualitative description stage, and a quantitative method for incorporating key parameters such as the effective water collecting area of the rock surface, the expansion range of the rock surface flow and the like into a computing system is lacked, so that the infiltration rate computing result is poor in comparability and low in repeatability. Disclosure of Invention The invention aims to provide a research device and a method for the water penetration rate of an in-situ rock-soil interface of a stony desertification area, and aims to solve or improve at least one of the technical problems, realize the stable generation of controllable rock surface flow under the condition of a complex rock-soil interface, provide a reliable technical platform for the in-situ water penetration rate measurement and overcome the technical bottlenecks that the existing device cannot simulate the confluence of rock surfaces and is difficult to adapt to heterogeneous interfaces. In order to achieve the aim, the invention provides a research device for the water permeation rate of an in-situ rock-soil interface of a stony desertification area, which comprises: the water inlet device comprises a water tank, a rotor flowmeter and a connecting pipeline, wherein the water tank is arranged at a position higher than the rotor flowmeter so as to form gravity-driven siphon water supply; The water outlet device comprises a water inlet, an internal steady flow cavity and a plurality of water outlet small holes uniformly distributed along the length direction, the water inlet is arranged at the lower part of the steady flow cavity and is connected with the connecting pipeline, and the water