Real-time rapid calculation method of county soil and water conservation rate based on monitoring and evaluation

Abstract

The present invention discloses a real-time and rapid calculation method for the county soil and water conservation rate based on monitoring and evaluation, and obtains the soil and water loss area M of the county-level administrative area in the previous year according to the national soil and water loss dynamic monitoring results. B , calculate the background value S of soil and water conservation rate in county-level administrative areas B ; According to the first-level national soil and water conservation zoning, determine the allowable soil loss in different regions; classify the impact of different land use types on soil and water conservation rates; calculate the current soil and water loss change area T of different land types N ; Calculate the current value S of soil and water conservation rate increase or decrease under different land use type changes N ; Dynamic evaluation of current soil and water conservation rate S N Differences between soil and water conservation rate targets in different periods S c The present invention can quickly grasp the change of soil and water conservation rate of different land uses after soil and water loss control at any time, and can be used to assess the completion of soil and water conservation rate of different departments. It can realize comparative evaluation with annual and time-divided soil and water conservation rate targets.

Description

Technical Field

[0001] The invention belongs to the technical field of soil and water conservation and remote sensing monitoring, and relates to a real-time and rapid calculation method of county soil and water conservation rate based on monitoring and evaluation. Background Art

[0002] The status of soil and water conservation is an important indicator reflecting the quality and stability of the ecosystem. In order to implement the decision-making and deployment on the construction of ecological civilization, the soil and water conservation rate is used as a binding indicator for the assessment of the "14th Five-Year Plan" goal of soil and water conservation. At present, the country has completed the decomposition of the long-term target value of the soil and water conservation rate, and decomposed the work tasks to the county-level administrative regions, and proposed the long-term (2050) and 2025, 2030, and 2035 phased soil and water conservation rate target values.

[0003] The national soil and water loss dynamic monitoring publishes the soil and water loss area and soil and water conservation rate of each province in the previous year from June to July each year, and each provincial administrative region publishes the soil and water conservation rate of each county-level administrative region in the previous year 1-2 months after the release of the bulletin. Therefore, it is difficult for county-level administrative regions to grasp the completion of the soil and water conservation rate in real time, and there is a serious lag phenomenon, which is not conducive to the supervision and supervision of the soil and water conservation process assessment and the annual compliance rate. In order to complete the soil and water conservation rate planning period target on schedule, it is urgent to provide a real-time and rapid calculation method for the soil and water conservation rate, so as to achieve comparative evaluation with the annual and time-divided soil and water conservation rate targets, and effectively respond to the staged target assessment of the soil and water conservation rate. The method can provide an evaluation basis for the formulation of a comprehensive soil and water loss control plan, and provide important data and technical support for various industries, grassroots departments and relevant technical personnel in county-level administrative regions to quickly, conveniently and in real time evaluate the completion of the soil and water loss control area and soil and water conservation rate targets. Summary of the invention

[0004] The purpose of the present invention is to provide a real-time and rapid calculation method for the county's soil and water conservation rate based on monitoring and evaluation, so that the county-level administrative regions can grasp the completion status of the soil and water conservation rate in real time, and provide technical means for effectively responding to the annual and phased soil and water conservation rate target assessment.

[0005] The technical solution adopted by the present invention is: a real-time rapid calculation method of county soil and water conservation rate based on monitoring and evaluation, and the specific operation steps are as follows:

[0006] Step 1: Based on the results of the national soil and water loss dynamic monitoring, obtain the soil and water loss area M of the county-level administrative area in the previous year B , calculate the background value S of soil and water conservation rate in county-level administrative areas B ;

[0007] Step 2: Determine the allowable soil loss in different areas according to the national soil and water conservation zoning level one;

[0008] Step 3: Divide the impact of different land use types on soil and water conservation rate; combine remote sensing soil and water conservation measures interpretation data, field soil and water conservation measures survey data and full-caliber soil and water conservation measures statistical data to calculate the soil and water loss change area T of different land use status N ;

[0009] Step 4: Based on steps 1 to 3, calculate the current value S of soil and water conservation rate increase or decrease under different land use type changes N ;

[0010] Step 5: Dynamically evaluate the current soil and water conservation rate S N Differences between soil and water conservation rate targets in different periods S c .

