A method for joint regulation of water resource utilization in desert riverbank vegetation based on ecological gate groups

Abstract

This invention discloses a method for jointly regulating water resource utilization of desert riverbank vegetation based on ecological gate groups. The method includes: obtaining vegetation change patterns using a fitting method based on the kNDVI vegetation index; dividing the vegetation in the desert watershed into three vegetation distribution zones based on the vegetation change patterns and vegetation coverage; acquiring all ecological gates in the desert watershed and dividing them into multiple ecological gate groups; determining the weights of the three vegetation distribution zones for ecological protection objectives using the analytic hierarchy process (AHP), and calculating the comprehensive score of the regulation zone based on the proportion of ecological functional zones in the regulation zone; solving the joint model of the ecological gate groups using a single-objective genetic algorithm to obtain the ecological water demand and ecological water supply of each control zone when the total water shortage of all ecological gate groups is minimized; dividing the ecological gate groups into five levels based on the comprehensive score, and then activating the ecological gate groups to irrigate the irrigation area according to the ecological gate group level, ecological water demand, and the importance of the irrigation area.

Description

Technical Field

[0001] This invention relates to the field of water resource utilization, specifically to a method for the joint regulation of water resource utilization in desert riverbank vegetation based on ecological gate groups. Background Technology

[0002] Dams and sluice gates are an important type of hydraulic engineering structure and a vital tool for humans to divert water from rivers. Domestic research on the ecological management of dams and sluice gates began in the late 1970s, but it wasn't until the 21st century that it truly entered a stage of comprehensive and systematic study.

[0003] In 2006, Lu Shiqiang et al., using the tidal river network of the Shanghai plain as their research object, coupled hydrodynamic and water quality data to construct a model. Through simulation analysis, they assessed the water quality changes of major rivers in Shanghai after the application of water diversion schemes and concluded that comprehensive water diversion can effectively improve the regional water quality during dry years. In 2012, Gu Hongmei et al., based on the actual conditions of the Beiyun River, comprehensively analyzed various factors related to the ecological scheduling of sluice gate groups in the river section, assessed the impact of sluice gate scheduling on the ecological environment, determined the ecological scheduling objectives, scheduling criteria, and scheduling methods for the Beiyun River, and proposed effective mitigation measures for water quality deterioration, achieving the dual goals of improving the water ecological environment and enhancing water resource utilization efficiency. In 2020, Li Shaohua further reviewed the comprehensive evaluation system of river ecosystems under sluice gate engineering scheduling, and the mechanism of influence between the two.

[0004] Existing technologies for ecological dam management typically aim to achieve minimum ecological flow, water quality, ecological flood, sediment, and ecological factor regulation. However, they primarily focus on meeting the temporal and spatial demands of river ecosystems for water volume and the physical regulation of river water quality through dam management. For river basins in the arid and desert regions of Northwest China, water resources are unevenly distributed in time and space. Vegetation along riverbanks suffers from water shortages, the integrated ecosystem of mountains, rivers, forests, fields, lakes, and grasslands is fragmented due to human activities, natural vegetation degradation in some areas continues to worsen, damaged downstream green corridors have not fully recovered, and the oasis-desert transition zone continues to shrink. Furthermore, with economic and social development, accelerated industrialization and urbanization, and large-scale hydropower development in various tributaries, the contradiction between water supply and demand will be further exacerbated. For river basins in the arid and desert regions of Northwest China, it is necessary to consider not only ecological protection and restoration but also the rational utilization of water resources; existing dam management methods struggle to address both simultaneously. Summary of the Invention

[0005] To address the aforementioned shortcomings in existing technologies, the present invention provides a method for utilizing water resources in desert riverbank vegetation based on the joint regulation of ecological gate groups. This method solves the problem that existing gate group scheduling methods cannot protect and restore the ecological environment of vegetation around desert watersheds when utilizing water resources.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0007] A method for jointly regulating water resource utilization of desert riverbank vegetation based on ecological sluice gate groups is provided, comprising the following steps:

[0008] S1. Obtain the kNDVI vegetation index of the desert watershed, and use the time series trajectory fitting method to obtain the vegetation change pattern based on the kNDVI vegetation index.

[0009] S2. Based on vegetation change patterns and vegetation coverage, the vegetation in the desert watershed is divided into three vegetation distribution areas: key protection areas, ecologically sensitive areas, and key restoration areas.

