A method for systematically controlling sediment in the Yellow River

Abstract

The present invention provides a method for systematically controlling the sedimentation of the Yellow River through an engineering system. The method comprises: analyzing and judging the concentrated sediment source areas, reservoir projects, plain and wide river sections, and estuary flow path swing areas within the basin, inputting the corresponding analysis and judgment results into corresponding control subsystems, thereby constructing a four-level control subsystem, identifying the control factors and feedback factors of each level of control subsystem, and further optimizing the control measures at each level based on the information transmission of the control factors and the feedback of the feedback factors in each level of control subsystem to achieve the control of the Yellow River sediment system. From a system perspective, the method tracks the evolution of the generation, transport, siltation, and scouring of river sediment, and feedback and transmission of sediment change information by setting up a cascade of engineering controls for inflow sediment control, node reservoir sediment control, river channel sediment control, and estuary sediment control, thereby achieving comprehensive treatment of the Yellow River sediment.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering sediment cascade control, and in particular to a method for systematically controlling the sediment of the Yellow River in an engineering system. Background Art

[0002] What makes a river with a lot of sediment different from a river with less sediment is that it has a high sediment content and a large sediment transport volume. The sediment problem often leads to serious floods in the lower reaches of the river, which has a serious impact on the management and development of the river basin.

[0003] The Yellow River's sediment problem is present throughout the basin, at key points such as reservoirs, river channels, and estuaries. This impact spans a wide range, and each link is interconnected and interacting, forming a complex, giant system governed by the natural evolution of sediment generation, transport, deposition, and scour. However, traditional approaches to addressing the Yellow River's sediment problem have long focused on basin-wide governance, reservoir development, or river channel regulation. However, at the basin scale, the sediment problem of sediment-laden rivers is a complex systemic issue, requiring a systematic approach that requires analysis and exploration of a multi-level, multi-link, basin-wide, multi-stage engineering control system.

[0004] In response to the above problems, the present invention, based on the basic understanding of systems science and engineering cybernetics, considers the evolutionary process of the generation, transport, deposition, and scouring of sediment in sediment-laden rivers from a systemic perspective, regards the entire system involving sediment as a controlled engineering system, and proposes a method for a systematic engineering system for controlling the sediment of the Yellow River. The present invention sets the sediment control subsystem involving the concentrated source area of sediment in the Yellow River basin as a first-level control subsystem, the reservoir engineering system at the key node as a second-level control subsystem, the wide river section downstream that has an important regulatory role in the water and sediment process as a third-level control subsystem, and the estuary area that receives the water and sediment outlet of the discharge basin as a fourth-level control subsystem. Through the "control-transmission-action-influence-feedback" association mechanism between the subsystems at all levels, the layout and implementation of the Yellow River sediment control measures are guided, and the Yellow River sediment is controlled by different links, projects, and methods, providing a new method for systematically managing the sediment problem of the Yellow River. Summary of the Invention

[0005] The present invention provides a method for an engineering system for systematically controlling the sediment of the Yellow River, which is used to track the evolution process of the generation, transportation, deposition, scouring, etc. of river sediment from a system perspective. By setting up a hierarchical cascade engineering control system for river sediment control, node reservoir sediment control, river channel sediment control, and estuary sediment control, the control factors and feedback factors of the control subsystems at each level are identified. Based on the information transmission of the control factors and the feedback of the feedback factors in the control subsystems at each level, the control measures at each level are further optimized to achieve comprehensive treatment of the sediment of the Yellow River.

[0006] The present invention proposes a method for systematically controlling sediment in the Yellow River, comprising:

[0007] Step 1: Identify and code the concentrated sediment source areas, reservoir projects, plain and wide river sections, and estuary flow path swing areas within the basin to form a four-level control subsystem;

[0008] Step 2: Collect rainfall data from various rainfall monitoring stations in the sediment source area and deduce the rainfall process in the watershed;

[0009] Step 3: Using the surface rainfall process as input, the water and sediment yields are calculated in combination with the underlying surface conditions of the sediment source area.

[0010] Step 4: Identify the control factors used for transmission and the feedback factors used for feedback in each level of control subsystem;

[0011] Step 5: Soil and water conservation engineering measures are arranged based on the characteristics of soil erosion in the concentrated sediment source areas. A new type of check dam engineering system is deployed at key nodes in the channel to build a final sediment interception line. The soil and water conservation engineering measures are integrated into a primary control subsystem. The rainfall water and sediment production calculation results are used as input to analyze and calculate the amount of sediment entering the river after being intercepted and reduced by the primary control subsystem, and this is used as the control factor of the primary control subsystem.

[0012] Step 6: Collect and organize the backbone reservoir projects at key nodes of the Yellow River mainstream and important tributaries, code them, and integrate them to build a secondary control subsystem. Taking the amount of sediment entering the river as the control factor of the primary control subsystem, determine the sediment entering the reservoirs at each level. Through the water and sediment regulation and control of the node reservoirs at each level, analyze and calculate the sediment interception and sediment discharge of the corresponding node reservoir projects in accordance with the coding order. The sediment inflow and sediment interception data are fed back to the primary control subsystem as the feedback factors of the secondary control subsystem, and the sediment discharge is input into the next level subsystem as the control factor of the secondary control subsystem;

[0013] Step 7: Collect cross-sectional topography and river defense engineering data along the wide beach section of the lower reaches of the Yellow River, analyze the characteristic data of the river channel and graded beach, integrate and construct a three-level control subsystem, use the reservoir sediment discharge as the control factor of the second-level control subsystem, and through the analysis and calculation of water and sediment regulation in the wide beach section, deduce the river channel scouring and silting process, river regime evolution, river channel sediment discharge, and river channel siltation of the downstream wide beach section. The river channel siltation process, river channel sedimentation, and river regime evolution data are fed back to the second-level control subsystem as feedback factors of the third-level control subsystem, and the river channel sediment discharge is input into the next-level subsystem as the control factor of the third-level control subsystem;

[0014] Step 8: Collect topographic data of the flood discharge area in the estuary flow path swing region, analyze the evolution characteristics of the flow paths at all levels in the estuary area, integrate and construct a four-level control subsystem, use the downstream river sediment discharge as the control factor of the third-level control subsystem as input, perform estuary water and sediment analysis and calculation based on the estuary flow path adjustment, and obtain the estuary sedimentation extension length and the upstream river channel erosion base level information as feedback factors of the third-level control subsystem.

