Method and device for predicting evapotranspiration of ecological system based on stomatal conductance model

Abstract

The invention relates to a method and device for predicting evapotranspiration of an ecological system based on a stomatal conductance model. The device comprises a data processing host, a remote sensing data acquisition assembly and a ground data acquisition assembly, and the ground data acquisition assembly is used for acquiring meteorological data and soil humidity of vegetation canopies in a mountainous area. According to the device, remote sensing images are acquired through the remote sensing data acquisition assembly, the multiple ground data acquisition assemblies are arranged to perform multi-point acquisition on vegetation in a mountainous area, regions are divided according to meteorological differences to perform meteorological data acquisition, and the meteorological data can be acquired in a multi-point manner through the unmanned aerial vehicle balloon throwing assembly and the falling assembly; the falling and fixing assembly not only can provide falling and fixing of the meteorological balloon, but also is provided with the percussion type soil sensor for collecting soil humidity information, and the ground data collection assembly reduces the throwing difficulty, can realize multi-point throwing, and improves the prediction precision.

Description

Technical Field

[0001] The invention belongs to the technical field of vegetation ecology research, and in particular relates to a method and a device for predicting ecosystem evapotranspiration based on a stomatal conductance model. Background Art

[0002] In the context of ecological and environmental protection, accurate estimation and prediction of vegetation evapotranspiration is of great significance for understanding water cycle, energy conversion and regional water resources management. The PML model is an evapotranspiration estimation model based on remote sensing technology. It originates from the classic Penman-Monteith equation and introduces parameters such as soil moisture index and leaf area index (LAI) on this basis to improve the accuracy and applicability of the model. The model combines field-measured meteorological and evapotranspiration data and uses the least squares method to optimize parameters such as stomatal conductance and soil moisture index in the model.

[0003] The evapotranspiration characteristics of different study areas and vegetation types may differ. Therefore, when applying the PML model for evapotranspiration inversion, the model parameters need to be appropriately adjusted and optimized according to the specific situation, and the optimization process needs to rely on the measured values ​​of various meteorological data. For mountainous areas, the climate varies greatly due to differences in airflow, temperature and humidity, and sun angle. Therefore, the collection of meteorological data cannot be represented by a certain point, and it is necessary to divide the area into zones and collect them separately. The collection of meteorological data needs to be carried out above the vegetation canopy, and the collection of soil moisture needs to be on the ground. Due to the poor roads in mountainous areas, it is difficult to set up enough detection points to obtain sufficiently accurate meteorological data, resulting in inaccurate prediction results. Summary of the invention

[0004] The purpose of the present invention is to provide a method and device for predicting ecosystem evapotranspiration based on a stomatal conductance model in order to solve the above problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] A device for predicting ecosystem evapotranspiration based on a stomatal conductance model, comprising a data processing host, a remote sensing data acquisition component, and a ground data acquisition component, wherein the ground data acquisition component is used to collect meteorological data and soil moisture of a vegetation canopy in a mountainous area, and the remote sensing data acquisition component is used to collect remote sensing data of vegetation in a mountainous area. The data processing host is used to predict ecosystem evapotranspiration based on meteorological data, remote sensing data, stomatal conductance, and soil moisture and using a PML model, wherein the stomatal conductance is obtained by inversion based on meteorological data and remote sensing data, wherein the ground data acquisition component comprises

[0007] The delivery component uses drones to deliver sensors to mountainous areas, including drones and delivery devices;

[0008] A balloon assembly, which includes a weather balloon, a weather collection assembly, and a photovoltaic panel for collecting vegetation canopy weather data and providing electricity;

[0009] A fixing component is used to fix a weather balloon by a weight block and detect soil moisture by a soil sensor. A sleeve is rotatably arranged on the surface of the weight block, and parallel cables and connecting ropes are wound around the surface of the sleeve. An elastic component for inserting a probe of the soil sensor into the soil is provided in the sleeve, and the elastic component is wound around the cable and the connecting rope and is in an energy storage state.

