A method for regulating groundwater storage based on branch infiltration and rotation irrigation

Abstract

The present invention discloses a method for regulating groundwater reserves based on branch infiltration and rotation irrigation, comprising the following steps: S1 divides an aerial image of a research area into a plurality of image blocks; S2 determines the plant population of each image block; S3 obtains the optimal groundwater reserves of the image block; S4 collects the real-time groundwater depth of the image block in the current time period; S5 determines whether the real-time groundwater depth is within the optimal groundwater reserves range, if so, it is considered that the groundwater reserves are sufficient and the method proceeds to S8; otherwise, the method proceeds to S6; S6 uses branch infiltration and rotation irrigation to irrigate the vegetation in the image block, and then proceeds to S7; S7 determines whether the number of executions of branch infiltration and rotation irrigation is greater than a preset number, if so, the groundwater reserves adjustment is stopped, otherwise it is considered that the groundwater reserves are sufficient and the method proceeds to S8; S8 determines whether the time from the current time to the last time when the groundwater reserves of the image block were sufficient is greater than a preset number of days, if so, the method proceeds to S4, otherwise, the method continues to execute S8.

Description

Technical Field

[0001] The invention relates to the technical field of ecological restoration of northwest deserts, and in particular to a method for regulating groundwater reserves based on branch infiltration and rotation irrigation. Background Art

[0002] The Tarim River is the longest inland river in China. Its lower reaches are located in the fortress of the southern route of the "Silk Road". It is the only way for Xinjiang to connect to the second major channel (including: Ruoqiang-Yining National Highway 218, Korla-Golmud Railway, Korla-Ruoqiang Expressway). It has a unique geographical location and an important position. The green corridor formed by the desert riverbank poplar forest in the lower reaches is a natural ecological barrier that blocks the merging of the two major deserts of Taklimakan and Kumtag, and its ecological status is irreplaceable. However, since the 1950s, due to climate change and intensified human activities, land desertification has intensified, the area of ​​desert riverbank poplar forests has been shrinking, and ecological damage has been serious. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the method for regulating groundwater reserves based on branch infiltration and rotation irrigation provided by the present invention can maintain the underground water output and storage in the study area at the optimal growth state of plants.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0005] A method for regulating groundwater reserves based on branch infiltration rotation irrigation is provided, which comprises the following steps:

[0006] S1. Obtain aerial images of vegetation in the study area and divide the aerial images into several image blocks;

[0007] S2, extracting the planting area of ​​each plant in the image block, and taking the plant with the largest planting area as the plant population of the image block;

[0008] S3, obtaining the water utilization rate of plant populations in multiple studied groundwater depth sections, and taking the studied groundwater depth section corresponding to the maximum water utilization rate as the optimal groundwater storage of the corresponding image block;

[0009] S4, collecting the real-time groundwater depth of the image block in the current time period;

[0010] S5, judging whether the real-time groundwater depth is within the optimal groundwater reserve range of the image block, if so, it is considered that the groundwater reserve is sufficient and the process goes to step S8; otherwise, the process goes to step S6;

[0011] S6, watering the vegetation in the image block for a first preset time by using a branch infiltration rotation irrigation method, and then proceeding to step S7;

[0012] S7, determining whether the number of executions of branch infiltration rotation irrigation is greater than a preset number, if so, stopping the adjustment of groundwater reserves, otherwise it is considered that the groundwater reserves are sufficient and proceeding to step S8;

[0013] S8, determining whether the time from the current time to the last time the groundwater reserves in the image block were sufficient is greater than a preset number of days, if so, proceeding to step S4, otherwise continuing to step S8.

[0014] Furthermore, the calculation method of the water utilization rate includes:

[0015] S31. Count all plants growing in the research area, and select plant species with a growth area larger than a preset area as research plants;

[0016] S32. Select a number of experimental fields with an area equal to the number of the studied groundwater depth sections, and plant all the studied plants in each experimental field;

[0017] S33. When the roots of all the research plants have grown to maturity, the experimental fields are irrigated by means of branch infiltration rotation irrigation until the groundwater depth of each experimental field corresponds to a research groundwater depth segment;

[0018] S34. When each experimental field remains at the corresponding research groundwater depth for the second preset time, the stable isotope mass spectrometer is used to measure the δ 13 C ratio;

[0019] S35, according to the study of plant δ 13 C ratio, the water use efficiency of each study plant in each experimental plot was calculated using the stable carbon isotope method.