[0015] Step 9: Taking the water-sediment coordination as the overall control goal, based on the information transmission of control factors and feedback of feedback factors in the control subsystems at all levels, continuously optimize the control measures at all levels to achieve the control of the Yellow River sediment system.

[0016] Preferably, the control measures at all levels include: layout of soil and water conservation measures in sediment concentrated source areas, adjustment of reservoir utilization methods, comprehensive management measures for downstream river sections, and layout of estuary flow path utilization.

[0017] Preferably, based on constructing a four-level control subsystem, the control factors in each level of control subsystem are identified as variables transferred between control subsystems to affect the next level of control subsystem; the feedback factors in each level of control subsystem are identified as feedback transferred between control subsystems to guide the optimization of control measures in each level of control subsystem.

[0018] Preferably, key reservoir projects at key nodes of the Yellow River mainstream and important tributaries are collected and coded, including:

[0019] The main stream reservoirs in the backbone reservoir project are coded as G+X from upstream to downstream, where G represents the main stream reservoir and X represents the upstream and downstream relationship of the reservoir;

[0020] The coding rule for the tributary reservoirs in the backbone reservoir project is Z+XX, where Z represents the tributary reservoir, the first digit X represents the coding number of the main stream reservoir where the tributary reservoir and the main stream reservoir outflow meet, and the second digit X is coded in the order of the upstream and downstream relationship of the tributary reservoir flowing into the Yellow River.

[0021] Preferably, after analyzing and calculating the sediment interception and discharge volumes of the corresponding node reservoir project in the coding order, the method further includes:

[0022] Determine the synchronous shaping method of the beach and channel in the reservoir area of the corresponding node reservoir project during the sediment retention period;

[0023] Classify and dispatch node reservoir projects during normal operation according to water and sediment classification;

[0024] Based on the synchronous shaping method of the reservoir beach and channel and the classified scheduling results, and combined with the engineering scale and conditions of each reservoir design and unconventional sediment discharge scheduling methods, the sediment entering the Yellow River is regulated based on the corresponding node reservoirs.

[0025] Preferably, the reservoir sediment discharge is used as input, and the water and sediment regulation analysis and calculation process of the Kuantan River section also includes:

[0026] Determine the channel characteristics of the lower Yellow River;

[0027] Among them, the river channel characteristics are related to the width of the river channel in the lower reaches of the Yellow River and the gradient of the lower reaches of the Yellow River.

[0028] Preferably, the overall control objective is to take water-sand coordination as the goal, including:

[0029] Capturing the water-sediment matching process in different river channels in the lower reaches of the Yellow River;

[0030] Analyze the process information of each water-sand matching process and determine the corresponding water-sand relationship;

[0031] The result that the coordination index describing the water-sediment relationship is less than or equal to 1 is used as the overall control target.

[0032] Preferably, before achieving control of the Yellow River sediment system by optimizing control measures at all levels based on information transmission and feedback from control subsystems at all levels, the method further includes:

[0033] Predict the information transmission and feedback of each level of control subsystem in the first place;

[0034] Determine to optimize the control measures at all levels according to the predicted first time as the optimization trigger time point, and determine whether each optimization time point meets the optimization association standard.

[0035] Preferably, determining to optimize the control measures at all levels according to the predicted first time as the optimization trigger time point, and determining whether each optimization time point meets the optimization association standard includes:

[0036] Obtaining the optimized trigger parameters corresponding to the first predicted time matched by each level of control subsystem;

[0037] According to the optimization trigger parameter, the process simulation model simulates the system optimization process of the corresponding level control subsystem;

[0038] Calculate the optimal matching degree Y2 between the control subsystems at all levels based on the first prediction;

[0039]

[0040] Where m represents the total number of control subsystems at all levels; sim represents the similarity sign; dj1 represents the simulation result of the j1-th control subsystem; di1 represents the simulation result of the i1-th control subsystem; e represents the sign of the exponential function; tj1 represents the end simulation time of the j1-th control subsystem based on the first time of prediction; ti1 represents the start simulation time of the i1-th control subsystem based on the first time of prediction; where i1 = j1 + 1; j1 = 1, 2, 3, ..., m; i1 = 0, 1, 2, ..., m-1; Y2 represents the optimization matching degree between the j1-th control subsystem and the i1-th control subsystem; Δ i1,j1 represents the standard simulation time difference between the j1th control subsystem and the i1th control subsystem; sim(dj1,di1) max represents the maximum value among all similar simulation results; sim0(dj1, di1) represents the standard similarity between the simulation results of the j1-th control subsystem and the simulation results of the i1-th control subsystem; sim(dj1, di1) represents the actual similarity between the simulation results of the j1-th control subsystem and the simulation results of the i1-th control subsystem; represents the matching adjustment factor based on the simulation results of the j1-th control subsystem and the simulation results of the i1-th control subsystem;

[0041] When all optimization matching degrees Y2 are qualified, it is determined that each optimization time point meets the optimization association standard;

[0042] Otherwise, extract the first control subsystem corresponding to the unqualified optimization matching degree Y2, and determine the time simulation delay coefficient and the non-similar simulation result according to the ratio of the corresponding actual simulation time difference and the standard simulation time difference;

[0043] Determining a re-optimization factor corresponding to the first control subsystem based on the time delay coefficient and the non-similar simulation result;

[0044] The corresponding first control subsystem is optimized based on the re-optimization factor.

