A soil moisture site planning method, device and storage medium considering hydrological characteristics

Abstract

The present invention discloses a soil moisture station planning method, device and storage medium taking into account hydrological characteristics. The method comprises the following steps: obtaining digital elevation model data and analyzing the data to extract basic geomorphological features of a watershed; then dividing the watershed into sub-watersheds in combination with a rainstorm center map obtained through interpolation and overlay analysis to obtain a sub-watershed partition map; obtaining satellite remote sensing data and measured data of soil moisture stations, and drawing a daily soil moisture sub-watershed distribution map in combination with the sub-watershed partition map; determining the layout density of sites in different sub-watersheds in combination with the sub-watershed division and the daily soil moisture sub-watershed distribution map; preliminarily planning the locations of soil moisture stations based on the layout density of sites in different sub-watersheds using a sub-watershed center method; optimizing the locations of soil moisture stations in combination with the soil type and land use type of the underlying surface, and completing soil moisture station planning. The present invention can reliably plan soil moisture stations and facilitate the acquisition of soil moisture monitoring data, thereby providing basic data for drought and flood forecasting in the watershed.

Description

Technical Field

[0001] The present invention relates to a soil moisture site planning method, device and storage medium taking hydrological characteristics into consideration, and belongs to the technical field of hydrology. Background Art

[0002] Floods are one of the most common natural disasters, causing devastating losses. Floods in mountainous areas can rise and fall dramatically, with short forecast horizons. Improving the forecast accuracy of hydrological models is a key measure to reduce flood losses. Hydrological models generalize the patterns of runoff generation and confluence in a watershed. Using inputs such as precipitation and initial water content, they simulate and calculate flow rates at the outlet of a watershed, serving as a crucial basis for decision-making by water forecasters. The initial water storage state of a watershed and its changes during a flood significantly influence the shape and magnitude of a flood. Therefore, the influence of soil moisture on runoff generation mechanisms cannot be ignored and is a key factor influencing the accuracy of reservoir hydrological forecasts. However, my country's hydrological station network is still incomplete and low in density, failing to meet the requirements of refined hydrological forecasting. This is particularly true in remote mountainous areas, where hydrological stations are almost nonexistent and soil moisture stations are even fewer, leaving areas with little or no data. Advances in computer technology, space remote sensing, and drone imaging have enabled the acquisition of large-scale meteorological, soil and land use data, and even soil moisture data, addressing the challenges of a limited ground-based network. Microwave remote sensing offers advantages such as all-weather coverage, multi-angle coverage, high resolution, and strong penetration, making it a highly effective method for monitoring soil moisture. However, satellite remote sensing products can only retrieve soil moisture within a depth of 5 cm, making it difficult to obtain soil moisture at deeper levels. Determining soil moisture at specific vertical depths requires planning and deploying more soil moisture stations.

[0003] The uneven distribution of precipitation and underlying surface characteristics across the watershed results in spatiotemporal variability in soil moisture. Our primary challenge is to plan a soil moisture monitoring network based on the watershed's hydrometeorological and underlying surface characteristics, ensuring that measured soil moisture is representative and readily available for hydrological modeling. The basin is home to diverse rainstorm centers, soil types, and land use types. Our primary technical challenge is to comprehensively account for these uneven distributions. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a soil moisture site planning method, device and storage medium that take hydrological characteristics into consideration, which can reliably obtain soil moisture monitoring data and provide basic data for drought and flood forecasting in the basin.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides a soil moisture site planning method taking hydrological characteristics into consideration, comprising:

[0007] Obtain and analyze digital elevation model data to extract basic geomorphological features of the watershed. Then, combine the rainstorm center map obtained through interpolation and overlay analysis to divide the sub-watershed and obtain the sub-watershed zoning map.

[0008] Obtain satellite remote sensing data and soil moisture site measured data, and draw a daily soil moisture sub-basin distribution map in combination with the sub-basin zoning map;

[0009] Determine the station layout density in different sub-basins based on the sub-basin division and the daily soil moisture sub-basin distribution map;

[0010] Based on the density of stations in different sub-basins, the locations of soil moisture stations are preliminarily planned using the sub-basin center method;

[0011] Optimize the location of soil moisture stations based on the soil type and land use type of the underlying surface and complete the soil moisture station planning.