[0011] The present invention is also characterized in that:

[0012] Step 1 is as follows:

[0013] Background soil and water conservation rate S B The following formula (1) is used for calculation:

[0014]

[0015] In the formula, S B M is the background value of soil and water conservation rate; B It is the total area of ​​soil erosion intensity below mild in different land use types within the county-level administrative region; M is the land area of ​​the county-level administrative region.

[0016] Step 2 is as follows:

[0017] According to the Soil Erosion Classification Standard (SL190-2007), the allowable soil loss in the Loess Plateau in Northwest my country is 1000t / (km 2 a); The allowable soil loss in the Northeast Black Soil Region and the Northern Rocky Mountain Region is 200t / (km 2 a); The allowable soil loss in the southern red soil area, the southwestern purple soil area and the southwestern karst area is 500t / (km 2 a).

[0018] Step 3 is as follows:

[0019] The Chinese Soil Loss Equation (CSLE) was used to calculate the soil erosion modulus.

[0020] A=RKLSBET(2)

[0021] Where: A is the soil erosion modulus (t / (hm 2 ·a)); R is the rainfall erosivity factor (MJ·mm / (hm 2·h·a)); K is the soil erodibility factor (t·hm 2 ·h / (hm 2 ·MJ·mm)); L and S are slope length and slope factors, dimensionless; B is vegetation cover and biological measures factor, dimensionless; E is engineering measures factor, dimensionless; T is tillage measures factor, dimensionless. Among them, R, K, L and S are all based on the 10m×10m grid data uniformly issued by the Ministry of Water Resources; B is calculated based on land use and vegetation cover; E is obtained according to the soil and water conservation measures; T is obtained by looking up the rotation measures assignment table.

[0022] On this basis, according to the allowable soil loss standard of each first-level area, if soil and water conservation measures are taken or the land use type changes within the map, the soil erosion intensity within the map needs to be revised, and the number of grid pixels (10m×10m) with erosion modulus higher than the allowable soil loss after revision in the map is counted, and the revised soil and water loss area T of different land use types is calculated. iN .

[0023]

[0024] A i =K i ×A(4)

[0025] In the formula, i is cultivated land (G), garden land (Y), forest land (L) and grassland (C); K is the revision factor, and the revision factor only involves vegetation coverage and biological measures B factor and engineering measures E factor, and other factors remain unchanged; Yes A i The number of pixels; A i is the revised soil erosion modulus;

[0026] (1) Cultivated land (T GN )

[0027] ① In the karst areas of the southwest, the soil and rocky mountains of the north, the purple soil areas of the southwest, the red soil areas of the south, and the loess plateau areas of the northwest, the construction of earthen ridges and stone ridges on sloping farmland with a slope of more than 6° is implemented. Among them, the earthen ridges and terraces measures, the E factor revision coefficient K G is 0.084; the stone sill level terrace measure K G is 0.121; slope terrace measure, K G is 0.414; the slope terrace measure and ground stalk measure k E Both are 0.347.

[0028] ② In the black soil region of Northeast China, ridge measures are implemented for sloping farmland with a slope greater than 2°, and the E factor revision coefficient K G It is 0.347.

[0029] (2) Garden YN )

[0030] In the six first-level soil and water conservation areas, when the vegetation coverage of the garden is less than 45%, after the construction of the horizontal step engineering measures, the E factor revision coefficient K Y It is 0.151.

[0031] (3) Woodland and grassland (T LN , T CN )

[0032] When the vegetation coverage (FVC) of different types of areas increases naturally or biological measures such as replanting and nurturing are taken, the area of ​​soil erosion is reduced, which means the soil and water conservation rate is improved. When the FVC deteriorates due to human interference, it means the soil and water conservation rate is reduced.

