Remote sensing hydrologic station layout method

Abstract

The invention relates to the technical field of remote sensing hydrologic station layout, and provides a remote sensing hydrologic station layout method, which comprises the following steps of: selecting an equal-flux river reach according to DEM data and rainfall data monitored by a satellite, extracting a waterline of the river reach by means of remote sensing data, screening open river reaches on two sides or a single side, and constructing a digital grid model DEM to obtain river topographic information of the river reaches; determining open-type and semi-open-type typical river reaches from the selected river reaches, constructing a relation curve of water surface area and reservoir capacity, determining the length of a unit river reach by combining water volumes and areas in different states, selecting a typical observation river reach with a specific length from the typical river reaches, arranging a remote sensing hydrometric station to enable the remote sensing hydrometric station to collect remote sensing images of the typical observation river reach, the remote sensing image of the typical observation river reach is used for calculating the river flow. According to the method, a good typical observation river reach can be selected, and the remote sensing observation effect is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of remote sensing hydrological station deployment, and in particular relates to a remote sensing hydrological station deployment method. Background Art

[0002] Hydrological monitoring is a key link in water resources management and flood prevention and disaster reduction. As the main means of obtaining hydrological information such as river flow, water level, and rainfall, traditional hydrological stations play an important role in water resources investigation, planning, and scheduling. However, due to the constraints of economic, social, and natural conditions, the density of hydrological stations in many river basins is currently low, especially in high mountain valleys and remote areas, where there are a large number of rivers without data. This phenomenon has brought huge challenges to the comprehensive acquisition of hydrological information and river basin management.

[0003] The deployment and operation of traditional hydrological stations usually rely on infrastructure, equipment maintenance, transportation, and support from on-site staff. Therefore, in areas with harsh natural conditions or few people, the deployment and maintenance costs of traditional hydrological stations are extremely high, and monitoring efficiency is also greatly affected. Faced with these difficulties, the existing hydrological station network density is insufficient and cannot provide comprehensive and timely data support for flood warning, dispatching, and flood prevention.

[0004] With the rapid development of remote sensing technology, remote sensing hydrological stations, as an emerging means of hydrological monitoring, provide important technical support for improving the wide-area coverage and timeliness of hydrological monitoring. Remote sensing hydrological stations can achieve dynamic monitoring of large-scale rivers, lakes and other water bodies without contact by using high-resolution, short-revisit period remote sensing satellites and drones. Especially in data-free river areas where it is difficult to deploy traditional hydrological stations, remote sensing hydrological stations provide a new solution for obtaining hydrological information.

[0005] However, although remote sensing technology has shown great potential in hydrological monitoring, the deployment and application of remote sensing hydrological stations still face many technical challenges.

[0006] First, the spatial resolution and temporal resolution of different remote sensing data need to be reasonably balanced. High-resolution images can provide detailed river information, but their coverage is small and the revisit period is long, which makes it difficult to meet the monitoring needs of rapid dynamic processes such as floods. Secondly, remote sensing images are limited in applicability in complex terrains such as high mountains and canyons. Factors such as mountain occlusion and terrain undulations will affect the acquisition and processing of remote sensing images. Third, the spatiotemporal dynamic characteristics of flood processes are complex, and remote sensing data at a single moment cannot fully capture the spatiotemporal evolution of floods, especially in mountainous areas. The propagation speed and path of floods are variable, and traditional remote sensing data are difficult to meet the timeliness requirements. Finally, the fusion and correction of multi-source remote sensing data and the interference of water surface reflection characteristics also put forward higher requirements on the accuracy and monitoring effect of remote sensing hydrological stations. Summary of the invention

[0007] To solve the above problems, the present disclosure provides a remote sensing hydrological station layout method, which selects equal flux river sections based on DEM data and rainfall data, extracts water edges, constructs digital grid model DEM to obtain river terrain information, selects typical river sections, constructs relationship curves to determine unit river section lengths and selects typical observation river sections, and finally deploys remote sensing hydrological stations to collect remote sensing images for calculating river flow. This method can improve the accuracy and monitoring effect of remote sensing hydrological stations.