[0010] S3. Obtain all ecological gates in the desert watershed, and divide all ecological gates into multiple ecological gate groups according to the distribution of the desert watershed and the control area of ​​the ecological gates.

[0011] S4. The weights of the three vegetation distribution areas in the control area of ​​the ecological gate group to the ecological protection target are determined by the analytic hierarchy process (AHP), and the comprehensive score of the control area is calculated based on the proportion of the ecological function zones in the control area.

[0012] S5. A single-objective genetic algorithm is used to solve the joint model of the ecological gate group, obtaining the ecological water demand and ecological water supply of each control area in each time period when the total water shortage of all ecological gate groups is minimized; the joint model of the ecological gate group is as follows:

[0013]

[0014] Where W represents the total water shortage of the ecological sluice gate group over many years; QX(n,i,j) and QG(n,i,j) represent the total water demand and total water supply of the sluice gate group control area n in the j-th period of the i-th year, respectively; I represents the total number of years for calculation (i = 1, 2, ..., 61); J represents the number of months in the year (j = 1, 2, ..., 12); and N represents the total number of years for calculation (n = 1, 2, 3, 4, 5).

[0015] S6. Based on the comprehensive score, the ecological gate group is divided into 5 levels. Then, based on the ecological gate group level, ecological water demand and the importance of the irrigation area, the ecological gate group is activated to irrigate the irrigation area.

[0016] Furthermore, methods for obtaining vegetation change patterns include:

[0017] S11. The kNDVI vegetation index is smoothed using the moving average method to obtain a smoothed time series, and the smoothed time series is extended with the time p with the largest vegetation change rate as the center point.

[0018] S12. Fit the extended time series after the extension process using an ensemble function, and determine whether the fitted pixels pass the F-test. If yes, proceed to step S13; otherwise, proceed to step S16. The ensemble function f(t) is:

[0019]

[0020] Where t is the sequence number of the extended time series, ranging from 1 to N; q is the difference between the maximum value of the extended time series and the background value; c is the initial background kNDVI value; and e is the natural logarithm.

[0021] S13, when When the integration function is equal to the logistic function, the integration function is equivalent to the logistic function. When the integrated function is equivalent to the asymmetric Gaussian function, the vegetation change pattern is Gaussian; a is the direction of vegetation change, and b is the time corresponding to (q+c) / 2.

[0022] S14. For the logistic function form, the time point with the maximum or minimum rate of change of curvature in the ensemble function is used as the year of abrupt change. The formula for calculating the rate of change of curvature is:

[0023]

[0024] in, Transition parameters; The first derivative of the transition parameter;

[0025] S15. Obtain the number of mutation years. If the number is 2, the vegetation change pattern is logarithmic. If the number is 1 and the mutation point time is before b, the vegetation change pattern is exponential. Otherwise, it is logarithmic.

[0026] S16. For pixels whose ensemble function fit fails the F-test, the least squares method is used to perform linear regression on the smoothed time series to obtain a univariate linear regression equation:

[0027] f(i)=s+slope×ii=1,2,…,N

[0028] Where i is the i-th year in the smoothed time series, s is the parameter of the linear regression, and slope is the trend of vegetation change;

[0029] S17. Perform an F-test on the univariate linear regression equation. If the F-test is passed, the vegetation change pattern is linear; if the F-test is not passed, the vegetation change pattern is a trendless pattern.

[0030] Furthermore, the method for dividing the distribution areas of the three vegetation types is as follows:

[0031] When the vegetation change pattern is logarithmic, logistic, or Gaussian, and the vegetation cover is ≥0.3, the corresponding area is a key protected area; when the vegetation change pattern is linear or exponential, and the vegetation cover is ≥0.3, the corresponding area is a key restoration area; when the vegetation cover is between 0.03 and 0.3, the corresponding area is an ecologically sensitive area.

[0032] Furthermore, methods for extending smoothed time series include:

[0033] S111. Calculate the difference Δy between the forward and backward directions at each time point in the smoothed time series. i :

[0034] Δy i =y i+1 -y i i = 1, 2, ..., 61

[0035] Among them, y i+1 and y i These are smoothed time series for the (i+1)th and ith years, respectively;

[0036] S112, Select interpolation Δy i The year with the largest absolute value is taken as the time p with the largest vegetation change rate. The length of the extended smoothed time series is symmetric about p, and the length L of the extended time series for each pixel is calculated as follows:

[0037]

[0038] when When, the time series is extended to become a smooth time series; when When the time series is extended, N elements are the same as the smoothed time series, and the remaining elements are the first term of the smoothed time series; when When the extended time series has the same first N elements as the smoothed time series, the remaining elements are the first term of the smoothed time series. This is the floor symbol.