[0045] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0046] This invention considers the evolution of the generation, transport, deposition, and scouring of the Yellow River sediment from a systematic perspective, and proposes a multi-level, multi-link, and basin-wide multi-stage engineering control system. Through the "control-transmission-action-influence-feedback" mechanism between subsystems at all levels, it achieves systematic regulation of the Yellow River sediment by link, project, and method, and more systematically and comprehensively manages the Yellow River sediment problem. Compared with traditional unilateral, single-link management methods, the management goals are clearer, the management ideas are more comprehensive, and the management measures complement each other. It can provide important theoretical and technical support for the systematic management of the Yellow River sediment problem, and provide a systematic solution for the ecological management of the concentrated source areas of the Yellow River sediment, flood control and silt reduction of reservoirs and the realization of comprehensive benefits, the ecological management of the downstream wide beach river section, and the ecological protection and high-quality development of the estuary area.

[0047] Through the joint control of the Yellow River sediment multi-line defense system, the level of soil and water conservation management in the Loess Plateau has been significantly improved, the effectiveness of soil and water conservation has been significantly enhanced, and the amount of sand entering the Yellow River has been greatly reduced; the reservoir runoff and sediment regulation capacity has been significantly enhanced, the coordination of the water and sediment relationship of the Yellow River has been significantly improved, and flood sediment has been effectively controlled to ensure that the riverbed does not rise and the levee does not burst, and the flood and sediment transport capacity of the middle water channel and the stability of the middle water flow path and river flow have been maintained for a long time; the comprehensive management level of the river channel has been comprehensively improved, the integrated effect of the ecological corridor function has been revealed, the harmonious relationship between man and water has been improved, the free exchange function of water and sediment in the shoal channel has been maintained, and the sediment transport channel is unobstructed; the ecological environment of the estuary has been significantly improved, the flow path into the sea is relatively stable, and the adverse effects of siltation at the estuary have been significantly weakened.

[0048] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0049] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0051] Attachment Figure 1 An analytical flow chart of a cascade engineering control method for Yellow River sediment provided by the present invention;

[0052] Attachment Figure 2 An example diagram of the layout of a new type of anti-breach and multi-sediment-trapping silt dam system provided by the present invention;

[0053] Attachment Figure 3A schematic diagram of the working principle of the new type of anti-break and multi-sediment-retaining silt dam provided by the present invention;

[0054] Attachment Figure 4 A schematic diagram of the node reservoir project coding provided by the present invention;

[0055] Attachment Figure 5 Schematic diagram of the Yellow River sediment four-level engineering control structure provided by the present invention;

[0056] Attachment Figure 6 This is a flow chart for analyzing the four-level engineering control method for sediment in the Yellow River Basin provided by the present invention. DETAILED DESCRIPTION

[0057] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0058] The present invention proposes a method for systematically controlling the sedimentation of the Yellow River. Figure 1 As shown, including:

[0059] Step 1: Identify and code the concentrated sediment source areas, reservoir projects, plain and wide river sections, and estuary flow path swing areas within the basin;

[0060] Furthermore, in step 1, the concentrated sediment source area targeted by the present invention mainly refers to the Loess Plateau region in the middle reaches of the Yellow River. This region experiences severe soil erosion during concentrated rainfall during the flood season, resulting in a large amount of water and soil loss. If left uncontrolled, the amount of sediment entering the river will be high. The purpose of reducing water and soil loss can be achieved by engineering the slope-gully system in the concentrated sediment source area.

[0061] Furthermore, in step 1, the node reservoir projects targeted by the present invention refer to large-scale water conservancy projects specially constructed in favorable terrain sections of the Yellow River before it enters the plains, as well as large-scale water conservancy projects constructed in favorable terrain sections of important tributaries for the purpose of regulating the sediment flow of the Yellow River. The key projects are used to control the sediment flow of the Yellow River by intercepting and flushing the incoming sediment, thereby shaping the outflow process of water and sediment that is conducive to preventing sedimentation in the downstream river channel and even causing scouring of the river channel.

[0062] Furthermore, in step 1, the plain wide river section and the estuary flow path swing area are located in the lower reaches of the Yellow River and even the tail bank. Generally, due to the gentle gradient, sediment is easily deposited, resulting in a significant impact of sediment problems.

[0063] In step 1, the concentrated sediment source area proposed in the present invention primarily refers to the Loess Plateau region in the middle reaches of the Yellow River. This region has sparse vegetation, numerous gullies, and severe soil erosion. Lost soil enters the Yellow River, dramatically increasing the sediment content of the water flow. This area, known as the concentrated sediment source area, contributes over 90% of the sediment entering the Yellow River. During concentrated rainfall during the flood season, soil erosion is intense, causing massive soil and water loss. If measures are not taken to control this, large amounts of sediment will accumulate through ditches and river channels at all levels and ultimately enter the Yellow River. This is the primary cause of sedimentation issues associated with the development and utilization of water conservancy and hydropower projects at all levels along the Yellow River, and the continuous silting and elevation of the riverbed in the lower reaches of the Yellow River.

[0064] In step 1, the node reservoir project proposed in the present invention refers to a large-scale water conservancy project specially built in a favorable terrain section of the Yellow River before it enters the plain river section, as well as a large-scale water conservancy project built in a favorable terrain section of an important tributary to regulate the sediment of the Yellow River. It mainly includes the water conservancy projects such as Qikou, Guxian, Sanmenxia, and Xiaolangdi on the main stream of the Yellow River, the Dongzhuang water conservancy project on the tributary Jinghe River, the Hekoucun water conservancy project on the Qinhe River, the Guxian and Luhun water conservancy projects on the Yiluo River, etc. After the construction of water conservancy projects at all levels, the water storage in the reservoir changes the sediment transport characteristics of the natural river channel, resulting in a large amount of sediment silting in the reservoir. If measures are not taken to reasonably control it, a large amount of sediment will be silted up, resulting in a loss of reservoir storage capacity, which greatly affects the flood control and benefit-generating role of the reservoir.