[0012] Furthermore, the acquisition and analysis of digital elevation model data to extract basic landform features of the watershed, and then the sub-watershed division based on the rainstorm center map obtained by interpolation and overlay analysis to obtain the sub-watershed zoning map, includes:

[0013] Obtain digital elevation model data and analyze it to extract basic geomorphological features of the watershed, including the watershed area, length, and shape;

[0014] Calculating the slope and aspect of the watershed based on the digital elevation model and basic geomorphic features of the watershed;

[0015] Obtain rainfall data corresponding to different flood events, and use Kriging interpolation and spline function interpolation methods to perform spatial interpolation of rainfall data for each event;

[0016] The interpolation results of different rainfall events are superimposed and analyzed to obtain the center map of multiple rainstorms in the basin;

[0017] The basin underlying surface characteristics are distinguished according to the basin slope and slope direction, and the sub-basin is divided in combination with the rainstorm center map to obtain the sub-basin zoning map.

[0018] Furthermore, the acquisition of satellite remote sensing data and soil moisture site measured data, combined with the sub-watershed zoning map to draw a daily soil moisture sub-watershed distribution map, includes:

[0019] Obtain the longitude and latitude coordinates of existing soil moisture stations and historical soil moisture monitoring data. The longitude and latitude coordinates are used to determine the location of the soil moisture stations, and the historical soil moisture monitoring data is used for subsequent interpolation calculations.

[0020] Obtain soil moisture remote sensing product datasets, reproject them, resample them using the nearest neighbor method, and unify the data format;

[0021] The historical soil moisture data were spatially deterministically interpolated using the spline interpolation method, with the same temporal and spatial resolution as the satellite remote sensing data.

[0022] Different soil moisture products are weighted and integrated based on the inverse coefficient of variation method;

[0023] The fused soil moisture products are represented by zones, and daily soil moisture sub-basin distribution maps for multiple years are drawn.

[0024] Furthermore, the determination of the station layout density in different sub-basins based on the sub-basin division and the daily soil moisture sub-basin distribution map includes:

[0025] Calculate the area of each sub-basin according to the sub-basin division;

[0026] Based on the principle of uniform distribution of sub-basins, taking into account the size of the sub-basin area, the number of soil moisture stations to be distributed in each sub-basin is determined, and the minimum distribution density is calculated;

[0027] Combined with the daily soil moisture sub-basin distribution map, encryption is performed on the basis of the minimum layout density to determine the layout density of sites in different sub-basin areas.

[0028] Furthermore, based on the density of stations in different sub-basins, the sub-basin center method is used to preliminarily plan the location of soil moisture stations, including:

[0029] Based on the number of stations in different sub-basins, the corresponding sub-basins are divided into basic units of soil moisture station layout with equal areas;

[0030] The sub-basin center method is used in the basic unit of soil moisture station layout, and the sub-basin centroid is taken as the sub-basin center to determine the preliminary planning location of the soil moisture station.

[0031] Furthermore, the optimization of soil moisture station locations based on the underlying surface soil type and land use type to complete soil moisture station planning includes:

[0032] Overlay, extract, and fuse sub-basin boundaries with topography, soil types, and land use types to obtain representative areas of soil moisture monitoring stations with hydrological characteristic attribute information.

[0033] Surface soil types, deep soil types, and land use types are classified and displayed respectively, and the proportion of different types in the sub-basin is calculated. Based on the proportion of various types, the location of soil moisture stations is optimized;

[0034] The site location is adjusted and determined based on the on-site survey results of network signals, traffic convenience and construction feasibility.

[0035] Furthermore, the site location is adjusted and determined based on the on-site survey results of network signals, transportation convenience, and construction feasibility, including:

[0036] Based on the optimized site locations, the proposed soil moisture sites were surveyed on site. The network signal levels were classified into three categories: real-time transmission, transmission, and non-transmission based on the signal transmission rate. The construction convenience levels were classified into three categories: convenient construction, construction possible, and non-construction based on the difficulty of transporting construction equipment and the difficulty of deploying soil moisture monitoring instruments on the corresponding plots. The sites were classified into three categories: I, II, and III based on the shortest distance between the site and a Class IV or higher highway, representing convenient transportation, relatively convenient transportation, and inconvenient transportation, respectively. The classification principles are as follows:

[0037]

[0038] Where: L standard is the level of transportation convenience, L is the shortest distance between the proposed site and a fourth-level or above highway, in meters;

[0039] Based on the results of the field survey in terms of network signal, transportation convenience, and construction feasibility, a single factor index evaluation method was used, with the worst index level selected as the site evaluation level. The site locations were evaluated, with Grade I sites being used, Grade II sites being reserved, and Grade III sites being abandoned.

