Groundwater water level elevation measurement method, groundwater water storage measurement system, and application

Abstract

To disclose a groundwater water level elevation measurement method, groundwater storage measurement system, and application.SOLUTION: According to a groundwater water level elevation measurement method in one aspect of the present invention, after boring at a measurement site, a permeable cylinder is placed therein so as to ensure that groundwater water enters the permeable cylinder, a water inlet of an aqueduct extends at or below a liquid level in the cylinder, a water outlet is led to the ground, a stable drainage flow rate is detected, and a water level elevation at the water inlet is measured and calculated according to a formula. A groundwater storage monitoring and measurement system according to one aspect of the present invention layouts a matrix of water level monitoring point matrix, measures and collects groundwater level elevations at all sites and related data, and constructs water storage feature data of a groundwater measurement space. The present invention is a new technological plan that makes it possible to measure a groundwater level elevation by using a groundwater flow rate, has high technological adaptability, and enables a direction of groundwater monitoring technological improvement to be changed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a geological environment monitoring measurement technology, in particular to a monitoring device and system for groundwater-related physical variables, which belongs to the technical field of groundwater environment monitoring measurement. [Background technology]

[0002] Groundwater level is the most common and most important element of groundwater monitoring. At present, the monitoring of groundwater level is generally performed by observing and measuring in a "deep burial" manner. There are two main instruments for automatically measuring groundwater level: float type and pressure type. Float type groundwater level gauges can generally operate in logging pipes with a diameter of 5cm to 10cm, but the sensitivity of detecting water level changes of small floats is relatively poor, and the sensitivity of water level detection is very susceptible to the objective operating conditions such as the buried depth of groundwater being relatively large and the span line being long. Pressure type water level gauges have a higher measurement accuracy than the former, but the quality of the measurement data depends on the water environment of the monitoring site. By measuring under favorable conditions such as relatively low sediment content and relatively stable water density, the results are better. The prior art's groundwater level measuring device and method under negative pressure conditions (ZL2014105963763), groundwater level visualization measuring method under negative pressure conditions (ZL2014106122303), groundwater level seal measuring device and method based on ultrasonic negative pressure (ZL2015107451162), water level measuring device and method in vacuum pre-pressure ground reinforcement area (ZL2006100853372) etc. partially overcome the deficiencies of the above two measuring methods by introducing technical features such as negative pressure and vacuum, but do not change the basic characteristics of the technical concept. The main working parts of the measuring device (such as measuring sensing members) work inside the rock body, and technological improvements are constantly striving to capture and collect more minute water level changes at the measuring site. This basic characteristic causes some obvious technical defects, including: first, the improvement of measurement technology can only result in a continuous increase in the cost of equipment at the expense of more precise instruments; second, in order to ensure the sensitivity of the measurement sensing components, the selection of monitoring sites needs to take into account the rock topography conditions more, which may result in the sacrifice of important but difficult-to-construct monitoring points; third, the controllability of external measurement operations is limited; and fourth, the main underground operating parts are difficult to inspect and repair, and once destroyed, they have no choice but to be abandoned, which directly results in various costs such as relatively high equipment, construction, etc. Summary of the Invention

[0003] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to address the shortcomings of the prior art by providing a groundwater monitoring measurement technique in which the main operating portion of the measurement device is above ground level.

[0004] To achieve the above object, the present invention first provides a method for measuring groundwater level elevation, the technical solution of which is as follows:

[0005] The method for measuring the groundwater level is to drill a hole in the measurement area and place a permeable tube in it, ensure that groundwater enters the permeable tube, and ensure that the inlet of the water conveyance pipe is below the liquid level in the permeable tube, and the outlet of the water conveyance pipe is led to the ground. When the water is steadily discharged from the outlet, the water level at the inlet can be calculated by the simultaneous equations in Equation 1. a Measure and calculate the In the formula JPEG2025079754000002.jpg7170JPEG2025079754000003.jpg36170, h a - is the water level elevation at the water inlet, m; h a1, h a2 - h a is the intermediate quantity calculated, m, k- is the computational intermediate quantity, e - a calculated intermediate quantity, f - is a calculation intermediate quantity, H - the maximum head height that the measured natural atmospheric pressure can provide, in m, either empirical or measured and recorded; h c - the maximum elevation of the top of the water pipe, m; experimental parameters / measurement data; h b - the water level elevation at the outlet, in meters, to be measured and recorded; S b - the flow velocity at the outlet of the water pipe, in m / s, measured and recorded; g - gravitational acceleration, m / s 2 and is a constant, λ - the longitudinal resistance coefficient of the water conduit, determined according to the prior art; C - length of the water conduit, m; j - inner diameter of the water conduit, m - experimental parameter, η - local resistance coefficient of the water conduit, characterized in that it is determined according to conventional techniques.