[0039] Furthermore, the method for obtaining the kNDVI vegetation index includes:

[0040] A1. Obtain MODIS NDVI data of the desert watershed, and perform format conversion, projection conversion, and cropping operations on the data;

[0041] A2. The data from 23 periods of each year are filtered by Savitzky-Golay, and then the NDVI data of each year are synthesized by the maximum value synthesis method to obtain the annual NDVI data.

[0042] A3. Calculate the vegetation dynamics monitoring index kNDVI based on annual NDVI data:

[0043] kNDVI = tanh(NDVI) 2 )

[0044] Where tanh(·) is the hyperbolic tangent function; NDVI is the annual NDVI data.

[0045] Furthermore, activating the ecological gate system for irrigation of the irrigation area includes:

[0046] When the ecological water supply of the corresponding watershed section of the ecological gate group meets the ecological water demand of its control area, the ecological gate group supplies water according to the ecological water demand of its corresponding control area.

[0047] When the ecological water supply of the corresponding watershed section of the ecological gate group does not meet the ecological water demand of its control area, after the high-level ecological gate group supplies water to its corresponding key protection area, any surplus water will be allocated to the lower-level ecological gate group until the water is completely consumed.

[0048] Furthermore, the formula for calculating the vegetation coverage is:

[0049]

[0050] Among them, V C NDVI represents vegetation cover. S NDVI value of bare land in desert watershed. v NDVI value for pure vegetation pixels. S and NDVI v Take the values ​​at the 5% and 95% points of the annual NDVI histogram, respectively.

[0051] Furthermore, the constraints for each ecological gate group in the joint ecological gate group model include:

[0052] ① Basin water balance constraints:

[0053] W 来水 (i,j)=W 供水 (i,j)+W 损失 (i,j)±W 水库供蓄水 (i,j)

[0054] Among them, W 来水 (i,j), W 供水 (i,j), W 损失(i,j) and W 水库供需水 (i,j) represent the natural runoff, water supply to the regulation area, total loss of the regulation area, and the difference between the reservoir's end-of-period capacity and initial capacity for the j-th time period in the i-th year, respectively. 水库供需水 When (i,j) is positive, it means that the reservoir is storing water for the system during this period; when it is negative, it means that the system is supplying water.

[0055] ②Water balance constraints of the reservoir section where the ecological sluice gate group is located:

[0056] V m (i,j+1)=V m (i,j)+3600×(QV m (i,j)-QC m (i,j))·Δt

[0057] Among them, V m (i,j), V m (i,j+1) represent the reservoir capacity of the m-th reservoir during the (j+1)-th and j-th time periods of the i-th year, respectively; QV m (i,j) represents the inflow of the m-th reservoir during the j-th time period of the i-th year; QC m (i,j) represents the outflow of the m-th reservoir in the j-th time period of the i-th year; Δt represents the time difference between the (j+1)-th time period and the j-th time period.

[0058] Reservoir capacity constraints in the section where the ecological sluice gate group is located:

[0059]

[0060] in, Let the upper and lower limits of the reservoir capacity of the m-th reservoir be defined for the j-th time period of the i-th year.

[0061] ③ Irrigation water supply constraints in the regulation area corresponding to the ecological gate group:

[0062] QGg(h)≥QGx(h)

[0063] Where QGg(h) and QGx(h) are the irrigation water supply and irrigation water demand of node h in the regulation process, respectively;

[0064] ④ Ecological water supply constraints:

[0065] The external ecology of the corresponding watershed segment in the regulation zone: QSg(n)≥QSx(n)

[0066] Ecological base current: Q Sg (n)≥Q Sx (n)

[0067] In the formula: QSg(n), Q Sg (n) represent external ecological and ecological base flow water supply, respectively; QSx(n), QSx (n) represents the water demand for the extra-channel ecology and the ecological base flow, respectively;

[0068] ⑤ Constraints on industrial and domestic water supply:

[0069] GS g (n)≥GS x (n)

[0070] Among them, GS g (n), GS x (n) represents water supply for domestic and industrial use and water demand for domestic and industrial use, respectively.

