Flood prevention block stone reserve high-precision measuring and calculating method

Abstract

The invention relates to a flood prevention block stone reserve high-precision measuring and calculating method, which comprises the following steps: aerial photography and three-dimensional modeling are carried out on the overground part of a flood prevention block stone by using two modes of unmanned aerial vehicle oblique photography and unmanned aerial vehicle laser radar, and the overground volume of the flood prevention block stone is measured and calculated; a ground penetrating radar is adopted to detect the settlement depth of the flood prevention block stone, the volume of the underground part of the block stone is calculated, the volume of the whole block stone can be obtained by adding the volume of the overground part of the flood prevention block stone and the volume of the underground part of the block stone, and the weight of the flood prevention block stone can be calculated. According to the invention, the reserve of the overground and underground parts of the flood prevention block stone can be accurately measured, and technical support is provided for flood prevention and emergency rescue.

Description

Technical Field

[0001] The invention relates to a high-precision calculation method for flood control block stone reserve, belonging to the technical field of water conservancy and flood control projects. Background Art

[0002] In order to effectively respond to the occurrence of flood disasters, effective preventive measures should be taken in disaster-prone areas. Through the preparation of various flood control materials, sufficient flood control materials can be provided for the first time to control the dangerous situation when the flood occurs, and then effective measures can be taken to control the dangerous situation, avoid the expansion of the dangerous area, and further maintain the stable development of society. Flood control block stone is one of the important materials for flood control and rescue. It plays an important role in emergency rescue work such as embankment breach and bank slope collapse. The reserve quantity of flood control block stone is crucial to ensure flood control safety. Therefore, it is necessary to survey the number of blocks before and after the flood every year to ensure that there are enough blocks of stone for rescue work when floods occur.

[0003] However, the current investigation of the number of flood control stones still has the following problems: (1) Currently, the amount of rock reserves is mainly calculated by manual measurement. However, some flood control rocks are piled irregularly, and the amount of rock reserves calculated by manual measurement is quite different from the actual amount of rock reserves. (2) Since most of the rocks are piled directly on the soil, they all settle due to their own weight, and conventional measurement methods are difficult to estimate the number of underground rocks. The overall settlement of the rocks is usually calculated by excavating the soil around the rocks, but the settlement in the middle of the rocks is often greater than the settlement at the edges of the rocks. The uneven settlement of the rocks will lead to a large deviation between the rock reserve calculated by conventional measurement methods and the actual rock reserve.

[0004] In view of the above problems, the present invention proposes a method for accurately calculating the amount of flood control rock reserves to improve the accuracy of rock reserve calculation. Summary of the invention

[0005] In order to solve the above problems, the present invention discloses a method for high-precision calculation of flood control block stone reserves, and its specific technical solution is as follows: A high-precision calculation method for flood control rock reserves comprises the following steps:

[0006] Step 1: Calibrate the volume measurement method of the above-ground part of the flood-control block stone: Use UAV oblique photography and UAV laser radar to take aerial photos of the above-ground part of the flood-control block stone and perform three-dimensional modeling. Measure and calculate the volumes of the three-dimensional models constructed by UAV oblique photography and UAV laser radar, which are V1 and V2 respectively. If the volume difference between V1 and V2 is within 5%, that is, |V1-V2|×100% / V1 is less than or equal to 5%, |V1-V2|×100% / V2 is less than or equal to 5%, it means that both the UAV oblique photography and UAV laser radar measurement methods are reliable. If the volume difference between the UAV oblique photography and UAV laser radar is greater than 5%, adjust the data resolution collected by the two measurement methods to improve the measurement accuracy until the volume difference between the UAV oblique photography and UAV laser radar is less than or equal to 5%. Step 2: Use the UAV oblique photography and UAV LiDAR calibrated in step 1 to measure the volume of the above-ground part of the flood-control block stones. The volume Vs of the above-ground part of the flood-control block stones is the average volume of the above-ground part of the flood-control block stones measured by the UAV oblique photography and UAV LiDAR, that is, Vs = (V1 + V2) / 2;

