A desertification risk assessment model construction and desertification risk assessment method and device

Abstract

The invention discloses a desertification risk assessment model construction and a desertification risk assessment method and device. The method comprises: obtaining historical land spatial distribution data of multiple target watersheds containing land desertification areas for consecutive years, determining the spatial distribution of sand-affected areas in the target watershed, determining the impact threshold interval of each land desertification influencing factor, grading the impact threshold interval of each land desertification influencing factor to obtain multiple grade intervals, counting the total proportion of the land desertification area in each grade interval to the total land desertification area and scoring, determining the desertification score of the target watershed based on the scores corresponding to the multiple grade intervals of each land desertification influencing factor and the corresponding weights, storing the desertification scores and desertification risk levels corresponding to different target watersheds, realizing the prediction and early warning of the potential risk of land desertification in the target watershed, and providing technical support for the prevention, control and comprehensive management of land desertification in the watershed.

Description

Technical Field

[0001] This invention relates to the fields of remote sensing applications and ecological protection technology, specifically to a desertification risk assessment model construction and a desertification risk assessment method and apparatus. Background Technology

[0002] Land desertification refers to the process of natural desert expansion and vegetation destruction on sandy soils caused by climate change and human activities. Accurately identifying the occurrence, development, and potential risks of land desertification in a watershed can provide support for overcoming development bottlenecks constrained by land desertification within the watershed and promote a virtuous cycle of the ecosystem. However, existing technologies are mostly supported by remote sensing data, which only assess the historical and current spatiotemporal distribution of land desertification in the watershed, lacking proactive prevention and control measures. Therefore, there is an urgent need to propose a method for constructing a desertification risk assessment model that can predict and warn of potential land desertification risks in target watersheds, providing technical support for the prevention, control, and comprehensive management of land desertification in watersheds. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the deficiency of existing methods that lack the ability to predict potential risks of land desertification, thereby providing a desertification risk assessment model construction and a desertification risk assessment method and apparatus.

[0004] According to a first aspect, embodiments of the present invention disclose a method for constructing a desertification risk assessment model. The method includes: acquiring historical land spatial distribution data of multiple target watersheds containing desertified areas over several consecutive years; for any target watershed, determining the spatial distribution of desertified areas within the target watershed based on the historical land spatial distribution data over several consecutive years, wherein the desertified areas represent regions that have changed from non-desertified land areas to desertified land areas; determining land desertification influencing factors and the corresponding impact threshold intervals for each land desertification influencing factor based on the spatial distribution of the desertified areas in the target watershed; classifying the impact threshold intervals corresponding to each land desertification influencing factor into multiple level intervals, statistically analyzing the proportion of the land desertified area corresponding to each level interval to the total land desertified area, and assigning a score; determining the desertification score of the target watershed based on the scores corresponding to the multiple level intervals of each land desertification influencing factor and their corresponding weights; and storing the desertification scores corresponding to different target watersheds and the desertification risk levels corresponding to different desertification scores to obtain a desertification risk assessment model for conducting desertification risk assessment of the target watershed.

[0005] Optionally, obtaining historical land spatial distribution data of multiple target watersheds containing desertified areas over several consecutive years includes: determining watersheds containing potentially desertified land based on historical remote sensing data of multiple watersheds; and determining target watersheds containing desertified areas based on remote sensing data corresponding to watersheds containing potentially desertified land.

[0006] Optionally, determining the spatial distribution of sand-affected areas in the target watershed based on historical land spatial distribution data over several consecutive years includes: performing unified rasterization processing on the land spatial distribution data corresponding to any year other than the first year over several consecutive years and the land spatial distribution data of the first year; if any raster area in the land spatial distribution of the first year is a non-desertified land area and the corresponding raster area in the land spatial distribution of any year other than the first year is a desertified land area, then the raster area is determined to be a sand-affected area.

[0007] Optionally, the step of classifying the impact threshold intervals corresponding to each land desertification influencing factor into multiple level intervals, and statistically analyzing and scoring the total proportion of land desertification area corresponding to each level interval to the total land desertification area, includes: statistically analyzing the proportion of land desertification area to the total land desertification area in each year of multiple level intervals corresponding to any land desertification influencing factor over several consecutive years; comprehensively processing the statistically analyzed proportions of land desertification area to the total land desertification area in each year corresponding to any level interval over several consecutive years to obtain the total proportion of land desertification area corresponding to the level interval; and scoring the level interval based on the obtained total proportion of land desertification area corresponding to any level interval.

[0008] According to the second aspect, embodiments of the present invention also disclose a desertification risk assessment method, the method comprising: determining the land desertification influencing factors and influencing threshold intervals corresponding to the sand-affected areas within the watershed to be assessed over several consecutive years, wherein the several consecutive years include the current year; classifying the influencing threshold intervals corresponding to each land desertification influencing factor into multiple level intervals, statistically analyzing the proportion of land desertification area corresponding to each level interval to the total land desertification area and assigning a score; determining the desertification score of the watershed to be assessed based on the scores corresponding to the multiple level intervals of each land desertification influencing factor and their corresponding weights; comparing the desertification score with a desertification risk assessment model, wherein the desertification risk assessment model is constructed using the desertification risk assessment model construction method described in the first aspect; and determining the desertification risk level corresponding to the area to be assessed based on the comparison results.