[0020] Furthermore, the δ 13 The C ratio is calculated as:

[0021] δ 13 C pjk =δ 13 C aj -a jk -(b jk -a jk )C ijk / G aj

[0022] Among them, δ 13 C pjk is the δ in the tissue of the kth plant in the jth experimental field. 13 C ratio; δ 13 C aj is the δ in the air of the jth experimental field 13 C ratio; a jk For CO2 b fractionation of diffusion process in leaves of the kth study plant in the jth experimental plot; b jk The carbon isotope fractionation during carboxylation of the k-th plant studied in the j-th experimental field; C ijk The intercellular CO in leaves of the kth plant studied in the jth experimental field 2 Concentration; G aj is the atmospheric CO in the jth experimental field 2 concentration.

[0023] Furthermore, the step S35 further comprises:

[0024] Calculate the water vapor pressure difference VPD inside and outside the leaves of the kth research plant in the jth experimental field ij :

[0025] VPD ij =Ee

[0026] Where E is the saturated water vapor pressure at the same temperature; e is the actual water vapor pressure;

[0027] According to VPD ij and δ 13 C pjk , calculate the water use efficiency WUE of the kth research plant in the jth experimental field jk :

[0028]

[0029] Furthermore, the calculation formula of the saturated water vapor pressure E at the same temperature is:

[0030] E=0.611×10 17.502T / (240.97+T)

[0031] Where T is the air temperature.

[0032] Furthermore, the calculation formula of the saturated water vapor pressure E at the same temperature is:

[0033] E=e / RH

[0034] Among them, e is the actual water vapor pressure; RH is the relative humidity of the air.

[0035] Furthermore, the δ 13 During the C ratio determination process, the plant leaf sample collection and processing methods include:

[0036] Mature leaves were collected from the sunny side of the study plants between 10 and 12 a.m., 10 to 20 leaves were collected from each tree, and the sampling was repeated 3 times for a single plant;

[0037] After leaf samples were collected, they were rinsed with distilled water, then sterilized at 105°C for 15 min, dried, placed in sampling bottles, and sealed and taken back to the laboratory;

[0038] Dry the leaves in a 60°C oven indoors to constant weight, then use a plant sample grinder to crush the leaves through a 0.25mm sieve. After processing, the samples are sent for isotope determination.

[0039] Furthermore, the method of dividing the aerial image into a plurality of image blocks includes:

[0040] Obtain the branch infiltration rotation irrigation system in the study area and determine the irrigation units corresponding to the branch infiltration rotation irrigation system;

[0041] The scale of the aerial image is adjusted to be equal to the plan layout of the branch infiltration irrigation system, and the aerial image is divided so that each image block covers at least one complete irrigation unit.

[0042] The beneficial effects of the present invention are as follows: this scheme divides the study area into several image blocks, and then determines the plant with the largest growth area in each block, and determines the optimal groundwater reserves in each image block based on the optimal water utilization rate of the plant, so as to supply water to each block in a targeted manner, thereby ensuring that the plants in each block are in the best growth state, thereby promoting the rapid growth of plants in the study area to achieve ecological restoration of the study area. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The flowchart of the method for regulating groundwater storage based on branch infiltration rotation irrigation is shown in FIG. DETAILED DESCRIPTION

[0044] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0045] In this plan, the basic connotation of branch infiltration rotation irrigation is mainly reflected in the five aspects of "induction, diffusion, infiltration, storage and rotation".

[0046] (1) “Divert” means ecological water diversion, that is, to divert ecological water to areas with higher terrain away from the main river channel through reservoirs, rivers, ecological gates, ditches, tributaries, low-head mobile pumping stations, etc., so as to expand the area of ​​irrigation control and radiation.

[0047] (2) “Man” refers to the overflow of water, which forms an irrigation method of flooding in the main river channel and ditches, promoting the implantation and germination of seeds.

[0048] (3) “Infiltration” refers to the surface ecological water transport method through ditches and tributaries during the ecological water transport process. Surface water infiltrates into the ground through ditches and tributaries, maintaining good living conditions for vegetation and improving the quality and stability of the ecosystem.

[0049] (4) “Storage” refers to storing water underground, that is, in the process of ecological water transfer, groundwater is replenished through ditches and tributaries, the groundwater level is raised, water is stored underground, ineffective evaporation from the water surface is reduced, and the utilization efficiency of ecological water is improved.

[0050] (5) “Rotation” refers to the rotation irrigation of vegetation. During the water transfer period, the infiltration rotation irrigation area is divided into different levels, and the water demand of each ecological zone is calculated according to the phenological characteristics of drought-tolerant vegetation and the regional groundwater level. The irrigation order of each zone is arranged according to the priority of protection and restoration. In principle, the most water-deficient zone is rotated for irrigation, and the release order, flow rate, duration and other indicators of the ecological gate are adjusted by feedback, so as to gradually achieve the ecological protection and restoration goals of “targeted irrigation, target area irrigation, and irrigation as much as possible” within multiple scheduling cycles.