[0008] The following is the technology of the present invention:

[0009] A method for laying out a remote sensing hydrological station, characterized by comprising:

[0010] Select river sections with equal flux based on DEM data and satellite-monitored rainfall data;

[0011] Based on remote sensing data, the waterside of equal-flux river sections is extracted, and river sections with open sides or one side are selected from the equal-flux river sections; based on the waterside, a digital grid model DEM of the river sections with open sides or one side is constructed, and the river topography information of the river section of the river section is obtained using the digital grid model DEM;

[0012] Select open and semi-open river sections from river sections with open sides or one side as typical river sections;

[0013] Based on the river terrain information, a relationship curve between water surface area and reservoir capacity is constructed. The length of a unit river section is determined by combining the water volume and water surface area of ​​a typical river section under normal conditions and when a flood comes. A river section with a length that is n times the length of the unit river section is selected as a typical observation river section.

[0014] Remote sensing hydrological stations are deployed to collect remote sensing images of typical observed river sections, and the remote sensing images of the typical observed river sections are used to calculate the river flow of the typical observed river sections.

[0015] Further,

[0016] Calculate the river flow of typical observed river sections, including:

[0017] Using remote sensing images of typical observed river sections, the multi-temporal water surface widths of multiple sections of typical observed river sections are extracted; based on the multi-station hydraulic geometry relationship of typical observed river sections and the multi-temporal section water surface widths, the river flow is calculated.

[0018] Further,

[0019] The method is based on the multi-station hydraulic geometry relationship of a typical observed river section, the water surface width of a multi-phase section, and the calculation of river flow; including:

[0020] The initial cross section is set at a distance of 500m between river sections, and the flow is calculated based on the hydraulic geometry relationship between flow and water surface width:

[0021] w=aQ b

[0022] In the formula, w is the width of the water surface, m; Q is the flow rate, m3 / s; a and b are hydraulic geometric parameters;

[0023]

[0024] Where x is the section number; w x is the average cross-sectional width, a x , b x is the hydraulic geometric parameter of the xth section; E is the specific parameter in the river channel;

[0025]

[0026] In the formula, is the water surface width of each section; p and y are fitting coefficients;

[0027] The river width and flow rate were linked by measuring multiple fixed sections in the same river section and establishing a regression relationship between the water surface width and flow rate. The AMHG method was used to link the river width and flow rate at multiple sites through a log-linear relationship.

[0028] According to the range of parameters a and b and the log-linear relationship between a and b, the flow rate of any section can be calculated given a pair of a and b values ​​and the river width.

[0029] Further,

[0030] The values ​​of a and b are obtained using a genetic algorithm, which includes:

[0031] Given the initial value combination of hydraulic geometric parameters a and b;

[0032] The river flow is calculated using the initial value combination of hydraulic geometric parameters a and b and relevant data of the river, and the calculated value is compared with the actual observed flow to obtain the fitness value;

[0033] Select the value combination of a and b with fitness higher than the threshold as individuals to enter the next generation population;

[0034] Perform crossover and mutation operations based on the next generation population to obtain a new population;

[0035] Iterate the new population to obtain the values ​​of hydraulic geometric parameters a and b.

[0036] Further,

[0037] The selection of equal flux river sections based on DEM data and satellite-monitored rainfall data includes:

[0038] Based on DEM data, fill the depressions to generate a depression-free DEM, calculate the flow direction data and the cumulative runoff, extract the basin boundary and river network, divide the basin into levels according to the cumulative runoff, and identify the mainstream and tributaries of the runoff path; combine with rainfall data to obtain the runoff cumulative grid map;

[0039] From the upstream to the downstream of the river section, the benchmark points are determined by the cumulative flow grid map, the cumulative flow of each grid and the change trend of the river section are counted, and the runoff flux on the confluence path is calculated by the cumulative flow;

[0040] The locations where the cumulative flux intensity changes by 5% are identified, and the river sections where the change is within 5% are regarded as equal flux sections.

[0041] Further,

[0042] The method of extracting the water edge of the isoflux river section based on remote sensing data comprises:

[0043] Extract river water morphology information from remote sensing image data;

[0044] Calculate the normalized water index using different bands:

[0045]

[0046] Among them, Green and NIR are remote sensing reflectances in the green band and near infrared band respectively;

[0047] Based on the normalized water index, multiple water edge lines and center lines at different times are extracted;

[0048] Draw a perpendicular line through the center line to intersect the waterside line, and calculate the distance between the intersection points as the width of the water surface;

[0049] Calculate the average water surface width to get the average water surface width and determine the average water edge; compare the water surface widths to determine the maximum water edge and the minimum water edge.