[0010] As a further optimization scheme of the present invention, the elastic component includes a slider and a spring slidably arranged in a sleeve, the slider is rotatably connected to the soil sensor, a through groove is opened on the surface of the sleeve, a cover plate is arranged in the through groove, each cover plate is hinged to the slider through at least two connecting rods, the cover plate is wrapped with cables and connecting ropes and pushes the slider to compress the spring through the connecting rod, and the elastic component is used to push the soil sensor out through the spring when the cable or connecting rope completely leaves the sleeve, so that the probe can enter the soil to obtain soil moisture information.

[0011] As a further optimization scheme of the present invention, the dispenser is connected to the weight block through a first sling rope, and is connected to the weather balloon through a second sling rope. In order to release the weather balloon and the fixing component, the release device can be used to achieve sequential release.

[0012] As a further optimization scheme of the present invention, the dispenser includes a motor, a circular ring with an opening at the lower end, and spokes arranged at the end of the motor output shaft. The spokes and the inner wall of the circular ring form a fan-shaped area that is nested with links arranged at the ends of the first and second suspension ropes. When the spokes rotate to the opening of the circular ring, the links fall off. This scheme proposes a specific dispenser. By rotating the spokes to the gap in the circular ring to release the corresponding suspension rope, the fixing assembly and the balloon assembly can share a set of dispensers to achieve the purpose of sequential release.

[0013] As a further optimization scheme of the present invention, the weight block is of a pebble type. In order to prevent the weight block from being caught by branches when falling and to keep the sleeve facing upward after landing, that is, to make the probe of the soil sensor face downward, the weight block is set to this shape. In order to prevent the weight block from falling too quickly and causing a collision, a damping rotation can be set between the sleeve and the weight block. During the falling process, the sleeve rotates slowly to release the cables and connecting ropes wrapped around its surface, thereby delaying the falling process.

[0014] As a further optimization scheme of the present invention, the weather balloon is filled with helium through a high-pressure gas cylinder. After the weather balloon is inflated, its volume is large, which affects the flight of the drone. Therefore, it can be inflated after flying to the destination. The weather balloon is inflated through a high-pressure gas cylinder. The high-pressure gas cylinder is controlled by a valve and can be set on the drone or directly on the weather balloon for disposable use.

[0015] As a further optimization scheme of the present invention, a connecting block is provided at the bottom of the weather balloon, and the connecting block is directly fixed to the cable. A single-through slot is opened inside the connecting block, and the connecting rope passes through the single-through slot. A rope collection assembly is also provided under the drone, which is used to pull the connecting rope through the single-through slot so that the connecting rope is tightened between the connecting block and the weight block. Since the weather balloon is fixed by gravity through the weight block, if the weather balloon floats too high, it will be blown by the wind and sway severely. Therefore, after the weight block falls to the ground, the excess connecting rope is tightened to make the weather balloon descend to the same height as the tree canopy, and the weather balloon is laterally fixed with the help of the tree canopy to effectively reduce the impact of wind.

[0016] As a further optimization scheme of the present invention, the rope collecting assembly includes a driving motor, a threaded shaft driven by the driving motor, and a driven shaft that clamps the connecting rope together with the threaded shaft, wherein the thread of the threaded shaft is used to move the connecting rope axially through forward and reverse rotation, so as to reversely rotate after the pulling is completed and discard the connecting rope. The driving motor is set to pull the connecting rope so that the connecting rope slides in the single-pass groove. When the weather balloon descends to a suitable height, the threaded shaft is reversed to disengage the drone from the connecting rope to facilitate the drone to leave.

[0017] In order to apply the above device, the present invention also proposes a method for predicting ecosystem evapotranspiration based on the stomatal conductance model of the above device, comprising the following steps:

[0018] S1: Divide the mountainous area into several regions according to local meteorological differences;

[0019] S2: The meteorological data and soil moisture of various areas in the mountainous area are obtained through the ground data collection component, and the balloon component and the fixing component are placed in various areas through the delivery component, so that the balloon component carries the meteorological collection component to detect the meteorological data of the vegetation canopy and obtain electricity, while the fixing component fixes the balloon component through gravity and inserts the soil sensor into the soil;

[0020] S3: Obtain stomatal conductance through inversion of meteorological data and remote sensing data, and predict ecosystem evapotranspiration data based on meteorological data, remote sensing data, stomatal conductance, soil moisture and the PML model;

[0021] S4: Summarize the evapotranspiration data of regional vegetation to obtain the evapotranspiration data of mountain vegetation.