[0007] Step 3: Calibrate the depth measurement method of the underground part of the flood control block stone: For the underground part of the flood control block stone, use ground penetrating radar to detect its settlement depth. The specific process is as follows: First, at least three edge parts of the rock pile are selected, and the edge parts of the rock pile are preliminarily explored using a ground penetrating radar to obtain the total pile height h1 of the edge parts. After the soil at the edge of the rock pile is completely excavated, the total pile height h2 of the edge parts of the rock pile is measured using a ruler. The total pile height h1 measured by the ground penetrating radar is compared with the total pile height h2 measured by the ruler after excavation. If the difference between the two is greater than 5 cm, the propagation speed of the radar wave of the ground penetrating radar in the rock pile is adjusted, and the height of the rock pile is recalculated until the difference between the two is less than or equal to 5 cm. The propagation speed of the radar wave of the ground penetrating radar in the medium at this time is recorded, and then the radar wave parameters of this group of ground penetrating radar are used to detect the entire rock pile. Step 4: According to the 3D model of flood control rock generated by the drone, find the longest side L of the 3D model of flood control rock, arrange several ground penetrating radar detection sections perpendicular to the longest side, and arrange several detection points at equal intervals on each section, every 5m 2 Set up at least one detection point; Step 5: According to the radar wave parameters of the ground penetrating radar described in step 3, all detection points are detected point by point to obtain the total pile height Hz of the blocks at each detection point; Step 6: Extract the ground height Hs of these detection points from the three-dimensional model of flood control blocks generated by the drone; Step 7: Subtract the ground height Hs of each detection point from the total pile height Hz of the blocks of stone at each detection point to obtain the settlement value Hd of the blocks of stone at the detection point; Step 8: If the difference in the settlement value Hd between two adjacent detection points is greater than 10 cm, add a detection point between the two adjacent detection points and repeat steps 5-7;

[0008] Step 9: Finally, use the Kriging interpolation algorithm of the pykrige library in Python to interpolate the settlement values ​​Hd of all detection points, and then use the border filling algorithm (cv2.copyMakeBorder) in OpenCV to expand the interpolated settlement value to the block stone boundary area to obtain the settlement value Hd' covering the entire block stone area. Use the grid method to calculate the volume Vd of the underground part of the block stone: divide the entire block stone area into several square grids, and multiply the area of ​​each square grid by the settlement value Hdn' ​​corresponding to the grid to obtain the block stone volume Vd' corresponding to the grid. Add the block stone volume of each grid to obtain the volume Vd of the entire underground part of the block stone. Add the volume Vs of the above-ground part of the flood control block stone to the volume Vd of the underground part of the block stone to obtain the volume V of the entire block stone, and then calculate the weight M of the flood control block stone: (ton) In the formula, 0.95 is 0.95 times the actual measured volume according to the provisions of SL 297-2004, the Acceptance Standard for Flood Control Materials, also known as the volume correction coefficient; 1.7 tons is measured according to the standard of not less than 1.7 tons per cubic meter as stipulated in SL 297-2004, the Acceptance Standard for Flood Control Materials.

[0009] Furthermore, the specific process of the drone oblique photography to take aerial photos of the above-ground part of the flood control block stone and perform three-dimensional modeling is as follows: Data collection Step 1.1: According to the specific location of the stone, set the route and flight parameters, including flight altitude, heading overlap, lateral overlap, flight speed and gimbal angle; Step 1.2: Fly and take photos according to the route set in step 1.1. After the aerial photography is completed, the aerial photography data is obtained. The aerial photography data includes the photos taken, the flight parameters when the photos were taken, and the route position; Data preprocessing Step 1.3: Image POS processing: Compare the aerial photography data with the POS data, remove the test flight and test photography photos before the operation begins, ensure that the image and the POS are one-to-one corresponding, import the POS data into the aerial photography data, and form the image POS; Step 1.4: File management: save the image control points and image POS of each flight into a folder in the format of "project + date + flight" to facilitate later query management; Step 1.5: Data import: Import the aerial data and image POS pre-processed in step 1.3 into the DJI Terra modeling software, and accurately enter the camera parameters; Step 1.6: Aerial triangulation: ① Densely match the camera parameters, image data, and POS data to multi-view image feature points, perform joint constraint adjustment of the multi-view image regional network, establish a stereo model that can be freely deformed in spatial scale, and complete relative orientation; ② The photo control points obtained by field survey are transferred to the indoor environment, and the existing regional network model is constrained and adjusted using the photo control points. The regional network is incorporated into the coordinate system required by the project to complete absolute orientation. Transferring means finding and marking the photo control points measured in the field on the photos taken by the drone. Step 1.7: White model creation: Submit the result data processed by aerial triangulation in step 1.6 directly for TIN grid construction and white body 3D model creation; Step 1.8: Calculation of stone volume: After the 3D model is built, import the 3D model into the EPS 3D real scene model processing system, use EPS to accurately depict the boundaries of the stone, and then calculate the total area of ​​the flood control stone; Next, take points at equal intervals of 1m and record the three-dimensional coordinates of the points, including the longitudinal, transverse and pile height. Import the file containing the three-dimensional coordinates of all points into Southern CASS to calculate the volume of the stone block.

