Decision-making method and system for influence of water and sand linkage above slope on erosion amount below

Abstract

The invention provides a decision-making method and system for the influence of water and sand linkage above a slope on the erosion amount below the slope. The system comprises an experiment control unit, an REE element layout unit, a dynamic monitoring network unit and a data acquisition and analysis unit. The experiment control unit comprises a parameterization experiment design module and a process sample dynamic sampling module, and the REE element laying unit comprises a layering marking module and a tracer agent selection and stability control module; the method not only objectively describes the temporal and spatial change rule of relative erosion amounts of different parts of the slope in the erosion occurrence process, but also can continuously analyze the influence of water and sand coming from the upper part of a certain section of the slope on the erosion process below, thereby dynamically judging and measuring the slope sediment source and analyzing the influence of water and sand linkage above on the erosion process below. The purpose of monitoring the sediment source and the soil erosion amount of different terrain parts is achieved.

Description

Technical Field

[0001] The invention relates to a decision-making method and system for the influence of water-sand linkage on a slope on the amount of erosion below, and belongs to the technical field of soil erosion. Background Art

[0002] Soil erosion, also known as water and soil loss, is one of the major environmental issues of universal concern in the world today. As it seriously affects the environment on which people depend for survival, soil erosion research has attracted widespread attention from all walks of life. Traditional research methods currently used in soil erosion include runoff plot observation, field survey, remote sensing and stereo photography, etc. However, these traditional research methods are only effective in studying the results of erosion, but are powerless to study the erosion sediment production and temporal and spatial variation patterns of different parts of the slope during the erosion process. With the development of science and technology and the improvement of analytical methods, nuclear tracer technology has shown great potential in soil erosion research. Compared with traditional research methods, it not only has a high degree of technical quantification, but is also suitable for various landform types. In particular, it can monitor both temporal and spatial variations, making soil erosion research simpler, faster and more accurate. Therefore, its application in soil erosion research is becoming more and more extensive. Currently, nuclear tracer technology used in soil erosion research can be divided into two categories: radionuclide tracer method and stable rare earth element tracer method. Although radionuclide tracer method makes up for the shortcomings of traditional soil erosion research in characterizing the erosion intensity and sediment sources in different terrain locations, most available natural radioactive elements are distributed in the soil surface. If the topsoil in severely eroded areas is completely eroded, the natural radioactive tracer element method is powerless. In order to solve the above technical problems, a decision-making method and system for the influence of water-sediment linkage on the slope surface on the erosion amount below are proposed. Summary of the Invention

[0003] In view of this, the present invention provides a decision-making method and system for the impact of water-sediment linkage on the slope on the amount of erosion below, so as to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial option.

[0004] The technical solution of the present invention is achieved as follows: a decision-making system for the influence of water-sediment linkage above the slope on the amount of erosion below includes an experimental control unit, a REE element layout unit, a dynamic monitoring network unit and a data acquisition and analysis unit; The experimental control unit includes a parameterized experimental design module and a process sample dynamic sampling module; the REE element layout unit includes a layered labeling module and a tracer selection and stability control module; the dynamic monitoring network unit includes a hydrological sediment sensor and a terrain scanning and spatial positioning module; and the data acquisition and analysis unit includes a spatiotemporal evolution modeling module and a multi-source data fusion algorithm module.

[0005] Further preferably, the parameterized test design module controls the variables of slope and flow through artificially simulated rainfall or water scour tests to study the impact of different water and sand conditions on the erosion process. The process sample dynamic sampling module collects eroded sediment samples in different time periods during the test, and analyzes the critical conditions for erosion morphological transformation in combination with REE concentration detection.

[0006] Further preferably, the layered marking module arranges different rare earth oxides in layers in the vertical direction of the slope surface, and realizes accurate identification of erosion morphology through element combinations at different depths and positions. The tracer selection and stability control module selects rare earth oxides with high stability to ensure that the tracer does not chemically migrate during the scouring process and only reflects the source of sediment through the physical erosion process.