[0009] According to a third aspect, embodiments of the present invention also disclose a desertification risk assessment model construction device, the device comprising: a spatial distribution data acquisition module, used to acquire historical land spatial distribution data of multiple target watersheds containing land desertification areas over several consecutive years; a sand-affected area spatial determination module, used to determine the spatial distribution of sand-affected areas in any target watershed based on historical land spatial distribution data over several consecutive years, wherein the sand-affected area represents the region that has changed from a non-desertified land area to a desertified land area; and an impact threshold interval determination module, used to determine land desertification influencing factors and each land desertification impact factor based on the spatial distribution of sand-affected areas in the target watershed. The system comprises four modules: an impact threshold range corresponding to each land desertification influencing factor; a graded interval scoring module, which classifies the impact threshold range corresponding to each land desertification influencing factor into multiple graded intervals, calculates the proportion of land desertification area corresponding to each graded interval to the total land desertification area, and scores the intervals; a desertification score determination module, which determines the desertification score of the target watershed based on the scores corresponding to the multiple graded intervals of each land desertification influencing factor and their corresponding weights; and a risk assessment module, which stores the desertification scores corresponding to different target watersheds and the desertification risk levels corresponding to different desertification scores to obtain a desertification risk assessment model for conducting desertification risk assessment of the target watershed.

[0010] Optionally, the sand-affected area spatial determination module includes: a data processing submodule, used to perform unified rasterization processing on the land spatial distribution data corresponding to any year other than the first year within consecutive years and the land spatial distribution data of the first year; and a sand-affected area determination submodule, used to determine that the raster area is a sand-affected area if any raster area in the land spatial distribution of the first year is a non-desertified land area and the corresponding raster area in the land spatial distribution of any year other than the first year is a desertified land area.

[0011] According to the fourth aspect, the present invention also discloses a desertification risk assessment device, the device comprising: a data acquisition module, used to determine the land desertification influencing factors and influence threshold intervals corresponding to the sand-affected areas included in the watershed to be assessed over several consecutive years, wherein the several consecutive years include the current year; a score determination module, used to classify the influence threshold intervals corresponding to each land desertification influencing factor to obtain multiple level intervals, and to calculate and score the proportion of the land desertification area corresponding to each level interval to the total land desertification area; a desertification score determination module, used to determine the desertification score of the watershed to be assessed based on the scores corresponding to the multiple level intervals of each land desertification influencing factor and their corresponding weights; a data comparison module, used to compare the desertification score with a desertification risk assessment model, wherein the desertification risk assessment model is constructed by the desertification risk assessment model construction method described in the first aspect; and a risk level determination module, used to determine the desertification risk level corresponding to the area to be assessed based on the comparison results.

[0012] According to a fifth aspect, embodiments of the present invention also disclose an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform steps of the desertification risk assessment model construction method as described in the first aspect or any optional embodiment of the first aspect, or steps of the desertification risk assessment method as described in the second aspect or any optional embodiment of the second aspect.

[0013] According to a fourth aspect, embodiments of the present invention also disclose a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the desertification risk assessment model construction method as described in the first aspect or any optional embodiment of the first aspect, or the steps of the desertification risk assessment method as described in the second aspect or any optional embodiment of the second aspect.

[0014] The technical solution of this invention has the following advantages:

[0015] The desertification risk assessment model construction method provided by this invention obtains historical land spatial distribution data of multiple target watersheds containing desertified areas over several consecutive years, determines the spatial distribution of desertified areas in the target watersheds, then identifies the influencing factors of land desertification and the corresponding impact threshold intervals for each factor, classifies the impact threshold intervals for each factor into multiple level intervals, calculates the proportion of desertified area in each level interval to the total desertified area and assigns a score, determines the desertification score of the target watershed based on the scores and weights of each factor across multiple level intervals, and stores the desertification scores for different target watersheds and the corresponding desertification risk levels for use in desertification risk assessment of the target watersheds. This method can predict and warn of potential land desertification risks in target watersheds, providing technical support for the prevention, control and comprehensive management of land desertification in watersheds. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a specific example of the desertification risk assessment model construction method in this invention.

[0018] Figure 2 This is a specific example diagram corresponding to the desertification risk assessment model construction method in this embodiment of the invention;

[0019] Figure 3 This is a flowchart illustrating a specific example of the desertification risk assessment model construction method in this embodiment of the invention.

[0020] Figure 4 A flowchart illustrating a specific example of the desertification risk assessment method in this invention;

[0021] Figure 5 This is a schematic diagram illustrating a specific example of the desertification risk assessment model construction device in this invention.