[0040] Subsequently, the abandoned site was adjusted and surveyed according to the above steps to determine the new proposed location, until the evaluation results of the three factors of network signal, transportation convenience and construction feasibility of the proposed site were better than level III, and the site location was determined as the proposed soil moisture site location for the corresponding sub-basin.

[0041] In a second aspect, the present invention provides a soil moisture site planning device that takes hydrological characteristics into consideration, comprising:

[0042] The extraction and division module is used to obtain and analyze digital elevation model data, extract basic geomorphological features of the watershed, and then divide the sub-watershed into sub-watersheds based on the rainstorm center map obtained through interpolation and overlay analysis to obtain sub-watershed zoning maps;

[0043] A drawing module is used to obtain satellite remote sensing data and soil moisture site measured data, and draw a daily soil moisture sub-basin distribution map in combination with the sub-basin zoning map;

[0044] The station density determination module is used to determine the station layout density of different sub-basins based on the sub-basin division and the daily soil moisture sub-basin distribution map;

[0045] A preliminary planning module, configured to preliminarily plan the locations of soil moisture stations using a sub-basin center method based on the density of stations in different sub-basins;

[0046] The site location optimization module is used to optimize the location of soil moisture sites based on the soil type and land use type of the underlying surface, and complete soil moisture site planning.

[0047] In a third aspect, the present invention provides a soil moisture site planning device that considers hydrological characteristics, including a processor and a storage medium;

[0048] The storage medium is used to store instructions;

[0049] The processor is configured to operate according to the instructions to execute the steps of any of the aforementioned methods.

[0050] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of any of the aforementioned methods when executed by a processor.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] The present invention provides a soil moisture station planning method, device and storage medium that take hydrological characteristics into consideration. The method comprehensively considers the hydrological characteristics that affect soil moisture, such as the basin topography, rainstorm center, soil type and land use type, and pays attention to the dynamic changes of soil moisture in the basin. It can reflect the influence of rainstorm center, soil type and land use type on soil moisture. These practices reflect the rationality of soil moisture station planning, make the constructed soil moisture stations more representative, and make the measured soil moisture more reliable. It solves the layout problem of the soil moisture station network in the basin, can be used for basin hydrological forecasting, and is conducive to further research on soil moisture station network planning. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a schematic diagram of the process provided by the implementation case of the present invention;

[0054] Figure 2 This is the DEM data map of the implementation case;

[0055] Figure 3 It is a schematic diagram of the slope and aspect of the implementation case;

[0056] Figure 4 It is the rainstorm center map of the implementation case;

[0057] Figure 5 It is the sub-basin division map of the implementation case;

[0058] Figures 6 to 8 It is the daily soil moisture quantum basin distribution map of the implementation case;

[0059] Figure 9 It is a map of surface soil types in the implementation case watershed;

[0060] Figure 10 is a deep soil type map of the implementation case watershed;

[0061] Figure 11 It is the land use type map of the implementation case watershed;

[0062] Figure 12 It is the soil moisture station network planning map of the implementation case. DETAILED DESCRIPTION

[0063] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0064] Example 1

[0065] This embodiment introduces a soil moisture site planning method that considers hydrological characteristics, including:

[0066] Obtain and analyze digital elevation model (DEM) data to extract basic geomorphological features of the watershed. Then, combine the rainstorm center map obtained through interpolation and overlay analysis to divide the sub-watershed and obtain the sub-watershed zoning map.

[0067] Obtain satellite remote sensing data and soil moisture site measured data, and draw a daily soil moisture sub-basin distribution map in combination with the sub-basin zoning map;

[0068] Determine the station layout density in different sub-basins based on the sub-basin division and the daily soil moisture sub-basin distribution map;

[0069] Based on the density of stations in different sub-basins, the locations of soil moisture stations are preliminarily planned using the sub-basin center method;

[0070] Optimize the location of soil moisture stations based on the soil type and land use type of the underlying surface and complete the soil moisture station planning.