[0006] The above-mentioned method for measuring groundwater level elevation is a technical proposal based on the communicator principle, which guides groundwater to the surface to carry out measurement. Due to the complexity of the groundwater "buried" environment, in order to realize measurement of underground water level on the surface using the communicator principle, it is necessary to consider the effect of the siphon head on the surface water flow rate. A large amount of experimental research prior to the present invention has shown that in a measurement system built using the communicator principle, the liquid flow rate in the water pipe is not determined by the difference in the height of the liquid level at both ends of the water pipe, but is determined by H and the siphon head H of the water pipe. o It was found that the difference between the elevation of the water pipe and the elevation difference between the water pipe and the water outlet of the water pipe is both influential. Based on the analysis model of this influence, the present invention provides a technical solution different from the above-mentioned traditional "deep burial" method of measurement.

[0007] The above-mentioned method for measuring groundwater level elevation is applicable when the pressure of the inlet of the water conduit is obviously higher than that of the outlet. In some operating conditions, when the water cannot be automatically discharged stably after the equipment is installed, the optimization of the above-mentioned measuring method is to introduce a negative pressure device. Specifically, the outlet of the water conduit is connected to a negative pressure device, and the negative pressure device is used to create a pressure difference between the openings of both ends of the water conduit, which induces the water outflow of the outlet and stabilizes the pressure. After the water is discharged stably from the outlet, the water level elevation h of the inlet is calculated according to the formula 2. a Measure and calculate.

[0008] In the JPEG2025079754000004.jpg9170 formula, y b - Pressure stabilization value of the negative pressure device (kpa), which is measured and recorded; μ - Density of groundwater (kg / m 3 ) which can be measured and recorded or can be a constant.

[0009] The present invention further uses the optimized design of the device in the technical measurement method, and includes the following aspects:

[0010] The permeable pipe adopts a coaxial multi-layered elastic sleeve structure, the walls of each layer of the sleeve are permeable to the permeable holes, and the permeable holes are as fine as possible, thereby reducing the disturbance of the water supply. There is a tapered permeable stone at the end of the core layer sleeve of the permeable pipe. The outer walls of each layer of the sleeve (11) and the outer circumference of the tapered permeable stone are both wrapped with highly permeable fabric. The inner diameter of the water pipe is less than 4mm.

[0011] In order to ensure the measurement effect, when drilling and installing the permeable tube, the permeable rock should extend 3.5 m to 6.5 m below the groundwater level, and when installing the equipment, ensure that there is as large an elevation difference as possible between the inlet and outlet of the water conveyance pipe.

[0012] The method for measuring groundwater level elevation of the present invention can be carried out as long as the pipeline is open. After the pipeline is filled and the water is discharged stably, there is no specific requirement for the amount of water discharged each time the measurement is performed, and the water discharge can be stopped when the flow rate is detected. Therefore, when a high-precision micro liquid flow rate meter is adopted, an extremely thin water pipe can be used, and the S b The detection is completed instantly and the disturbance to the groundwater level is extremely small and can be neglected.

[0013] Based on the above-mentioned method for measuring groundwater level elevation, the present invention also provides a groundwater storage volume monitoring and measurement system, and the technical solution is as follows:

[0014] The groundwater storage monitoring system defines a groundwater measurement space and measures the permeability of the watershed rock and soil, hydraulic gradient, and topographic gradient to determine the measurement area A in the measurement space. i Determine and design all A i 3D measurement dot matrix A 3D The above-mentioned method for measuring groundwater level elevation is used to construct all A i Groundwater level elevation data h at different points in time t aiMeasure and collect the dot matrix A 3D A data set D is obtained, and the data set D is a dot matrix A 3D Each h in ai and its corresponding A i The set D includes the number, spatial coordinates, and time, and is characterized in that the set D is used to construct water storage characteristic data of the groundwater measurement space.

[0015] In the above groundwater storage volume monitoring measurement system, according to different sets of data D, the storage volume characteristic data of the groundwater measurement space may be dynamic and / or static data / graphics / models / equations, etc.

[0016] The present invention further provides an application scheme for the above-mentioned groundwater storage monitoring and measurement system.