[0051] refer to Figure 1 , Figure 1 A flow chart of a method for regulating groundwater storage based on branch infiltration and rotation irrigation is shown, as Figure 1 As shown, the method S includes steps S1 to S8.

[0052] In step S1, an aerial image of vegetation in a study area is obtained, and the aerial image is divided into a plurality of image blocks; wherein the method for obtaining the aerial image includes:

[0053] Step S11, set up several markers above the study area, and control the drone equipped with a camera to hover above the study area at a distance of 10 to 20 meters;

[0054] Step S12, controlling the drone to collect images of the study area at a preset speed and using an S-shaped planned path, and finding two adjacent images according to the markers;

[0055] Step S13, performing intersection processing on the foreground images in the two adjacent images to obtain the overlapping area corresponding to the foreground images of the two adjacent images;

[0056] Step S14, performing feature point matching processing on the overlapping area to obtain the target relative displacement between the two adjacent images, and splicing the two adjacent splicing images based on the target relative displacement;

[0057] Step S15: After all adjacent images are stitched together, the overall image obtained by stitching is used as the final aerial image of the study area.

[0058] During the process of acquiring aerial images, the landmarks set above the study area can be used to quickly find two adjacent aerial images, shortening the time for stitching aerial images; stitching two adjacent images based on the foreground image can improve the accuracy of image stitching and alignment, ensuring that the stitched aerial image is closer to the actual study area.

[0059] During implementation, the method for dividing the aerial image into a number of image blocks preferably includes:

[0060] Obtain the branch infiltration rotation irrigation system in the study area and determine the irrigation units corresponding to the branch infiltration rotation irrigation system;

[0061] The scale of the aerial image is adjusted to be equal to the plan layout of the branch infiltration irrigation system, and the aerial image is divided so that each image block covers at least one complete irrigation unit.

[0062] This solution uses the above method to divide the image blocks, which can facilitate the accurate control of each block during the subsequent branch infiltration and irrigation.

[0063] In step S2, the planting area of ​​each plant in the image block is extracted, and the plant with the largest planting area is taken as the plant population of the image block;

[0064] In step S3, the water utilization rate of the plant population in multiple studied groundwater depth sections is obtained, and the studied groundwater depth section corresponding to the maximum water utilization rate is used as the optimal groundwater reserve of the corresponding image block; the groundwater depth of each experimental field is located in a different studied groundwater depth section.

[0065] In one embodiment of the present invention, the water utilization rate calculation method further comprises:

[0066] S31. Count all plants growing in the research area, and select plant species with a growth area larger than a preset area as research plants;

[0067] S32. Select a number of experimental fields with an area equal to the number of the studied groundwater depth sections, and plant all the studied plants in each experimental field;

[0068] S33. When the roots of all the research plants have grown to maturity, the experimental fields are irrigated by means of branch infiltration rotation irrigation until the groundwater depth of each experimental field corresponds to a research groundwater depth segment;

[0069] S34. When each experimental field remains in the corresponding research groundwater depth section for the second preset time, a stable isotope mass spectrometer is used to measure the δ 13 C Ratio:

[0070] δ 13 C pjk=δ 13 C aj -a jk -(b jk -a jk )C ijk / G aj

[0071] Among them, δ 13 C pjk is the δ in the tissue of the kth plant in the jth experimental field. 13 C ratio; δ 13 C aj is the δ in the air of the jth experimental field 13 C ratio; a jk For CO 2 b fractionation of diffusion process in leaves of the kth study plant in the jth experimental plot; b jk The carbon isotope fractionation during carboxylation of the k-th plant studied in the j-th experimental field; C ijk The intercellular CO in leaves of the kth plant studied in the jth experimental field 2 Concentration; G aj is the atmospheric CO in the jth experimental field 2 concentration.

[0072] S35, according to the study of plant δ 13 C ratio, the water use efficiency of each study plant in each experimental plot was calculated using the stable carbon isotope method.

[0073] This scheme uses the experimental field method to simulate the water utilization of plants in each groundwater depth section in a targeted manner, which can facilitate targeted irrigation of the area corresponding to each image block in subsequent ecological regulation to ensure the rapid recovery of the ecosystem.