[0071] Furthermore, methods for jointly regulating water resource utilization in desert riverbank vegetation based on ecological sluice gate groups also include:

[0072] In key protected areas, seepage irrigation through ditches is used to regulate groundwater levels. In ecologically sensitive areas, the process of flood overflow is controlled to promote vegetation growth and sapling formation. In key restoration areas, seepage irrigation through ditches is combined with flood overflow to raise groundwater levels and promote seed germination. The irrigation period is from July to September.

[0073] The beneficial effects of this invention are as follows: This solution obtains vegetation change patterns through the kNDVI vegetation index, which can accurately identify the non-monotonic change process of natural vegetation, so as to avoid considering the inherent state of some areas as degradation; based on the vegetation change patterns and vegetation coverage, the vegetation in the desert watershed is divided, and irrigation can be carried out according to the importance of the tank area, so as to achieve the purpose of ecological protection and restoration of the vegetation around the desert watershed while making rational use of water resources.

[0074] This plan, through the division of ecological gate groups, ensures that the control area of ​​each gate group is within the reasonable water resource transportation range, thereby avoiding excessive irrigation distances and increased water resource losses. During irrigation, by combining the ecological gate group level, ecological water demand, and the importance of the irrigation area, important areas can be irrigated according to the priority of the ecological gate groups when water supply is limited.

[0075] The joint regulation and control model of ecological gate groups not only fully leverages the joint regulation and control potential among ecological gate groups in the basin, improves the ecological water conveyance conditions outside the main channel, and promotes the protection and restoration of the basin's ecological environment, but also saves precious water resources and effectively ensures water security for various industries along the main channel. Attached Figure Description

[0076] Figure 1 This is a flowchart of a method for jointly regulating the utilization of water resources in desert riverbank vegetation based on ecological gate groups. Detailed Implementation

[0077] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0078] refer to Figure 1 , Figure 1 This demonstrates a method for jointly regulating water resource utilization in desert riverbank vegetation based on ecological sluice gate systems; such as... Figure 1 As shown, the method S includes steps S1 to S6.

[0079] In step S1, the kNDVI vegetation index of the desert watershed is obtained, and the vegetation change pattern is obtained by time series trajectory fitting method based on the kNDVI vegetation index.

[0080] During implementation, this scheme preferentially uses the following methods to obtain the kNDVI vegetation index:

[0081] A1. Obtain MODIS NDVI data of the desert watershed, and perform format conversion, projection conversion, and cropping operations on the data;

[0082] A2. The data from 23 periods of each year are filtered by Savitzky-Golay, and then the NDVI data of each year are synthesized by the maximum value synthesis method to obtain the annual NDVI data.

[0083] A3. Calculate the vegetation dynamics monitoring index kNDVI based on annual NDVI data:

[0084] kNDVI = tanh(NDVI) 2 )

[0085] Where tanh(·) is the hyperbolic tangent function; NDVI is the annual NDVI data.

[0086] In one embodiment of the present invention, the method for obtaining vegetation change patterns includes:

[0087] S11. The kNDVI vegetation index is smoothed using the moving average method to obtain a smoothed time series, and the smoothed time series is extended with the time p with the largest vegetation change rate as the center point.

[0088] S12. Fit the extended time series after the extension process using an ensemble function, and determine whether the fitted pixels pass the F-test. If yes, proceed to step S13; otherwise, proceed to step S16. The ensemble function f(t) is:

[0089]

[0090] Where t is the sequence number of the extended time series, ranging from 1 to N; q is the difference between the maximum value of the extended time series and the background value; c is the initial background kNDVI value; and e is the natural logarithm.

[0091] S13, when When the integration function is equal to the logistic function, the integration function is equivalent to the logistic function. When the integrated function is equivalent to the asymmetric Gaussian function, the vegetation change pattern is Gaussian; a is the direction of vegetation change, and b is the time corresponding to (q+c) / 2.

[0092] S14. For the logistic function form, the time point with the maximum or minimum rate of change of curvature in the ensemble function is used as the year of abrupt change. The formula for calculating the rate of change of curvature is:

[0093]

[0094] in, Transition parameters; The first derivative of the transition parameter;

[0095] S15. Obtain the number of mutation years. If the number is 2, the vegetation change pattern is logarithmic. If the number is 1 and the mutation point time is before b, the vegetation change pattern is exponential. Otherwise, it is logarithmic.