[0033] ① In the black soil area of ​​Northeast China, the Loess Plateau area of ​​Northwest China, and the soil and rocky mountainous area of ​​North China, when the FVC is less than 45%, after taking measures such as natural recovery or artificial replanting, the FVC of forest land and grassland is restored to more than 75% and 70% respectively. The revised coefficient K of forest land and grassland vegetation coverage and biological measure factor B is calculated. L , K C .

[0034] ② In the southwestern karst area, southwestern purple soil area, and southern red soil area, when FVC is less than 45%, after natural recovery or artificial replanting, the FVC of forest land and grassland is increased to more than 90% and 75% respectively. The revised coefficient K of forest land and grassland vegetation coverage and biological measure factor (B) is calculated. L , K C , the calculation method is shown in formulas (5) to (6).

[0035] K L =0.44468×e (-3.20096×GD) -0.04099×e (FVC-FVC×GD) +0.025(5)

[0036]

[0037] Where GD is the understory vegetation coverage, which is determined based on field surveys.

[0038] ③ When the vegetation coverage of forest land or grassland is greater than 75%, the FVC deteriorates due to human activities such as deforestation, land renewal, and returning forest to farmland. If the land use type remains unchanged after the change, the correction coefficient is calculated according to formulas (5) to (6) to obtain the amount of soil erosion after the change; if the land use type changes, the B factor is directly assigned according to the land use type after the change. According to the Technical Guidelines for Dynamic Monitoring of Soil and Water Loss, the B factor for cultivated land or rural roads is 1; the B factor for urban construction land, rural construction land, human disturbance land, other construction land or other transportation land is 0.01, 0.025, 0.01 and 0.01 respectively; the B factor for water areas or other land is 0.

[0039] (4) Human-disturbed land (T RWN )

[0040] For the land that was originally disturbed by human beings and had no measures and a ground slope greater than 5 degrees, the on-site investigation showed that measures such as covering, hardening or forest and grass were taken. Forest and grass measures included replanting grassland or economic forest land. When the degree of soil and water loss control was greater than 70%, the soil erosion intensity was judged to be slight (no soil and water loss).

[0041] For other land use types such as cultivated land, gardens, forest land, grassland, etc., if the current land use type or measures are changed due to human activities, they should be corrected according to steps (1) to (3) based on the changed type.

[0042] (5) Land use type changes to water area (T BN )

[0043] If the land use type in the comparison year is cultivated land, orchard, forest land, grassland or land disturbed by human beings, and in the current year it is converted into water area and water conservancy facility land, such soil and water erosion plots can be judged as having no soil and water erosion.

[0044] Step 4 is as follows:

[0045] Using the revised T iN (T GN 、T YN 、T LN 、T CN 、T RWN 、T BN ), and use formula (7) to calculate the change of current soil and water conservation rate:

[0046]

[0047] In the formula, S N is the current value of soil and water conservation rate after the change; T B is the basic soil and water loss area of ​​each category; T iNis the area of ​​change of soil erosion in each category; M is the regional land area; n is the number of plots of soil erosion reduced in each category.

[0048] Step 5 is as follows:

[0049] Based on the current status of soil and water conservation rates in county-level administrative areas, formula (8) is used to calculate the difference between the current status and the target values ​​of soil and water conservation rates in 2025, 2030 and 2035, and to assess whether the soil and water conservation rates meet the standards.

[0050]

[0051] S c S is the change value of soil and water conservation rate in different stages, which is used to judge whether the soil and water conservation rate target has been achieved. If it is a negative value, it means that the soil and water conservation rate target has been achieved. If it is a positive value, it indicates the soil and water conservation rate improvement rate that needs to be achieved each year. N is the current soil and water conservation rate; S M is the target value of soil and water conservation rate in 2025, 2030 and 2035; n is the difference with the target year. Among them, the target values ​​of soil and water conservation rate in 2025, 2030 and 2035 of each county-level administrative area can be determined according to the long-term target value of soil and water conservation rate of each province (city, district) and the phased target decomposition and report to the Ministry of Water Resources.