[0007] Further preferably, the hydrological sediment sensor integrates a runoff sensor and a sediment transport rate monitor to collect rainfall intensity, runoff velocity, and sediment concentration in real time, and analyzes them in conjunction with REE tracer data. The terrain scanning and spatial positioning module uses a high-precision scanner to regularly acquire three-dimensional slope terrain data, and combines GPS positioning technology to verify the spatial displacement of the REE tracer belt.

[0008] Further preferably, the spatiotemporal evolution modeling module constructs a spatiotemporal distribution model of erosion rate based on the migration characteristics of REE elements, quantifies the contribution ratio of surface erosion and rill erosion in different time periods, and the multi-source data fusion algorithm module integrates REE tracing data, hydrological parameters and terrain scanning results, establishes a water-sand-bed mutual feedback mechanism model, and predicts the migration trend of erosion hotspots.

[0009] The decision-making method for the impact of water-sediment interaction on the slope surface on the erosion below includes the following steps: S1. Selection of tracer elements and estimation of release concentration; S2. Estimation of tracer element requirements; S3. Prepare tracer soil sample; S4. Tracer soil sample placement and layout; S5, scour test; S6. Sample collection and preparation.

[0010] Further preferably, in said S1, the estimation of REE release concentration must take into account not only the maximum erosion depth that may occur during the study period, but also other factors such as the element neutron activation cross section, detection line, and the degree of mutual interference between nuclides' characteristic gamma rays.

[0011] Further preferably, in said S3, when preparing a soil sample with a high concentration of tracer elements, first weigh a certain proportion of the required amount of elements and mix it with the soil sample, knead and stir it by hand until it is basically uniform, and then sieve the mixed soil sample with a high concentration of tracer elements to make it more uniform.

[0012] Further preferably, in said S4, the test slope is first divided into several slope sections, each slope section is separated by tinplate, and then the configured high-concentration tracer soil sample is fully mixed with the entire amount of soil in each slope section and then laid out on the slope surface in sequence. Finally, the tinplate between each slope section is removed in preparation for the test. During the laying process, the rolling of soil particles to cause cross contamination must be strictly prevented.

[0013] Further preferably, in said S6, the runoff sediment samples collected during the test are air-dried at room temperature, evenly mixed, taken out using a grid method, ground, and then sieved, and finally the samples are packaged in high-purity aluminum foil bags, and then wrapped with aluminum foil as an activated target, and the contents of the four elements are determined and analyzed at each characteristic energy using a gamma spectrometer, and then the erosion sand yield of different parts of the slope is calculated using the content of each element according to the principle of conservation of matter.

[0014] The embodiment of the present invention adopts the above technical solution, which has the following advantages: The present invention can not only objectively describe the temporal and spatial variation of the relative erosion amount at different parts of the slope during the erosion process, but also continuously analyze the influence of water and sand above a certain section of the slope on the erosion process below. The stable rare earth element tracer method is used to study the soil erosion distribution. The tracer element compound is evenly mixed with the soil and then arranged at different terrain parts of the studied area, so that it migrates with the runoff sediment during the entire erosion process. The sediment samples in the runoff pool are collected, and the content of the tracer element is determined by the neutron activation analysis method, so as to dynamically judge the source of the slope sediment and analyze the influence of the linkage between water and sediment above on the erosion process below, so as to achieve the purpose of monitoring the sediment source and the soil erosion amount at different terrain parts.

[0015] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 This is a decision-making system diagram of the influence of water-sediment linkage on the slope surface on the amount of erosion below; Figure 2 It is a functional module diagram of the system in the present invention; Figure 3 is a flow chart of the decision-making method of the present invention; Figure 4 This is a schematic diagram of the REE layout for the flushing test in the present invention; Figure 5 This is a graph showing the change in relative erosion of each section under different slopes and flow rates in the present invention; Figure 6 This is a time-varying diagram of the proportion of the total erosion amount of each section surface at different flow rates and different slopes in the present invention; Figure 7 The figure is a result difference diagram of the measured value and the calculated value of the experimental result in the present invention; Figure 8 This is an evolution diagram of the slope erosion process in the present invention.