[0022] Figure 6 This is a schematic diagram illustrating a specific example of the desertification risk assessment device in this invention.

[0023] Figure 7 This is a specific example diagram of an electronic device in an embodiment of the present invention. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] This invention discloses a method for constructing a desertification risk assessment model, such as... Figure 1 As shown, the method includes the following steps:

[0029] Step 101: Obtain historical land spatial distribution data for multiple target watersheds containing desertified areas over several consecutive years. For example, in this embodiment, the remote sensing data for multiple watersheds over several consecutive years already contains spatial distribution data for various land types. The continuous land spatial distribution data for target watersheds containing desertified areas can be directly obtained from this data. Alternatively, land type identification processing can be performed on the remote sensing data of multiple watersheds over several consecutive years, and the continuous land spatial distribution data for multiple target watersheds containing desertified areas can be determined based on the identification results. This is merely an example. In this embodiment, the target watershed can be a watershed with a known desertification risk level. The years for obtaining the continuous historical land spatial distribution data can be consecutive years from the time the desertification area in the target watershed was detected. By obtaining data from the year the desertification area first appeared, it is easier to predict the desertification risk of the watershed earlier and more accurately. This embodiment does not limit the number of consecutive years; those skilled in the art can determine this according to actual needs.

[0030] Step 102: For any target watershed, determine the spatial distribution of the sand-affected areas in the target watershed based on historical land spatial distribution data over several consecutive years. The sand-affected areas represent regions that have changed from non-desertified land areas to desertified land areas.

[0031] For example, in this embodiment of the application, for any target watershed containing desertified areas, historical land spatial distribution data over several consecutive years can be selected. This data can be uniformly rasterized. If a raster area in a certain year is not a desertified area, but becomes a desertified area in the following year, then that raster area is determined to be a desertified area. In a specific embodiment, historical land spatial distribution data from 1990 to 2000 is selected. If a raster area in 1992 is not a desertified area, but becomes a desertified area in 1993, then that raster area is determined to be a desertified area. This is merely an example.

[0032] Step 103: Based on the spatial distribution of sand-affected areas in the target watershed, determine the factors influencing land desertification and the corresponding threshold range for each factor influencing land desertification.

[0033] For example, in this embodiment of the application, factors influencing land desertification may include meteorological factors such as precipitation, temperature, and evaporation; topographical factors such as land use, land type, terrain elevation, and slope; and socioeconomic factors such as population and GDP. These are just examples; specific factors can be determined through monitored watershed desertification data. This embodiment of the application utilizes the ArcGIS platform to interpolate or resample the spatial distribution data of land desertification influencing factors such as precipitation and the sand-affected areas in the target watershed to achieve the same spatial resolution of 1km*1km, facilitating data comparison and fusion. The spatial distribution data of the sand-affected areas includes at least various attribute data, such as precipitation values ​​and temperature. Then, the mask extraction tool in ArcGIS is used to extract the specific values ​​corresponding to the attribute data. The specific values ​​can be determined by using a threshold range of a certain attribute under normal conditions, which can be determined through pre-determined human experience. Whether precipitation is a factor influencing land desertification is a question. For example, the threshold for precipitation under normal conditions should be 500-600 mm, but if the precipitation in a certain desertified area is found to be around 400 mm in a certain year, then precipitation can be identified as a factor influencing land desertification. Then, based on the precipitation data of multiple desertified areas that do not meet the normal threshold requirements, the influence threshold range of precipitation as a factor can be determined. For example, if the precipitation in another desertified area is 300 mm, then in this watershed, the influence threshold range corresponding to precipitation as a factor is [300, 400]. This is just an example.

[0034] Step 104: Classify the impact threshold intervals corresponding to each land desertification influencing factor to obtain multiple level intervals, and calculate and score the proportion of land desertification area corresponding to each level interval to the total land desertification area.

[0035] For example, in this embodiment of the application, the natural breakpoint method is used to classify the magnitude of the influence values ​​within the influence threshold interval corresponding to each land desertification influencing factor to obtain multiple level intervals. Each level interval includes different target level influence threshold intervals. For example, the influence threshold interval of precipitation influencing factors is divided into 5 level intervals: ≤300mm, 300-400mm, 400-500mm, 500-600mm, and ≥600mm. This is just an example. Then, the proportion of land desertification area corresponding to each level interval of precipitation influencing factors to the total land desertification area is calculated. Each level interval is scored according to the total proportion. The scoring method can be based on the size of different proportions, with a higher proportion resulting in a higher score. Specifically, as shown below... Figure 2 As shown, the total proportion of desertified land area corresponding to the precipitation level range of 400-500mm is the highest, so the 400-500mm level range can be assigned 5 points. The total proportion of desertified land area corresponding to the precipitation level range of ≥600mm is the lowest, so the ≥600mm level range can be assigned 1 point. And so on, the precipitation level range of ≤300mm can be assigned 2 points, the precipitation level range of 300-400mm can be assigned 4 points, the precipitation level range of 400-500mm can be assigned 5 points, the precipitation level range of 500-600mm can be assigned 3 points, and the precipitation level outside the level range can be assigned 0 points. The scoring method for different level areas is not limited. Those skilled in the art can use other scoring methods to score, which is only used as an example.