[0022] The beneficial effects of the present invention are:

[0023] The present invention acquires remote sensing images through a remote sensing data acquisition component, and performs multi-point acquisition of vegetation in mountainous areas by setting up multiple ground data acquisition components, collects meteorological data in regions divided by meteorological differences, and uses an unmanned aerial vehicle to drop a balloon component and a fixing component to collect meteorological data at multiple points. The fixing component not only provides a falling and fixed meteorological balloon, but also provides a trigger-type soil sensor for collecting soil moisture information. The ground data acquisition component reduces the difficulty of delivery, can achieve multi-point delivery, and improves prediction accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the overall structural front view of the present invention;

[0025] Figure 2 It is a side view of the overall structure of the present invention;

[0026] Figure 3 The present invention Figure 1 A magnified view of the structure of part A;

[0027] Figure 4 The present invention Figure 2 A magnified view of the structure of part B;

[0028] Figure 5 The present invention Figure 4 Middle CC view;

[0029] Figure 6 is a schematic diagram of a sinking assembly of the present invention;

[0030] Figure 7 The present invention Figure 6 The structure of part D is enlarged;

[0031] Figure 8 It is a schematic diagram of the balloon assembly and the sinking assembly of the present invention after being launched;

[0032] In the figure: 1. delivery assembly; 11. UAV; 12. dispenser; 13. first lifting rope; 14. second lifting rope; 2. balloon assembly; 21. weather balloon; 22. photovoltaic panel; 23. weather collection assembly; 24. connecting block; 25. single through slot; 3. fixing assembly; 31. weight block; 32. sleeve; 33. soil sensor; 34. slider; 35. spring; 36. cover plate; 37. connecting rod; 38. cable; 39. connecting rope; 4. rope collection assembly; 41. driving motor; 42. threaded shaft; 43. driven shaft. DETAILED DESCRIPTION

[0033] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0034] Example 1

[0035] like Figure 1-7 As shown, a device for predicting ecosystem evapotranspiration based on a stomatal conductance model comprises a data processing host, a remote sensing data acquisition component, and a ground data acquisition component. The ground data acquisition component is used to collect meteorological data and soil moisture of vegetation canopy in mountainous areas. The remote sensing data acquisition component is used to collect remote sensing data of vegetation in mountainous areas. The data processing host is used to predict ecosystem evapotranspiration based on meteorological data, remote sensing data, stomatal conductance, soil moisture and a PML model. The stomatal conductance is obtained by inverting the meteorological data and remote sensing data. The ground data acquisition component comprises

[0036] A delivery component 1, which delivers various sensors to the mountainous area via a drone 11, includes a drone 11 and a delivery device 12;

[0037] The balloon assembly 2 includes a weather balloon 21, a weather collection assembly 23, and a photovoltaic panel 22, which is used to collect vegetation canopy weather data and provide electricity;

[0038] The fixing component 3 is used to fix the weather balloon 21 by a weight block 31 and detect soil moisture by a soil sensor 33. A sleeve 32 is rotatably provided on the surface of the weight block 31. A parallel cable 38 and a connecting rope 39 are wound around the surface of the sleeve 32. An elastic component for inserting a probe of the soil sensor 33 into the soil is provided inside the sleeve 32. The elastic component is wound around the cable 38 and the connecting rope 39 and is in an energy storage state.

[0039] This scheme obtains remote sensing images through a remote sensing data acquisition component, and performs multi-point collection of vegetation in mountainous areas by setting up multiple ground data acquisition components, and collects meteorological data in areas divided by meteorological differences. Among them, stomatal conductance and soil moisture index are both key parameters of the model. The balloon component 2 and the pendant component 3 are released by the drone 11, so that meteorological data can be collected at multiple points. The pendant component 3 can not only provide a falling fixed meteorological balloon 21, but also has a soil sensor for collecting soil moisture information. The meteorological data of the vegetation canopy can also be combined with the remote sensing data acquisition component to invert stomatal conductance. For specific methods of inverting stomatal conductance, please refer to 202111550144.0 A method for inverting plant stomatal conductance based on satellite remote sensing data. This ground data acquisition component reduces the difficulty of delivery, can achieve multi-point delivery, and improves prediction accuracy.