[0052] The beneficial effects of the present invention are:

[0053] The present invention can quickly evaluate the change of soil erosion area in county-level administrative areas according to the implementation of control measures, judge whether the soil erosion intensity of the soil erosion patches after control can be reduced to a micro degree, and realize real-time measurement of the compliance of soil and water conservation rate in county-level administrative areas, thus providing important technical support for meeting the target responsibility assessment of soil and water conservation rate, soil and water conservation prevention supervision, comprehensive control and soil and water conservation function evaluation in county-level administrative areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is the soil and water loss distribution based on the background soil erosion modulus in Fenggang County, a rocky desertification area in the southwest of China, in the embodiment of the method for real-time and rapid calculation of the county water and soil conservation rate based on monitoring and evaluation of the present invention;

[0055] Figure 2 It is a soil and water loss distribution map after calculating the current soil and water conservation rate of Fenggang County in the rocky desertification area of ​​the southwest according to Example 3 of the method for real-time and rapid calculation of the soil and water conservation rate of a county based on monitoring and evaluation of the present invention;

[0056] Figure 3(a) is Figure 2 A local enlarged image of the middle A (image spot before correction);

[0057] FIG3( b ) is a schematic diagram of the corrected image spot of FIG3( a ). DETAILED DESCRIPTION

[0058] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0059] Example 1

[0060] The present invention provides a method for quickly calculating the county soil and water conservation rate based on monitoring and evaluation, and the specific operation steps are as follows:

[0061] Step 1: Based on the results of the national soil and water loss dynamic monitoring, obtain the soil and water loss area M of the county-level administrative region in that year B , calculate the background value S of soil and water conservation rate in county-level administrative areas B ;

[0062] Step 2: Determine the allowable soil loss in different areas according to the national soil and water conservation zoning level one;

[0063] Step 3: Divide the impact of different land use types on soil and water conservation rate; combine remote sensing soil and water conservation measures interpretation data, field soil and water conservation measures survey data and full-caliber soil and water conservation measures statistical data to calculate the current soil and water loss change area T of different land types N ;

[0064] Step 4: Based on steps 1 to 3, calculate the current value S of soil and water conservation rate increase or decrease under different land use type changes N ;

[0065] Step 5: Dynamically evaluate the current soil and water conservation rate S N Differences between soil and water conservation rate targets in different periods S c .

[0066] Example 2

[0067] Based on Example 1,

[0068] The background soil and water conservation rate S in step 1 B The following formula (1) is used for calculation:

[0069]

[0070] In the formula, S B M is the background value of soil and water conservation rate; B It is the total area of ​​different land use types with soil erosion intensity below mild within the county-level administrative area; M is the area of ​​the county-level administrative area.

[0071] Step 2 is as follows:

[0072] According to the Soil Erosion Classification Standard (SL190-2007), the allowable soil loss in the Loess Plateau in Northwest my country is 1000t / km 2 a; The allowable soil loss in the Northeast Black Soil Region and the Northern Rocky Mountain Region is 200t / km 2 a; The allowable soil loss in the southern red soil area, southwestern purple soil area and southwestern karst area is 500t / km 2 a.

[0073] Step 3 is as follows:

[0074] The soil erosion modulus is calculated using the Chinese Soil Loss Equation (CSLE):

[0075] A=PKLSBET (2)

[0076] In the formula: A is the soil erosion modulus; R is the rainfall erosivity factor; K is the soil erodibility factor; L and S are the slope length and slope factors respectively; B is the vegetation cover and biological measure factor; E is the engineering measure factor; T is the tillage measure factor; R, K, L and S are all based on the 10m×10m grid data uniformly issued by the Ministry of Water Resources; B is calculated based on land use and vegetation cover; E is obtained according to the soil and water conservation measures; T is obtained by looking up the rotation measures assignment table;

[0077] On this basis, according to the allowable soil loss standard of each first-level area, the soil erosion intensity within the map needs to be revised, and the number of grid pixels N whose erosion modulus in the revised map is higher than the allowable soil loss is counted, and the revised soil and water loss area T of different land use types is calculated. iN ;