[0065] The various water conservancy hub projects form a node reservoir engineering system in the form of series and parallel connection, which realizes the regulation and control of the Yellow River silt by intercepting and discharging silt according to the conditions of water and sand inflow. It is a key link in controlling the impact of Yellow River silt on reservoir projects and on the siltation of downstream river channels.

[0066] In step 1, the plain, wide river section proposed in this invention refers to the main stream section of the Yellow River from Taohuayu to Lijin. For a long time, due to the low water content and high sediment content entering the lower reaches of the Yellow River, the riverbed has been continuously silted up and raised, and the mainstream has frequently swung. Currently, the lower riverbed is generally 4 to 6 meters above the ground on both sides, and in some sections it exceeds 10 meters. This has become a natural watershed between the Huaihe and Haihe River basins, causing the main stream to hang high above the ground, becoming the world-famous "hanging river" on the ground. Except for the right bank of the river section from Dongping Lake to Jinan, the main stream relies entirely on large levees to control water flow and carry floodwaters. The upper section of the plain, wide river section of the lower Yellow River flows through Henan Province, with a wide river channel and a levee distance generally around 10 kilometers, which provides a large channel storage function. The lower section flows through Shandong Province, where the river channel is relatively narrow, with a levee distance of 1 to 3 kilometers. The lower plain, wide river section is generally characterized by being wide at the top and narrow at the bottom.

[0067] In step 1, the estuary flow path swing zone proposed in this invention refers to the area from the Yellow River's Lijin station to its estuary. The Yellow River estuary is the discharge zone for the Yellow River's water and sediment, and also serves as the ultimate erosion base for the Yellow River basin. Because the Yellow River estuary is an accumulation estuary characterized by weak tides, low water volume, high sediment content, and frequent swings, the tailwater of the estuary is subject to a long-term evolutionary process of siltation, extension, swinging, and diversion, significantly impacting the erosion and deposition of the Yellow River's lower reaches. Therefore, the rational regulation of sediment at the Yellow River estuary must be coordinated with sediment management arrangements in the lower reaches.

[0068] Step 2: Collect rainfall data from various rainfall monitoring stations in the sediment source area and deduce the rainfall process in the watershed;

[0069] In step 2, the present invention proposes a relatively mature calculation method for inferring the surface rainfall process of the watershed based on the rainfall monitoring stations. After years of development, a network of rainfall monitoring stations with a certain density has been established in the concentrated source area of the Yellow River sediment. Based on the contemporaneous rainfall monitoring data from each monitoring station in the region, the surface rainfall process of the watershed is calculated using methods such as the Thiessen polygon method, the arithmetic mean method, and the inverse square distance method according to the actual conditions of each area. The application of the various surface rainfall calculation methods mentioned above can be found in relevant literature.

[0070] Step 3: Using the surface rainfall process as input, the water and sediment yields are calculated in combination with the underlying surface conditions of the sediment source area.

[0071] Furthermore, in step 3, the calculation of water and sediment production in the concentrated sediment source area should be classified and graded according to the underlying surface characteristics of all study areas, and an appropriate rainfall flood and sediment production model should be used for calculation;

[0072] In step 3, the Yellow River's concentrated sediment source area faces significant sedimentation challenges, necessitating simultaneous simulation of sediment production alongside rainfall runoff simulation. The Loess Plateau is divided into distinct zones due to varying rainfall conditions and underlying surface characteristics. Each zone exhibits distinct characteristics of water and sediment production. Therefore, a distributed simulation model is employed for calculating rainfall water and sediment production. For detailed model selection, please refer to relevant literature.

[0073] Step 4: Based on the four-level engineering control system for the Yellow River sediment constructed above, identify the control factors in the first-level control subsystem, the control factors and feedback factors in the second- and third-level control subsystems, and the feedback factors in the fourth-level control subsystem respectively; the control factors are transmitted as variables between control subsystems to affect the next-level control subsystem, and the feedback factors are transmitted as feedback between control subsystems to guide the optimization of control measures in control subsystems at all levels.

[0074] Step 5: Soil and water conservation engineering measures are arranged based on the characteristics of soil erosion in the sediment source areas. A new type of check dam system is deployed at key nodes in the channel to construct a final sediment interception line. The soil and water conservation engineering measures are integrated into a primary control subsystem. Using the calculated results of rainfall water and sediment production as input, the amount of sediment entering the river after being intercepted and reduced by the primary control subsystem is analyzed and calculated.

[0075] Furthermore, in step 5, the concentrated sediment source area refers to the Loess Plateau. Soil and water loss control engineering measures primarily include forestry and grassland vegetation, terraced fields, and check dams. Forestry and grassland vegetation and terraced fields primarily conserve water resources and reduce slope erosion. Check dams primarily trap sediment, raise the gully erosion base level, reduce gully erosion, and reduce sediment intrusion into the Yellow River. They are the last line of defense for soil and water conservation in small watersheds and the most direct and effective measure for soil and water loss control.

[0076] Furthermore, in step 5, the primary control subsystem intercepts and utilizes sediment on-site through a soil and water loss control engineering system in the sediment concentrated source area, thereby reducing the amount of sediment entering the river;

[0077] Furthermore, in step 5, by identifying the key nodes of the channel, new-type silt dams with multiple functions of preventing collapse and retaining sediment are set up at the key nodes, and a new dam system of the new-type silt dams with multiple functions of preventing collapse and retaining sediment is constructed in combination with ordinary silt dams to form a lasting and stable final silt retention line. Through the cascade application of the new-type silt dam system, the cascade sharing of the dam system's excessive flood sediment can be achieved, and the lasting and stable silt retention effect of the silt dam system can be achieved.

[0078] In step 5, the concentrated sediment source area refers to the Loess Plateau. Soil and water conservation efforts in this region have undergone various phases and accumulated extensive practical experience. Forest and grassland vegetation, terraced fields, and check dams constitute the primary engineering measures for soil and water conservation. Forest and grassland vegetation and terraced fields primarily conserve water resources and reduce slope erosion. Check dams primarily trap sediment, raise the erosion base level in gullies, reduce gully erosion, and prevent sediment from entering the Yellow River. They are the last line of defense for soil and water conservation in small watersheds and the most direct and effective measure for soil and water loss control.