[0017] The application of the above-mentioned groundwater storage volume monitoring and measurement system is used for groundwater monitoring and early warning, and is characterized in that the groundwater storage volume monitoring and measurement system is used to monitor changes in groundwater characteristics and issue warning information according to preset conditions.

[0018] In the above application scheme, the groundwater monitoring early warning may further include a water quality detection device, which simultaneously realizes the function of detecting groundwater quality and issuing warning information according to preset conditions.

[0019] Compared with the conventional technology, the beneficial effects of the present invention are as follows: (1) The groundwater level measurement method of the present invention is a new concept different from the conventional "deep burial" and "in situ measurement" technical framework. On the basis of solving the key technical problem in the problem of using the communicator principle to measure groundwater level elevation by drainage flow velocity on the ground, which is the difference value between the maximum lift height that the measured natural atmospheric pressure can provide and the siphon head of the aqueduct, and the elevation difference value between the supply and drainage outlets of the aqueduct, which need to be measured and calculated, both affect the liquid flow velocity in the aqueduct, the present invention provides a new groundwater level measurement technical solution. (2) Since the outlet flow velocity is adopted as the monitoring index, the technical solution can improve the measurement accuracy at a relatively low technical cost by introducing the mature technology of conventional flow velocity detection into the measurement system. Compared with the conventional measurement technology improvement means of improving the sensitivity to the fluctuation of the underground part liquid level at the expense of the degree of precision of the equipment or the creation of a small environment for closed underground measurement, the technical solution has obvious advantages. (3) This technology can reduce the equipment precision of the underground operating part to a certain extent, thereby easing the installation conditions, and the technology also enhances the controllability of the ground measurement operation. Therefore, the whole technology has better adaptability. (4) This technology can effectively avoid the cost loss caused by the damage inspection and repair of the underground operating part. [Brief description of the drawings]

[0020] [Figure 1] This is an example of a schematic plan view of the groundwater level monitoring points in the monitoring area. [Diagram 2] This is an example of a schematic diagram of the groundwater storage monitoring measurement system structure. [Diagram 3] FIG. 2 is a schematic diagram of the external structure of the water permeation tube (each layer sleeve extended state). [Figure 4] FIG. 4 is a schematic diagram of the cross-sectional structure of FIG. [Diagram 5] This is an example of a schematic diagram of the three-dimensional groundwater level elevation in the groundwater measurement space of the monitoring area (the arrow in the diagram indicates the groundwater level surface). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] In the following, preferred embodiments of the present invention will be further described in conjunction with the drawings.

[0022] Example 1 As shown in Figures 1 to 5, the method of the present invention is used to design a groundwater monitoring system scheme for a small watershed, which is used to measure groundwater elevation and estimate water storage level.

[0023] 1. Watershed site survey and meter layout The small watershed studied (hereafter referred to as the monitoring area) is located in Fenghua City, Zhejiang Province. The whole watershed is trumpet-shaped, with a watershed area of ​​0.17 km2. 2 and groundwater resources are abundant.

[0024] Basic data is obtained through on-site investigation, including the permeability of rock soil in the monitoring area, hydraulic gradient, topographic gradient, etc. Based on the basic data, the area where the topography is small and relatively flat and where drilling is easy to carry out is selected as the measurement area, and a drilling installation layout method is adopted. According to the on-site drilling construction conditions and hydrogeological conditions, since the monitoring area is relatively small and the geological structure is relatively uniform, the drilling interval is set to 20m, and more drilling points (shown in Figure 1) are added in the corresponding areas with relatively large topographic changes. Each drilling point A i Mark and coordinate A (x,y,z) Corresponding to all A i 3D measurement dot matrix A 3D Configure.

[0025] FIG. 2 is a schematic diagram of the structure of the groundwater storage volume monitoring measurement system, FIG. 3 is a schematic diagram of the structure of the permeable tube, and FIG. 4 is a schematic diagram of the AA cross-sectional structure of FIG.

[0026] The permeable tube (1) has a coaxial elastic sleeve structure, the walls of each layer sleeve (11) extend to the permeable holes (12), the end of the core layer sleeve (13) has a tapered permeable stone (14), and the outer wall of the sleeve (11) and the outer circumference of the tapered permeable stone (14) are wrapped with a highly permeable fabric. In this example, geotextile is selected as the highly permeable fabric.

