Optimal calculation method and system for sediment transport ratio of multi-pit-pond area

Abstract

The invention provides a multi-pit-pond area sediment transport ratio optimization calculation method and system, and relates to the technical field of water and soil conservation and sediment transport, and the method comprises the steps: obtaining grid data (such as type, area, water storage capacity, hydraulic retention time and hydrological characteristics) of pits and ponds; calculating sediment interception efficiency and a water flow delay factor; the confluence time is optimized; iteratively calculating the sediment transportation influence; and the sediment conveying ratio is optimized. According to the method, the silt conveying prediction accuracy is improved, the unique characteristics of the multi-pit pond area are reflected, and support is provided for drainage basin silt management.

Description

Technical Field

[0001] The present invention relates to the technical field of soil and water conservation and sediment transport, and in particular to a method and system for optimizing sediment transport ratio calculation in a multi-pond area. Background Art

[0002] The Sediment Delivery Ratio (SDR) is a key parameter in the Sediment Delivery Distributed Model (SEDD) and other related models. It describes the efficiency of sediment transport from the source to the outlet of a water body and is widely used in fields such as soil erosion, pollutant transport, water resource management, and environmental protection. Calculating the SDR effectively predicts sediment flow within a watershed and helps formulate soil and water conservation and water quality protection measures.

[0003] However, in many watersheds, especially those with numerous ponds, ponds significantly impact sediment transport. By detaining water flow, intercepting sediment, and slowing down water flow, ponds alter the path and velocity of sediment transport. Existing sediment transport models often fail to fully account for the impact of ponds, resulting in inaccurate calculations of sediment transport ratios. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a method and system for optimizing the calculation of the sediment transport ratio in a multi-pond area. By combining the cumulative effects of water flow delay, sediment interception and multi-pond systems, the calculation of the sediment transport ratio is optimized to make up for the shortcomings of the existing model.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A method for optimizing sediment transport ratio in a multi-pond area, comprising:

[0007] Obtaining raster data of at least one pond in a watershed; the raster data includes: pond type, pond area, water storage capacity, hydraulic retention time, and watershed hydrological characteristics;

[0008] determining the sediment interception efficiency of each of the ponds according to the pond type and the pond area;

[0009] Determining a water flow delay factor of the pond based on the hydraulic retention time of the pond, and taking into account the water flow delay effect of the pond, optimizing the original confluence time according to the water flow delay factor to obtain an optimized confluence time;

[0010] Based on the optimized confluence time and the sediment interception efficiency, iteratively calculating the impact of each pond on sediment transport, and updating the sediment concentration step by step;

[0011] Taking into account the cumulative effects of water flow delay factor and sediment interception effect, the initial sediment transport ratio in the process of step-by-step sediment concentration update is optimized to obtain the optimized sediment transport ratio.

[0012] Preferably, the pond types include: artificial breeding ponds, landscape ponds and natural ponds.

[0013] Preferably, the calculation formula for the sediment interception efficiency is:

[0014]

[0015] Among them, E j is the sediment interception efficiency of the jth pond, k is the preset area influence coefficient, A j is the area of ​​the jth pond.

[0016] Preferably, the calculation formula of the water flow delay factor is:

[0017]

[0018] Among them, A j is the area of ​​the jth pond, V j is the water storage capacity of the jth pond, D j is the water flow delay factor of the jth pond.

[0019] Preferably, the calculation formula for the optimized confluence time is:

[0020]

[0021] Among them, T i is the original confluence time, D j is the water flow delay factor of the j-th pond, The confluence time is optimized as described above.

[0022] Preferably, the calculation formula of the initial sediment transport ratio is:

[0023]

[0024] in, is the initial sediment transport ratio of the i-th pixel after optimization, For the optimized confluence time, E j is the sediment interception efficiency of the j-th pond, and β is an empirical coefficient used to describe the attenuation rate of sediment transport efficiency.

[0025] Preferably, the calculation formula for optimizing the sediment transport ratio is:

[0026]

[0027] in, is the optimized sediment transport ratio, β is the empirical coefficient, and β is used to describe the attenuation rate of sediment transport efficiency. For the optimized confluence time, A j is the area of ​​the jth pond, V j is the water storage capacity of the jth pond, E j is the sediment interception efficiency of the j-th pond.