[0036] Step 105: Determine the desertification score of the target watershed based on the scores corresponding to multiple level intervals of each land desertification influencing factor and their corresponding weights.

[0037] For example, the weights corresponding to different land desertification influencing factors can be based on the deviation of each land desertification influencing factor from the normal threshold; the greater the deviation, the greater the weight. Alternatively, the weights can be pre-set based on the predetermined importance levels of different land desertification influencing factors. In this embodiment, based on the proportion of land desertification area within each level interval corresponding to the total land desertification area, an analysis of variance statistical model is established using SPSS to evaluate and calculate the contribution weights of different influencing factors to land desertification using the following formula:

[0038] CT i =(SS) 因 -f 因 ×MSE) / SST

[0039] Among them, CT i This indicates the weight of factor i's contribution to land desertification; SS 因f represents the sum of squared deviations of the sample under the influence of factor i; 因 The degree of freedom of influencing factor i is represented; MSE represents the root mean square error of the sample under the influence of influencing factor i; SST represents the total sum of squares of deviations of the sample under the combined influence of the interaction of each influencing factor; in the embodiments of this application, the sample represents the land desertification area of ​​different grade intervals under the influence of influencing factor i.

[0040] The desertification score for the target watershed is calculated using the following formula:

[0041]

[0042] Among them, Score j ω represents the land desertification score of the target watershed j; ji This represents the weight of the influence factor i corresponding to the target watershed j on land desertification; value ji This represents the score of influencing factor i corresponding to the target watershed j. This score can be obtained by summing the scores corresponding to multiple level intervals.

[0043] Step 106: Store the desertification scores corresponding to different target watersheds and the desertification risk levels corresponding to different desertification scores to obtain a desertification risk assessment model for conducting desertification risk assessment of target watersheds.

[0044] For example, in this embodiment of the application, the method for determining the desertification risk level corresponding to different desertification scores can be to statistically analyze the data of land desertification influencing factors in the corresponding target watershed over several consecutive years, as well as the corresponding actual desertification evolution and severity, and pre-determine the possible desertification risk faced by the corresponding target area through human experience, predict and determine the desertification risk level in advance, and associate and store it with the corresponding desertification score; for example, the desertification risk of the target land is classified as low risk (1≤Score). i <2), Medium risk (2≤Score) i <3), High risk (3≤Score) i <4) and extremely high risk (4≤Score) i <5), as an example only, the desertification scores corresponding to different target watersheds and the desertification risk levels corresponding to different desertification scores are stored in the desertification risk assessment model, which can be used for subsequent desertification risk assessment.

[0045] The desertification risk assessment model construction method provided by this invention obtains historical land spatial distribution data of multiple target watersheds containing desertified areas over several consecutive years, determines the spatial distribution of sand-affected areas in the target watersheds, then identifies the influencing factors of land desertification and the corresponding impact threshold intervals for each influencing factor, classifies the impact threshold intervals for each influencing factor into multiple level intervals, calculates and scores the proportion of desertified area to the total desertified area for each level interval, and determines the desertification score of the target watershed based on the scores and weights of the multiple level intervals for each influencing factor of land desertification, stores the desertification scores for different target watersheds and the desertification risk levels corresponding to different desertification scores, and obtains a desertification risk assessment model. This model can predict and warn of potential land desertification risks in target watersheds, providing technical support for the prevention, control, and comprehensive management of land desertification in watersheds.

[0046] As an optional embodiment of the present invention, the step of obtaining historical land spatial distribution data of multiple target watersheds containing land desertification areas over several consecutive years includes: determining watersheds containing potentially desertified land based on historical remote sensing data of multiple watersheds; and determining target watersheds containing land desertification areas based on remote sensing data corresponding to watersheds containing potentially desertified land.

[0047] For example, embodiments of this application acquire continuous multi-year remote sensing data for multiple watersheds. ENVI software can be used for radiometric calibration, atmospheric correction, and influence mosaicking operations to obtain data covering the entire watershed under study. Figure 3 As shown, a decision tree classifier with coupled optimization algorithms is constructed based on feature indices. These feature indices can include Normalized Difference Vegetation Index (NDVI), Novel Water Indices (NWI), Improved Soil-Regulated Vegetation Index (MSAVI), and Albedo. The optimization algorithm determines the thresholds for each feature index. For example, if the NWI of a land space is ≥ a, the land space is classified as a water body and masked, without further calculation; the rest are unclassified. If the NDVI of an unclassified land space is ≥ b, it is classified as green vegetation; if NDVI < b, it is classified as unclassified. If the MSAVI of an unclassified land space is ≥ c, it is considered bare land. The remaining unclassified lands are potential desertification areas. Based on NDVI and Albedo feature indices, and using field surveys and typical points of desertification distribution in Google Earth imagery as references, a Land Desertification Difference Index (DDI) model is constructed. The following formula further subdivides potential desertification areas into desertification zones and non-desertification zones:

[0048] DDI = a × NDVI - Albedo

[0049] Wherein, DDI represents the difference in land desertification; a represents the model's formal parameters, determined based on the fitting relationship of the NDVI-Albedo feature space; and NDVI-Albedo represents the area and spatial distribution of desertified land of different surface types covering the entire watershed.