[0010] Furthermore, the expansion distance is set when the drone collects data. In order to capture all the rocks, the drone needs to expand a certain distance when taking aerial photos. The expansion distance satisfies: , Where: L is the expansion distance, m; H is the flight altitude, m; H1 is the height of the photographic reference surface, m; θ is the camera tilt angle; H2 is the height of the lowest point at the edge of the measurement area.

[0011] Furthermore, the specific process of the UAV laser radar performing three-dimensional modeling on the ground part of the flood control block stone is as follows: Step 1) Import data and preprocess data The drone can obtain high-precision point cloud data through its high-resolution camera and laser scanner. The point cloud data includes spatial position information, reflection intensity information and color information. By processing and analyzing the point cloud data, the three-dimensional shape, surface texture and height information of the object can be obtained. The source data exported after the flight, including point cloud, photos, GNSS, inertial navigation and base station data; Step 2) Data processing One-click processing: select the laser radar file directory, automatically identify the point cloud, photos, GNSS, inertial navigation and base station data in the folder, automatically generate point cloud data, and form a flood control block stone laser point cloud 3D model rendering; After the 3D model is built, calculate the volume of the stone according to step 1.8.

[0012] Furthermore, the measurement method of the ground penetrating radar is: select a radar transmitting point and a radar receiving point in the detection area, transmit the radar at the radar transmitting point, receive the radar signal at the radar receiving point, and record the time difference between transmission and reception: the distance between the radar transmitting point and the radar receiving point is x, the depth of the exploration target body in the detection area from the horizon between the radar transmitting point and the radar receiving point is z, and the time difference between radar transmission and radar reception is t.

[0013] Furthermore, the calculation process of the ground penetrating radar is: (1) Radar wave propagation time , In the formula: z is the depth of the target object; x is the distance between the transmitting and receiving antennas, where x is ignored because Z>x; V is the propagation speed of radar waves in the medium; (2) The propagation speed of radar waves in the medium, , Where: c—the propagation speed of radar waves in vacuum, taken as 0.29979m / ns, — relative dielectric constant of the medium, —Relative magnetic permeability of the medium, taken ; (3) Relationship between the propagation time of radar waves recorded by ground penetrating radar and the exploration depth , Where: z is the depth of the survey target; t—The travel time of the radar wave recorded by the radar.

[0014] The beneficial effects of the present invention are: The present invention provides a method for accurately calculating the reserve quantity of flood-control boulders, which can accurately measure the reserve quantity of the above-ground and underground parts of the flood-control boulders, and provide technical support for flood control and rescue operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a technical flow chart of the present invention. DETAILED DESCRIPTION

[0016] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0017] Combined with Figure 1 It can be seen that the present invention takes the selection of a certain flood prevention block stone reserve point as an experimental area as an example to introduce the principle of the present invention.

[0018] First, the drone was used to take aerial photos of the flood-control block stone ground using oblique photography and laser radar, and three-dimensional modeling was performed. The volumes of the three-dimensional models constructed by the two methods were measured and calculated to be V1 and V2 respectively. If the volume difference measured by the two methods is within 5%, that is, |V1-V2|*100% / V1 is less than or equal to 5%, and |V1-V2|*100% / V2 is less than or equal to 5%, it means that the two measurement methods are reliable. If the volume difference measured by the two methods is greater than 5%, the data resolution collected by the two measurement methods is adjusted to improve the measurement accuracy, so that the volume difference measured by the two methods is less than 5%. Next, the average volume measured by the two methods is taken as the volume of the flood-control block stone ground Vs=(V1+V2) / 2.