[0071] like Figures 1 to 12 As shown, the soil moisture site planning method considering hydrological characteristics provided in this embodiment specifically involves the following steps:

[0072] S1. Extract basin topography based on DEM data and divide sub-basins into sub-basins based on the rainstorm center map, which specifically includes the following steps:

[0073] 1) Perform hydrological analysis on the original DEM data, extracting basic geomorphic features through steps such as filling depressions, flow direction analysis, flow analysis, setting extraction accuracy, selecting watershed outlets, calculating watersheds, extracting masks, converting river network grids to lines, and extracting watershed boundaries;

[0074] 2) Depression filling eliminates depressions in the data by filling the grid's sinks. Using the D8 algorithm and the steepest slope method, the maximum weighted drop between the center grid and adjacent grids is calculated, with the direction of the maximum weighted drop difference being the flow direction. Based on the flow direction and the principles of energy conservation and water balance, the cumulative runoff is calculated, with the grid value representing the total number of points flowing into that grid. A threshold for cumulative runoff is set, assuming that grids with a runoff cumulative value greater than the threshold constitute a river network. The watershed outlet is selected, and grids with a zero cumulative runoff are extracted to form a watershed, resulting in the catchment area above the outlet. Basic basin geomorphological features are extracted through steps such as raster-to-line and raster-to-surface conversion. Basic basin geomorphological features include drainage area and shape.

[0075] 3) Obtain the area between different contour lines, the length of each contour line and the grid spatial resolution based on the DEM data of the study area;

[0076] 4) Calculate the slope based on the contour interval and the horizontal distance between two contour lines. Calculate the slope change rate a second time based on the calculation of the surface slope to calculate the slope direction.

[0077] Slope and aspect calculations generally use the fitted surface method, which uses a quadratic surface, as shown in the figure below. The center point value of each grid is the elevation data.

[0078]

[0079]

[0080] The slope and aspect calculation formula is:

[0081]

[0082] ASPECT=SLOPE sn / SLOPE we

[0083]

[0084]

[0085] Where: SLOPE is the slope, in degrees; ASPECT is the slope direction, in degrees; SLOPE we is the slope in the X direction, SLOPE sn is the slope in the Y direction, in degrees; Cellsize is the grid spatial resolution, in km.

[0086] 1) Compile historical hydrological data and derive typical rainfall events based on the rainfall events corresponding to different flood events. Compile the coordinates of hydrological stations, rainfall stations, and rainfall data for subsequent interpolation calculations.

[0087] 2) Spatial interpolation of rainfall amounts for each rainfall event. Since rainfall amounts collected by hydrological stations and rain gauges are point rainfall amounts, they cannot accurately represent area rainfall amounts. Furthermore, rainfall is spatially and temporally heterogeneous. The most commonly used method is the inverse distance weighted spatial interpolation method, which assigns lower weights to points farther from the center. This method clearly does not conform to the basin-wide distribution characteristics of rainfall. Therefore, this invention employs both kriging and spline interpolation for spatial interpolation, taking the arithmetic mean of the two methods as the final interpolation result.

[0088] Kriging interpolation applies the first law of geography, which states that all spatial values are correlated, and this correlation is inversely proportional to the distance between locations. When using kriging to characterize spatial distributions, the spatial field is considered a random field, where the values at each point are random and follow a specific probability distribution. It is assumed that the mathematical expectation of the random field exists and is independent of location, and that the covariance function between any two points in the random field is related to the vector between them.

[0089]

[0090] in: is the point (x o ,y o ), the estimated value at z o =z(x o ,y o );λ i is the weight coefficient, which means it can satisfy and The optimal coefficient of .

[0091] Spline function interpolation is to obtain n interpolation intervals by segmenting two adjacent nodes. In each interpolation interval, a k-order polynomial S is used. i (x) Interpolation avoids the Runge phenomenon and makes the interpolation result smoother.

[0092] S i (x i )=f(x i ), S i (x i+1 )=f(x i+1 ), 0≤i≤n-1

[0093]

[0094] Where f(x) is the function to be interpolated, S i (x) is the interpolation polynomial.

[0095] Cubic spline function interpolation is to use S i (x) is set to S i (x) = a i +b i x+c i x 2 +d i x 3 .

[0096] According to the cubic spline interpolation principle and continuity conditions, four types of boundary conditions are added to construct the spline interpolation function group.