[0079] Regarding the silt dam project as a key sediment retention measure, considering that the existing silt dam is a homogeneous earth dam with low flood resistance capacity, easy to overtopping and collapse, often inducing dam system collapse, and easily leading to the loss of sediment retention defense line, and the problem of loss of governance effect, in order to solve the above problems, in the construction of the first-level control subsystem, the traditional silt dam system construction method is changed, and a new type of silt dam project with anti-break and multi-sediment retention technology is used at the key nodes of the channel to build a long-lasting and stable silt dam system project. The layout of the new silt dam system is shown in the attached Figure 2 , which can achieve long-term safety and stability of the silt dam system and ensure the lasting effect of sediment retention.

[0080] The aforementioned new type of silt dam technology with multiple sediment retention and anti-burst functions is based on the idea of "putting on 'protective clothing' for silt dams, preventing them from overflowing and blocking the chain of dam failure disasters". It has overcome three major technical difficulties: the design of dam surface protection structures, the development of dam body anti-scouring materials, and the design of small-basin high-sediment-content floods. A new type of silt dam has been developed. Its working principle is shown in the attached figure. Figure 3 .

[0081] Step 6: Collect and organize the backbone reservoir projects at key nodes of the Yellow River mainstream and important tributaries, code them, and integrate them to build a secondary control subsystem. Taking the amount of sediment entering the river as input, determine the sediment entering the reservoirs at each level. Through the water and sediment regulation and control of the reservoirs at each level, analyze and calculate the sediment interception and discharge of the corresponding node reservoir projects according to the coding order. The sediment inflow and interception data are fed back to the primary control subsystem, and the discharge volume is input into the next level subsystem.

[0082] Furthermore, in step 6, the secondary control subsystem utilizes the water conservancy projects of important tributaries with high sediment content and key node water conservancy projects in the main stream with high sediment content through serial and parallel scheduling to achieve control over the accumulation and discharge of inflowing sediment, so as to shape the reservoir into a favorable sedimentation form and storage capacity utilization conditions, so that the discharged water and sediment meet the designed water and sediment conditions. The secondary control subsystem is the most direct and effective system for river sediment engineering control and is the core system for river sediment engineering control;

[0083] In step 6, water and sediment control is implemented through “blocking, regulating, and discharging” of node reservoirs at all levels.

[0084] In step 6, the backbone reservoir projects at key nodes of the Yellow River mainstream and important tributaries mainly include the reservoirs to be (or under) construction such as Qikou, Guxian, and Dongzhuang, and the reservoirs that have been built such as Wanjiazhai, Sanmenxia, Xiaolangdi, Luhun, Guxian, and Hekoucun, which together constitute the secondary control subsystem.

[0085] In step 6, the reservoir project code is coded as G+X from upstream to downstream according to the main stream reservoir, where G represents the main stream reservoir and X represents the upstream and downstream relationship of the reservoir (for example, Wanjiazhai Reservoir is G1). The coding rule for tributary reservoirs is Z+XX, where Z represents the tributary reservoir. The first digit X represents the main stream reservoir code number where the tributary reservoir and the main stream reservoir outflow intersect, and the second digit X is coded according to the upstream and downstream relationship of the tributary reservoir flowing into the Yellow River (for example, Dongzhuang Reservoir intersects with Guxian Reservoir outflow, and Dongzhuang Reservoir is the upstreammost reservoir among the tributary backbone reservoirs, so it is coded as Z3-1). For the specific coding format of each reservoir, please refer to the attached Figure 4 .

[0086] After the coding of the above reservoirs is completed, each reservoir will adopt a comprehensive coordinated regulation of "blocking, regulating, and discharging" according to the water and sediment situation. That is, the scheduling method will be flexibly determined in combination with the development tasks, operation stage and water and sediment conditions of the reservoir. It is necessary to give full play to the "blocking and discharging" functions of the reservoir, and pay more attention to the "regulation" function. That is, during the sediment blocking period of the reservoir, the synchronous shaping technology of the reservoir beach and channel is adopted, "small water blocking, large water discharge, timely peak building, and silting beach shaping channel" is used. During the normal operation period, the reservoir is regulated according to the classification of water and sediment. At the same time, combined with the engineering scale and conditions of each reservoir design, unconventional sediment discharge scheduling is used to achieve the reservoir's regulation of sediment entering the Yellow River. Reservoirs at all levels are regulated step by step according to the upstream and downstream relationships to achieve joint regulation of the reservoir group. The regulatory role of the backbone reservoir is fully utilized at the key nodes of the river channel to form an overall regulatory force.

[0087] In step 6, after different reservoirs and different operation modes have been used to control sediment, statistics are collected on the sediment interception capacity of the reservoir group and the sediment discharge capacity of the terminal reservoirs (Xiaolangdi, Luhun, Guxian, Hekou Village, etc.) entering the downstream river channel. The sediment interception capacity of the reservoir group is used as important feedback data of the secondary control subsystem and fed back to the primary control subsystem to guide the optimization of the layout and measures of soil and water conservation projects in the primary control subsystem. The sediment discharge capacity data is used as the output of the secondary control subsystem and transmitted to the downstream river channel (tertiary control subsystem) as the sediment input of the tertiary control subsystem.

[0088] Step 7: Collect cross-sectional topography and river defense engineering data along the wide river section of the lower Yellow River plain, analyze the characteristic data of the river channel and graded beach, and integrate them to construct a three-level control subsystem. Using the sediment discharge of the reservoir as input, through the water and sediment regulation analysis and calculation of the wide river section, the river scouring and silting process, river regime evolution, river sediment discharge, and river sedimentation of the downstream wide river section are deduced. The river sedimentation process, river sedimentation, and river regime evolution data are fed back to the second-level control subsystem, and the river sediment discharge is input into the next-level subsystem.