[0018] Figure numerals: 10, experimental control unit; 11, parametric experimental design module; 12, process sample dynamic sampling module; 20, REE element layout unit; 21, layered labeling module; 22, tracer selection and stability control module; 30, dynamic monitoring network unit; 31, hydrological sediment sensor; 32, terrain scanning and spatial positioning module; 40, data acquisition and analysis unit; 41, spatiotemporal evolution modeling module; 42, multi-source data fusion algorithm module. DETAILED DESCRIPTION

[0019] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0020] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0021] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a decision-making system for the impact of water-sediment linkage on the slope surface on the amount of erosion below, which is composed of an experimental control unit 10, a REE element layout unit 20, a dynamic monitoring network unit 30 and a data acquisition and analysis unit 40.

[0022] The experimental control unit 10 includes a parameterized test design module 11 and a process sample dynamic sampling module 12. The parameterized test design module 11 controls the slope variable 15°-21° and the flow variable 3.5-5.5 L / min through artificially simulated rainfall or water release scour tests to study the impact of different water and sand conditions on the erosion process, dynamically adjust the scour duration, and capture the time when the erosion rate peak occurs. The process sample dynamic sampling module 12 collects eroded sediment samples in different time periods during the test and analyzes the critical conditions for erosion morphological transformation in combination with REE concentration detection.

[0023] The REE element placement unit 20 includes a layered labeling module 21 and a tracer selection and stability control module 22. The layered labeling module 21 layers different rare earth oxides in the vertical direction of the slope surface, accurately identifying the erosion morphology through element combinations at different depths and locations. The tracer selection and stability control module 22 selects rare earth oxides with high stability to ensure that the tracer does not chemically migrate during the scouring process and only reflects the source of sediment through the physical erosion process.

[0024] In one embodiment, a cross-layout strategy is adopted to simultaneously track the evolution of erosion in the downslope direction and in the depth direction. For example, the upper 50 cm area on the slope is preferentially marked to capture the starting point of gully development.

[0025] The dynamic monitoring network unit 30 includes a hydrological and sediment sensor 31 and a terrain scanning and spatial positioning module 32. The hydrological and sediment sensor 31 integrates a runoff sensor and a sediment transport rate monitor to collect rainfall intensity, runoff velocity, and sediment concentration in real time, and analyzes them in conjunction with REE tracer data. The terrain scanning and spatial positioning module 32 uses a high-precision scanner to regularly obtain three-dimensional slope terrain data and combines it with GPS positioning technology to verify the spatial displacement of the REE tracer band.

[0026] In one embodiment, critical flow threshold monitoring is used to identify severe erosion stages and trigger regulatory mechanisms.

[0027] In one embodiment, the REE tracking accuracy is calibrated by erosion gully measurement, and the error is controlled within ±5%.

[0028] The data acquisition and analysis unit 40 includes a spatiotemporal evolution modeling module 41 and a multi-source data fusion algorithm module 42. The spatiotemporal evolution modeling module 41 constructs a spatiotemporal distribution model of erosion rate based on the migration characteristics of REE elements, and quantifies the contribution ratio of surface erosion and gully erosion in different time periods. The multi-source data fusion algorithm module 42 integrates REE tracing data, hydrological parameters and terrain scanning results, establishes a water-sand-bed mutual feedback mechanism model, and predicts the migration trend of erosion hotspots.

[0029] In one embodiment, the dynamic changes of the erosion active zone are analyzed to identify the dominant erosion mode.