[0097] Natural boundary: S”(x0)=S”(x n )=0

[0098] Fixed boundary: S'(x0) = c1, S'(x n )=c2

[0099] Periodic spline: S'(x0)=S'(x n ), S”(x0)=S”(x n )

[0100] Not-a-knot: S"'(x0)=S"'(x1), S"'(x n-1 )=S”'(x n )

[0101] Where: S'(x), S”(x), S”'(x) are the first-order, second-order, and third-order derivatives of the interpolation polynomial at x, respectively.

[0102] 3) The interpolated rainfall will have different distributions on the watershed surface. Modify the display color of the symbol system in the figure. The depth of the color represents the amount of rainfall.

[0103] 4) The interpolation results of rainfall events of different times are superimposed and analyzed to obtain the rainstorm center map of multiple watersheds. At the same time, the sub-basin is divided according to the characteristics of the underlying surface of the watershed based on the slope and aspect of the watershed. The sub-basin division results are continuously adjusted using the visual method to ensure that there is at most one rainstorm center in the sub-basin, thus obtaining the sub-basin partition.

[0104] S2. Draw a daily soil moisture sub-basin distribution map based on the sub-basin zoning map, satellite remote sensing data, and soil moisture site measured data, specifically including the following steps:

[0105] 1) Organize the latitude and longitude coordinates of existing soil moisture stations and historical soil moisture monitoring data. The latitude and longitude coordinates are used to determine the location of the soil moisture stations, and the soil moisture monitoring data is used for subsequent interpolation calculations;

[0106] 2) Download soil moisture remote sensing product datasets. The historical time series of soil moisture remote sensing product datasets must be long, with at least the last five years of inversion products and minimal missing data. The inversion results must be good, consistent, and reliable. L2 and L3 soil moisture product datasets that have undergone geometric correction, radiometric correction, and geometric rectification are preferred.

[0107] 3) Reproject, resample using the nearest neighbor method, crop based on the study area, unify the data format, convert the data into GeoTIFF format, convert the spatial resolution to 25 km, and convert the temporal resolution to daily;

[0108] The nearest neighbor method takes four points adjacent to the calculation point, compares their distances with the calculated point, determines the distance between the two points, and selects the pixel value with the closest distance between the two points as the pixel value of the calculation point.

[0109] 4) Perform spatial deterministic interpolation of historical soil moisture data using spline interpolation, with the same temporal and spatial resolution as satellite remote sensing data;

[0110] 5) Weights are assigned to and integrated across soil moisture products based on the inverse coefficient of variation method. This is an objective weighting method that objectively reflects the fluctuations in the evaluation indicator based on its statistical patterns. If the fluctuation is small, the weight is increased; if it is small, the weight is decreased. The coefficient of variation, also known as the coefficient of variation or dispersion, reflects the degree of dispersion between the sample and the mean and is often calculated as the ratio of the standard deviation to the mean.

[0111] The steps to calculate the weight are:

[0112] Calculate the mean of the indicator

[0113]

[0114] Where: n is the number of soil moisture products. i is the soil moisture product value of the corresponding sub-basin i, is the average value of different soil moisture products in the jth sub-basin, in m 3 / m 3 .

[0115] Calculating standard deviation

[0116]

[0117] Where: σ ij is the standard deviation of the i-th soil moisture product in the j-th sub-basin.

[0118] Calculate the coefficient of variation and perform inverse coefficient of variation normalization

[0119]

[0120]

[0121] Where: C vji is the coefficient of variation of the j-th sub-basin and the i-th soil moisture product, C' vji is the coefficient of variation of the i-th soil moisture product.

[0122] Calculate the weights based on the corresponding inverse coefficient of variation of different soil moisture products.

[0123]

[0124]

[0125] where ω i is the weight corresponding to the j-th sub-basin and the i-th soil moisture product.

[0126] Repeat the above steps for each sub-basin, calculate the corresponding weights of each soil moisture product in different sub-basins, and fuse the multi-source soil moisture products for each sub-basin according to the weights of the inverse coefficient of variation.

[0127]

[0128] Where: SM j is the fusion value of multi-source soil moisture products in the jth sub-basin, in m 3 / m 3 SM ji is the soil moisture product value of the jth sub-basin and the i-th sub-basin, in m 3 / m 3 .