[0027] The permeable tube (1) is placed in the borehole, and the permeable stone (14) is ensured to extend 3.5 m to 6.5 m below the groundwater level. When the core layer sleeve (13) is submerged in groundwater, the water conveyance pipe (2) extends into the permeable tube (1), and the water inlet (21) is submerged below the liquid level in the core layer sleeve (13). The outlet (22) of the water conveyance pipe (2) is laid above ground and connected to the flow rate measuring device (4). It is ensured that there is an elevation difference between the water inlet (21) and the outlet (22) of the water conveyance pipe (2), and the elevation of the outlet (22) is as lower as possible than the water inlet (21). In this example, a high-precision micro liquid flow rate meter is selected as the flow rate measuring device (4).

[0028] Test whether water can be discharged naturally and stably from the drains (22) of each monitoring point. The monitoring points from which water can be discharged stably are classified as Class A points, and the rest as Class B points.

[0029] 2. Monitoring point groundwater level measurement The groundwater level elevation of each monitoring point is measured, where the A-class points are applicable to measurement plan A, and the B-class points are applicable to measurement plan B. Below, the measurement process of the two measurement plans A and B is described using one of the two types of points A and B as an example. Except for the technical explanation, the measurement method of the same type of points is the same.

[0030] 2.1 Measurement method A For the A monitoring point of the sample, various data are collected. Here, the longitudinal resistance coefficient λ of the water conduit is calculated and determined according to the conventional technology (determined by experience), the local resistance coefficient η of the water conduit is actually measured and determined, and the flow velocity S of the drainage outlet bis measured when water is steadily discharged from the drain. Each parameter is substituted into the simultaneous equation in Equation 1 to calculate (g = 9.8 m / s 2 ). Relevant data are shown in Table 1.

[0031] 2.2 Measurement method B For the B monitoring point of the sample, the drain outlet (22) of the water conduit (2) is connected to the negative pressure device (3). The negative pressure device (3) is adjusted to create a pressure difference between both ends of the water conduit (2), inducing water to flow out of the drain outlet (22) and stabilizing the negative pressure. When water is steadily discharged from the drain outlet (22), the reading of the negative pressure device (3) becomes y b , the flow velocity S of the drain (22) b Other data collection methods are the same as in part 2.1.

[0032] Substitute each parameter into Equation 2 and calculate (g = 9.8 m / s 2 ). Relevant data are shown in Table 1.

[0033] Table 1. Data related to groundwater elevation measurements at monitoring points for Sample A and Sample B JPEG2025079754000005.jpg97170

[0034] 3. Draw a three-dimensional map of the groundwater level in the watershed Dot Matrix A 3D All A's in i Groundwater level elevation data for point h ai Collect the dot matrix A 3D We obtain a groundwater data set D for each monitoring point A. i Groundwater elevation value h ai , each A i The data includes the number, spatial coordinates, and measurement time t, and describes the groundwater characteristics of the monitoring area.

[0035] The water storage characteristic data of the groundwater measurement space is constructed using set D, which is specifically as follows: i Groundwater level elevation data h aiAn interpolation calculation is performed to obtain a three-dimensional groundwater level elevation diagram of the groundwater measurement space of the monitoring area. Figure 5 is a three-dimensional groundwater level elevation schematic diagram of the groundwater measurement space of the monitoring area, and the arrows in the figure indicate the groundwater level. i h ai By collecting the values, a groundwater dynamic model in the groundwater measurement space of the monitoring area can be established. The groundwater storage volume in the groundwater measurement space of the monitoring area can be measured and calculated based on the three-dimensional model.

[0036] 4. Expanding the early warning function of the groundwater storage monitoring system In the groundwater storage monitoring measurement system, a monitoring threshold condition can be added in the host computer, and each item of real-time monitoring data or pre-calculated value can be compared with the threshold value to perform a preliminary evaluation of the groundwater change and issue an early warning signal according to the preset conditions when necessary. A water quality detection unit can be added to further detect the safety of groundwater quality and also issue an early warning signal according to the preset conditions when necessary. [Explanation of symbols]

[0037] 1 Water tube 11 Sleeve 12 Water hole 13 Core layer sleeve 14 Translucent stone 2. Water Pipe 21 Water inlet 22 Drain port 3. Negative pressure device 4 Flow velocity meter 5 Groundwater level 6 Soil body / soil layer