[0019] With regard to the underground part of the flood control block stone, the present invention adopts ground penetrating radar to detect its settlement depth.

[0020] Since it is impossible to move the above-ground part of the block stone and then use the ground penetrating radar for detection, the ground penetrating radar can only be used to detect the top of the block stone. The height of the block stone pile detected by the ground penetrating radar is the sum of its above-ground height and underground height, but its detection density is low. First, at least three edge parts of the block stone pile are selected, and the ground penetrating radar is used to conduct preliminary exploration of the edge part of the block stone pile to obtain the total pile height h1 of the edge part. Then, after the soil at the edge of the block stone pile is completely excavated, the height of the edge part of the block stone pile is measured with a ruler. The ground height Hs of these detection points is extracted from the three-dimensional model of flood control block stone generated by the drone. The pile heights h1 and h2 measured by the two methods are compared. If the difference between the two is large, that is, the difference between the two is greater than 5cm, the propagation speed of the ground penetrating radar radar wave in the block stone is adjusted to recalculate the block stone pile height until the difference between the two is less than 5cm. The parameters of the ground penetrating radar at this time (the propagation speed of the radar wave in the block stone) are recorded, and then this set of parameters is used to detect the entire block stone. Subtract Hs from the total height of the rocks at the edge, h2, to get the settlement value of the rocks at the detection point, Hd.

[0021] According to the three-dimensional model of flood control blocks generated by the drone, the longest side L of the model is found, and the ground penetrating radar detection section is arranged perpendicular to the longest side. The detection points are arranged at equal intervals on each section, and every 5m 2At least one detection point is set up. After the detection section position is determined, according to the detection section design requirements, first use a tape measure to measure and mark the stone blocks at a certain distance, and then use the GPS real-time phase difference RTK measurement method to measure to ensure the accuracy and completeness of the data. The detection section pile number is in meters and is marked with paint. According to the above-mentioned ground penetrating radar parameters, all detection points are detected point by point to obtain the total pile height Hz of the blocks at all detection points, and then the ground height Hs of these detection points is extracted from the three-dimensional model of flood control blocks generated by the drone. The settlement value Hd of the blocks at the detection point can be obtained by subtracting Hs from the total pile height Hz of the blocks.

[0022] If the difference in the settlement value Hd between two adjacent detection points is large (greater than 10cm), add a detection point between the two adjacent detection points. According to the above ground penetrating radar parameters, detect the newly added detection points point by point, obtain the total pile height Hz of the blocks at the newly added detection points, and then subtract Hs to obtain the settlement value Hd of the blocks at the newly added detection points.

[0023] Finally, the settlement values ​​Hd of all detection points are interpolated using the Kriging interpolation method, and then the interpolated settlement values ​​are expanded to the boundary area of ​​the block stone using the border filling algorithm to obtain the settlement value Hd' covering the entire block stone area. The volume Vd of the underground part of the block stone is calculated using Hd'. The volume Vs of the above-ground part of the flood control block stone is added to the volume Vd of the underground part of the block stone to obtain the volume V of the entire block stone. According to the "Flood Control Material Acceptance Standard" SL 297-2004, the weight M of the flood control block stone can be calculated.

[0024] (ton) In the formula, 0.95 is 0.95 times the actual measured volume according to SL 297-2004, also known as the volume correction factor, and 1.7 tons is measured according to the standard of not less than 1.7 tons per cubic meter as stipulated in SL 297-2004.

[0025] Here is another example of how to use oblique photography and laser radar to take aerial photos of the flood-control block stone ground and perform 3D modeling to measure the volume of the flood-control block stone ground: Example 1 introduces an example of drone tilt photography: Take a provincial flood control block as an example to illustrate the specific process of calculating the volume of blocks using the drone oblique photography method. The number of flood control blocks applied for review is 1,000 tons, and the number of on-site signs is 1,000 tons. The blocks are divided into 5 piles on site, neatly stacked, with a wide field of view without obvious obstacles and protected by fences.