[0050] Further,

[0051] The step of selecting a river section with open sides or one side from the river sections with equal flux includes:

[0052] Calculating a first distance between the center line corresponding to the maximum water edge line and the minimum water edge line, and a second distance between the center line corresponding to the average water edge line and the minimum water edge line;

[0053] For the waterside lines on both sides of the river, calculate the moving distance ratio value according to the formula (first distance - second distance) / second distance * 100%;

[0054] If the moving distance ratio of the water edge lines on both sides is <10%, the river section is a vertical section; if the moving distance ratio of the water edge lines on one side is <10% and the other side is ≥10%, it is a one-sided vertical and one-sided open section; if the moving distance ratio of the water edge lines on both sides is ≥10%, it is a double-sided open section, thus selecting the river section with open sides or one-sided open.

[0055] Further,

[0056] The digital grid model DEM of the open river sections on both sides or the open river section on one side is constructed based on the waterside line, including:

[0057] Determine the water edge elevation value;

[0058] Extract multiple waterside lines and merge them to generate an outer envelope line. Interpolate the elevation value on the waterside line within the maximum interpolation range based on the elevation value of the outer envelope line to obtain continuous elevation information.

[0059] The digital grid model DEM of the river terrain is generated using continuous elevation information. The river terrain includes: underwater terrain, terrain from the maximum water edge to the minimum water edge, and terrain above the maximum water edge.

[0060] Further,

[0061] Determining the length of the unit river section includes:

[0062] Find the length of the unit river section l such that

[0063] Where ΔA i =A 1i -A 0i , A 1i A is the water surface area of ​​a unit river section when a flood occurs; 0i It is the water surface area of ​​a unit river section under normal conditions.

[0064] A method system for deploying a remote sensing hydrological station, characterized by comprising:

[0065] Selection module, used to select isoflux river sections based on DEM data and satellite-monitored rainfall data;

[0066] The river terrain information acquisition module is used to extract the waterside line of the isoflux river section based on remote sensing data, and select the river section with open sides or one side in the isoflux river section; construct the digital grid model DEM of the river section with open sides or one side based on the waterside line, and use the digital grid model DEM to obtain the river terrain information of the river section of the river section;

[0067] A typical observation river section selection module is used to select open and semi-open river sections from river sections with open sides or one side as typical river sections;

[0068] Based on the river terrain information, a relationship curve between water surface area and reservoir capacity is constructed. The length of a unit river section is determined by combining the water volume and water surface area of ​​a typical river section under normal conditions and when a flood comes. A river section with a length that is n times the length of the unit river section is selected as a typical observation river section.

[0069] The deployment module is used to deploy remote sensing hydrological stations to collect remote sensing images of typical observation river sections, and the remote sensing images of typical observation river sections are used to calculate the river flow of the typical observation river sections.

[0070] Compared with the prior art, the present invention has the following advantages:

[0071] The selection of equal-flux river sections based on DEM data and satellite-monitored rainfall data, whose stable hydrological characteristics help reduce uncertainty and provide a stable basis for subsequent operations;

[0072] The water edge is extracted using remote sensing data, and a digital grid model DEM is constructed based on it to obtain accurate terrain information. Accurate water edge and terrain information helps to select open and semi-open river sections with less interference and good visibility as typical river sections. The water flow conditions in such river sections are simple and the data is more representative, thus overcoming the problem that traditional hydrological stations are difficult to effectively cover a large area of ​​the basin.

[0073] Open and semi-open river sections are selected as typical river sections from river sections that are open on both sides or one side. The relationship curve between water surface area and reservoir capacity is constructed based on the river terrain information. The reasonable unit river section length is determined based on the different state data of typical river sections. The typical observation river sections selected based on this can comprehensively reflect the characteristics of the river channel, which is helpful to solve the problems of poor accuracy and monitoring effect of existing remote sensing hydrological stations.

[0074] The present invention can improve the overall remote sensing observation effect, realize the accurate identification and spatiotemporal dynamic monitoring of flood processes, and overcome the problems of insufficient time continuity and spatial coverage of traditional hydrological stations.