Claims

1. A method for measuring groundwater level elevation, comprising the steps of: boring a measurement site and placing a permeable cylinder (1) in the measurement site; making sure that groundwater enters the permeable cylinder (1); making the inlet (21) of the water conveyance pipe (2) extend below the liquid level in the permeable cylinder (1); making the outlet (22) of the water conveyance pipe (2) lead to the ground; when water is steadily discharged from the outlet (22), the water level elevation h of the inlet (21) is calculated by the simultaneous equations of Equation 1. a Measure and calculate the In the formula, h a - water level elevation of the water inlet (21), m; h a1, h a2 - h a is an intermediate calculation quantity, m is k - a computational intermediate quantity, e - a calculation intermediate quantity, f - a computational intermediate quantity, H - the maximum head of water that can be provided by the measured natural atmospheric pressure, in m, either empirical or measured and recorded; h c - the maximum elevation of the top of the water conduit (2), m; experimental parameters / measurement data; h b - water level elevation of the drain (22), in meters, to be measured and recorded; S b - the flow velocity at the outlet (22) of the water conduit (2), in m / s, measured and recorded; g - gravitational acceleration, m / s 2 and is a constant, λ - the longitudinal resistance coefficient of the water conduit (2), determined according to the prior art; C - length of the water conduit (2), m, experimental parameter; j - the inner diameter of the water conduit (2), m is an experimental parameter, η - local resistance / head loss coefficient of the aqueduct (2), determined according to conventional techniques.

2. The drainage outlet (22) of the water conduit (2) is connected to the negative pressure device (3), and the negative pressure device (3) is used to create a pressure difference between the openings at both ends of the water conduit (2), inducing water to flow out of the drainage outlet (22) and stabilizing the pressure. When the water is steadily discharged from the drainage outlet (22), the indication y of the negative pressure device (3) ｂ The flow rate of the water from the drain outlet (22) S ｂ The water level elevation h of the water supply inlet (21) is recorded according to the formula 2. a Measure and calculate the In the formula, y ｂ - the pressure stabilization value of the negative pressure device (3), in kpa, measured and recorded; μ - density of groundwater, kg / m 3 2. The method of claim 1, wherein the water level elevation is measured and recorded or is a constant.

3. Using a micro liquid flow meter ｂ Once S ｂ 3. The method for measuring water level elevation according to claim 1, further comprising the step of immediately closing the drain outlet (22) when the water level elevation is recorded.

4. The water level elevation measuring method according to claim 3, characterized in that the water permeable tube (1) is a coaxial multi-layered telescopic sleeve structure, the wall of each layer sleeve (11) extends to a water permeable hole (12), and there is a tapered water permeable stone (14) at the end of the core layer sleeve (13), and the outer wall of the sleeve (11) and the outer circumference of the tapered water permeable stone (14) are wrapped with a highly permeable fabric.

5. 5. The method for measuring water level elevation according to claim 4, wherein the inner diameter j of the water conduit (2) is ≦4 mm, and the hole diameter of the water permeable hole (12) is 5 mm or less.

6. The water level elevation measuring method according to claim 5, characterized in that, when drilling and installing the permeable tube (1), the permeable stone (14) extends 3.5 m to 6.5 m below the groundwater liquid level, and when installing the equipment, it is ensured that there is an elevation difference between the water supply inlet (21) and the drain outlet (22) of the water conveyance pipe (2).

7. A groundwater storage monitoring system, which defines a groundwater measurement space and measures the permeability, hydraulic gradient and topographical gradient of the monitoring area rock and soil to determine a measurement site A in the measurement space. ｉ Determine and design all A ｉ 3D measurement dot matrix A ３Ｄ The method for measuring groundwater level elevation according to claim 6 is used to measure all A ｉ Groundwater level elevation data h at different points in time t ai Measure and collect the dot matrix A ３Ｄ A data set D is obtained, and the data set D is a dot matrix A ３Ｄ Each h in ai and its corresponding A ｉ The groundwater storage volume monitoring and measurement system is characterized in that the set D includes a number, spatial coordinates, and time, and uses the set D to construct water storage volume characteristic data of the groundwater measurement space.

8. The groundwater storage monitoring measurement system of claim 7, wherein the groundwater storage volume characteristic data of the groundwater measurement space includes dynamic and / or static data / graphics / models / equations.

9. An application of the groundwater storage volume monitoring and measurement system as described in claim 7, which is used for groundwater monitoring and early warning, and is characterized in that the groundwater storage volume monitoring and measurement system is used to monitor changes in groundwater characteristics and issue warning information according to preset conditions.

10. The application of claim 9, further comprising a water quality detection device for detecting groundwater quality, and issuing warning information according to a preset condition.

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