[0078]

[0079] A i =K i ×A(4)

[0080] In the formula, i represents cultivated land G, garden land Y, forest land L and grassland C respectively; K i The revised coefficient only involves the vegetation cover and biological measures B factor and engineering measures E factor, and other factors remain unchanged. Yes A i The number of pixels; A i is the revised soil erosion modulus;

[0081] Calculate the current soil erosion change area of ​​different land types:

[0082] (1) Cultivated land T GN

[0083] ① In the karst areas of the southwest, the soil and rocky mountains of the north, the purple soil areas of the southwest, the red soil areas of the south, and the loess plateau areas of the northwest, the construction of earthen ridge horizontal terraces and stone ridge horizontal terraces on sloping cultivated land with a slope of more than 6° shall be implemented; among them, the earthen ridge terrace measures, the E factor revision coefficient K G is 0.084; the stone sill level terrace measure K G is 0.121; slope terrace measure, K G is 0.414; the slope separation terrace measures and ground stalk measures K E Both are 0.347;

[0084] ② In the black soil region of Northeast China, ridge measures are implemented for sloping farmland with a slope greater than 2°, and the E factor revision coefficient K G is 0.347;

[0085] (2) Garden T YN

[0086] In the six first-level soil and water conservation zonings, when the vegetation coverage of the garden is less than 45%, after the construction of the horizontal step engineering measures, the E factor revision coefficient K Y is 0.151;

[0087] (3) Woodland T LN and Grassland T CN

[0088] ① In the black soil area of ​​Northeast China, the Loess Plateau area of ​​Northwest China, and the rocky mountainous area of ​​North China, when the FVC is less than 45%, after natural recovery or artificial replanting measures are taken, the FVC of forest land and grassland is increased to more than 75% and 70% respectively. The revised coefficient K of forest land and grassland vegetation coverage and biological measure factor B is calculated. L , K C ;

[0089] ② In the southwestern karst area, southwestern purple soil area, and southern red soil area, when FVC is less than 45%, after natural recovery or artificial replanting measures are taken, the FVC of forest land and grassland is increased to more than 90% and 75% respectively. The revised coefficient K of forest land and grassland vegetation coverage and biological measure factor B is calculated. L , K C , the calculation method is shown in formulas (5) to (6).

[0090] K L =0.44468×e (-3.20096×GD) -0.04099×e (FVC-FVC×GD) +0.025(5)

[0091]

[0092] In the formula, GD is the understory vegetation coverage, which is determined based on field surveys;

[0093] ③ When the vegetation coverage of forest land or grassland is greater than 75%, the vegetation coverage has deteriorated due to deforestation, land renewal, and forest-to-farm conversion. If the land use type remains unchanged after the change, the correction coefficient is calculated according to formulas (5) to (6) to obtain the soil erosion amount after the change. If the land use type changes, the B factor is directly assigned according to the land use type after the change. According to the Technical Guidelines for Dynamic Monitoring of Soil and Water Loss, the B factor for cultivated land or rural roads is 1; the B factor for urban construction land, rural construction land, human disturbance land, other construction land or other transportation land is 0.01, 0.025, 0.01 and 0.01 respectively; the B factor for water area or other land is 0.

[0094] (4) Human-disturbed land T RWN

[0095] For the land that was originally disturbed by human beings and had no measures and a ground slope greater than 5 degrees, if the on-site investigation shows that covering, hardening or forest and grass measures are taken, the forest and grass measures include replanting grassland or economic forest land; when the degree of soil and water loss control is greater than 70%, the soil erosion intensity is judged to be slight, that is, there is no soil and water loss;

[0096] If the current land use type of cultivated land, garden land, forest land, or grassland changes, the corresponding land type in steps (1) to (3) should be corrected according to the changed type;

[0097] (5) Land use type changes to water area T BN

[0098] For land use types such as cultivated land, garden land, forest land, grassland or land disturbed by humans in previous years, which have been converted into water areas or water conservancy facility land in the current year, such soil and water erosion plots are judged as having no soil and water erosion.