[0050] In this embodiment of the application, the potential desertified land is classified into different levels based on the calculation results of DDI. The DDI threshold is set by comparing the classification results of DDI with the actual desertified land survey. Land exceeding the DDI threshold is defined as desertified land, and land not exceeding the DDI threshold is defined as non-desertified land. This is only an example.

[0051] As an optional embodiment of the present invention, determining the spatial distribution of the sand-affected area in the target watershed based on historical land spatial distribution data over several consecutive years includes: performing unified rasterization processing on the land spatial distribution data corresponding to any year other than the first year over several consecutive years and the land spatial distribution data of the first year; if any raster area in the land spatial distribution of the first year is a non-desertified land area and the corresponding raster area in the land spatial distribution of any year other than the first year is a desertified land area, then the raster area is determined to be a sand-affected area.

[0052] For example, this application embodiment uses the Map Algebra tool of the ArcGIS platform to intersect and rasterize the land spatial distribution containing desertification areas in any year other than the first year with the land desertification spatial distribution in the first year. If any raster area in the land spatial distribution of the first year is a non-desertification area and the corresponding raster area in the land spatial distribution of any year other than the first year is a desertification area, then the raster area is determined to be a desertification area; if any raster area in the land spatial distribution of the first year is a desertification area and the corresponding raster area in any year other than the first year is still a desertification area, then the raster area is determined to be a sand source area. This is only an example.

[0053] As an optional embodiment of the present invention, the step of classifying the impact threshold intervals corresponding to each land desertification influencing factor into multiple level intervals, and statistically analyzing and scoring the total proportion of land desertification area corresponding to each level interval to the total land desertification area, includes: statistically analyzing the proportion of land desertification area corresponding to each of the multiple level intervals for any influencing factor over several consecutive years to the total land desertification area in that year; comprehensively processing the statistically analyzed proportions of land desertification area corresponding to any level interval over several consecutive years to the total land desertification area in that year to obtain the total proportion of land desertification area corresponding to the level interval; and scoring the level interval based on the obtained total proportion of land desertification area corresponding to any level interval.

[0054] For example, in this application embodiment, the proportion of land desertification area corresponding to multiple level intervals for any influencing factor over several consecutive years is statistically calculated to the total land desertification area of ​​that year. Then, the proportions corresponding to each level interval for any influencing factor over several consecutive years are comprehensively and uniformly processed to obtain the total proportion of land desertification area corresponding to each level interval. In a specific embodiment, such as... Figure 2 As shown, the total proportion of desertified land area corresponding to precipitation in the 400-500mm range is the highest, so the 400-500mm range is assigned 5 points. The total proportion of desertified land area corresponding to precipitation in the ≥600mm range is the lowest, so the ≥600mm range is assigned 1 point. And so on, precipitation in the ≤300mm range is assigned 2 points, precipitation in the 300-400mm range is assigned 4 points, precipitation in the 400-500mm range is assigned 5 points, precipitation in the 500-600mm range is assigned 3 points, and precipitation outside the range is assigned 0 points. This is just an example.

[0055] This invention also discloses a method for assessing desertification risk, such as... Figure 4 As shown, the method includes:

[0056] Step 301: Determine the land desertification influencing factors and their impact threshold ranges for the sand-affected areas within the watershed to be assessed over several consecutive years. These consecutive years include the current year. For example, the watershed to be assessed can be a watershed that has not fully evolved into a desertified watershed but already has sand-affected areas. The consecutive years can be a certain number of years monitored from the time sand-affected areas were first detected, or a certain number of years counted backwards from the current year. For accurate prediction, the number of years is the same as the number of years used when constructing the desertification risk assessment model. Obtain the impact values ​​corresponding to each influencing factor affecting land desertification in the area to be assessed. The impact values ​​can be current data values ​​or future predicted data values ​​of the influencing factors; this is only an example.

[0057] Step 302: The impact threshold intervals corresponding to each land desertification influencing factor are classified into multiple level intervals. The proportion of land desertification area corresponding to each level interval to the total land desertification area is calculated and scored. For example, the calculation formula for determining the desertification score of the area to be evaluated based on the magnitude of the obtained impact value of the land desertification influencing factor is consistent with the method in the above embodiment, and will not be repeated here.

[0058] Step 303: Determine the desertification score of the watershed to be evaluated based on the scores corresponding to multiple level intervals of each land desertification influencing factor and their corresponding weights; for example, the method for determining the desertification score of the watershed to be evaluated is the same as in the above embodiment, and will not be repeated here.

