Multi-parameter forecasting method for hydraulic debris flow in small watershed

Abstract

The invention provides a small watershed hydraulic debris flow multi-parameter forecasting method, and relates to the technical field of geological disaster prevention and control. According to the small watershed hydraulic debris flow multi-parameter forecasting method provided by the embodiment of the invention, the design rainfall process is determined according to the design rainfall parameters and the rainfall type, and then hydrological analysis and debris flow process analysis are performed according to the design rainfall process; therefore, whether debris flow occurs or not, the debris flow starting time and the debris flow flow process can be obtained as debris flow forecasting parameters, and forecasting of debris flow starting and process is realized. According to the embodiment of the invention, the debris flow process forecast including abundant parameters (whether debris flow occurs or not, the flow required for starting the debris flow and the corresponding moment) can be output based on the designed rainfall parameters and land parameters of the target drainage basin, so that the possible occurrence of the debris flow can be warned in advance before a rainfall event occurs. And timely precautionary measures can be taken, so that the life safety and property safety of personnel are protected.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of geological disaster prevention and control, and in particular to a multi-parameter prediction method for hydraulic debris flows in a small watershed. Background Art

[0002] Debris flow is a common natural disaster that poses a serious threat to people's lives and property. Due to its complex causes and high cost of control, it is currently impossible to achieve comprehensive control. Debris flow forecasting, as a rapid means of disaster reduction, is of great significance to disaster prevention and mitigation work.

[0003] The methods used for debris flow forecasting in related technologies are mainly statistical methods that rely on historical rainfall data, specifically including: collecting rainfall conditions for debris flow events that occurred in history and rainfall conditions for when debris flow events did not occur. The rainfall conditions include meteorological data such as rainfall amount, rainfall intensity, and rainfall duration, conducting statistical analysis, determining the threshold line of rainfall conditions, and then combining rainfall monitoring to predict debris flow forecasts.

[0004] However, these methods rely on data from historical debris flow events. Therefore, if the historical data is insufficient or inaccurate, it will affect the accuracy of the determined threshold line, and thus affect the accuracy of the forecast. In addition, these methods rely on the relationship between historical rainfall conditions and the occurrence of debris flow, but the occurrence of debris flow is also affected by other factors, such as topography, soil type, groundwater level, etc. Therefore, the prediction results obtained by the above methods have low reference significance. In addition, the forecast of the peak flow and scale of debris flow is very important for debris flow disaster reduction. However, the existing debris flow forecast only focuses on the time of occurrence of debris flow, which cannot meet the actual needs of debris flow disaster reduction.

[0005] It can be seen that a new debris flow prediction method is urgently needed. Summary of the invention

[0006] The embodiment of the present invention provides a multi-parameter prediction method for hydraulic debris flow in a small watershed, so as to at least partially solve the problems existing in the related art.

[0007] A first aspect of an embodiment of the present invention provides a multi-parameter prediction method for hydraulic debris flow in a small watershed, the method comprising:

[0008] Acquire design rainfall parameters and land parameters of the target watershed, wherein the design rainfall parameters include: maximum rainfall values ​​at different rainfall recurrence periods, and the land parameters include: land use type and soil type;

[0009] Determining a design rainfall process according to the design rainfall parameters and rainfall type;

[0010] Calculate and determine the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process, land parameters and hydrological conditions;

[0011] Determine the debris flow rate at each moment according to the surface runoff at each moment;

[0012] Determine whether a debris flow occurs, the debris flow start time, and the debris flow process after the debris flow starts based on the debris flow flow at each moment;

[0013] Output debris flow prediction parameters, the debris flow prediction parameters including: whether a debris flow occurs, the debris flow start time and the debris flow flow process parameters after the start.