[0099] Step 4 is as follows:

[0100] Using the revised T iN , T iN Including T GN 、T YN 、T LN 、T CN 、T RWN 、T BN , use formula (7) to calculate the change of current soil and water conservation rate:

[0101]

[0102] In the formula, S N is the current value of soil and water conservation rate after the change; T B is the basic soil and water loss area of ​​each category; T iNis the area of ​​change of soil erosion in each category; M is the regional land area; n is the number of plots of soil erosion reduced in each category.

[0103] Step 5 is as follows:

[0104] Based on the current status of soil and water conservation rates in county-level administrative areas, formula (8) is used to calculate the difference between the current status and the target values ​​of soil and water conservation rates in 2025, 2030 and 2035, and to assess whether the soil and water conservation rates meet the standards.

[0105]

[0106] S c S is the change value of soil and water conservation rate in different stages, which is used to judge whether the soil and water conservation rate target has been achieved. If it is a negative value, it means that the soil and water conservation rate target has been achieved. If it is a positive value, it indicates the soil and water conservation rate improvement rate that needs to be achieved each year. N is the current soil and water conservation rate; S M are the target values ​​of soil and water conservation rates in 2025, 2030 and 2035; n is the difference with the target year; among them, the target values ​​of soil and water conservation rates in 2025, 2030 and 2035 for each county-level administrative area are determined according to the long-term target values ​​of soil and water conservation rates of each province, city or district and the documents reported to the Ministry of Water Resources by phased target decomposition.

[0107] Example 3

[0108] The present invention takes Fenggang County in the southwest rocky desertification area as an example. Figure 1-Figure 3(b) As shown, quickly calculate the current status of soil and water conservation target achievement rate. Collect data on key soil and water conservation projects and implementation of biological measures in county-level administrative areas.

[0109] Step 1: Based on the results of the national soil and water loss dynamic monitoring in August 2023, the land area of ​​Fenggang County is 1883km 2 In 2022, the total area of ​​soil erosion in each secondary land category is 470.44km 2 (Table 1), using formula (1) to calculate the background value of soil and water conservation rate S B It is 75.02%.

[0110] Table 1 Calculation of the background value of soil and water conservation rate in Fenggang County, Guizhou Province

[0111]

[0112] Step 2: For cultivated land, based on the visual interpretation of soil and water conservation engineering measures from remote sensing images and field verification results, by December 2023, Fenggang County will add 1.52 km of earthen terraces. 2Formulas (3) and (4) were used to calculate the revised area of ​​soil erosion for cultivated land. The revision coefficient for the implementation of horizontal terraces was 0.084. The calculation results showed that the erosion modulus in the area where terraces were implemented was reduced to a slight level, and the total area of ​​soil erosion was reduced by 1.52 km. 2 .

[0113] For gardens, if there is no increase in horizontal step measures, the area of ​​soil erosion in the garden will remain unchanged.

[0114] For forest land and grassland, according to the vegetation coverage FVC remote sensing monitoring, after the vegetation coverage of forest land and grassland in Fenggang County was improved, the calculation results were as follows: 2 and 0.02km 2 .

[0115] According to the on-site review and determination results for the artificially disturbed land, the area of ​​soil erosion in the artificially disturbed land increased by 0.88km 2 .

[0116] In addition, the area of ​​other land use types changed to water area is 0.

[0117] Step 3: Based on step 2, the change in soil erosion area in Fenggang County is -3.62km 2 . Using formula (7), after treatment, the current value of soil and water conservation rate at the end of 2023 is s N It is 75.20%, an increase of 0.18% compared with the baseline soil and water conservation rate target.