[0028] A multi-pond area sediment transport ratio optimization calculation system, comprising:

[0029] A data acquisition unit is used to acquire raster data of at least one pond in the watershed; the raster data includes: pond type, pond area, water storage capacity, hydraulic retention time and watershed hydrological characteristics;

[0030] an efficiency determination unit, configured to determine the sediment interception efficiency of each of the ponds according to the pond type and the pond area;

[0031] a time optimization unit, configured to determine a water flow delay factor of the pond based on the hydraulic retention time of the pond, and optimize the original confluence time according to the water flow delay factor, taking into account a water flow delay effect of the pond, to obtain an optimized confluence time;

[0032] An iterative calculation unit, configured to iteratively calculate the effect of each pond on sediment transport based on the optimized confluence time and the sediment interception efficiency, and to update the sediment concentration step by step;

[0033] The result optimization unit is used to comprehensively consider the cumulative effect of the water flow delay factor and the cumulative effect of the sediment interception effect, optimize the initial sediment transport ratio in the process of gradually updating the sediment concentration, and obtain the optimized sediment transport ratio.

[0034] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0035] The present invention provides a method and system for optimizing the calculation of sediment transport ratios in a multi-pond area. The method comprises: obtaining raster data for at least one pond within a watershed; the raster data includes pond type, area, water storage capacity, hydraulic retention time, and watershed hydrological characteristics; determining the sediment interception efficiency of each pond based on the pond type and area; determining a flow delay factor for the pond based on the hydraulic retention time, and optimizing the original confluence time based on the flow delay factor to obtain an optimized confluence time, taking into account the flow delay effect of the pond; iteratively calculating the impact of each pond on sediment transport based on the optimized confluence time and the sediment interception efficiency, and progressively updating the sediment concentration; and optimizing the initial sediment transport ratio during the progressive sediment concentration update process, taking into account the cumulative effects of the flow delay factor and the sediment interception effect, to obtain an optimized sediment transport ratio. This method not only improves the accuracy of sediment transport predictions but also reflects the unique sediment transport characteristics of multi-pond areas. This method can provide strong support for watershed sediment management and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 A flow chart of a method provided by an embodiment of the present invention;

[0038] Figure 2 A schematic diagram of the implementation process of the calculation method provided in an embodiment of the present invention; Figure 3 A schematic diagram of the system structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] The purpose of the present invention is to provide a method and system for optimizing the calculation of sediment transport ratio in a multi-pond area, which can provide strong support for basin sediment management and has broad application prospects.

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Figure 1 A flow chart of the method provided in the embodiment of the present invention is shown in FIG. Figure 1 As shown, the present invention provides a method for optimizing the calculation of sediment transport ratio in a multi-pond area, comprising:

[0043] Step 100: Obtain raster data of at least one pond in the watershed; the raster data includes: pond type, pond area, water storage capacity, hydraulic retention time, and watershed hydrological characteristics;

[0044] Step 200: Determine the sediment interception efficiency of each pond based on the pond type and pond area;

[0045] Step 300: Determine a water flow delay factor of the pond based on the hydraulic retention time of the pond, and consider the water flow delay effect of the pond, optimize the original confluence time according to the water flow delay factor to obtain an optimized confluence time;

[0046] Step 400: Based on the optimized confluence time and sediment interception efficiency, iteratively calculate the impact of each pond on sediment transport and update the sediment concentration step by step;

[0047] Step 500: Comprehensively considering the cumulative effect of the water flow delay factor and the cumulative effect of the sediment interception effect, the initial sediment transport ratio in the process of gradually updating the sediment concentration is optimized to obtain the optimized sediment transport ratio.

[0048] This paper provides a method for optimizing the calculation of sediment delivery ratio (SDR) in multi-pond areas. By incorporating the flow delay, sediment interception, and cumulative interception effects of ponds, this method optimizes the sediment transport calculation in the traditional SEDD model, particularly the key parameter, SDR. The innovations of this method are primarily reflected in the following aspects:

[0049] Specifically, in the original SEDD model, the sediment transport ratio (SDR) calculation formula is:

[0050] SDR i =exp(-β·T i ) (1)

[0051] SDR i is the sediment transport ratio of the i-th pixel, β is the empirical coefficient, describing the attenuation rate of sediment transport efficiency, T i is the original confluence time from the i-th pixel to the basin outlet.