[0059] Step 304: Compare the desertification score with the desertification risk assessment model. The desertification risk assessment model is constructed using the desertification risk assessment model construction method described in any of the above optional embodiments. For example, the desertification score corresponding to the area to be assessed obtained in the above embodiments is input into the desertification risk assessment model and compared with the desertification scores corresponding to different target watersheds and the desertification risk levels corresponding to different desertification scores stored in the desertification risk assessment model.

[0060] Step 305: Based on the comparison results, determine the desertification risk level corresponding to the area to be assessed. For example, in this embodiment of the application, the desertification score of the target watershed is determined based on the input desertification score of the area to be assessed, thereby determining its desertification risk level.

[0061] The desertification risk assessment method provided by this invention determines the land desertification influencing factors and their impact threshold ranges for the sand-affected areas within the watershed to be assessed over several consecutive years, including the current year. The impact threshold ranges corresponding to each land desertification influencing factor are graded to obtain multiple level ranges. The proportion of land desertification area corresponding to each level range to the total land desertification area is statistically analyzed and scored. Based on the scores and weights of the multiple level ranges corresponding to each land desertification influencing factor, the desertification score of the watershed to be assessed is determined. The desertification score is compared with a desertification risk assessment model. Based on the comparison results, the desertification risk level of the area to be assessed is determined. This method can accurately predict the land desertification risk of the area to be assessed, enabling proactive prevention and control of land desertification and promoting a virtuous cycle of the ecosystem.

[0062] This invention also discloses a device for constructing a desertification risk assessment model, such as... Figure 5As shown, the device includes: a spatial distribution data acquisition module 201, used to acquire historical land spatial distribution data of multiple target watersheds containing land desertification areas over several consecutive years; a sand-affected area spatial determination module 202, used to determine the spatial distribution of sand-affected areas in any target watershed based on historical land spatial distribution data over several consecutive years, wherein the sand-affected areas represent regions that have changed from non-desertified land areas to desertified land areas; and an influence threshold interval determination module 203, used to determine land desertification influencing factors and the influence threshold interval corresponding to each land desertification influencing factor based on the spatial distribution of sand-affected areas in the target watershed; and a rating system. The interval scoring module 204 is used to classify the impact threshold intervals corresponding to each land desertification influencing factor into multiple level intervals, and to calculate and score the proportion of land desertification area corresponding to each level interval to the total land desertification area; the desertification score determination module 205 is used to determine the desertification score of the target watershed based on the score corresponding to the multiple level intervals of each land desertification influencing factor and its corresponding weight; the risk assessment module 206 is used to store the desertification scores corresponding to different target watersheds and the desertification risk levels corresponding to different desertification scores to obtain a desertification risk assessment model for conducting desertification risk assessment of the target watershed.

[0063] The desertification risk assessment model construction device provided by this invention obtains historical land spatial distribution data of multiple target watersheds containing desertified areas over several consecutive years, determines the spatial distribution of desertified areas in the target watersheds, and then determines the influencing factors of land desertification and the corresponding impact threshold intervals for each influencing factor. The impact threshold intervals for each influencing factor are then graded to obtain multiple level intervals. The proportion of desertified area in each level interval to the total desertified area is calculated and scored. Based on the scores and weights of the multiple level intervals for each influencing factor, the desertification score of the target watershed is determined. The desertification scores for different target watersheds and the corresponding desertification risk levels are stored to obtain a desertification risk assessment model. This model can predict and warn of potential land desertification risks in target watersheds, providing technical support for the prevention, control, and comprehensive management of land desertification in watersheds.

[0064] As an optional embodiment of the present invention, the spatial distribution data acquisition module includes: a potential desertification land determination submodule, used to determine watersheds containing potential desertification land based on historical remote sensing data of multiple watersheds; and a land desertification determination submodule, used to determine target watersheds containing land desertification areas based on remote sensing data corresponding to watersheds containing potential desertification land.

[0065] As an optional embodiment of the present invention, the sand-affected area spatial determination module includes: a data processing submodule, used to perform unified rasterization processing on the land spatial distribution data corresponding to any year other than the first year within consecutive years and the land spatial distribution data of the first year; and a sand-affected area determination submodule, used to determine that the raster area is a sand-affected area if any raster area in the land spatial distribution of the first year is a non-desertified land area and the corresponding raster area in the land spatial distribution of any year other than the first year is a desertified land area.

[0066] As an optional embodiment of the present invention, the grade interval scoring module includes: a proportion determination submodule, used to calculate the proportion of land desertification area corresponding to multiple grade intervals for any influencing factor over several consecutive years to the total land desertification area in that year; a total proportion determination submodule, used to comprehensively process the proportions of land desertification area corresponding to any grade interval over several consecutive years to the total land desertification area in that year to obtain the total proportion of land desertification area corresponding to the grade interval; and an interval scoring module, used to score the grade interval based on the obtained total proportion of land desertification area corresponding to any grade interval.