[0075] Other features and advantages of the present disclosure will be described in the following description, and partly become apparent from the description, or be understood by implementing the present disclosure. The purpose and other advantages of the present disclosure can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0077] Figure 1 A schematic diagram of the method of the present invention is shown. DETAILED DESCRIPTION

[0078] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0079] The monitoring method of traditional hydrological stations can be summarized as "trading time for space", that is, through long-term monitoring at fixed sites, hydrological data such as flow and water level that change over time at a certain location are obtained. This method describes the evolution of hydrological events through time series and is suitable for long-term hydrological observation and data accumulation. However, traditional hydrological stations are limited by the distribution and density of stations, making it difficult to effectively cover a large range of river basins, especially in the monitoring of rivers with no data and remote mountainous areas.

[0080] Remote sensing hydrological stations use the method of "trading space for time", that is, through large-scale monitoring of fixed flow fields, remote sensing data is used to capture instantaneous water distribution and spatial characteristics. The advantage of remote sensing hydrological stations lies in their wide-area coverage capability. Through multi-source remote sensing image data, they can comprehensively and instantly capture the hydrological characteristics of different locations in the basin, thereby describing hydrological events in the spatial dimension.

[0081] This approach overcomes the problems of insufficient temporal continuity and spatial coverage in traditional methods, and is particularly suitable for dynamic flood monitoring of data-free rivers and large-scale water resources management.

[0082] Based on this, Figure 1 A schematic diagram of the method according to the present invention is shown, and the specific implementation details of the present invention include:

[0083] Remote sensing hydrological station establishment process:

[0084] 1. Step 1: Select the isoflux river section

[0085] Specifically, they include:

[0086] 1.1) Data collection and preprocessing

[0087] Data collection: Use Copernicus DEM with a resolution of 30m to collect rainfall station data in the basin (or use satellite remote sensing rainfall products).

[0088] Watershed division: Based on the DEM data, fill the depressions to generate a depression-free DEM, calculate the water flow direction data and the cumulative runoff, extract the basin boundaries and river networks, divide the basin into sub-basins according to the cumulative runoff, and clarify the mainstream and tributaries of the runoff path.

[0089] 1.2) Calculation and analysis of cumulative flux intensity

[0090] 1.2.1) Based on the cumulative number of confluence (method 1)

[0091] From upstream to downstream, the benchmark points are determined by the cumulative confluence grid map, the cumulative confluence numbers of each grid and the changing trends of the river section are counted, and the runoff flow on the confluence path is calculated using the cumulative confluence numbers.

[0092] Identify the location where the cumulative flux intensity changes by 5%, and regard the river section with a change within 5% as a stable flux river section. The confluence classification index is calculated based on the cumulative number of confluences at the benchmark points of adjacent stable flux river sections for classification.

[0093] 1.2.2) Based on runoff accumulation and rainfall data (Method 2)

[0094] The point rainfall is spread into a surface rainfall distribution map using interpolation methods such as the inverse distance weighted method, and the rainfall per unit area of ​​each cell in the basin is calculated.

[0095] The cumulative flux intensity of the hydrological station is calculated in combination with the cumulative number of confluence, and then the stable flux river section is identified and the confluence classification index is calculated in the same way as method 1.

[0096] 1.3) Confluence classification and river section determination

[0097] According to the river flow monitoring specifications, sections with flux errors within 5% are determined to be stable sections, and the rest are unstable sections.

[0098] 2. Step 2: Identify the topographic features of typical river sections and select river sections with open sides or one side based on remote sensing data.

[0099] Specifically, they include:

[0100] 2.1) Data collection and processing

[0101] Identify the river channels in the study area, specify the time range, and collect remote sensing image data from satellites such as Landsat series, Sentinel series, and Gaofen series at different times.

[0102] Perform radiation correction, atmospheric correction, geometric correction and other operations on remote sensing image data to ensure image accuracy and consistency.

[0103] 2.2) Extract waterside and centerline

[0104] Extract river water morphology information from remote sensing image data and calculate water body normalization index using different bands Based on this index, multiple waterside lines and center lines at different times are extracted. Among them, Green and NIR are the remote sensing reflectance of the green band and near infrared band respectively.

[0105] 2.3) Determine the relevant waterside and centerline

[0106] The perpendicular line through the center line intersects with the water edge line, and the distance between the intersection points is calculated as the water surface width.