[0040] The elastic component includes a slider 34 and a spring 35 slidably arranged in the sleeve 32. The slider 34 is rotatably connected to the soil sensor 33. A through groove is opened on the surface of the sleeve 32, and a cover plate 36 is arranged in the through groove. Each cover plate 36 is hinged to the slider 34 through at least two connecting rods 37. The cover plate 36 is wrapped with a cable 38 and a connecting rope 39 and pushes the slider 34 to compress the spring 35 through the connecting rod 37. The elastic component is used to push the soil sensor 33 out through the spring 35 when the cable 38 or the connecting rope 39 completely leaves the sleeve 32, so that the probe can enter the soil to obtain soil moisture information.

[0041] The dispenser 12 is connected to the weight block 31 via a first sling rope 13 , and is connected to the weather balloon 21 via a second sling rope 14 . In order to release the weather balloon 2 and the sinking assembly 3 , the dispenser 12 can be used to achieve sequential release.

[0042] Specifically, the dispenser 12 includes a motor, a ring with an opening at the lower end, and spokes arranged at the end of the motor output shaft. The spokes and the inner wall of the ring form a fan-shaped area and are nested with links arranged at the ends of the first suspension rope 13 and the second suspension rope 14. When the spokes rotate to the opening of the ring, the links fall off. This solution proposes a specific dispenser 12, such as Figure 3 As shown, by rotating the spokes to the notch of the annular ring to release the corresponding suspension rope, the fixing assembly 3 and the balloon assembly 21 can share a set of dispensers to achieve the purpose of sequential release.

[0043] The weight block 31 is of a pebble type. In order to prevent the weight block 31 from being caught by branches when falling and to keep the sleeve 32 facing upward after landing, that is, to make the probe of the soil sensor 33 face downward, the weight block 31 is set to this shape. In order to prevent the weight block 31 from falling too quickly and causing a collision, a damping rotation can be set between the sleeve 32 and the weight block 31. During the falling process, the sleeve 32 rotates slowly to release the cable 38 and the connecting rope 39 wrapped around its surface, thereby delaying the falling process. The weather balloon 21 is filled with helium through a high-pressure gas cylinder (not shown in the figure). The weather balloon 21 is larger in size after being inflated, which affects the flight of the drone 11. Therefore, it can be inflated after flying to the destination. The weather balloon 21 is inflated through a high-pressure gas cylinder. The high-pressure gas cylinder is controlled by a valve and can be set on the drone 11 or directly on the weather balloon 21 for disposable use.

[0044] A connecting block 24 is provided at the bottom of the weather balloon 21, and the connecting block 24 is directly fixed to the cable 38. A single-through slot 25 is opened inside the connecting block 24, and the connecting rope 39 passes through the single-through slot 25. A rope collection assembly 4 is also provided under the drone 11, which is used to pull the connecting rope 39 through the single-through slot 25 so that the connecting rope 39 is tightened between the connecting block 24 and the weight block 31. Since the weather balloon 21 is fixed by gravity through the weight block 31, the weather balloon 21 will be blown by the wind and sway severely if it floats too high. Therefore, after the weight block 31 falls to the ground, the excess connecting rope 39 is tightened to make the weather balloon 21 descend to the same height as the tree canopy, and the tree canopy is used for lateral protection to effectively reduce the impact of wind. For this reason, the weather balloon 21 is in contact with the tree canopy and should be made of wear-resistant material.

[0045] As a further optimization scheme of the present invention, the rope collecting assembly 4 includes a driving motor 41, a threaded shaft 42 driven by the driving motor 41, and a driven shaft 43 that clamps the connecting rope 39 together with the threaded shaft 42, wherein the thread of the threaded shaft 42 is used to move the connecting rope 39 axially through forward and reverse rotation, so as to rotate in the opposite direction after the pulling is completed and discard the connecting rope 39. The driving motor 41 is set to pull the connecting rope 39 so that the connecting rope 39 slides in the single-through groove 25. When the weather balloon 21 descends to a suitable height, the threaded shaft 42 is reversed to disengage the drone 11 from the connecting rope 39, so that the drone 11 can leave.