[0096] S16. For pixels whose ensemble function fit fails the F-test, the least squares method is used to perform linear regression on the smoothed time series to obtain a univariate linear regression equation:

[0097] f(i)=s+slope×ii=1,2,…,N

[0098] Where i is the i-th year in the smoothed time series, s is the parameter of the linear regression, and slope is the trend of vegetation change;

[0099] S17. Perform an F-test on the univariate linear regression equation. If the F-test is passed, the vegetation change pattern is linear; if the F-test is not passed, the vegetation change pattern is a trendless pattern.

[0100] In step S2, based on vegetation change patterns and vegetation coverage, the vegetation in the desert watershed is divided into three vegetation distribution areas: key protection areas, ecologically sensitive areas, and key restoration areas.

[0101] During implementation, the preferred formula for calculating vegetation cover in this plan is:

[0102]

[0103] Among them, V C NDVI represents vegetation cover. S NDVI value of bare land in desert watershed. v NDVI value for pure vegetation pixels. S and NDVI v Take the values ​​at the 5% and 95% points of the annual NDVI histogram, respectively.

[0104] The method for dividing the distribution areas of the three types of vegetation is as follows:

[0105] When the vegetation change pattern is logarithmic, logistic, or Gaussian, and the vegetation cover is ≥0.3, the corresponding area is a key protected area; when the vegetation change pattern is linear or exponential, and the vegetation cover is ≥0.3, the corresponding area is a key restoration area; when the vegetation cover is between 0.03 and 0.3, the corresponding area is an ecologically sensitive area.

[0106] In step S3, all ecological gates in the desert watershed are obtained, and based on the distribution of the desert watershed and the control area of ​​the ecological gates, all ecological gates are divided into multiple ecological gate groups.

[0107] In step S4, the analytic hierarchy process (AHP) is used to determine the weights of the three vegetation distribution zones in the control area of ​​the ecological gate group to the ecological protection target, and the comprehensive score of the control area is calculated based on the proportion of ecological function zones in the control area.

[0108] The weights for the key protected areas, ecologically sensitive areas, and key restoration areas in this scheme are 0.62, 0.24, and 0.14, respectively. Assuming that the proportions of these three vegetation distribution areas within the control area are 0.5, 0.4, and 0.1, respectively, the comprehensive score is 0.62×0.4+0.24×0.3+0.14×0.4=0.43.

[0109] In step S5, a single-objective genetic algorithm is used to solve the joint model of the ecological gate group, obtaining the ecological water demand and ecological water supply of each control area in each time period when the total water shortage of all ecological gate groups is minimized; the joint model of the ecological gate group is as follows:

[0110]

[0111] Where W represents the total water shortage of the ecological gate group over many years; QX(n,i,j) and QG(n,i,j) represent the total water demand and total water supply of the gate group control area n in the j-th period of the i-th year, respectively; I represents the total number of years for calculation (i = 1, 2, ..., 61); J represents the number of monthly periods within the year (j = 1, 2, ..., 12); and N represents the total number of years for calculation (n = 1, 2, 3, 4, 5).

[0112] During implementation, the constraints for each ecological gate group in the preferred ecological gate group joint model of this scheme include:

[0113] ① Basin water balance constraints:

[0114] W 来水 (i,j)=W 供水 (i,j)+W 损失 (i,j)±W 水库供蓄水 (i,j)

[0115] Among them, W 来水 (i,j), W 供水 (i,j), W 损失 (i,j) and W 水库供需水 (i,j) represent the natural runoff, water supply to the regulation area, total loss of the regulation area, and the difference between the reservoir's end-of-period capacity and initial capacity for the j-th time period in the i-th year, respectively. 水库供需水 When (i,j) is positive, it means that the reservoir is storing water for the system during this period; when it is negative, it means that the system is supplying water.

[0116] ②Water balance constraints of the reservoir section where the ecological sluice gate group is located:

[0117] V m (i,j+1)=V m (i,j)+3600×(QV m (i,j)-QC m (i,j))·Δt

[0118] Among them, V m (i,j), V m (i,j+1) represent the reservoir capacity of the m-th reservoir during the (j+1)-th and j-th time periods of the i-th year, respectively; QV m (i,j) represents the inflow of the m-th reservoir during the j-th time period of the i-th year; QC m (i,j) represents the outflow of the m-th reservoir in the j-th time period of the i-th year; Δt represents the time difference between the (j+1)-th time period and the j-th time period.