[0089] Furthermore, in step 7, the three-level control subsystem aims to achieve the coordinated realization of flood control and security, ecological protection, and economic and social development within the downstream river channel. It utilizes the river channel of the plain and wide riverbed to carry floodwaters and transport sediment, and the flood and sediment retention and sedimentation on the beach. It implements flood and sediment control through flood classification, sediment deposition by zone, and beach management by zone. This improves the flood and sediment transport capacity of the downstream river channel, ensures ecological safety, stabilizes the river channel morphology, and achieves high-quality economic and social development in the beach area.

[0090] In step 7, first collect various types of data on the Kuantan section of the lower Yellow River, including sections along the river, topography, river defense projects, and control and guidance projects. Then analyze and determine the characteristic data of the river section to form a three-level control subsystem. Then, use the sediment discharge of the terminal reservoirs (Xiaolangdi, Luhun, Guxian, Hekou Village, etc.) entering the downstream river as the input of the system.

[0091] Based on the amount of sediment discharged and the size of the outflow flow, we fully utilize the characteristics of the lower reaches of the Yellow River, which is wide at the top and narrow at the bottom, and has a large gradient at the top and a small gradient at the bottom, to give play to the water and sediment regulation function of the "lotus root node" shaped river section, and carry out water and sediment regulation analysis and calculation of wide beach river sections. At the same time, we optimize the comprehensive management measures of the downstream river sections, analyze the scouring and siltation adjustment process of the downstream wide beach river sections, and obtain the river sediment discharge, river sedimentation and river flow evolution information.

[0092] The data on river sedimentation and river flow evolution are fed back to the secondary control subsystem to guide the water and sediment discharge process of the secondary control subsystem, thereby changing the reservoir regulation method, and taking the river sediment discharge as the output of the tertiary control subsystem and transmitting it to the estuary area (fourth-level control subsystem) as the sediment input of the fourth-level control subsystem.

[0093] Step 8: Collect topographic data of the estuary flow path swing zone and flood discharge area, analyze the evolution characteristics of the flow paths at all levels in the estuary area, integrate and construct a four-level control subsystem, use the sediment transport of the downstream river channel as input, perform estuary water and sediment analysis and calculation based on the estuary flow path adjustment, and obtain the estuary sedimentation extension length and upstream estuary channel erosion base level information, which are then fed back to the three-level control subsystem;

[0094] Furthermore, in step 8, the regulation of sediment by the fourth-level control subsystem must be coordinated with the flood and sediment control measures in the downstream river channel, comprehensively considering the arrangement of the flow path into the sea and the regulation of the tailwater river channel, mainly to solve the impact of the upstream sedimentation of the estuary on the sedimentation and elevation of the downstream river channel. The sediment control of this subsystem is mainly a feedback process to the first three levels of regulation.

[0095] In step 8, we first collect the topographic data of the river sections in the flood-carrying area of the estuary, study the evolution characteristics of the flow path in the estuary, and use the flow path changes as the fourth-level control subsystem to play the terminal feedback role and system output function of the Yellow River sediment engineering control.

[0096] Taking the sediment transport volume of the downstream river channel as the input of the system, the impact of the water and sediment volume in the estuary area on the siltation extension, branching and channel diversion, and headwater siltation of the estuary flow channel is analyzed. The siltation extension length of the estuary flow channel and the erosion base level information of the upstream river channel in the estuary area are determined. These information are used as important feedback information of the Yellow River sediment control system and fed back to the three-level control subsystem to guide the implementation of control measures such as river defense projects, diversion projects, ecological governance, and comprehensive improvement in the three-level control subsystem.

[0097] Step 9: Taking the water-sediment coordination as the overall control goal, based on the information transmission and feedback of the control subsystems at all levels, the control of the Yellow River sediment system is achieved by optimizing the control measures at all levels.

[0098] In step 9, the process of maintaining the Yellow River's lower reaches (main channel) without or slightly silted up over a long period of time is called the coordinated water-sediment relationship of the Yellow River. Therefore, the coordination index describing the water-sediment relationship is less than or equal to 1 as the overall goal of system control. Based on the information transmission and feedback between the aforementioned control subsystems at all levels, the Yellow River sediment engineering control system maintains its own stability in a constantly changing environment and has an automatic adjustment and self-optimization mechanism. Then, through the layout of soil and water conservation measures such as the layout of multiple sediment-blocking dams in the sediment concentrated source area to prevent collapse, adjust the use of reservoirs, optimize the comprehensive management measures of the downstream river section, adjust the layout of the estuary flow path, and other control measures at all levels, the Yellow River sediment system is controlled. See the attached figure. Figure 5 , Attachment Figure 6 .

[0099] The beneficial effects of the above technical solution are: tracking the evolution process of river sediment generation, transportation, siltation, scouring, etc. from a system perspective, and feedback and transmission of sediment change information by setting up hierarchical cascade engineering controls such as river inflow sediment control, node reservoir sediment control, river channel sediment control, and estuary sediment control, thereby achieving comprehensive treatment of the Yellow River sediment.

[0100] The present invention proposes a method for an engineering system for systematically controlling the sedimentation of the Yellow River. Based on information transmission and feedback from control subsystems at all levels, the method optimizes control measures at all levels to achieve control of the sedimentation system of the Yellow River. The method also includes:

[0101] Predict the information transmission and feedback of each level of control subsystem in the first place;

[0102] Determine to optimize the control measures at all levels according to the predicted first time as the optimization trigger time point, and determine whether each optimization time point meets the optimization association standard.