[0030] As Figure 3-Figure 6 shown, the embodiment of the present invention also provides a decision-making method for the influence of the water-sediment linkage above the slope on the erosion amount below, including the following steps: S1. Selection of tracer elements and estimation of application concentration: Select four rare earth elements, Ce, Sm, Nd, and Dy, which have low background values and high detection sensitivities in loess as tracer elements. In addition to considering the maximum erosion depth that may occur during the research period when estimating the REE application concentration, factors such as the neutron activation cross-section of the element, the detection line, and the degree of mutual interference between the characteristic γ-rays of the nuclides must also be considered. In order to ensure the statistical significance of the measured values, the content of tracer elements in the sediment should be significantly different from the soil background value. Considering the above factors comprehensively, the application concentration of various tracer REEs can be calculated according to the following formula: Cj = K·Bj·10-3 / Rj (g / kg) j = 1, 2, 3, …… n (1) In the formula: n—the number of segments into which the studied slope is divided; Cj—the application concentration of the j-th tracer element; Bj—the soil background value of the j-th tracer element; Rj—the minimum expected value of the relative erosion amount at the application site of the j-th tracer element; K—a comprehensive guarantee coefficient considering other factors; S2. Estimation of the required amount of tracer elements: After calculating the required concentration of tracer elements according to formula (1), as long as the application area and application depth are determined according to the test requirements, the required amount of a certain element can be calculated through the following formula (2). In this test, the application depth of REE on the slope is set to 20 cm. Qj = K·Bj·Wj·10-6 / Rj j = 1, 2, 3, …… n (2) In the formula: n—the number of segments into which the studied slope is divided; Qj—the total application amount of the j-th tracer element; Bj—the soil background value (mg / kg) of the j-th tracer element; Rj—the most probable erosion rate in the j-th erosion type area (0 < Rj < 1); Wj—the total amount of soil in kg represented by the j-th tracer element; S3. Preparation of tracer soil samples: When preparing high-concentration tracer element soil samples, first weigh 1 / 8 of the required amount of the element and mix it with 2 kg of soil samples. Knead and stir by hand until it is basically uniform. Then sieve 1 / 8 of the well-mixed high-concentration tracer element soil samples to make it more uniform. Repeat the above steps 8 times to prepare enough tracer soil samples. Finally, mix, stir, and sieve the 8 prepared soil samples to ensure complete uniformity and weigh a certain amount of the well-mixed tracer soil samples for neutron activation analysis to determine the accurate application concentration; S4. Tracer soil sample placement and layout. The layout of the test rare earth elements on the slope surface adopts the segment placement method. First, the test slope is divided into several slope sections, and each slope section is separated by tinplate. Then, the high-concentration tracer soil sample is fully mixed with the entire amount of soil in each slope section and then laid on the slope surface in sequence. Finally, the tinplate between each slope section is removed for testing. During the layout process, it is necessary to strictly prevent the rolling of soil particles and cause cross contamination. The specific test layout is as follows: Figure 4 As shown; S5. Scour test: the area of ​​the test slope is 500cm×100cm, the test slope is selected to be 6°, 9°, and 12°, and the discharge flow rate is changed to 2.5l / min, 3.5l / min, 4.5l / min, 5.5l / min, and 6.5l / min for combined test. The test soil sample is Lou soil. Before the start of the test, the selected rare earth elements Dy, Nd, Sm, and Ce are filled with the earthwork volume calculated according to the concentration of rare earth elements. After mixing evenly, fill the soil into the pre-marked slope section. After filling, the dry bulk density of the soil in the test tank is controlled between 1.25-1.3g / cm3. The water supply equipment in the test uses a constant head water supply to control the flow rate. After the test starts, when the slope begins to produce runoff, the runoff sediment sample at the slope outlet is collected. In the early stage of runoff, the runoff sediment sample is collected once every minute. After three minutes, the runoff sediment sample is collected once every two minutes. The whole test process lasts for 15 minutes, and each water discharge value is repeated twice in a row. S6. Sample collection and preparation. The runoff sediment samples collected during the experiment were air-dried at room temperature. After uniform mixing, about 100 g was ground using the grid method and then passed through a 100-mesh sieve. Finally, 50-100 mg of the sample was packaged in a high-purity aluminum foil bag of about 1 cm × 1 cm. The aluminum foil was then wrapped to serve as an activated target. Finally, the prepared sample was sent to a nuclear reactor for irradiation. The content of the four elements was determined and analyzed at each characteristic energy using a gamma spectrometer. Then, the content of each element was used to calculate the erosion sand yield at different parts of the slope according to the principle of conservation of matter.