[0014] Optionally, determining the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process, land parameters and hydrological calculations includes:

[0015] The surface runoff in each time period corresponding to the designed rainfall process is determined according to the following formula:

[0016] P t =(PI a ) 2 / (PI a +S);

[0017] I a =0.2S;

[0018] S = 25400 / CN-254;

[0019] Among them, P t I is the surface runoff corresponding to time t, P is the cumulative rainfall depth at time t, and the cumulative rainfall depth is determined according to the rainfall intensity at each time; a represents the initial rainfall loss, S represents the maximum water storage capacity of the soil in the target basin, CN represents the dimensionless parameter of the target basin's ability to form surface runoff, and represents the runoff curve value of the target basin's hydrological conditions, land use type, and soil type.

[0020] Optionally, determining the debris flow rate at each moment according to the surface runoff at each moment includes:

[0021] The debris flow rate at each moment is determined according to the following formula:

[0022] Q d =(1+λ)Q w D u ;

[0023] Where Qd represents the debris flow, Qw represents the flood flow, Qw = P t, Du represents the channel blockage coefficient, and λ represents the flow correction coefficient.

[0024] Optionally, determining whether a debris flow occurs, a debris flow start time, and a debris flow process after the debris flow starts according to the debris flow flow at each moment includes:

[0025] The critical starting flow rate of debris flow is determined by the following formula:

[0026] Among them, Q C Denotes the critical starting flow rate of debris flow, D m is the particle size of solid matter in the target watershed, θ is the channel bed gradient of the target watershed;

[0027] During the designed rainfall process, if the debris flow rate at the first moment is greater than the critical flow rate for starting the debris flow, it is determined that a debris flow will occur under the designed rainfall conditions, and the first moment is taken as the debris flow starting moment. The debris flow rates at various moments after the debris flow occurs are obtained, and the debris flow process after the debris flow starts is determined.

[0028] Optionally, the rainfall types include: first strong then weak type, first weak then strong type and center type. According to the designed rainfall parameters and rainfall types, determining the designed rainfall process includes:

[0029] According to the rainfall type, the maximum rainfall values ​​in different time periods are flattened to obtain the first design rainfall process corresponding to the first strong then weak type, the second design rainfall process corresponding to the first weak then strong type, and the third design rainfall process corresponding to the center type;

[0030] Determining the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process, land parameters and hydrological calculations, including:

[0031] According to the first designed rainfall process, the second designed rainfall process and the third designed rainfall process, the surface runoff at each moment corresponding to each of the three designed rainfall processes is determined in combination with land parameters and hydrological calculations.

[0032] Optionally, whether a debris flow occurs, the debris flow start time, and the debris flow flow process after the debris flow starts are determined as debris flow prediction parameters, and the debris flow prediction is output, including:

[0033] Obtaining a flood process line according to the surface runoff at each time;

[0034] Obtaining a debris flow process line according to the debris flow flow at each moment;

[0035] Superimposing the flood process line and the debris flow process line at different times to obtain a flood-debris flow process line;

[0036] Output whether a debris flow occurs, the debris flow start time and the flood-debris flow process line.

[0037] A second aspect of an embodiment of the present invention provides a multi-parameter forecasting device for hydraulic debris flow in a small watershed, the device comprising:

[0038] A parameter acquisition module, used to acquire the design rainfall parameters and land parameters of the target watershed, wherein the design rainfall parameters include: maximum rainfall values ​​of different rainfall recurrence periods, and the land parameters include: land use type and soil type;

[0039] A rainfall process determination module, used to determine the designed rainfall process according to the designed rainfall parameters and rainfall type;

[0040] A surface runoff determination module, used to calculate and determine the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process, land parameters and hydrological conditions;

[0041] A debris flow flow determination module, used to determine the debris flow flow at each moment according to the surface runoff at each moment;

[0042] A debris flow process determination module is used to determine whether a debris flow occurs, the debris flow start time, and the debris flow flow process after the debris flow starts according to the debris flow flow at each moment;

[0043] The prediction module is used to output debris flow prediction parameters, which include: whether a debris flow occurs, the debris flow starting time, and the debris flow flow process parameters after starting.