[0026] Based on the size and accuracy requirements of the stone storage area, the DJI M300 drone equipped with a Zenmuse P1 lens with a speed of 15m / s was used for this operation.

[0027] Based on the scope of the survey area, the external expansion width is calculated to be 70m using the following formula.

[0028]

[0029] Where: L is the expansion distance, m; H is the flight altitude, m; H 1 is the height of the photographic reference surface, m; θ is the camera tilt angle; H 2 is the height of the lowest point at the edge of the measurement area.

[0030] Set the route according to the above parameters and the specific location of the stone blocks, fly along the set route and take photos. After the aerial photography is completed, import the aerial photography data into the computer for three-dimensional modeling of flood control stone blocks.

[0031] (1) Data preprocessing 1) Image POS processing Compare the image data with the POS data, eliminate the photos of the test flight and test photography before the operation begins, ensure that the image corresponds to the POS one by one, and import the POS information into the image.

[0032] 2) File Management The image control points and image POS of each flight are stored in a folder in the format of "project + date + flight" to facilitate later query and management.

[0033] (2) Aerial triangulation 1) Data import Import the pre-processed image data and image POS into the modeling software, and accurately input the camera parameters.

[0034] 2) Aerial triangulation ①Densely match the multi-view image feature points of camera parameters, image data, and POS data, perform joint constraint adjustment of the multi-view image regional network, establish a stereo model that can be deformed freely at a moderate spatial scale, and complete relative orientation; ②Transform the image control points obtained in the field into the indoor environment, use these points to perform constrained adjustment on the existing regional network model, incorporate the regional network into the coordinate system required by the project, and complete absolute orientation.

[0035] (3) White model creation The aerial triangulation results data is directly submitted for TIN grid construction and white body three-dimensional model creation.

[0036] (4) Calculation of stone volume After the 3D model is built, it is imported into the EPS 3D real-scene model processing system. EPS is used to accurately depict the boundaries of the five piles of stones, and the total area of ​​the flood control stones can be calculated to be 686.9m 2 .

[0037] Next, we take points at equal intervals of 1m and record the 3D coordinates of the points (including the pile height). We import the file containing the 3D coordinates of all the points into South CASS to calculate the volume of the block. The volume of the block at this location is 592.152m 3 .

[0038] Example 2 introduces an example of drone laser radar: Another example is to use the UAV LiDAR method to calculate the volume of rocks. The number of rocks for flood control that were applied for review was 10,000 tons, and the number of on-site signs was 10,000 tons. The rocks were piled up neatly, with a wide field of vision without obvious obstacles and protected by a wall.

[0039] (1) UAV equipment selection According to the size and accuracy requirements of the flood control block reserve area, the DJI M300 drone equipped with a DJI L1 lens was selected for this operation, with a flight altitude of 50 meters. The specific equipment parameters are shown in Table 1.

[0040] Table 1 SW-1 equipment parameter table

[0041] (2) Field flight Set the route according to the above parameters and the specific location of the stone blocks, fly along the set route and take photos. After the aerial photography is completed, import the aerial photography data into the computer for flood control stone laser point cloud data processing and three-dimensional modeling.

[0042] (3) Data preprocessing 1) Import data requirements DJI L1 drone can obtain high-precision point cloud data through its high-resolution camera and laser scanner. These point cloud data include spatial position information, reflection intensity information, color information, etc. By processing and analyzing these data, the three-dimensional shape, surface texture, height and other information of the object can be obtained.

[0043] The source data exported after the flight includes RTK base station data, etc. First, check the data to ensure its integrity.

[0044] (4) Data processing (DJI Map) One-click processing: Select the LiDAR file directory, and the point cloud, photos, GNSS, inertial navigation and base station data in the folder will be automatically identified and point cloud data will be automatically generated.

[0045] After the 3D model is built, the volume of the rock can be calculated according to the process of calculating the rock volume. The volume of the rock obtained by the lidar method is 5926.08m 3 The volume of the rock mass obtained by using the oblique photography method is 5957.38m 3 The difference between the two is 0.5%, which proves that both measurement methods are reliable.