[0052] Optionally, the optimized sediment transport ratio (initial sediment transport ratio) calculation formula takes into account the water flow delay effect and sediment interception effect of the pond. The optimized formula is:

[0053]

[0054] is the sediment transport ratio of the i-th pixel after optimization, is the optimized confluence time, considering the delay effect of the pond, E j is the sediment interception efficiency of the j-th pond.

[0055] Furthermore, the water flow delay effect of this embodiment is the optimized confluence time (optimized confluence time), and the optimized confluence time Delay factor D j Corrected, the formula is as follows:

[0056]

[0057] Among them, T i is the original confluence time, D j is the water flow delay factor of the jth pond.

[0058] Specifically, the water flow delay factor D of the pond in this embodiment is j It can be calculated by the following formula:

[0059]

[0060] Among them, A j is the area of ​​the jth pond (m2). j is the water storage capacity of the jth pond (m3).

[0061] Optionally, the sediment interception rate E of the pond j It depends on the type of pond, which can be artificial breeding pond, landscape pond or natural pond. The specific calculation formula is:

[0062]

[0063] Where k is the area influence coefficient, which is usually an empirical value.

[0064] Specifically, in this embodiment, all factors are combined together, and the calculation formula for the optimized sediment transport ratio (optimized sediment transport ratio) is:

[0065]

[0066] in, In order to optimize the sediment transport ratio, the flow delay and sediment interception effects were considered. is the cumulative effect of the water flow delay factor in the pond, It is the cumulative effect of the sediment interception effect of ponds.

[0067] Furthermore, the optimization advantages of this embodiment are as follows:

[0068] (1) Water flow delay effect: By considering the impact of water flow delay in ponds on sediment transport, the model can more accurately reflect the role of ponds in the watershed.

[0069] (2) Sediment interception effect: The interception efficiency of the pond is introduced to dynamically adjust the sediment interception capacity of each pond.

[0070] (3) Cumulative effect: The delay effect and interception effect of multiple ponds along the water flow path are superimposed step by step, which improves the simulation accuracy of the model for the actual situation of the basin.

[0071] like Figure 2 As shown, the calculation method of the present invention can be implemented by the following steps:

[0072] (1) Obtain raster data of ponds in the watershed, including information such as pond type, area, and water storage capacity.

[0073] (2) Calculate the sediment interception efficiency of each pond based on its type and area.

[0074] (3) Based on the hydraulic retention time of the pond, calculate the water flow delay factor and optimize the confluence time.

[0075] (4) Calculate the impact of each pond on sediment transport step by step based on the water flow delay and interception effect, and update the sediment concentration along the path.

[0076] Corresponding to the above method, such as Figure 3 As shown, this embodiment also provides a multi-pond area sediment transport ratio optimization calculation system, including:

[0077] A data acquisition unit is used to acquire raster data of at least one pond in the watershed; the raster data includes: pond type, pond area, water storage capacity, hydraulic retention time and watershed hydrological characteristics;

[0078] an efficiency determination unit, configured to determine the sediment interception efficiency of each of the ponds according to the pond type and the pond area;

[0079] a time optimization unit, configured to determine a water flow delay factor of the pond based on the hydraulic retention time of the pond, and optimize the original confluence time according to the water flow delay factor, taking into account a water flow delay effect of the pond, to obtain an optimized confluence time;

[0080] An iterative calculation unit, configured to iteratively calculate the effect of each pond on sediment transport based on the optimized confluence time and the sediment interception efficiency, and to update the sediment concentration step by step;

[0081] The result optimization unit is used to comprehensively consider the cumulative effect of the water flow delay factor and the cumulative effect of the sediment interception effect, optimize the initial sediment transport ratio in the process of gradually updating the sediment concentration, and obtain the optimized sediment transport ratio.

[0082] The beneficial effects of the present invention are as follows:

[0083] (1) Improving simulation accuracy: The present invention can more accurately simulate sediment transport in multi-pond areas by optimizing the sediment transport ratio (SDR) calculation method and combining water flow delay and sediment interception effects.

[0084] (2) Simplified calculation process: The present invention introduces the water flow delay and sediment interception effect through a simple formula, avoiding complex hydrological model calculations and improving calculation efficiency.