[0031] When the present invention is working, four rare earth elements, Ce, Sm, Nd, and Dy, are selected as tracer elements, the application concentration of various tracer REEs is calculated, the application area and application depth are determined according to the test requirements, and the required amount of a certain element is calculated. When preparing a soil sample with a high concentration of tracer elements, a certain proportion of the required amount of the element is first weighed and mixed with the soil sample, and kneaded and stirred by hand until it is basically uniform. Then, the mixed soil sample with a high concentration of tracer elements is sieved to make it more uniform, and the required tracer soil sample is prepared. Finally, the prepared soil sample is mixed, stirred, and sieved to ensure complete uniformity, and a certain amount of the mixed tracer soil sample is weighed for preparation. The accurate application concentration was determined by the activation analysis of the sub-elements. The layout of the test rare earth elements on the slope surface adopted the segmental application method. First, the test slope was divided into several slope sections, and the slope sections were separated by tinplate. Then, the high-concentration tracer soil sample was fully mixed with the entire amount of soil in each slope section and then laid on the slope surface in sequence. Finally, the tinplate between the slope sections was removed for testing. During the layout process, the rolling of soil particles to cause cross contamination was strictly prevented. Then, the scouring test was carried out. The area of ​​the test slope was 500cm×100cm. The test slope was selected to change to three levels: 6°, 9°, and 12°. The water discharge rate was 2.5l / m In the test, the five-level change of 1.5l / min, 2.5l / min, 4.5l / min, 5.5l / min and 6.5l / min was carried out. Lou soil was used as the test soil sample. Before the test, the selected rare earth elements Dy, Nd, Sm and Ce were mixed with the earthwork volume calculated according to the concentration of rare earth elements and then filled into the slope section marked in advance. After the filling was completed, the dry bulk density of the soil in the test tank was controlled between 1.25-1.3g / cm3. The water supply equipment in the test used a fixed head water supply to control the flow rate. After the test started, when the runoff began on the slope, the runoff sediment sample at the slope outlet was collected. At the initial stage of runoff, the runoff sediment sample was collected. Runoff sediment samples were taken once every minute, and once every two minutes after three minutes. The entire test process lasted 15 minutes, and the test was repeated twice for each discharge flow value. The runoff sediment samples collected during the test were air-dried at room temperature, evenly mixed, and then taken out and ground using the grid method and sieved. The samples were packaged in high-purity aluminum foil bags, and then wrapped with aluminum foil as activation targets. Finally, the prepared samples were sent to a nuclear reactor for irradiation, and the contents of the four elements were determined and analyzed at each characteristic energy using a gamma spectrometer. Then, the erosion and sand yield of different parts of the slope were calculated based on the content of each element according to the principle of conservation of matter.

[0032] like Figure 4 As shown: By analyzing the content of each element in the sediment process samples, the erosion amount of each section on the slope surface in different time periods can be calculated using the following formula:

[0033] Where, —No. The amount of erosion in the area where the element is applied (kg); —No. The concentration of the element; —No. Background value of the element; —In the mud and sand The concentration of the element; is the total sediment volume for each sample.

[0034] The relative erosion amount at different parts of the test slope was calculated using the above formula, and the accuracy test results are shown in Table 1 below.