[0046] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0047] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A high-precision method for calculating the reserve of flood control rocks, characterized in that: The following steps are involved: Step 1: Calibrate the volume measurement method of the above-ground part of the flood-control block stone: Use UAV oblique photography and UAV laser radar to take aerial photos of the above-ground part of the flood-control block stone and perform three-dimensional modeling. Measure and calculate the volumes of the three-dimensional models constructed by UAV oblique photography and UAV laser radar, which are V1 and V2 respectively. If the volume difference between V1 and V2 is within 5%, that is, |V1-V2|×100% / V1 is less than or equal to 5%, |V1-V2|×100% / V2 is less than or equal to 5%, it means that both the UAV oblique photography and UAV laser radar measurement methods are reliable. If the volume difference between the UAV oblique photography and UAV laser radar is greater than 5%, adjust the data resolution collected by the two measurement methods to improve the measurement accuracy until the volume difference between the UAV oblique photography and UAV laser radar is less than or equal to 5%. Step 2: Use the UAV oblique photography and UAV LiDAR calibrated in step 1 to measure the volume of the above-ground part of the flood-control block stones. The volume Vs of the above-ground part of the flood-control block stones is the average volume of the above-ground part of the flood-control block stones measured by the UAV oblique photography and UAV LiDAR, that is, Vs = (V1 + V2) / 2; Step 3: Calibrate the depth measurement method of the underground part of the flood control block stone: For the underground part of the flood control block stone, use ground penetrating radar to detect its settlement depth. The specific process is as follows: First, at least three edge parts of the rock pile are selected, and the edge parts of the rock pile are preliminarily explored using a ground penetrating radar to obtain the total pile height h1 of the edge parts. After the soil at the edge of the rock pile is completely excavated, the total pile height h2 of the edge parts of the rock pile is measured using a ruler. The total pile height h1 measured by the ground penetrating radar is compared with the total pile height h2 measured by the ruler after excavation. If the difference between the two is greater than 5 cm, the propagation speed of the radar wave of the ground penetrating radar in the rock pile is adjusted, and the height of the rock pile is recalculated until the difference between the two is less than or equal to 5 cm. The propagation speed of the radar wave of the ground penetrating radar in the medium at this time is recorded, and then the radar wave parameters of this group of ground penetrating radar are used to detect the entire rock pile. Step 4: According to the 3D model of flood control rock generated by the drone, find the longest side L of the 3D model of flood control rock, arrange several ground penetrating radar detection sections perpendicular to the longest side, and arrange several detection points at equal intervals on each section, every 5m 2 Set up at least one detection point; Step 5: According to the radar wave parameters of the ground penetrating radar described in step 3, all detection points are detected point by point to obtain the total pile height Hz of the blocks at each detection point; Step 6: Extract the ground height Hs of these detection points from the three-dimensional model of flood control blocks generated by the drone; Step 7: Subtract the ground height Hs of each detection point from the total pile height Hz of the blocks of stone at each detection point to obtain the settlement value Hd of the blocks of stone at the detection point; Step 8: If the difference in the settlement value Hd between two adjacent detection points is greater than 10 cm, add a detection point between the two adjacent detection points and repeat steps 5-7; Step 9: Finally, use the Kriging interpolation algorithm of the pykrige library in Python to interpolate the settlement values ​​Hd of all detection points, and then use the border filling algorithm cv2.copyMakeBorder in OpenCV to expand the interpolated settlement value to the block stone boundary area to obtain the settlement value Hd' covering the entire block stone area. Use the grid method to calculate the volume Vd of the underground part of the block stone: divide the entire block stone area into several square grids, and multiply the area of ​​each square grid by the settlement value Hdn' ​​corresponding to the grid to obtain the block stone volume Vd' corresponding to the grid. Add the block stone volume of each grid to obtain the volume Vd of the entire block stone underground. Add the volume Vs of the above-ground part of the flood control block stone to the volume Vd of the underground part of the block stone to obtain the volume V of the entire block stone, and then calculate the weight M of the flood control block stone: 。 2. The high-precision calculation method for flood control rock reserves according to claim 1 is characterized in that: The specific process of using the drone oblique photography to take aerial photos of the above-ground part of the flood control block stone and perform three-dimensional modeling is as follows: Step 1.1: According to the specific location of the stone, set the route and flight parameters, including flight altitude, heading overlap, lateral overlap, flight speed and gimbal angle; Step 1.2: Fly and take photos according to the route set in step 1.