[0107] The average water surface width is calculated to obtain the average water surface width and determine the average water edge. The water surface widths are compared to determine the maximum water edge and the minimum water edge, and the center line corresponding to the minimum water edge is used as the basis for subsequent calculations.

[0108] 2.4) Calculate the moving distance ratio and identify the river section shape

[0109] The distance between the center line corresponding to the maximum water edge line and the minimum water edge line (first distance) and the distance between the center line corresponding to the average water edge line and the minimum water edge line (second distance) are calculated.

[0110] For the waterside lines on both sides of the river, the moving distance ratio is calculated according to the formula (first distance - second distance) / second distance * 100%, and the threshold is set to 10%.

[0111] If the moving distance ratio of the water edge lines on both sides is <10%, the river section is a vertical section; if the moving distance ratio of the water edge lines on one side is <10% and the other side is ≥10%, it is a one-sided vertical and one-sided open section; if the moving distance ratio of the water edge lines on both sides is ≥10%, it is a double-sided open section, thus selecting the river section with open sides or one-sided open.

[0112] The deployment of remote sensing hydrological stations enables remote sensing images to clearly observe selected river sections that are open on both sides or on one side, making it easier to conduct hydrological observations based on remote sensing images using remote sensing hydrological stations.

[0113] 3. Step 3: Make river section terrain:

[0114] Specifically, the steps to construct the river section terrain based on the water surface line are as follows:

[0115] 3.1) Determine the waterside elevation;

[0116] For straight river sections: if the altimetry satellite measuring point coincides with the river section, take the elevation value at the intersection; if there is an angle, select the elevation value at the intersection of the altimetry satellite measuring point and the flow section, and assign it to the corresponding point on the waterside line.

[0117] For curved river sections: due to the lateral gradient of centrifugal force, the elevation value at the water's edge is determined based on linear fitting of several existing points.

[0118] 3.2) Interpolation of elevation points and generation of digital grid model: Extract multiple waterside lines and fuse them to generate outer envelope lines, which are used as the maximum interpolation range. The elevation values ​​on the waterside lines are interpolated to obtain comprehensive and continuous elevation information;

[0119] Generate digital grid model DEM of river terrain using elevation information

[0120] 4. Step 4: Roughly determine the typical river section:

[0121] Open and semi-open river sections are selected as typical river sections among river sections with stable runoff flow.

[0122] 5. Step 5: Determine the length of the unit river section:

[0123] The length of a typical river section is 5 unit river section lengths. Once the unit river section length is determined, the specific length of the typical river section can be confirmed.

[0124] The water volume of a typical river section under normal conditions is V0, and the water surface area of ​​the river section is A0. when When a flood comes, the water volume in a typical river section will rise. At this time, the water volume in the typical river section will increase to V1, and the water surface area of ​​the river section will also increase to A1.

[0125] Normal state: the amount of water in a unit river section is V 01 、V 02 、V 03 、V 04 、V 05 , the water surface area corresponding to a unit river section is A 01 , A 02 , A 03 , A 04 , A 05 ;

[0126] When a flood occurs: the amount of water in a unit river section is V 11 、V 12 、V 13 、V 14 、V 15 , the water surface area corresponding to a unit river section is A 11 , A 12 , A 13 , A 14 , A 15 ;

[0127] In a unit river section, when a flood occurs, the amount of water that changes is ΔV i , the changing water surface area is ΔA i Then we have:

[0128] ΔV i =V 1i -V 0i

[0129] ΔA i =A 1i -A 0i

[0130] In the formula, i=1,2,3,4,5.

[0131] Since the topography of the river section is known, there is a definite correlation between the water volume per unit section and the water surface area per unit section:

[0132] ΔV i =f(ΔA i )

[0133] The water surface area of ​​a unit river section is related to the length of the unit river section. According to the correlation between the volume of water in the river section and the water surface area of ​​the river section, there is a unit river section length 1 such that:

[0134]

[0135] The length l at this time is taken as the unit river section length.

[0136] Based on the unit river section length, a river section whose length is n times the unit river section length is selected from the typical river sections as a typical observation river section. The length of the typical river section is greater than 5 times the unit river section length.