[0118] Step 4: According to the soil and water conservation rate target decomposition file of Guizhou Province (cities and prefectures), the soil and water conservation rate targets of Fenggang County in 2025, 2030 and 2035 are 75.90%, 77.61% and 79.40% respectively. Calculated by formula (8), the current soil and water conservation rate is 0.70% lower than the 2025 target, and an average annual increase of 0.23% is required to achieve the 2025 target. Compared with the soil and water conservation rate improvement rate in 2022, it is necessary to further accelerate soil and water loss control to achieve the assessment target. The soil and water conservation rate target in 2030 is 2.41% lower, and an average annual increase of 0.30% is required; the soil and water conservation rate target in 2035 is 4.20% lower, and an average annual increase of 0.32% is required. The results can obtain the status of soil and water conservation rate completion in county-level administrative areas in real time, grasp the progress of soil and water loss control, solve the problem of delayed announcement of soil and water loss dynamic monitoring results, and provide support for the phased soil and water conservation rate process assessment and the inspection and supervision of annual compliance rate.

Claims

1. Real-time rapid calculation method of county soil and water conservation rate based on monitoring and evaluation. The specific operation steps are as follows: Step 1: Based on the results of the national soil erosion dynamic monitoring, obtain the soil erosion area of ​​the county-level administrative area in the previous year , calculate the background value of soil and water conservation rate in county-level administrative areas ; Background value of soil and water conservation rate The following formula (1) is used for calculation: （1） In the formula, is the background value of soil and water conservation rate; Different land use types within the county administrative area The total area where soil erosion intensity is mild or less; is the administrative area of ​​the county; Step 2: Determine the allowable soil loss in different areas according to the national soil and water conservation zoning level one; Step 3: Divide the impact of different land use types on soil and water conservation rate; combine remote sensing soil and water conservation measures interpretation data, field soil and water conservation measures survey data and full-caliber soil and water conservation measures statistical data to calculate the current soil and water loss change area of ​​different land types ; The soil erosion modulus is calculated using the Chinese Soil Loss Equation (CSLE): （2） Where: A is the soil erosion modulus; R is the rainfall erosivity factor; K is the soil erodibility factor; L and S are slope length and slope factor respectively; B is the vegetation cover and biological measure factor; E is the engineering measure factor; T is the farming measure factor; among them, R , K , L and S All use the 10m×10m grid data uniformly issued by the Ministry of Water Resources; B Calculated based on land use and vegetation cover; E Obtained according to the value assigned by soil and water conservation measures; T Obtained by searching the crop rotation measure assignment table; On this basis, according to the allowable soil loss standard of each first-level area, the soil erosion intensity within the map block needs to be revised, and the number of raster pixels whose erosion modulus is higher than the allowable soil loss after the revision is counted. N , calculate the revised soil erosion area of ​​different land use types T iN ; （3） （4） In the formula, i They represent cultivated land G, garden land Y, forest land L and grassland C respectively; The revised coefficient only involves vegetation cover and biological measures. B Factors and Engineering Measures E factor, and all other factors remain unchanged. yes The number of pixels; is the revised soil erosion modulus; Calculate the current soil erosion change area of ​​different land types: (1) Cultivated land ① In the southwestern rocky mountainous areas, northern rocky mountainous areas, southern red soil hilly areas, and northwestern loess plateau areas, earthen ridge horizontal terraces and stone ridge horizontal terraces are constructed on sloping cultivated land with a slope greater than 6°. Among them, the earthen ridge terrace measures, the E factor revision coefficient 0.084; Stone level terrace measures is 0.121; Slope terrace measures, is 0.414; slope terrace measures and ground stalk measures K E Both are 0.347; ② In the black soil region of Northeast China, ridge measures are implemented for sloping farmland with a slope greater than 2°, and the E factor is revised is 0.347; (2) Garden In the five first-level soil and water conservation areas, when the vegetation coverage of the garden is less than 45%, after the construction of the horizontal step engineering measures, the E factor revision coefficient is 0.151; (3) Woodland and grass ① In the black soil area of ​​Northeast China, the Loess Plateau area of ​​Northwest China, and the rocky mountainous area of ​​North China, when the vegetation coverage FVC is less than 45%, after natural restoration or artificial replanting measures are taken, the vegetation coverage FVC of forest land and grassland is increased to more than 75% and more than 70% respectively. The revised coefficient of forest land and grassland vegetation coverage and biological measure factor B is calculated. , ; ② In the rocky mountainous areas in the southwest and the red soil hilly areas in the south, when the vegetation coverage FVC is less than 45%, after natural restoration or artificial replanting measures are taken, the forest and grassland vegetation coverage FVC will be increased to more than 90% and more than 75% respectively. The revised coefficient of forest and grassland vegetation coverage and biological measure factor B is calculated. , , the calculation method is shown in formula (5)~(6); （5） （6） In the formula, GD is the coverage of understory vegetation; ③ When the vegetation coverage of forest land or grassland is greater than 75%, the vegetation coverage has deteriorated due to deforestation, land renewal, and returning forest to farmland. If the land use type remains unchanged after the change, the correction coefficient is calculated according to formulas (5) to (6) to obtain the soil erosion amount after the change. If the land use type changes, B is directly assigned according to the land use type after the change. For cultivated land or rural roads, B is 1; for urban construction land, rural construction land, land disturbed by human beings, other construction land or other transportation land, B is 0.01, 0.025, 0.01 and 0.01 respectively; for water areas or other land, B is 0. (4) Land disturbed by human activities For the land that was originally disturbed by human beings and had no measures and a ground slope greater than 5 degrees, if the on-site investigation shows that covering, hardening or forest and grass measures are taken, the forest and grass measures include replanting grassland or economic forest land; when the degree of soil and water loss control is greater than 70%, the soil erosion intensity is judged to be slight, that is, there is no soil and water loss; If the current land use type of cultivated land, garden land, forest land, or grassland changes, the corresponding land type in steps (1) to (3) should be corrected according to the changed type; (5) Land use type changes to water area For the land use types of cultivated land, garden land, forest land, grassland or human-disturbed land in previous years, which have been converted into water areas or water conservancy facilities land in the current year, such soil and water erosion plots are judged as having no soil and water erosion; Step 4: Based on steps 1 to 3, calculate the current value of soil and water conservation rate increase or decrease under different land use type changes ; Step 5: Dynamically evaluate the current soil and water conservation rate Differences in soil and water conservation rate targets in different periods .