[0074] During implementation, the preferred step S35 of this solution further includes:

[0075] Calculate the water vapor pressure difference VPD inside and outside the leaves of the kth research plant in the jth experimental field ij :

[0076] VPD ij =Ee

[0077] Where E is the saturated water vapor pressure at the same temperature; e is the actual water vapor pressure;

[0078] According to VPD ij and δ 13 C pjk , calculate the water use efficiency WUE of the kth research plant in the jth experimental field jk :

[0079]

[0080] In this scheme, two methods of calculating the saturated water vapor pressure E at the same temperature are provided. The first method is: E = 0.611 × 10 17.502T / (240.97+T) , T is the air temperature.

[0081] The second implementation method is: E=e / RH, e is the actual water vapor pressure; RH is the relative humidity of the air.

[0082] In step S4, the real-time groundwater depth of the image block in the current time period is collected; the real-time groundwater depth can be monitored by using humidity sensors buried at different depths in the soil, or by using a more mature groundwater monitoring device on the market.

[0083] In step S5, it is determined whether the real-time groundwater depth is within the optimal groundwater reserve range of the image block. If so, it is considered that the groundwater reserve is sufficient and the process proceeds to step S8; otherwise, the process proceeds to step S6;

[0084] In step S6, the vegetation in the image block is watered for a first preset time period by using a branching and rotation irrigation method, and then the process proceeds to step S7;

[0085] In step S7, it is determined whether the number of executions of the branch infiltration rotation irrigation is greater than the preset number. If so, the groundwater reserve adjustment is stopped. Otherwise, it is considered that the groundwater reserve is sufficient and the process proceeds to step S8.

[0086] During irrigation, part of the water is absorbed by the vegetation and part of the water will seep into the soil for storage to change the groundwater depth. After multiple infiltration irrigations, a large amount of water will enter the soil, making the groundwater depth relatively stable.

[0087] In step S8, it is determined whether the time from the current time to the last time when the groundwater reserves in the image block were sufficient is greater than a preset number of days. If so, the process proceeds to step S4, otherwise, the process continues to step S8.

[0088] Further judgment in step S8 can avoid evaporation and absorption by plants of the part that has not been irrigated for a long time, and change of groundwater depth, which affects the rapid growth of plants. That is, the restoration speed of the ecosystem can be increased by judging by the preset number of days.

[0089] In one embodiment of the present invention, the 13 During the C ratio determination process, the plant leaf sample collection and processing methods include:

[0090] Mature leaves were collected from the sunny side of the study plants between 10 and 12 a.m., 10 to 20 leaves were collected from each tree, and the sampling was repeated 3 times for a single plant;

[0091] After leaf samples were collected, they were rinsed with distilled water, then sterilized at 105°C for 15 min, dried, placed in sampling bottles, and sealed and taken back to the laboratory;

[0092] Dry the leaves in a 60°C oven indoors to constant weight, then use a plant sample grinder to crush the leaves through a 0.25mm sieve. After processing, the samples are sent for isotope determination.

[0093] This scheme uses the above method to carry out plant δ 13 C ratio measurement can collect the best plant growth status of the day. 13 C. This can improve the accuracy of the calculated plant water utilization rate, thereby ensuring the accuracy of branch infiltration and rotation irrigation.

[0094] In summary, this plan adjusts the irrigation method of branch infiltration rotation irrigation through plant water utilization rate to ensure that the land where the plants in the study area are located is at the optimal groundwater depth for plant growth, thereby ensuring the rapid restoration of the ecosystem.

Claims

1. A method for regulating groundwater reserves based on branch infiltration and rotation irrigation. It is characterized in that Includes steps: S1. Obtain an aerial image of vegetation in the study area and divide the aerial image into several image blocks; S2, extracting the planting area of ​​each plant in the image block, and taking the plant with the largest planting area as the plant population of the image block; S3, obtaining the water utilization rate of plant populations in multiple studied groundwater depth sections, and taking the studied groundwater depth section corresponding to the maximum water utilization rate as the optimal groundwater storage of the corresponding image block; S4, collecting the real-time groundwater depth of the image block in the current time period; S5, judging whether the real-time groundwater depth is within the optimal groundwater reserve range of the image block, if so, it is considered that the groundwater reserve is sufficient and the process goes to step S8; otherwise, the process goes to step S6; S6, watering the vegetation in the image block for a first preset time by using a branch infiltration rotation irrigation method, and then proceeding to step S7; S7, determining whether the number of executions of the branch infiltration rotation irrigation is greater than the preset number, if so, stopping the adjustment of the groundwater reserves, otherwise it is considered that the groundwater reserves are sufficient and proceeding to step S8; S8, determining whether the time from the current time to the last time when the groundwater reserves in the image block were sufficient is greater than a preset number of days, if so, proceeding to step S4, otherwise continuing to step S8.