[0044] Optionally, the surface runoff determination module is used to:

[0045] The surface runoff in each time period corresponding to the designed rainfall process is determined according to the following formula:

[0046] P t =(PI a ) 2 / (PI a +S);

[0047] I a =0.2S;

[0048] S = 25400 / CN-254;

[0049] Among them, P t I is the surface runoff corresponding to time t, P is the cumulative rainfall depth at time t, and the cumulative rainfall depth is determined according to the rainfall intensity at each time; arepresents the initial rainfall loss, S represents the maximum water storage capacity of the soil in the target basin, CN represents the dimensionless parameter of the target basin's ability to form surface runoff, and represents the runoff curve value of the target basin's hydrological conditions, land use type, and soil type.

[0050] Optionally, the debris flow flow determination module is used to:

[0051] The debris flow rate at each moment is determined according to the following formula:

[0052] Q d =(1+λ)Q w D u ;

[0053] Where Qd represents the debris flow, Qw represents the flood flow, Qw = P t , Du represents the channel blockage coefficient, and λ represents the flow correction coefficient.

[0054] Optionally, the debris flow process determination module is used to:

[0055] The critical starting flow rate of debris flow is determined by the following formula:

[0056]

[0057] Among them, Q C Denotes the critical starting flow rate of debris flow, D m is the particle size of solid matter in the target watershed, θ is the channel bed gradient of the target watershed;

[0058] During the designed rainfall process, if the debris flow rate at the first moment is greater than the critical flow rate for starting the debris flow, it is determined that a debris flow will occur under the designed rainfall conditions, and the first moment is taken as the debris flow starting moment. The debris flow rates at various moments after the debris flow occurs are obtained, and the debris flow process after the debris flow starts is determined.

[0059] Optionally, the rainfall types include: strong first then weak type, weak first then strong type and center type, and the rainfall process determination module is used to: perform flattening processing on the maximum rainfall values ​​in different time periods according to the rainfall types to obtain a first designed rainfall process corresponding to the strong first then weak type, a second designed rainfall process corresponding to the weak first then strong type, and a third designed rainfall process corresponding to the center type;

[0060] The surface runoff determination module is used to determine the surface runoff at each moment corresponding to each of the three designed rainfall processes according to the first designed rainfall process, the second designed rainfall process and the third designed rainfall process, respectively in combination with land parameters and hydrological calculations.

[0061] Optionally, the forecast module is used to:

[0062] Obtaining a flood process line according to the surface runoff at each time;

[0063] Obtaining a debris flow process line according to the debris flow flow at each moment;

[0064] Superimposing the flood process line and the debris flow process line at different times to obtain a flood-debris flow process line;

[0065] Output whether a debris flow occurs, the debris flow start time and the flood-debris flow process line.

[0066] A third aspect of an embodiment of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when executed, the processor implements the multi-parameter prediction method for hydraulic debris flows in a small watershed as described in the first aspect of the present invention.

[0067] A fourth aspect of an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the multi-parameter prediction method for hydraulic debris flows in a small watershed as described in the first aspect of the present invention.

[0068] A fifth aspect of an embodiment of the present invention provides a computer program product, including a computer program / instruction, which is used by a processor to implement the steps in the multi-parameter prediction method for hydraulic debris flows in a small watershed as described in the first aspect of the present invention.

[0069] In the multi-parameter forecasting method for hydraulic debris flows in small watersheds provided by an embodiment of the present invention, the designed rainfall process is determined according to the designed rainfall parameters and rainfall type, and then hydrological analysis and debris flow process analysis are performed based on the designed rainfall process, so as to judge whether a debris flow will occur, determine the starting time of the debris flow and the debris flow process, and use them as debris flow forecasting parameters.