[0129] 6) The fused soil moisture product is represented by regions, and a daily sub-basin soil moisture distribution map is drawn. The daily soil moisture content of each sub-basin is represented as a unique value, and the soil moisture distribution is represented using a gradient color band, with darker colors indicating greater soil moisture.

[0130] S3. Determine the station layout density based on the sub-basin area and the daily spatial distribution of soil moisture. The specific steps are as follows:

[0131] 1) Calculate the area of each sub-basin based on the sub-basin division. Project the sub-basin onto the corresponding projection band and calculate the area.

[0132] 2) Based on the principle of uniform distribution of sub-basin units, the minimum distribution density is determined taking into account the size of the sub-basin. The preliminary plan is to deploy at least one soil moisture station in each sub-basin, with one station in the largest sub-basin as the minimum distribution density.

[0133] 3) Consider the daily spatial distribution of soil moisture content and appropriately increase the density of stations based on the minimum deployment density. Obtain a daily spatial distribution map of soil moisture content. If the spatial variation of soil moisture content within a sub-basin is significant, appropriately increase the number of stations based on the minimum deployment density. Second, consider adding soil moisture stations based on the distance of the sub-basin from the reservoir dam site to obtain more detailed soil moisture changes near the dam.

[0134] S4. Preliminary planning of soil moisture station locations based on the sub-basin center method. The specific steps are as follows:

[0135] 1) Divide the sub-basins using a visual estimate based on the number of soil moisture stations in each sub-basin and soil type. If the sub-basin plans to have one soil moisture station, proceed directly to step 2). If the sub-basin plans to have n soil moisture stations, where n > 1, divide the sub-basin into equal-sized units using a visual estimate based on soil type.

[0136] 2) Calculate the center point of the soil moisture station layout unit as the initial planning location of the soil moisture station. Convert the center point location to longitude and latitude coordinates. The formula for calculating the polygon centroid is:

[0137]

[0138]

[0139]

[0140] Among them, S 1,i,i+1 is the area of the triangle after the polygon is decomposed; is the position vector; m represents an m-gon.

[0141] Considering the spatial variation of soil moisture in a watershed by using sub-basin centers can better account for the spatial distribution of runoff generation and the physical characteristics of runoff confluence, and has a strong physical basis. Therefore, it is proposed that each sub-basin center be used as the initial location for additional soil moisture stations.

[0142] S5. Optimize the station network layout based on the main soil types and land use types of the underlying surface.

[0143] 1) Overlay, extract, and fuse the sub-basin boundary with topography, soil type, and land use type to obtain representative areas of soil moisture monitoring stations with hydrological attribute information (topography, soil type, and land use type). Mask extraction of topography, soil type, and land use type is performed using the sub-basin boundary. The extracted layers all have fields that record the attributes of the mask layer (i.e., the sub-basin layer), and these fields are the same. Therefore, this same field can be used for fusion to obtain representative areas of soil moisture monitoring stations with hydrological attribute information (topography, soil type, and land use type).

[0144] 2) Optimize station locations based on representativeness of surface soil type, deep soil type, and land use type. Surface soil type, deep soil type, and land use type are categorized and displayed, and the proportion of each type in the sub-basin is calculated. Based on this proportion, the location of soil moisture stations is optimized.

[0145] 3) Conduct on-site surveys of the proposed soil moisture monitoring stations based on the optimized site locations. The network signal levels are divided into three categories based on the signal transmission rate: real-time transmission (I), transmission (II), and non-transmission (III); the construction convenience levels are divided into three categories based on the difficulty of transporting construction equipment and the difficulty of deploying soil moisture monitoring instruments on the corresponding plots: convenient construction (I), construction possible (II), and non-construction possible (III); and the shortest distance between the station and a Class 4 or higher highway is divided into three categories: I, II, and III, representing convenient transportation, relatively convenient transportation, and inconvenient transportation, respectively. The classification principles are as follows:

[0146]

[0147] Where: L standard is the level of transportation convenience, and L is the shortest distance between the proposed site and a fourth-level or above highway, in meters.

[0148] Based on the results of on-site investigations in three aspects, namely network signal, traffic convenience and construction feasibility, the single-factor index evaluation method was adopted, and the worst index level was selected as the site evaluation level to evaluate the site location. It is planned to use Grade I sites, spare Grade II sites and abandon Grade III sites.