[0119] Reservoir capacity constraints in the section where the ecological sluice gate group is located:

[0120]

[0121] in, Let represent the upper and lower limits of reservoir capacity for the m-th reservoir during the j-th time period of the i-th year.

[0122] ③ Irrigation water supply constraints in the regulation area corresponding to the ecological gate group:

[0123] QGg(h)≥QGx(h)

[0124] Where QGg(h) and QGx(h) are the irrigation water supply and irrigation water demand of node h in the regulation, respectively.

[0125] ④ Ecological water supply constraints:

[0126] The external ecology of the corresponding watershed segment in the regulation zone: QSg(n)≥QSx(n)

[0127] Ecological base current: Q Sg (n)≥Q Sx (n)

[0128] In the formula: QSg(n), Q Sg (n) represent external ecological and ecological base flow water supply, respectively; QSx(n), Q Sx (n) represents the water demand for the external ecological and ecological base flow, respectively.

[0129] ⑤ Constraints on industrial and domestic water supply:

[0130] GS g (n)≥GS x (n)

[0131] Among them, GS g (n), GS x (n) represents water supply for domestic and industrial use and water demand for domestic and industrial use, respectively.

[0132] In step S6, the ecological gate group is divided into 5 levels based on the comprehensive score (see Table 1 for details). Then, the ecological gate group is activated to irrigate the irrigation area according to the ecological gate group level, ecological water demand and the importance of the irrigation area.

[0133] Table 1 Classification of Ecological Gate Groups

[0134]

[0135] During implementation, this plan preferentially utilizes the ecological gate system for irrigation of the irrigation area, further including:

[0136] When the ecological water supply of the corresponding watershed section of the ecological gate group meets the ecological water demand of its control area, the ecological gate group supplies water according to the ecological water demand of its corresponding control area.

[0137] When the ecological water supply of the corresponding watershed section of the ecological gate group does not meet the ecological water demand of its control area, after the high-level ecological gate group supplies water to its corresponding key protection area, any surplus water will be allocated to the lower-level ecological gate group until the water is completely consumed.

[0138] For example, when the ecological water supply of a fourth-level ecological irrigation area is insufficient, the third-level ecological irrigation area can supply water to its key protected areas, and then supply the remaining ecological water supply to the fourth-level ecological irrigation area. If the ecological water supply from the third-level ecological irrigation area can still meet the ecological water demand of its area, then it can continue to irrigate the remaining ecologically sensitive areas and key restoration areas. If it cannot meet the demand, then the second-level ecological irrigation area can supply water to its key protected areas, and then supply the remaining ecological water supply to the third-level ecological irrigation area. This process can be repeated to achieve the purpose of joint regulation of the ecological gate group.

[0139] In one embodiment of the present invention, a method for extending a smoothed time series includes:

[0140] S111. Calculate the difference Δy between the forward and backward directions at each time point in the smoothed time series. i :

[0141] Δy i =y i+1 -y i i = 1, 2, ..., 61

[0142] Among them, y i+1 and y i These are smoothed time series for the (i+1)th and ith years, respectively;

[0143] S112, Select interpolation Δy i The year with the largest absolute value is taken as the time p with the largest vegetation change rate. The length of the extended smoothed time series is symmetric about p, and the length L of the extended time series for each pixel is calculated as follows:

[0144]

[0145] when When, the time series is extended to become a smooth time series; when When the time series is extended, N elements are the same as the smoothed time series, and the remaining elements are the first term of the smoothed time series; when When the extended time series has the same first N elements as the smoothed time series, the remaining elements are the first term of the smoothed time series. This is the floor symbol.

[0146] In implementation, this scheme preferably incorporates the following methods for jointly regulating the utilization of water resources in desert riverbank vegetation based on ecological sluice gate groups:

[0147] In key protected areas, seepage irrigation through ditches is used to regulate groundwater levels. In ecologically sensitive areas, the process of flood overflow is controlled to promote vegetation growth and sapling formation. In key restoration areas, seepage irrigation through ditches is combined with flood overflow to raise groundwater levels and promote seed germination. The irrigation period is from July to September.

[0148] After irrigating the three zones using the above method, the monthly ecological water supply under the rotational irrigation model is more even, effectively ensuring the stability and reliability of water supply during the ecological irrigation period. For example, under the rotational irrigation model, agricultural irrigation and ecological water supply outside the river in each zone meet the design guarantee rate requirements, and the agricultural and ecological water shortages have both decreased significantly by 51%.