[0137] 6. Step 6: Conduct hydrological observations using remote sensing images

[0138] Specifically include:

[0139] 6.1) Estimation of river flow

[0140] Based on the selected typical river sections, river sections with open sides or one side are preferred for flow calculation, and measurement points are avoided in river sections with steep or vertical sides. Taking a 10-kilometer river section as a unit, a measurement point is set every 500 meters to measure the width of the river section. The flow of the river section is calculated through the hydraulic geometry relationship of multiple sites to achieve the estimation of river flow.

[0141] 6.2) River width extraction

[0142] Remote sensing images (such as Landsat and Sentinel-2) are used to extract the multi-temporal cross-sectional water surface width of typical river sections.

[0143] 6.3) Establish hydraulic geometry

[0144] This method sets the initial cross section at a distance of 500m between river sections, obtains the spatiotemporal width changes of the river through remote sensing images, and calculates the flow rate based on the hydraulic geometric relationship between the flow rate and the water surface width.

[0145] w=aQ b

[0146] Where w is the water surface width, m; Q is the flow rate, m3 / s; a and b are hydraulic geometric parameters.

[0147]

[0148] Where x is the section number; w x is the average cross-sectional width, a x , b x is the hydraulic geometric parameter of the xth section; E is the specific parameter in the river channel;

[0149]

[0150] In the formula, is the water surface width of each section; p and y are fitting coefficients; x1, x2, ..., x n Subscripts correspond to the cross-section locations within the river reach.

[0151] Multiple fixed sections in the same river section were measured to establish a regression relationship between width and flow. The AMHG method was used to link the river width and flow at multiple stations through a log-linear relationship, where Approximate y to calculate specific hydraulic geometric parameters a and b.

[0152] 6.4) Traffic estimation and optimization:

[0153] According to the range of hydraulic geometric parameters a and b and the logarithmic linear relationship between a and b, the flow of any section can be calculated given a pair of a and b values ​​and the river width. The flow is solved using a genetic algorithm (GA), and the flow difference is minimized as the optimization goal to ensure that the estimated result is within a reasonable range. Finally, the average value of the multi-station flow is used as the flow estimation result of the river section.

[0154] Table 1 GA parameter recommendation table

[0155]

[0156]

[0157] (1) For a pair of cross sections within a range, use GA to converge to the values ​​of a and b to calculate the optimal flow (calculated based on the classical hydraulic geometry and the observed multi-time width). The flow range is assumed to be as follows:

[0158] Minimum allowable flow rate = minimum observed width × 0.5m depth × 0.1m / s velocity

[0159] Maximum allowable flow rate = maximum observed width × 10m depth × 5m / s velocity

[0160] (2) Repeat step 1 50 times to obtain 100 estimates of the hydraulic geometry of a pair of cross sections.

[0161] (3) Arranging steps 1 and 2 in geographic space and applying GA to all possible cross-sections in pairs within the mass conservation range will produce (n 2 The hydraulic geometry parameters of each interface selected by GA are estimated using 10 × 100 GAs, where n is the number of cross sections within 10 km.

[0162] (4) Summary (n 2 -n)×100 hydraulic geometry estimates are performed to obtain the final hydraulic geometry for each interface in the n sections. The GA output must be obtained from (n 2 The GA-based method extracts the hydraulic geometry estimates from a set of 100 (-n) × 100 ensemble hydraulic geometry estimates provided by the spatial arrangement of the individual hydraulic geometries for each cross section. The single parameter nature of AMHG is exploited. The median a value provided by GA is used in conjunction with the remote sensing AMHG approximation to calculate the b value corresponding to each cross section. This process is repeated using the median b value estimated by GA and the a value calculated by AMHG to give the a and b values ​​for each channel cross section.

[0163] (5) Calculate the flow rate Q based on the final selected hydraulic geometry parameters a and b. After determining the hydraulic geometry relationship a and b, the obtained parameters are applied to the cross-sectional water surface width obtained from the remote sensing image, and the flow rate of each cross section is estimated based on the relationship between the flow rate and the water surface width. This generates n flow estimates (one for each cross section), and the average flow rate is used as the estimated flow rate.

[0164] To sum up: This patent proposes a method for deploying remote sensing hydrological stations, aiming to use multi-source remote sensing data to dynamically monitor rivers and water bodies, especially for flood monitoring and early warning needs in rivers with no data and remote mountainous areas.