1. After the aerial photography is completed, the aerial photography data is obtained. The aerial photography data includes the photos taken, the flight parameters when the photos were taken, and the route position; Step 1.3: Image POS processing: Compare the aerial photography data with the POS data, remove the test flight and test photography photos before the operation begins, ensure that the image and the POS are one-to-one corresponding, import the POS data into the aerial photography data, and form the image POS; Step 1.4: File management: save the image control points and image POS of each flight into a folder in the format of "project+date+flight" to facilitate later query management; Step 1.5: Data import: Import the aerial data and image POS pre-processed in step 1.3 into the DJI Terra modeling software, and accurately enter the camera parameters; Step 1.6: Aerial triangulation: ① Densely match the camera parameters, image data, and POS data to multi-view image feature points, perform joint constraint adjustment of the multi-view image regional network, establish a stereo model that can be freely deformed in spatial scale, and complete relative orientation; ②Transfer the photo control points obtained in the field to the indoor environment, use the photo control points to perform constrained adjustment on the existing regional network model, incorporate the regional network into the coordinate system required by the project, and complete absolute orientation; Step 1.7: White model creation: Submit the result data processed by aerial triangulation in step 1.6 directly for TIN grid construction and white body 3D model creation; Step 1.8: Calculation of stone volume: After the 3D model is built, import the 3D model into the EPS 3D real scene model processing system, use EPS to accurately depict the boundaries of the stone, and then calculate the total area of ​​the flood control stone; Next, take points at equal intervals of 1m and record the three-dimensional coordinates of the points, including the longitudinal, transverse and pile height. Import the file containing the three-dimensional coordinates of all points into Southern CASS to calculate the volume of the stone block.

3. The high-precision calculation method for flood control rock reserves according to claim 1 is characterized in that: When the drone collects data, an expansion distance is set, and the expansion distance satisfies: , Where: L is the expansion distance, m; H is the flight altitude, m; H1 is the height of the photographic reference surface, m; θ is the camera tilt angle; H2 is the height of the lowest point at the edge of the measurement area.

4. The high-precision calculation method for flood control rock reserves according to claim 2 is characterized in that: The specific process of the UAV laser radar to perform three-dimensional modeling of the above-ground part of the flood control block stone is as follows: Step 1) Import data and preprocess data The drone can obtain high-precision point cloud data through its high-resolution camera and laser scanner. The point cloud data includes spatial position information, reflection intensity information and color information. By processing and analyzing the point cloud data, the three-dimensional shape, surface texture and height information of the object can be obtained. The source data exported after the flight, including point cloud, photos, GNSS, inertial navigation and base station data; Step 2) Data processing One-click processing: select the laser radar file directory, automatically identify the point cloud, photos, GNSS, inertial navigation and base station data in the folder, automatically generate point cloud data, and form a flood control block stone laser point cloud 3D model rendering; After the 3D model is built, calculate the volume of the stone according to step 1.

8.

5. The high-precision calculation method for flood control rock reserves according to claim 1 is characterized in that: The measurement method of the ground penetrating radar is as follows: a radar transmitting point and a radar receiving point are selected in the detection area, radar transmission is performed at the radar transmitting point, radar signals are received at the radar receiving point, and the time difference between transmission and reception is recorded: the distance between the radar transmitting point and the radar receiving point is x, the depth of the exploration target body in the detection area from the horizon between the radar transmitting point and the radar receiving point is z, and the time difference between radar transmission and radar reception is t.

6. The high-precision calculation method for flood control rock reserves according to claim 5 is characterized in that: The calculation process of the ground penetrating radar is: (1) Radar wave propagation time ， In the formula: z is the depth of the target object; x is the distance between the transmitting and receiving antennas, where x is ignored because Z>x; V is the propagation speed of radar waves in the medium; (2) The propagation speed of radar waves in the medium, ， Where: c—the propagation speed of radar waves in vacuum, taken as 0.29979m / ns, — relative dielectric constant of the medium, —Relative magnetic permeability of the medium, taken ; (3) Relationship between the propagation time of radar waves recorded by ground penetrating radar and the exploration depth ， Where: z is the depth of the survey target; t—The travel time of the radar wave recorded by the radar.

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