[0103] Preferably, determining to optimize the control measures at all levels according to the predicted first time as the optimization trigger time point, and determining whether each optimization time point meets the optimization association standard includes:

[0104] Obtaining the optimized trigger parameters corresponding to the first predicted time matched by each level of control subsystem;

[0105] According to the optimization trigger parameter, the process simulation model simulates the system optimization process of the corresponding level control subsystem;

[0106] Calculate the optimal matching degree Y2 between the control subsystems at all levels based on the first prediction;

[0107]

[0108] Where m represents the total number of control subsystems at all levels; sim represents the similarity sign; dj1 represents the simulation result of the j1-th control subsystem; di1 represents the simulation result of the i1-th control subsystem; e represents the sign of the exponential function; tj1 represents the end simulation time of the j1-th control subsystem based on the first time of prediction; ti1 represents the start simulation time of the i1-th control subsystem based on the first time of prediction; where i1 = j1 + 1; j1 = 1, 2, 3, ..., m; i1 = 0, 1, 2, ..., m-1; Y2 represents the optimization matching degree between the j1-th control subsystem and the i1-th control subsystem; Δ i1,j1 represents the standard simulation time difference between the j1th control subsystem and the i1th control subsystem; sim(dj1,di1) max represents the maximum value among all similar simulation results; sim0(dj1, di1) represents the standard similarity between the simulation results of the j1-th control subsystem and the simulation results of the i1-th control subsystem; sim(dj1, di1) represents the actual similarity between the simulation results of the j1-th control subsystem and the simulation results of the i1-th control subsystem; represents the matching adjustment factor based on the simulation results of the j1-th control subsystem and the simulation results of the i1-th control subsystem;

[0109] When all optimization matching degrees Y2 are qualified, it is determined that each optimization time point meets the optimization association standard;

[0110] Otherwise, extract the first control subsystem corresponding to the unqualified optimization matching degree Y2, and determine the time simulation delay coefficient and the non-similar simulation result according to the ratio of the corresponding actual simulation time difference and the standard simulation time difference;

[0111] Determining a re-optimization factor corresponding to the first control subsystem based on the time delay coefficient and the non-similar simulation result;

[0112] The corresponding first control subsystem is optimized based on the re-optimization factor.

[0113] In this embodiment, the prediction of the first time of information transmission and feedback is obtained based on a time prediction model, and the time prediction model is obtained by sample training of the feedback control time of the information combination corresponding to different systems after different systems receive the transmission and feedback information. Therefore, the first time can be predicted.

[0114] In this embodiment, the purpose of optimizing the triggering time point is to enable the corresponding system to perform optimization work when the triggering time point is reached.

[0115] In this embodiment, the optimization association standard mainly refers to whether the time-based optimization matching degree is greater than a preset matching degree, and the preset matching degrees corresponding to different systems are different.

[0116] In this embodiment, the optimized trigger parameters are related to the control process of the measures mainly executed by the corresponding system, such as determining the siltation extension length of the estuary flow channel and the erosion base level information of the upstream river channel in the estuary area, which are used as important feedback information of the Yellow River sediment control system and fed back to the three-level control subsystem to guide the implementation of the three-level control subsystem's river defense projects, diversion projects, ecological governance, comprehensive improvement and other control measures.

[0117] In this embodiment, the non-similar simulation result refers to a result that is different between a standard similar simulation result and an actual similar simulation result, and the time simulation delay coefficient is the ratio of the actual time difference to the standard time difference.

[0118] In this embodiment, the re-optimization factor is obtained based on a coefficient-result-factor database, and the database includes different time delay coefficients, non-similar simulation results, and matching factors.

[0119] The beneficial effect of the above technical solution is that by analyzing the time-based simulation between each control subsystem, the timeliness of the control feedback can be effectively determined, wherein, first, the optimization trigger parameters of different subsystems are determined, and the process is simulated. Secondly, based on the ratio of the predicted simulation time to the standard simulation time difference at different times, and combined with the similarity of the simulation results, the time-based optimization matching degree is determined, and then the control subsystem corresponding to the unqualified optimization matching degree is optimized again, thereby further improving the feedback timeliness of the cascade control.

[0120] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for systematically controlling sediment in the Yellow River, characterized in that: include: Step 1: Identify and code the concentrated sediment source areas, reservoir projects, plain and wide river sections, and estuary flow path swing areas within the basin to form a four-level control subsystem; Step 2: Collect rainfall data from various rainfall monitoring stations in the sediment source area and deduce the rainfall process in the watershed; Step 3: Using the surface rainfall process as input, the water and sediment yields are calculated in combination with the underlying surface conditions of the sediment source area. Step 4: Identify the control factors used for transmission and the feedback factors used for feedback in each level of control subsystem; Step 5: Soil and water conservation engineering measures are arranged based on the characteristics of soil erosion in the concentrated sediment source areas. A check dam system is deployed at key nodes in the channel to construct a final sediment interception line. The soil and water conservation engineering measures are integrated into a primary control subsystem. The rainfall-induced water and sediment production calculation results are used as input to analyze and calculate the amount of sediment entering the river after being intercepted and reduced by the primary control subsystem, and this is used as the control factor of the primary control subsystem. Step 6: Collect and organize the backbone reservoir projects at key nodes of the Yellow River mainstream and important tributaries, code them, and integrate them to build a secondary control subsystem. Taking the amount of sediment entering the river as the control factor of the primary control subsystem, determine the sediment entering the reservoirs at each level. Through the water and sediment regulation and control of the node reservoirs at each level, analyze and calculate the sediment interception and sediment discharge of the corresponding node reservoir projects in accordance with the coding order. The sediment inflow and sediment interception data are fed back to the primary control subsystem as the feedback factors of the secondary control subsystem, and the sediment discharge is input into the next level subsystem as the control factor of the secondary control subsystem; Step 7: Collect cross-sectional topography and river defense engineering data along the wide beach section of the lower reaches of the Yellow River, analyze the characteristic data of the river channel and graded beach, integrate and construct a three-level control subsystem, use the reservoir sediment discharge as the control factor of the second-level control subsystem, and through the analysis and calculation of water and sediment regulation in the wide beach section, deduce the river scouring and silting process, river regime evolution, river sediment discharge, and river sedimentation of the downstream wide beach section. The river scouring and silting process, river sedimentation, and river regime evolution data are fed back to the second-level control subsystem as feedback factors of the third-level control subsystem, and the river sediment discharge is input into the next-level subsystem as the control factor of the third-level control subsystem; Step 8: Collect topographic data of the flood discharge area in the estuary flow path swing region, analyze the evolution characteristics of the flow paths at all levels in the estuary area, integrate and construct a four-level control subsystem, use the downstream river sediment discharge as the control factor of the third-level control subsystem as input, perform estuary water and sediment analysis and calculation based on the estuary flow path adjustment, and obtain the estuary sedimentation extension length and the upstream river channel erosion base level information as feedback factors of the third-level control subsystem. Step 9: Taking the water-sediment coordination as the overall control goal, based on the information transmission of control factors and feedback of feedback factors in the control subsystems at all levels, continuously optimize the control measures at all levels to achieve the control of the Yellow River sediment system.