[0067] This invention also provides a desertification risk assessment device, such as... Figure 6 As shown, the device includes: a data acquisition module 501, used to determine the land desertification influencing factors and influence threshold intervals corresponding to the sand-affected areas within the watershed to be evaluated over several consecutive years, wherein the consecutive years include the current year; a score determination module 502, used to classify the influence threshold intervals corresponding to each land desertification influencing factor into multiple level intervals, calculate the proportion of land desertification area corresponding to each level interval to the total land desertification area, and assign a score; a desertification score determination module 503, used to determine the desertification score of the watershed to be evaluated based on the scores corresponding to the multiple level intervals of each land desertification influencing factor and their corresponding weights; a data comparison module 504, used to compare the desertification score with a desertification risk assessment model, wherein the desertification risk assessment model is constructed using the desertification risk assessment model construction method as described in any of the above optional embodiments; and a risk level determination module 505, used to determine the desertification risk level corresponding to the area to be evaluated based on the comparison results.

[0068] The desertification risk assessment device provided by this invention determines the land desertification influencing factors and their impact threshold ranges for the sand-affected areas within the watershed to be assessed over several consecutive years, including the current year. It then classifies the impact threshold ranges corresponding to each land desertification influencing factor into multiple level ranges, calculates the proportion of desertified area in each level range to the total desertified area, and assigns a score. Based on the scores and weights of the multiple level ranges for each land desertification influencing factor, it determines the desertification score of the watershed to be assessed. The desertification score is then compared with a desertification risk assessment model. Based on the comparison results, the desertification risk level of the area to be assessed is determined. This device can accurately predict the land desertification risk of the area to be assessed, enabling proactive prevention and control of land desertification and promoting a virtuous cycle of the ecosystem.

[0069] This invention also provides an electronic device, such as... Figure 7 As shown, the electronic device may include a processor 401 and a memory 402, wherein the processor 401 and the memory 402 may be connected via a bus or other means. Figure 7 Taking the example of a connection between China and Israel via a bus.

[0070] Processor 401 may be a central processing unit (CPU). Processor 401 may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations thereof.

[0071] The memory 402, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the desertification risk assessment method in the embodiments of the present invention. The processor 401 executes various functional applications and data processing by running the non-transitory software programs, instructions, and modules stored in the memory 402, thereby implementing the desertification risk assessment model construction method or the desertification risk assessment method in the above method embodiments.

[0072] The memory 402 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the processor 401, etc. Furthermore, the memory 402 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 402 may optionally include memory remotely located relative to the processor 401, and these remote memories may be connected to the processor 401 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0073] The one or more modules are stored in the memory 402, and when executed by the processor 401, they perform actions such as... Figure 1 or Figure 4 The desertification risk assessment model construction method or desertification risk assessment method shown in the embodiments.

[0074] For specific details regarding the aforementioned electronic devices, please refer to the relevant documentation. Figure 1 or Figure 4 The relevant descriptions and effects in the illustrated embodiments are for understanding purposes only and will not be repeated here.

[0075] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0076] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the defined scope.

Claims

1. A method for constructing a desertification risk assessment model, characterized in that: include: Obtain historical land spatial distribution data of multiple target basins containing land desertification areas for many consecutive years. The acquisition of historical land spatial distribution data of multiple target watersheds containing land desertification areas for consecutive years includes: determining watersheds containing potential desertified land based on historical remote sensing data of multiple watersheds; determining target watersheds containing land desertification areas based on remote sensing data corresponding to watersheds containing potential desertified land; For any target watershed, the spatial distribution of sand-affected areas in the target watershed is determined based on historical land spatial distribution data for many consecutive years. The sand-affected areas represent areas that have changed from non-desertified land areas to desertified land areas. Determining the spatial distribution of the sand-affected area in the target watershed based on the historical land spatial distribution data in consecutive years includes: uniformly rasterizing the land spatial distribution data corresponding to any year other than the first year in consecutive years and the land spatial distribution data of the first year; if any grid area in the land spatial distribution of the first year is a non-desertified land area and the corresponding grid area in the land spatial distribution corresponding to any year other than the first year is a land desertified area, then determining that the grid area is a sand-affected area; Based on the spatial distribution of sand-affected areas in the target watershed, determine the factors affecting land desertification and the corresponding threshold range of each factor affecting land desertification; The impact threshold interval corresponding to each land desertification influencing factor is graded to obtain multiple grade intervals, and the total proportion of land desertification area corresponding to each grade interval to the total land desertification area is counted and scored. The method of calculating the total proportion of the land desertification area corresponding to each grade interval to the total land desertification area and scoring the proportions includes: calculating the proportion of the land desertification area in each year of multiple grade intervals corresponding to any land desertification influencing factor for consecutive years to the total land desertification area of ​​the year; comprehensively processing the proportion of the land desertification area corresponding to any grade interval for consecutive years to the total land desertification area of ​​the year to obtain the total proportion of the land desertification area corresponding to the grade interval; and scoring the grade interval according to the obtained total proportion of the land desertification area corresponding to any grade interval; Determine the desertification score of the target watershed based on the scores corresponding to the multiple level intervals of each land desertification influencing factor and its corresponding weight; The desertification scores corresponding to different target watersheds and the desertification risk levels corresponding to different desertification scores are stored to obtain a desertification risk assessment model for conducting desertification risk assessment on the target watershed.