2. The method for regulating groundwater reserves based on branch infiltration and rotation irrigation according to claim 1, It is characterized in that The calculation method of the water utilization rate includes: S31. Count all plants growing in the research area, and select plant species with a growth area larger than a preset area as research plants; S32. Select a number of experimental fields with an area equal to the number of the studied groundwater depth sections, and plant all the studied plants in each experimental field; S33. When the roots of all the research plants have grown to maturity, the experimental fields are irrigated by means of branch infiltration rotation irrigation until the groundwater depth of each experimental field corresponds to a research groundwater depth segment; S34. When each experimental field remains in the corresponding research groundwater depth section for the second preset time, a stable isotope mass spectrometer is used to measure the δ 13 C ratio; S35, according to the study of plant δ 13 C ratio, the water use efficiency of each study plant in each experimental plot was calculated using the stable carbon isotope method.

3. The method for regulating groundwater reserves based on branch infiltration and rotation irrigation according to claim 2, It is characterized in that The δ of each plant species in each experimental plot 13 The C ratio is calculated as: d 13 C pjk =d 13 C aj -a jk -(b) jk -a jk )C ijk / G aj Among them, δ 13 C pjk is the δ in the tissue of the kth plant in the jth experimental field. 13 C ratio; δ 13 C aj is the δ in the air of the jth experimental field 13 C ratio; a jk For CO 2 b fractionation of diffusion process in leaves of the kth study plant in the jth experimental plot; b jk The carbon isotope fractionation during carboxylation of the k-th plant studied in the j-th experimental field; C ijk The intercellular CO in leaves of the kth plant studied in the jth experimental field 2 Concentration; G aj is the atmospheric CO in the jth experimental field 2 concentration.

4. The method for regulating groundwater reserves based on branch infiltration and rotation irrigation according to claim 3, It is characterized in that Step S35 further includes: Calculate the water vapor pressure difference VPD inside and outside the leaves of the kth research plant in the jth experimental field ij : VPD ij =E-e Where E is the saturated water vapor pressure at the same temperature; e is the actual water vapor pressure; According to VPD ij and δ 13 C pjk , calculate the water use efficiency WUE of the kth research plant in the jth experimental field jk :

5. The method for regulating groundwater reserves based on branch infiltration and rotation irrigation according to claim 4, It is characterized in that The calculation formula of the saturated water vapor pressure E at the same temperature is: E＝0.611×10 17.502T / (240.97+T) Where T is the air temperature.

6. The method for regulating groundwater reserves based on branch infiltration and rotation irrigation according to claim 4, It is characterized in that The calculation formula of the saturated water vapor pressure E at the same temperature is: E=e / RH Among them, e is the actual water vapor pressure; RH is the relative humidity of the air.

7. The method for regulating groundwater reserves based on branch infiltration and rotation irrigation according to claim 4, It is characterized in that The δ 13 During the C ratio determination process, the plant leaf sample collection and processing methods include: Mature leaves were collected from the sunny side of the study plants between 10 and 12 a.m., 10 to 20 leaves were collected from each tree, and the sampling was repeated 3 times for a single plant; After leaf samples were collected, they were rinsed with distilled water, then sterilized at 105°C for 15 min, dried, placed in sampling bottles, and sealed and taken back to the laboratory; Dry the leaves in a 60°C oven indoors to constant weight, then use a plant sample grinder to crush the leaves through a 0.25mm sieve. After processing, the samples are sent for isotope determination.

8. The method for regulating groundwater reserves based on branch infiltration and rotation irrigation according to claim 1, It is characterized in that Methods for dividing an aerial image into a number of image blocks include: Obtain the branch infiltration rotation irrigation system in the study area and determine the irrigation units corresponding to the branch infiltration rotation irrigation system; The scale of the aerial image is adjusted to be equal to the plan layout of the branch infiltration irrigation system, and the aerial image is divided so that each image block covers at least one complete irrigation unit.

9. The method for regulating groundwater reserves based on branch infiltration and rotation irrigation according to claim 1, It is characterized in that The method for acquiring the aerial image includes: S11. Set up several landmarks above the research area and control the drone equipped with a camera to hover over the research area at a distance of 10 to 20 meters; S12, controlling the drone to collect images of the study area at a preset speed and using an S-shaped planned path, and then finding two adjacent images according to the markers; S13, performing intersection processing on the foreground images in the two adjacent images to obtain an overlapping area corresponding to the foreground images of the two adjacent images; S14, performing feature point matching processing on the overlapping area to obtain a target relative displacement between two adjacent images, and splicing two adjacent splicing images based on the target relative displacement; S15. After all adjacent images are stitched together, the overall image obtained by stitching is used as the final aerial image of the study area.

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