2. The method for controlling sediment in the Yellow River according to claim 1, characterized in that: The control measures at all levels include: layout of soil and water conservation measures in sediment source areas, adjustment of reservoir utilization methods, comprehensive management measures for downstream river sections, and layout of estuary flow path utilization.

3. The method for controlling sediment in the Yellow River according to claim 1, wherein: After constructing the four-level control subsystem, the control factors in each level of control subsystem are identified as variables transferred between control subsystems to affect the next level of control subsystem; the feedback factors in each level of control subsystem are identified as feedback transferred between control subsystems to guide the optimization of control measures in each level of control subsystem.

4. The method for controlling sediment in the Yellow River according to claim 1, wherein: Collect and organize key reservoir projects at key nodes of the Yellow River mainstream and important tributaries and encode them, including: The main stream reservoirs in the backbone reservoir project are coded as G+X from upstream to downstream, where G represents the main stream reservoir and X represents the upstream and downstream relationship of the reservoir; The coding rule for the tributary reservoirs in the backbone reservoir project is Z+XX, where Z represents the tributary reservoir, the first digit X represents the coding number of the main stream reservoir where the tributary reservoir and the main stream reservoir outflow meet, and the second digit X is coded in the order of the upstream and downstream relationship of the tributary reservoir flowing into the Yellow River.

5. The method for controlling sediment in the Yellow River according to claim 1, wherein: After analyzing and calculating the sediment interception and discharge volume of the corresponding node reservoir project according to the coding order, it also includes: Determine the synchronous shaping method of the beach and channel in the reservoir area of the corresponding node reservoir project during the sediment retention period; Classify and dispatch node reservoir projects during normal operation according to water and sediment classification; Based on the synchronous shaping method of the reservoir beach and channel and the classified scheduling results, and combined with the engineering scale and conditions of each reservoir design and unconventional sediment discharge scheduling methods, the sediment entering the Yellow River is regulated based on the corresponding node reservoirs.

6. The method for controlling sediment in the Yellow River according to claim 1, characterized in that: Taking the sediment discharge from the reservoir as input, the water and sediment regulation analysis and calculation process of the Kuantan River section also includes: Determine the channel characteristics of the lower Yellow River; Among them, the river channel characteristics are related to the width of the river channel in the lower reaches of the Yellow River and the gradient of the lower reaches of the Yellow River.

7. The method for controlling sediment in the Yellow River according to claim 1, characterized in that: The overall control goal is to coordinate water and sediment, including: Capturing the water-sediment matching process in different river channels in the lower reaches of the Yellow River; Analyze the process information of each water-sand matching process and determine the corresponding water-sand relationship; The result that the coordination index describing the water-sediment relationship is less than or equal to 1 is used as the overall control target.

8. The method for controlling sediment in the Yellow River according to claim 1, wherein: Based on the information transmission and feedback of the control subsystems at all levels, and by optimizing the control measures at all levels, before achieving the control of the Yellow River sediment system, it also includes: Predict the information transmission and feedback of each level of control subsystem in the first place; Determine to optimize the control measures at all levels according to the predicted first time as the optimization trigger time point, and determine whether each optimization time point meets the optimization association standard.

9. The method for controlling sediment in the Yellow River according to claim 7, wherein: Determine the first predicted time as the optimization trigger time point for optimizing control measures at all levels, and determine whether each optimization time point meets the optimization association criteria, including: Obtaining the optimized trigger parameters corresponding to the first time of the prediction matched by each level of control subsystem; According to the optimization trigger parameter, the process simulation model simulates the system optimization process of the corresponding level control subsystem; Calculate the optimal matching degree Y2 between the control subsystems at all levels based on the first prediction; Where m represents the total number of control subsystems at all levels; sim represents the similarity sign; dj1 represents the simulation result of the j1-th control subsystem; di1 represents the simulation result of the i1-th control subsystem; e represents the sign of the exponential function; tj1 represents the end simulation time of the j1-th control subsystem based on the first time of prediction; ti1 represents the start simulation time of the i1-th control subsystem based on the first time of prediction; where i1 = j1 + 1; i1 = 1, 2, 3, ..., m; j1 = 0, 1, 2, ..., m-1; Y2 represents the optimization matching degree between the j1-th control subsystem and the i1-th control subsystem; Δ i1,j1 represents the standard simulation time difference between the j1th control subsystem and the i1th control subsystem; sim(dj1,di1) max represents the maximum value among all similar simulation results; sim0(dj1, di1) represents the standard similarity between the simulation results of the j1-th control subsystem and the simulation results of the i1-th control subsystem; sim(dj1, di1) represents the actual similarity between the simulation results of the j1-th control subsystem and the simulation results of the i1-th control subsystem; represents the matching adjustment factor based on the simulation results of the j1-th control subsystem and the simulation results of the i1-th control subsystem; When all optimization matching degrees Y2 are qualified, it is determined that each optimization time point meets the optimization association standard; Otherwise, extract the first control subsystem corresponding to the unqualified optimization matching degree Y2, and determine the time simulation delay coefficient and the non-similar simulation result according to the ratio of the corresponding actual simulation time difference and the standard simulation time difference; Determining a re-optimization factor corresponding to the first control subsystem based on the time simulation delay coefficient and the non-similar simulation result; The corresponding first control subsystem is optimized based on the re-optimization factor.

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