2. A desertification risk assessment method, characterized in that: The method comprises: Determine the land desertification influencing factors and influencing threshold ranges corresponding to the sand-affected areas in the watershed to be assessed in consecutive years, including the current year; The impact threshold interval corresponding to each land desertification influencing factor is graded to obtain multiple grade intervals, and the total proportion of the land desertification area corresponding to each grade interval to the total land desertification area is counted and scored; Determine the desertification score of the watershed to be assessed based on the scores corresponding to the multiple level intervals of each land desertification influencing factor and its corresponding weight; comparing the desertification score with a desertification risk assessment model, wherein the desertification risk assessment model is constructed by the desertification risk assessment model construction method according to claim 1; According to the comparison results, the desertification risk level corresponding to the watershed to be assessed is determined.

3. A desertification risk assessment model construction device, characterized in that: The device comprises: The spatial distribution data acquisition module is used to obtain the historical land spatial distribution data of multiple target basins including land desertification areas for many consecutive years. The spatial distribution data acquisition module includes: a potential desertified land determination submodule, which is used to determine the river basin containing potential desertified land based on the historical remote sensing data of multiple river basins; a land desertification determination submodule, which is used to determine the target river basin containing land desertification area based on the remote sensing data corresponding to the river basin containing potential desertified land; The sand-affected area spatial determination module is used to determine the spatial distribution of sand-affected areas in any target watershed based on historical land spatial distribution data for many consecutive years. The sand-affected areas represent areas that have changed from non-desertified land areas to desertified land areas. The sand-affected area spatial determination module includes: a data processing submodule, which is used to uniformly rasterize the land spatial distribution data corresponding to any year other than the first year in a number of consecutive years and the land spatial distribution data of the first year; a sand-affected area determination submodule, which is used to determine that the grid area is a sand-affected area if any grid area in the land spatial distribution of the first year is a non-desertified land area and the corresponding grid area in the land spatial distribution corresponding to any year other than the first year is a land desertified area; An impact threshold interval determination module is used to determine the land desertification influencing factors and the impact threshold interval corresponding to each land desertification influencing factor based on the spatial distribution of the sand-affected areas in the target watershed; The grade interval scoring module is used to classify the impact threshold interval corresponding to each land desertification influencing factor to obtain multiple grade intervals, calculate the total proportion of the land desertification area corresponding to each grade interval to the total land desertification area and score it. The grade interval scoring module includes: a proportion determination submodule, which is used to count the proportion of the land desertification area in each year of multiple grade intervals corresponding to any land desertification influencing factor in consecutive years to the total land desertification area of ​​the year; a total proportion determination submodule, which is used to comprehensively process the proportion of the land desertification area in consecutive years corresponding to any grade interval to the total land desertification area of ​​the year to obtain the total proportion of the land desertification area corresponding to the grade interval; and an interval scoring submodule, which is used to score the grade interval according to the obtained total proportion of the land desertification area corresponding to any grade interval; A desertification score determination module is used to determine the desertification score of the target watershed based on the scores corresponding to the multiple level intervals of each land desertification influencing factor and the corresponding weights; The risk assessment module is used to store the desertification scores corresponding to different target watersheds and the desertification risk levels corresponding to different desertification scores to obtain a desertification risk assessment model for conducting desertification risk assessment on the target watershed.

4. A desertification risk assessment device, characterized in that: The device comprises: A data acquisition module is used to determine the land desertification influencing factors and influencing threshold intervals corresponding to the sandy areas included in the watershed to be assessed in consecutive years, wherein the consecutive years include the current year; The score determination module is used to classify the impact threshold interval corresponding to each land desertification influencing factor to obtain multiple grade intervals, calculate the total proportion of the land desertification area corresponding to each grade interval to the total land desertification area and give a score; A desertification score determination module is used to determine the desertification score of the watershed to be evaluated based on the scores corresponding to the multiple level intervals of each land desertification influencing factor and their corresponding weights; A data comparison module, used for comparing the desertification score with a desertification risk assessment model, wherein the desertification risk assessment model is constructed by the desertification risk assessment model construction method according to claim 1; The risk level determination module is used to determine the desertification risk level corresponding to the area to be assessed based on the comparison result.

5. An electronic device, characterized in that: include: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the steps of the desertification risk assessment model construction method as described in claim 1, or the steps of the desertification risk assessment method as described in claim 2.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the desertification risk assessment model construction method according to claim 1 or the steps of the desertification risk assessment method according to claim 2 are implemented.

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