[0035] Table 1 Erosion amount and relative erosion amount at different parts of the slope

[0036] Note: A, B, C, D are the slope section numbers divided evenly from the bottom to the top of the slope From the table above, we can see that most of the test errors are within 13%, which meets the accuracy requirements in soil erosion research. This shows that it is feasible to use the rare earth element tracer method to study the laws of slope soil erosion.

[0037] like Figure 5-7 As shown: Numerous studies have shown that the amount of sediment produced on a slope depends on the relationship between the sediment-carrying capacity of the runoff and the amount of sediment supplied. This conclusion forms the core of physical process models such as WEPP. The basic model can be expressed as follows:

[0038] Where: WT is the sediment yield of the slope; T C is the sediment-carrying capacity of the slope runoff; Sa is the amount of sediment available for runoff on the slope; and Df is the runoff erosion on the slope. Sa can be expressed as Sa = qs + DR, where DR is the amount of raindrop erosion on the slope. In this study, since the water flushing method was used, raindrop erosion is zero and is not considered. Therefore, Sa = qs.

[0039] According to the law of conservation of mass, the slope erosion transport equation can be written as follows: (3) Where: A is the cross-sectional area of ​​runoff flowing through the slope rill (m²), S is the sediment content of the runoff (kg / m³), Q is the runoff volume in the rill (m³ / s), Dr is the scour dispersion rate per unit time and per unit length of the rill (kg / m·s), and Ds is the amount of sediment entering the rill per unit length per unit time due to raindrop erosion and thin layer overland flow (kg / m·s). If the temporal variation of the cross-sectional area of ​​runoff flowing through the rill is not considered, the above formula can be written as: (4) Since the test method is the water flushing method, Ds=0 in the above formula. The above formula can be further simplified: (5) The rill erosion rate is proportional to the difference between the rill flow's transport capacity and the actual sediment transport rate. (6) Where: α is the coefficient; T C is the sediment-carrying capacity of rill runoff (kg / m3), and qs is the sediment transport rate per unit width of rill runoff (kg / m·s).

[0040] According to the experimental design, the upper section D of the slope was used as the upper sediment-laden water flow to study the erosion and sediment production effect of the slope section D on the lower slope sections A, B, and C. The difference between the measured and calculated values ​​was determined based on the experimental results.

[0041] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various modifications and substitutions within the technical scope disclosed in the present invention, and such modifications and substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A decision-making system for the impact of water-sediment linkage on slope erosion below, characterized by: It includes an experimental control unit (10), a REE element layout unit (20), a dynamic monitoring network unit (30) and a data acquisition and analysis unit (40); The experimental control unit (10) includes a parameterized experimental design module (11) and a process sample dynamic sampling module (12); the REE element layout unit (20) includes a layered labeling module (21) and a tracer selection and stability control module (22); the dynamic monitoring network unit (30) includes a hydrological sediment sensor (31) and a terrain scanning and spatial positioning module (32); and the data acquisition and analysis unit (40) includes a spatiotemporal evolution modeling module (41) and a multi-source data fusion algorithm module (42).

2. The decision-making system for the impact of water-sediment linkage on slope erosion below according to claim 1, characterized in that: The parameterized test design module (11) controls the variables of slope and flow through artificially simulated rainfall or water release scouring tests to study the effects of different water and sediment conditions on the erosion process. The process sample dynamic sampling module (12) collects eroded sediment samples at different time periods during the test and analyzes the critical conditions for erosion morphological transformation in combination with REE concentration detection.

3. The decision-making system for the impact of water-sediment linkage on slope erosion below according to claim 1 is characterized by: The layered marking module (21) layers different rare earth oxides in the vertical direction of the slope surface, and realizes accurate identification of erosion morphology through element combinations at different depths and positions. The tracer selection and stability control module (22) selects rare earth oxides with high stability to ensure that the tracer does not undergo chemical migration during the scouring process, and only reflects the source of sediment through the physical erosion process.