[0149] Subsequently, the location of the proposed site is adjusted and surveyed according to the above steps for the abandoned site until the evaluation results of the three factors of network signal, transportation convenience and construction feasibility of the proposed site are better than level III, and the location of the site is determined as the location of the proposed soil moisture site in the corresponding sub-basin.

[0150] Example 2

[0151] This embodiment provides a soil moisture site planning device that considers hydrological characteristics, including:

[0152] The extraction and division module is used to obtain and analyze digital elevation model data, extract basic geomorphological features of the watershed, and then divide the sub-watershed into sub-watersheds based on the rainstorm center map obtained through interpolation and overlay analysis to obtain sub-watershed zoning maps;

[0153] A drawing module is used to obtain satellite remote sensing data and soil moisture site measured data, and draw a daily soil moisture sub-basin distribution map in combination with the sub-basin zoning map;

[0154] The station density determination module is used to determine the station layout density of different sub-basins based on the sub-basin division and the daily soil moisture sub-basin distribution map;

[0155] A preliminary planning module, configured to preliminarily plan the locations of soil moisture stations using a sub-basin center method based on the density of stations in different sub-basins;

[0156] The site location optimization module is used to optimize the location of soil moisture sites based on the soil type and land use type of the underlying surface, and complete soil moisture site planning.

[0157] Example 3

[0158] This embodiment provides a soil moisture site planning device that considers hydrological characteristics, including a processor and a storage medium;

[0159] The storage medium is used to store instructions;

[0160] The processor is configured to operate according to the instructions to execute the steps of the method according to any one of the first embodiments.

[0161] Example 4

[0162] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the steps of any one of the methods described in Embodiment 1 are implemented.

[0163] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A soil moisture site planning method considering hydrological characteristics, characterized in that: include: Acquire and analyze digital elevation model data to extract basic geomorphological features of the watershed, then divide the watershed into sub-watersheds using a rainstorm center map obtained through interpolation and overlay analysis to obtain a sub-watershed zoning map. Acquiring the rainstorm center map includes spatially interpolating rainfall data corresponding to different flood events using Kriging interpolation and spline function interpolation, and overlaying and analyzing the interpolation results of multiple rainfall events to generate a rainstorm center map. Obtain satellite remote sensing data and soil moisture site measured data, and draw a daily soil moisture sub-basin distribution map in combination with the sub-basin zoning map; the drawing of the daily soil moisture sub-basin distribution map includes: Obtain the longitude and latitude coordinates of existing soil moisture stations and historical soil moisture monitoring data. The longitude and latitude coordinates are used to determine the location of the soil moisture stations, and the historical soil moisture monitoring data is used for subsequent interpolation calculations. Obtain soil moisture remote sensing product datasets, reproject them, resample them using the nearest neighbor method, and unify the data format; The historical soil moisture data were spatially deterministically interpolated using the spline interpolation method, with the same temporal and spatial resolution as the satellite remote sensing data. Different soil moisture products are weighted and integrated based on the inverse coefficient of variation method; The fused soil moisture product is represented by different regions, and the daily soil moisture sub-basin distribution map for multiple years is drawn; Determine the station layout density in different sub-basins based on the sub-basin division and the daily soil moisture sub-basin distribution map; Based on the density of stations in different sub-basins, the locations of soil moisture stations are preliminarily planned using the sub-basin center method; Optimize the location of soil moisture stations based on the soil type and land use type of the underlying surface and complete the soil moisture station planning.

2. The soil moisture site planning method considering hydrological characteristics according to claim 1 is characterized in that: The digital elevation model data is obtained and analyzed to extract basic landform features of the watershed, and then the sub-watershed is divided in combination with the rainstorm center map obtained by interpolation and overlay analysis to obtain a sub-watershed zoning map, including: Obtain digital elevation model data and analyze it to extract basic geomorphological features of the watershed, including the watershed area, length, and shape; Calculating the slope and aspect of the watershed based on the digital elevation model and basic geomorphic features of the watershed; Obtain rainfall data corresponding to different flood events, and use Kriging interpolation and spline function interpolation methods to perform spatial interpolation of rainfall data for each event; The interpolation results of different rainfall events are superimposed and analyzed to obtain the center map of multiple rainstorms in the basin; The basin underlying surface characteristics are distinguished according to the basin slope and slope direction, and the sub-basin is divided in combination with the rainstorm center map to obtain the sub-basin zoning map.