[0046] The specific implementation method is as follows: when the balloon assembly 2 and the fixing assembly 3 are released, the drone 11 is used to fly to a suitable position, and the fixing assembly 3 is first released. The launcher 12 releases the first suspension rope 13, and the fixing assembly 3 falls between the tree crowns. At the same time, the cable 38 and the connecting rope 39 wrapped around the surface of the sleeve 32 are continuously released until the fixing assembly falls completely. The surface of the sleeve 32 may still be partially wrapped. The drone 11 slightly increases the lift force, slowly rises, and pulls the cable 38 and the connecting rope 39 to continue to release, and slightly increases the lift force to prevent the heavy object 31 from being pulled up again. After the wrapping on the surface of the sleeve 32 is released, the spring 35 pushes the slider 34 and the soil sensor 33 out, wherein a rotating connection portion is provided between the slider 34 and the soil sensor 33 so that the slider 34 can rotate with the sleeve 32, and the soil sensor 33 probe is inserted into the soil to obtain data. The cable 38 is used to be powered by the photovoltaic panel 22 and transmit data, so as to facilitate the transmission of the data of the meteorological collection assembly 23 together with the soil data to the data processing host through signals;

[0047] After the fall assembly 3 lands, it inflates the weather balloon 21, and at the same time pulls the redundant connecting rope 38 through the rope collection assembly 4. After the connecting rope 38 passes through the single-through slot 25, the balloon assembly 2 descends in height until the weather balloon 21 is lowered to the vicinity of the tree canopy, and with the help of the tree canopy for protection, Figure 8As shown, the connecting rope 38 is stuck in the single-through groove 25 and will not move in the reverse direction. Therefore, the forces at both ends of the connecting rope 38 are respectively applied between the connecting block 24 and the weight block 31. Finally, the launcher 12 releases the weather balloon 21, and the threaded shaft 42 in the rope collection assembly 4 rotates in the reverse direction to discard the connecting rope 38, and the drone 11 returns.

[0048] In order to apply the above device, the present invention also proposes a method for predicting ecosystem evapotranspiration based on the stomatal conductance model of the above device, comprising the following steps:

[0049] S1: Divide the mountainous area into several regions according to local meteorological differences;

[0050] S2: Obtain meteorological data and soil moisture of various areas in the mountainous area through the ground data collection component, and deploy the balloon component 2 and the fixing component 3 to various areas through the deployment component 1, so that the balloon component 2 carries the meteorological collection component 23 to detect the meteorological data of the vegetation canopy and obtain electricity, while the fixing component 3 fixes the balloon component 2 by gravity and inserts the soil sensor 33 into the soil;

[0051] S3: Obtain stomatal conductance through inversion of meteorological data and remote sensing data, and predict ecosystem evapotranspiration data based on meteorological data, remote sensing data, stomatal conductance, soil moisture and the PML model;

[0052] S4: Summarize the evapotranspiration data of regional vegetation to obtain the evapotranspiration data of mountain vegetation.

[0053] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A device for predicting ecosystem evapotranspiration based on a stomatal conductance model, comprising a data processing host, a remote sensing data acquisition component, and a ground data acquisition component, characterized in that: The ground data acquisition component is used to collect meteorological data and soil moisture of the vegetation canopy in mountainous areas. The remote sensing data acquisition component is used to collect remote sensing data of vegetation in mountainous areas. The data processing host is used to predict ecosystem evapotranspiration data based on meteorological data, remote sensing data, stomatal conductance, soil moisture and the PML model. The stomatal conductance is obtained by inversion based on meteorological data and remote sensing data. The ground data acquisition component includes A delivery component (1) is used to deliver various sensors to a mountainous area via a drone (11), and includes a drone (11) and a delivery device (12); A balloon assembly (2), comprising a weather balloon (21), a weather collection assembly (23) and a photovoltaic panel (22), for collecting vegetation canopy weather data and providing electricity; A fixing assembly (3) is used to fix a weather balloon (21) by means of a weight block (31) and detect soil moisture by means of a soil sensor (33). A sleeve (32) is rotatably arranged on the surface of the weight block (31). Parallel cables (38) and a connecting rope (39) are wound around the surface of the sleeve (32). An elastic component for inserting a probe of the soil sensor (33) into the soil is provided in the sleeve (32). The elastic component is wound around the cable (38) and the connecting rope (39) and is in an energy storage state.