[0149] In summary, the proposed method for the joint regulation of water resources utilization in desert riverbank vegetation based on ecological sluice gate groups can not only make rational use of water resources, but also protect and restore the vegetation around the desert watershed.

Claims

1. A method for jointly regulating water resource utilization of desert riparian vegetation based on an ecological gate group, characterized in that, Including the following steps: S1. Obtain the kNDVI vegetation index of the desert watershed, and use the time series trajectory fitting method to obtain the vegetation change pattern based on the kNDVI vegetation index. S2. Based on vegetation change patterns and vegetation coverage, the vegetation in the desert watershed is divided into three vegetation distribution areas: key protection areas, ecologically sensitive areas, and key restoration areas. S3. Obtain all ecological gates in the desert watershed, and divide all ecological gates into multiple ecological gate groups according to the distribution of the desert watershed and the control area of ​​the ecological gates. S4. The weights of the three vegetation distribution areas in the control area of ​​the ecological gate group to the ecological protection target are determined by the analytic hierarchy process (AHP), and the comprehensive score of the control area is calculated based on the proportion of the ecological function zones in the control area. S5. A single-objective genetic algorithm is used to solve the joint model of the ecological gate group, obtaining the ecological water demand and ecological water supply of each control area when the total water shortage of all ecological gate groups is minimized; the joint model of the ecological gate group is as follows: wherein, W is the total water deficit of the ecological gate group for many years; , is the total water demand of the gate group control area n in the first i of the year j period total water supply; I is the total number of years calculated (n i =1,2,…,61); J is the number of months in a year (m j =1,2,…,12); N is the total number of years calculated (n n =1,2,3,4,5); The constraints for each ecological gate group in the joint ecological gate group model include: ① Basin water balance constraints: in, , , and The first The year's first The natural runoff, water supply to the regulation area, total loss in the regulation area, and the difference between the reservoir's end capacity and initial capacity for the specified period. A positive value indicates that the reservoir is storing water for the system during this period, while a negative value indicates that the system is supplying water. ②Water balance constraints of the reservoir section where the ecological sluice gate group is located: in, , The first The reservoir in the first i The year's first Time period and the Reservoir capacity during a given period; For the first The reservoir in the first i The year's first Inbound flow during specific time periods; For the first The reservoir in the first i The year's first Outbound flow during specific time periods; For the first Time period and the Time difference between periods; Reservoir capacity constraints in the section where the ecological sluice gate group is located: in, , For the first The reservoir in the first i The year's first Upper and lower limits of warehouse capacity constraints for different time periods; ③ Irrigation water supply constraints in the regulation area corresponding to the ecological gate group: in, , These are the nodes in the regulation process. h Irrigation water supply and irrigation water demand; ④ Ecological water supply constraints: The external ecology of the corresponding watershed section in the regulation zone: Ecological base current: in, , They are respectively supplied by external ecological and ecological base flow water; , These are respectively the water demand for external river ecology and ecological base flow; ⑤ Constraints on industrial and domestic water supply: in, , These are respectively water supply for domestic and industrial use, and water demand for domestic and industrial use; S6. Based on the comprehensive score, the ecological gate group is divided into 5 levels. Then, based on the ecological gate group level, ecological water demand and the importance of the irrigation area, the ecological gate group is activated to irrigate the irrigation area.

2. The method for jointly regulating water resource utilization of desert riverbank vegetation based on ecological sluice gate groups according to claim 1, characterized in that, Methods for obtaining vegetation change patterns include: S11. The kNDVI vegetation index was smoothed using the moving average method to obtain a smoothed time series, and the time with the largest vegetation change rate was selected. p The smoothed time series is extended using the center point; S12. Fit the extended time series after the extension process using an integrated function, and determine whether the fitted pixels pass the F-test. If yes, proceed to step S13; otherwise, proceed to step S16. for: in, t To extend the sequence number of the time series, the range is 1 to N; q To extend the difference between the maximum value and the background value in the time series, c The initial background kNDVI value; e It is the natural logarithm; S13, when When the integration function is equal to the logistic function, the integration function is equivalent to the logistic function. When the integrated function is equivalent to the asymmetric Gaussian function, the vegetation change pattern is Gaussian. a The direction of vegetation change b equal to ( q + c The time corresponding to ) / 2; S14. For the logistic function form, the time point with the maximum or minimum rate of change of curvature in the ensemble function is used as the year of abrupt change. The formula for calculating the rate of change of curvature is: in, Transition parameters; The first derivative of the transition parameter; S15. Obtain the number of mutation years. If the number is 2, the vegetation change pattern is logical; if the number is 1, and the mutation point time is within... b Previously, the vegetation change pattern was exponential; otherwise, it was logarithmic. S16. For pixels whose ensemble function fit fails the F-test, the least squares method is used to perform linear regression on the smoothed time series to obtain a univariate linear regression equation: in, i For the smoothed time series, the first i Year, s For the parameters of linear regression, slope This indicates a trend in vegetation change; S17. Perform an F-test on the univariate linear regression equation. If the F-test is passed, the vegetation change pattern is linear; if the F-test is not passed, the vegetation change pattern is a trendless pattern.