[0165] This method combines the high spatial resolution advantages of remote sensing images with the dynamic simulation capabilities of traditional hydrological models. By rationally deploying remote sensing hydrological stations, it can achieve accurate identification and spatiotemporal dynamic monitoring of flood processes.

[0166] Based on the method of the present invention, the embodiment of the present disclosure also provides a system corresponding to the above method, which includes:

[0167] Selection module, used to select isoflux river sections based on DEM data and satellite-monitored rainfall data;

[0168] The river terrain information acquisition module is used to extract the waterside line of the isoflux river section based on remote sensing data, and select the river section with open sides or one side in the isoflux river section; construct the digital grid model DEM of the river section with open sides or one side based on the waterside line, and use the digital grid model DEM to obtain the river terrain information of the river section of the river section;

[0169] A typical observation river section selection module is used to select open and semi-open river sections from river sections with open sides or one side as typical river sections;

[0170] Based on the river terrain information, a relationship curve between water surface area and reservoir capacity is constructed. The length of a unit river section is determined by combining the water volume and water surface area of ​​a typical river section under normal conditions and when a flood comes. A river section with a length that is n times the length of the unit river section is selected as a typical observation river section.

[0171] The deployment module is used to deploy remote sensing hydrological stations to collect remote sensing images of typical observation river sections, and the remote sensing images of typical observation river sections are used to calculate the river flow of the typical observation river sections.

[0172] Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A method for deploying a remote sensing hydrological station, characterized in that: include: Select river sections with equal flux based on DEM data and satellite-monitored rainfall data; Based on remote sensing data, the waterside of equal-flux river sections is extracted, and river sections with open sides or one side are selected from the equal-flux river sections; based on the waterside, a digital grid model DEM of the river sections with open sides or one side is constructed, and the river topography information of the river section of the river section is obtained using the digital grid model DEM; Select open and semi-open river sections from river sections with open sides or one side as typical river sections; Based on the river terrain information, a relationship curve between water surface area and reservoir capacity is constructed. The length of a unit river section is determined by combining the water volume and water surface area of ​​a typical river section under normal conditions and when a flood comes. A river section with a length that is n times the length of the unit river section is selected as a typical observation river section. Remote sensing hydrological stations are deployed to collect remote sensing images of typical observed river sections, and the remote sensing images of the typical observed river sections are used to calculate the river flow of the typical observed river sections.

2. A method for deploying a remote sensing hydrological station according to claim 1, characterized in that: Calculate the river flow of typical observed river sections, including: Using remote sensing images of typical observed river sections, the multi-temporal water surface widths of multiple sections of typical observed river sections are extracted; based on the multi-station hydraulic geometry relationship of typical observed river sections and the multi-temporal section water surface widths, the river flow is calculated.

3. A method for laying out a remote sensing hydrological station according to claim 2, characterized in that: The method is to calculate the river flow based on the multi-station hydraulic geometry relationship of a typical observed river section and the water surface width of a multi-phase section; include: The initial cross section is set at a distance of 500m between river sections, and the flow is calculated based on the hydraulic geometry relationship between flow and water surface width: w=aQ b In the formula, w is the width of the water surface, m; Q is the flow rate, m3 / s; a and b are hydraulic geometric parameters; Where x is the section number; w x is the average cross-sectional width, a x 、b x is the hydraulic geometric parameter of the xth section; E is the specific parameter in the river channel; In the formula, is the water surface width of each section; p and y are fitting coefficients; The river width and flow rate were linked by measuring multiple fixed sections in the same river section and establishing a regression relationship between the water surface width and flow rate. The AMHG method was used to link the river width and flow rate at multiple sites through a log-linear relationship. According to the range of hydraulic geometry parameters a and b and the logarithmic linear relationship between a and b, the flow rate of any section can be calculated given a pair of a and b values ​​and the river width.

4. A method for laying out a remote sensing hydrological station according to claim 3, characterized in that: The values ​​of hydraulic geometric parameters a and b are obtained using genetic algorithm, which include: Given the initial value combination of hydraulic geometric parameters a and b; The river flow is calculated using the initial value combination of hydraulic geometric parameters a and b and relevant data of the river, and the calculated value is compared with the actual observed flow to obtain the fitness value; Select the value combination of a and b with fitness higher than the threshold as individuals to enter the next generation population; Perform crossover and mutation operations based on the next generation population to obtain a new population; Iterate the new population to obtain the values ​​of hydraulic geometric parameters a and b.