2. The device for predicting ecosystem evapotranspiration based on stomatal conductance model according to claim 1, characterized in that: The elastic component comprises a slider (34) and a spring (35) slidably arranged in a sleeve (32); the slider (34) is rotatably connected to the soil sensor (33); a through groove is provided on the surface of the sleeve (32); a cover plate (36) is arranged in the through groove; each cover plate (36) is hinged to the slider (34) through at least two connecting rods (37); the cover plate (36) is wound by a cable (38) and a connecting rope (39) and pushes the slider (34) to compress the spring (35) through the connecting rod (37).

3. The device for predicting ecosystem evapotranspiration based on stomatal conductance model according to claim 1, characterized in that: The dispenser (12) is connected to the weight block (31) via a first suspension rope (13), and is connected to the weather balloon (21) via a second suspension rope (14).

4. The device for predicting ecosystem evapotranspiration based on stomatal conductance model according to claim 3, characterized in that: The dispenser (12) comprises a motor, a circular ring with an opening at the lower end, and spokes arranged at the end of the motor output shaft. The spokes and the inner wall of the circular ring form a fan-shaped area that is nested with links arranged at the ends of the first hanging rope (13) and the second hanging rope (14). When the spokes rotate to the opening of the circular ring, the links fall off.

5. The device for predicting ecosystem evapotranspiration based on stomatal conductance model according to claim 1, characterized in that: The weight block (31) is of pebble type.

6. The device for predicting ecosystem evapotranspiration based on stomatal conductance model according to claim 1, characterized in that: The weather balloon (21) is filled with helium through a high-pressure gas cylinder.

7. The device for predicting ecosystem evapotranspiration based on stomatal conductance model according to claim 1, characterized in that: A connecting block (24) is provided at the bottom of the weather balloon (21), the connecting block (24) is directly fixed to the cable (38), a single-through slot (25) is provided inside the connecting block (24), the connecting rope (39) passes through the single-through slot (25), and a rope collecting assembly (4) is also provided below the drone (11) for pulling the connecting rope (39) through the single-through slot (25) so that the connecting rope (39) is tightened between the connecting block (24) and the weight block (31).

8. The device for predicting ecosystem evapotranspiration based on stomatal conductance model according to claim 7, characterized in that: The rope collecting assembly (4) comprises a driving motor (41), a threaded shaft (42) driven by the driving motor (41), and a driven shaft (43) which clamps the connecting rope (39) together with the threaded shaft (42), wherein the thread of the threaded shaft (42) is used to move the connecting rope (39) in an axial direction through forward and reverse rotation, so as to rotate in the reverse direction after pulling is completed and discard the connecting rope (39).

9. A method for predicting ecosystem evapotranspiration based on the stomatal conductance model of the device according to any one of claims 1 to 8, characterized in that: The steps include: S1: Divide the mountainous area into several regions according to local meteorological differences; S2: The meteorological data and soil moisture of each area in the mountainous area are obtained through the ground data collection component, and the balloon component (2) and the fixing component (3) are placed in each area through the placement component (1), so that the balloon component (2) carries the meteorological collection component (23) to detect the meteorological data of the vegetation canopy and obtain electricity, and the fixing component (3) fixes the balloon component (2) by gravity and inserts the soil sensor (33) into the soil; S3: Obtain stomatal conductance through inversion of meteorological data and remote sensing data, and predict ecosystem evapotranspiration data based on meteorological data, remote sensing data, stomatal conductance, soil moisture and the PML model; S4: Summarize the evapotranspiration data of regional vegetation to obtain the evapotranspiration data of mountain vegetation.

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