3. The method for jointly regulating water resource utilization of desert riverbank vegetation based on ecological sluice gate groups according to claim 2, characterized in that, The method for dividing the distribution areas of the three types of vegetation is as follows: When the vegetation change pattern is logarithmic, logistic, or Gaussian, and the vegetation cover... When the vegetation cover is 0.3, the corresponding area is a key protected area; when the vegetation change pattern is linear or exponential, and the vegetation cover is... When the vegetation coverage is 0.3, the corresponding area is a key restoration area; when the vegetation coverage is between 0.03 and 0.3, the corresponding area is an ecologically sensitive area.

4. The method for jointly regulating water resource utilization of desert riverbank vegetation based on ecological sluice gate groups according to claim 2, characterized in that, Methods for extending smoothed time series include: S111. Calculate the difference between the forward and backward directions at each time point in the smoothed time series. : in, and The first i +1、 i Smoothed time series of years; S112, Select interpolation The year with the largest absolute value is considered the time with the largest vegetation change rate. p The length of the smoothed time series is related to p Symmetry, the length of each pixel extended time series L The calculation is as follows: when When, the time series is extended to become a smooth time series; when When the time series is extended, N elements are the same as the smoothed time series, and the remaining elements are the first term of the smoothed time series; when When the extended time series has the same first N elements as the smoothed time series, the remaining elements are the first term of the smoothed time series. This is the floor symbol.

5. The method for jointly regulating water resource utilization of desert riverbank vegetation based on ecological sluice gate groups according to claim 1, characterized in that, The method for obtaining the kNDVI vegetation index includes: A1. Obtain MODIS NDVI data of the desert watershed, and perform format conversion, projection conversion, and cropping operations on the data; A2. The data from 23 periods of each year are filtered by Savitzky-Golay, and then the NDVI data of each year are synthesized by the maximum value synthesis method to obtain the annual NDVI data. A3. Calculate the vegetation dynamics monitoring index kNDVI based on annual NDVI data: in, is the hyperbolic tangent function; NDVI is the annual NDVI data.

6. The method for jointly regulating water resource utilization of desert riverbank vegetation based on ecological sluice gate groups according to claim 1, characterized in that, Activating the ecological gate system for irrigation of the irrigation area further includes: When the ecological water supply of the corresponding watershed section of the ecological gate group meets the ecological water demand of its control area, the ecological gate group supplies water according to the ecological water demand of its corresponding control area. When the ecological water supply of the corresponding watershed section of the ecological gate group does not meet the ecological water demand of its control area, after the high-level ecological gate group supplies water to its corresponding key protection area, any surplus water will be allocated to the lower-level ecological gate group until the water is completely consumed.

7. The method for jointly regulating water resource utilization of desert riverbank vegetation based on ecological sluice gate groups according to claim 1, characterized in that, The formula for calculating the vegetation coverage is: in, V C For vegetation coverage, NDVI S bare land in desert watershed NDVI value, NDVI v For pure vegetation elements NDVI value, NDVI S and NDVI v Take the values ​​at the 5% and 95% points of the annual NDVI histogram, respectively.

8. The method for jointly regulating water resource utilization of desert riverbank vegetation based on ecological sluice gate groups according to any one of claims 1-7, characterized in that, Also includes: In key protected areas, seepage irrigation through ditches is used to regulate groundwater levels. In ecologically sensitive areas, the process of flood overflow is controlled to promote vegetation growth and sapling formation. In key restoration areas, seepage irrigation through ditches is combined with flood overflow to raise groundwater levels and promote seed germination. The irrigation period is from July to September.

Images