2. The real-time rapid measurement of county soil and water conservation rate based on monitoring and evaluation according to claim 1 The calculation method is characterized in that Step 2 is as follows: According to the Soil Erosion Classification and Grading Standard (SL190-2007), the allowable soil loss in the Loess Plateau in northwest my country is 1,000 t / (km²·a); the allowable soil loss in the black soil region in northeast China and the earth and rocky mountainous areas in the north is 200 t / (km²·a); and the allowable soil loss in the red soil hilly regions in the south and the earth and rocky mountainous areas in the southwest is 500 t / (km²·a).

3. The method for real-time rapid calculation of county soil and water conservation rate based on monitoring and evaluation according to claim 1 is characterized in that: Step 4 is as follows: Using the revised , include , , , , , , use formula (7) to calculate the change of current soil and water conservation rate: （7） In the formula, is the current value of soil and water conservation rate after the change; T B The background water and soil erosion area of ​​each category; The area of ​​soil erosion change in each category; n Reduce the number of plots of land suffering from soil erosion for each category.

4. The method for real-time rapid calculation of county soil and water conservation rate based on monitoring and evaluation according to claim 1 is characterized in that: Step 5 is as follows: According to the current status of soil and water conservation rate in county-level administrative areas, the difference between the current status and the target values ​​of soil and water conservation rate in 2025, 2030 and 2035 is calculated using formula (8) to evaluate the status of soil and water conservation rate compliance; （8） It is the change value of soil and water conservation rate in different stages, which is used to judge whether the soil and water conservation rate target has been achieved. If it is a negative value, it indicates that the soil and water conservation rate target has been achieved. If it is a positive value, it indicates the soil and water conservation rate improvement rate that needs to be achieved each year. is the current soil and water conservation rate; are the target values ​​of soil and water conservation rates in 2025, 2030 and 2035; n is the difference with the target year.

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