[0085] (3) Wide adaptability: The present invention is applicable to multi-pond systems and can dynamically adjust the sediment delivery ratio (SDR) according to the actual conditions of the ponds in the basin, and has strong adaptability.

[0086] (4) Supporting watershed management: The present invention provides a scientific basis for watershed sediment management and ecological restoration, and helps formulate reasonable soil and water conservation and ecological restoration measures.

[0087] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0088] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A method for optimizing the sediment transport ratio in a multi-pond area, characterized in that: include: Obtain raster data of at least one pond in the watershed; The raster data includes: pond type, pond area, water storage capacity, hydraulic retention time and watershed hydrological characteristics; determining the sediment interception efficiency of each of the ponds according to the pond type and the pond area; Determining a water flow delay factor of the pond based on the hydraulic retention time of the pond, and taking into account the water flow delay effect of the pond, optimizing the original confluence time according to the water flow delay factor to obtain an optimized confluence time; Based on the optimized confluence time and the sediment interception efficiency, iteratively calculating the impact of each pond on sediment transport, and updating the sediment concentration step by step; Taking into account the cumulative effects of water flow delay factor and sediment interception effect, the initial sediment transport ratio in the process of step-by-step sediment concentration update is optimized to obtain the optimized sediment transport ratio.

2. The method for optimizing sediment transport ratio in a multi-pond area according to claim 1 is characterized in that: The types of ponds include artificial breeding ponds, landscape ponds and natural ponds.

3. The method for optimizing sediment transport ratio in a multi-pond area according to claim 2 is characterized in that: The calculation formula for the sediment interception efficiency is: Among them, E j is the sediment interception efficiency of the jth pond, k is the preset area influence coefficient, A j is the area of ​​the jth pond.

4. The method for optimizing sediment transport ratio in a multi-pond area according to claim 1 is characterized in that: The calculation formula of the water flow delay factor is: Among them, A j is the area of ​​the jth pond, V j is the water storage capacity of the jth pond, D j is the water flow delay factor of the jth pond.

5. The method for optimizing sediment transport ratio in a multi-pond area according to claim 1 is characterized in that: The calculation formula for the optimized confluence time is: T i adjusted =T i ·D j Among them, T i is the original confluence time, D j is the water flow delay factor of the jth pond, T i adjusted The confluence time is optimized as described above.

6. The method for optimizing sediment transport ratio in a multi-pond area according to claim 1 is characterized in that: The calculation formula of the initial sediment transport ratio is: in, is the initial sediment transport ratio of the i-th pixel after optimization, T i adjusted For the optimized confluence time, E j is the sediment interception efficiency of the j-th pond, and β is an empirical coefficient used to describe the attenuation rate of sediment transport efficiency.

7. The method for optimizing sediment transport ratio in a multi-pond area according to claim 1 is characterized in that: The calculation formula for the optimized sediment transport ratio is: in, is the optimized sediment transport ratio, β is the empirical coefficient, which is used to describe the attenuation rate of sediment transport efficiency, T i adjusted For the optimized confluence time, A j is the area of ​​the jth pond, V j is the water storage capacity of the jth pond, E j is the sediment interception efficiency of the j-th pond.

8. A multi-pond area sediment transport ratio optimization calculation system, characterized by: include: A data acquisition unit, configured to acquire raster data of at least one pond in the watershed; The raster data includes: pond type, pond area, water storage capacity, hydraulic retention time and watershed hydrological characteristics; an efficiency determination unit, configured to determine the sediment interception efficiency of each of the ponds according to the pond type and the pond area; a time optimization unit, configured to determine a water flow delay factor of the pond based on the hydraulic retention time of the pond, and optimize the original confluence time according to the water flow delay factor, taking into account a water flow delay effect of the pond, to obtain an optimized confluence time; An iterative calculation unit, configured to iteratively calculate the effect of each pond on sediment transport based on the optimized confluence time and the sediment interception efficiency, and to update the sediment concentration step by step; The result optimization unit is used to comprehensively consider the cumulative effect of the water flow delay factor and the cumulative effect of the sediment interception effect, optimize the initial sediment transport ratio in the process of gradually updating the sediment concentration, and obtain the optimized sediment transport ratio.

Images