4. The decision-making system for the impact of water-sediment linkage on slope erosion below according to claim 1 is characterized by: The hydrological sediment sensor (31) integrates a runoff sensor and a sediment transport rate monitor to collect rainfall intensity, runoff velocity, and sediment concentration in real time, and analyzes them in conjunction with REE tracer data. The terrain scanning and spatial positioning module (32) uses a high-precision scanner to regularly obtain three-dimensional slope terrain data, and combines GPS positioning technology to verify the spatial displacement of the REE tracer belt.

5. The decision-making system for the impact of water-sediment linkage on slope erosion below according to claim 1 is characterized by: The spatiotemporal evolution modeling module (41) constructs a spatiotemporal distribution model of erosion rate based on the migration characteristics of REE elements, and quantifies the contribution ratio of erosion and sediment production in different slope sections at different time periods. The multi-source data fusion algorithm module (42) integrates REE tracer data, hydrological parameters and terrain scanning results to establish a water-sand-bed mutual feedback mechanism model to predict the migration trend of erosion hotspots.

6. The decision-making method for the influence of water-sediment linkage on the slope on the amount of erosion below according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Selection of tracer elements and estimation of release concentration; S2. Estimation of tracer element requirements; S3. Prepare tracer soil sample; S4. Tracer soil sample placement and layout; S5, scour test; S6. Sample collection and preparation; S7. Element content analysis and erosion calculation: Determine the content of various rare earth elements in each sample and calculate the erosion amount of each slope section at different time periods. : ； S8. Linkage modeling of water and sediment in up and down slope sections. Taking slope section D as the upstream control source, establish the runoff sediment carrying capacity T based on the dynamic mechanism of slope sediment production. C Relationship model with sediment transport rate per unit width qs: When T C ≤qs, indicating that the sand production is limited by the sand supply capacity; when T C >qs, indicating that sediment production is limited by sediment carrying capacity; Using the formula Dr=α(T C -qs) to establish a relationship between the difference between the gully scour rate and the actual sediment transport rate, and analyze the impact of the upstream slope segment on the erosion of downstream slope segments A, B, and C.

7. The decision-making method for determining the impact of water-sediment linkage on slope erosion below according to claim 6, characterized in that: In S1, the estimation of REE release concentration must take into account not only the maximum erosion depth that may occur during the study period, but also the degree of mutual interference between the element neutron activation cross section, detection line, and nuclide characteristic gamma rays.

8. The decision-making method for determining the impact of water-sediment linkage on slope erosion below according to claim 6, characterized in that: In said S3, when preparing a soil sample with a high concentration of tracer elements, first weigh a certain proportion of the required amount of elements and mix it with the soil sample, knead and stir it by hand until it is basically uniform, and then sieve the mixed soil sample with a high concentration of tracer elements to make it more uniform.

9. The decision-making method for determining the impact of water-sediment linkage on slope erosion below according to claim 6, characterized in that: In S4, the test slope is first divided into several sections, each of which is separated by tinplate. Then, the configured high-concentration tracer soil sample is fully mixed with the entire amount of soil in each section and then laid out on the slope in sequence. Finally, the tinplate between each section is removed in preparation for the test. During the laying process, cross contamination caused by rolling of soil particles must be strictly prevented.

10. The decision-making method for the impact of water-sediment linkage on the slope on the erosion amount below according to claim 6, characterized in that: In S6, the runoff sediment samples collected during the test are air-dried at room temperature, evenly mixed, taken out using a grid method, ground, and then sieved. Finally, the samples are packaged in high-purity aluminum foil bags, which are then wrapped with aluminum foil to serve as activation targets. The contents of four elements are measured and analyzed at each characteristic energy using a gamma spectrometer. Then, the contents of each element are used to calculate the erosion sand yield at different parts of the slope according to the principle of conservation of matter.

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