3. The soil moisture site planning method considering hydrological characteristics according to claim 1 is characterized in that: The density of stations in different sub-basins is determined by combining the sub-basin division and the daily soil moisture sub-basin distribution map, including: Calculate the area of each sub-basin according to the sub-basin division; Based on the principle of uniform distribution of sub-basins, taking into account the size of the sub-basin area, the number of soil moisture stations to be distributed in each sub-basin is determined, and the minimum distribution density is calculated; Combined with the daily soil moisture sub-basin distribution map, encryption is performed on the basis of the minimum layout density to determine the layout density of sites in different sub-basin.

4. The soil moisture site planning method considering hydrological characteristics according to claim 1 is characterized in that: Based on the density of stations in different sub-basins, the sub-basin center method is used to preliminarily plan the location of soil moisture stations, including: Based on the number of stations in different sub-basins, the corresponding sub-basins are divided into basic units of soil moisture station layout with equal areas; The sub-basin center method is used in the basic unit of soil moisture station layout, and the sub-basin centroid is taken as the sub-basin center to determine the preliminary planning location of the soil moisture station.

5. The soil moisture site planning method considering hydrological characteristics according to claim 1 is characterized in that: The above mentioned optimization of soil moisture station locations based on the underlying soil type and land use type to complete soil moisture station planning includes: Overlay, extract, and fuse sub-basin boundaries with topography, soil types, and land use types to obtain representative areas of soil moisture monitoring stations with hydrological characteristic attribute information; Surface soil types, deep soil types, and land use types are classified and displayed respectively, and the proportion of different types in the sub-basin is calculated. Based on the proportion of various types, the location of soil moisture stations is optimized; The site location is adjusted and determined based on the on-site survey results of network signals, traffic convenience and construction feasibility.

6. The soil moisture site planning method considering hydrological characteristics according to claim 5 is characterized in that: The site location is adjusted and determined based on the on-site survey results of network signals, transportation convenience, and construction feasibility, including: Based on the optimized site locations, the proposed soil moisture sites were surveyed on site. The network signal levels were classified into three categories: real-time transmission, transmission, and non-transmission based on the signal transmission rate. The construction convenience levels were classified into three categories: convenient construction, construction possible, and non-construction based on the difficulty of transporting construction equipment and the difficulty of deploying soil moisture monitoring instruments on the corresponding plots. The sites were classified into three categories: I, II, and III based on the shortest distance between the site and a Class IV or higher highway, representing convenient transportation, relatively convenient transportation, and inconvenient transportation, respectively. The classification principles are as follows: ； Where: L standard is the level of transportation convenience, L is the shortest distance between the proposed site and a fourth-level or above highway, in meters; Based on the results of the field survey in terms of network signal, transportation convenience, and construction feasibility, a single factor index evaluation method was used, with the worst index level selected as the site evaluation level. The site locations were evaluated, with Grade I sites being used, Grade II sites being reserved, and Grade III sites being abandoned. Subsequently, the abandoned site was adjusted and surveyed according to the above steps to determine the new proposed location, until the evaluation results of the three factors of network signal, transportation convenience and construction feasibility of the proposed site were better than level III, and the site location was determined as the proposed soil moisture site location for the corresponding sub-basin.

7. A soil moisture site planning device considering hydrological characteristics, using the soil moisture site planning method considering hydrological characteristics according to claim 1, characterized in that: include: The extraction and division module is used to obtain and analyze digital elevation model data, extract basic geomorphological features of the watershed, and then divide the sub-watershed into sub-watersheds based on the rainstorm center map obtained through interpolation and overlay analysis to obtain sub-watershed zoning maps; A drawing module is used to obtain satellite remote sensing data and soil moisture site measured data, and draw a daily soil moisture sub-basin distribution map in combination with the sub-basin zoning map; The station density determination module is used to determine the station layout density of different sub-basins based on the sub-basin division and the daily soil moisture sub-basin distribution map; A preliminary planning module, configured to preliminarily plan the locations of soil moisture stations using a sub-basin center method based on the density of stations in different sub-basins; The site location optimization module is used to optimize the location of soil moisture sites based on the soil type and land use type of the underlying surface, and complete soil moisture site planning.

8. A soil moisture site planning device that takes hydrological characteristics into consideration, characterized by: including processors and storage media; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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