5. The method for deploying a remote sensing hydrological station according to claim 1, characterized in that: The selection of equal flux river sections based on DEM data and satellite-monitored rainfall data includes: Based on DEM data, fill the depressions to generate a depression-free DEM, calculate the flow direction data and the cumulative runoff, extract the basin boundary and river network, divide the basin into levels according to the cumulative runoff, and identify the mainstream and tributaries of the runoff path; combine with rainfall data to obtain the runoff cumulative grid map; From the upstream to the downstream of the river section, the benchmark points are determined by the cumulative flow grid map, the cumulative flow of each grid and the change trend of the river section are counted, and the runoff flux on the confluence path is calculated by the cumulative flow; The locations where the cumulative flux intensity changes by 5% are identified, and the river sections where the change is within 5% are regarded as equal flux sections.

6. A method for laying out a remote sensing hydrological station according to claim 1, characterized in that: The method of extracting the water edge of the isoflux river section based on remote sensing data comprises: Extract river water morphology information from remote sensing image data; Calculate the normalized water index using different bands: Among them, Green and NIR are remote sensing reflectances in the green band and near infrared band respectively; Based on the normalized water index, multiple water edge lines and center lines at different times are extracted; Draw a perpendicular line through the center line to intersect the waterside line, and calculate the distance between the intersection points as the width of the water surface; Calculate the average water surface width to get the average water surface width and determine the average water edge; compare the water surface widths to determine the maximum water edge and the minimum water edge.

7. A method for laying out a remote sensing hydrological station according to claim 6, characterized in that: The step of selecting a river section with open sides or one side from the river sections with equal flux includes: Calculating a first distance between the center line corresponding to the maximum water edge line and the minimum water edge line, and a second distance between the center line corresponding to the average water edge line and the minimum water edge line; For the waterside lines on both sides of the river, calculate the moving distance ratio value according to the formula (first distance - second distance) / second distance * 100%; If the moving distance ratio of the water edge lines on both sides is <10%, the river section is a vertical section; if the moving distance ratio of the water edge lines on one side is <10% and the other side is ≥10%, it is a one-sided vertical and one-sided open section; if the moving distance ratio of the water edge lines on both sides is ≥10%, it is a double-sided open section, thus selecting the river section with open sides or one-sided open.

8. The method for deploying a remote sensing hydrological station according to claim 1, characterized in that: The digital grid model DEM of the open river sections on both sides or the open river section on one side is constructed based on the waterside line, including: Determine the water edge elevation value; Extract multiple waterside lines and merge them to generate an outer envelope line. Interpolate the elevation value on the waterside line within the maximum interpolation range based on the elevation value of the outer envelope line to obtain continuous elevation information. The digital grid model DEM of the river terrain is generated by using continuous elevation information. The river terrain includes: underwater terrain, terrain from the maximum water edge to the minimum water edge, and terrain above the maximum water edge.

9. The method for deploying a remote sensing hydrological station according to claim 1, characterized in that: Determining the length of the unit river section includes: Find the length of the unit river section l such that Where ΔA i =A 1i -A 0i , A 1i A is the water surface area of ​​a unit river section when a flood occurs; 0i It is the water surface area of ​​a unit river section under normal conditions.

10. A method and system for deploying remote sensing hydrological stations, characterized in that: include: Selection module, used to select isoflux river sections based on DEM data and satellite-monitored rainfall data; The river terrain information acquisition module is used to extract the waterside line of the isoflux river section based on remote sensing data, and select the river section with open sides or one side in the isoflux river section; construct the digital grid model DEM of the river section with open sides or one side based on the waterside line, and use the digital grid model DEM to obtain the river terrain information of the river section of the river section; A typical observation river section selection module is used to select open and semi-open river sections from river sections with open sides or one side as typical river sections; Based on the river terrain information, a relationship curve between water surface area and reservoir capacity is constructed. The length of a unit river section is determined by combining the water volume and water surface area of ​​a typical river section under normal conditions and when a flood comes. A river section with a length that is n times the length of the unit river section is selected as a typical observation river section. The deployment module is used to deploy remote sensing hydrological stations to collect remote sensing images of typical observation river sections, and the remote sensing images of typical observation river sections are used to calculate the river flow of the typical observation river sections.

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