[0070] In the embodiment of the present invention, based on the designed rainfall parameters and land parameters of the target watershed, a debris flow process forecast including rich parameters (whether a debris flow will occur, the flow rate required for the debris flow to start and the corresponding time and debris flow flow process) can be output, so that the possibility of a debris flow can be warned in advance before the rainfall event occurs. This helps to take timely preventive measures to protect the safety of life and property.

[0071] In an embodiment of the present invention, a debris flow risk assessment of a target watershed can be implemented based on the design rainfall parameters of the target watershed, and the degree of debris flow danger in the target watershed can be determined. Then, corresponding planning and disaster prevention measures can be formulated, such as reasonable planning of buildings, roads, water conservancy facilities, etc., to reduce the risk of debris flow disasters. And based on the debris flow forecast, rescue and disaster prevention resources can be reasonably deployed before the debris flow disaster occurs. Specifically, when the actual rainfall reaches the design rainfall parameters, rescue teams, equipment and materials can be mobilized in advance to deal with possible debris flow disasters and improve rescue efficiency and emergency response capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0073] Figure 1 A flowchart showing the steps of a multi-parameter prediction method for hydraulic debris flow in a small watershed provided by an embodiment of the present invention is shown;

[0074] Figure 2 A schematic diagram of an overview of a target watershed in an exemplary embodiment provided by an embodiment of the present invention is shown;

[0075] Figure 3 A schematic diagram of a rainfall process of three rainfall types in an exemplary embodiment provided by an embodiment of the present invention is shown;

[0076] Figure 4 A schematic diagram of surface runoff process corresponding to three rainfall types in an exemplary embodiment provided by an embodiment of the present invention is shown;

[0077] Figure 5 A schematic diagram of a flood-mudslide process line in a forecast result in an exemplary embodiment provided by an embodiment of the present invention is shown;

[0078] Figure 6 The structural block diagram of the multi-parameter forecasting device for hydraulic debris flow in a small watershed provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0079] 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.

[0080] In the embodiment of the present invention, a multi-parameter prediction method for hydraulic debris flow in a small watershed is provided. Figure 1 As shown, Figure 1The flowchart of the multi-parameter prediction method for hydraulic debris flow in a small watershed provided by an embodiment of the present invention is shown; specifically, the method comprises the following steps:

[0081] S101, obtaining design rainfall parameters and land parameters of a target watershed, wherein the design rainfall parameters include: maximum rainfall values ​​at different rainfall return periods, and the land parameters include: land use type and soil type;

[0082] S102, determining a designed rainfall process according to the designed rainfall parameters and rainfall type;

[0083] S103, calculating and determining the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process, land parameters and hydrological conditions;

[0084] S104, determining the debris flow rate at each moment according to the surface runoff at each moment;

[0085] S105, determining whether a debris flow occurs, the debris flow start time, and the debris flow flow process after the debris flow starts according to the debris flow flow at each time;

[0086] S106, outputting debris flow prediction parameters, wherein the debris flow prediction parameters include: whether a debris flow occurs, the debris flow start time, and debris flow flow process parameters after the start.

[0087] In the embodiment of the present invention, the target basin that needs to be analyzed and studied can be determined first according to the actual debris flow forecast requirements. Further, according to the local meteorological and hydrological conditions of the target basin, the design rainfall parameters of the basin are determined. The design rainfall parameters are calculated through a large amount of historical data to obtain the maximum rainfall values ​​of the 10-, 20-, 50-year or even 100-year rainstorms in the region in different time periods. For example, the design rainfall parameters of a 20-year rainstorm in a basin are: 58.5 mm in 1 hour, 139.3 mm in 6 hours, and 264 mm in 24 hours. Specifically, they can be determined by referring to the local hydrological manual.

[0088] In an embodiment of the present invention, relevant hydrological calculation methods can be used to determine the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process and the land parameters of the target watershed, such as: full flow model, excess infiltration flow model, mixed flow model, unit line method and SCS flow calculation method, etc. The corresponding hydrological calculation method can be selected according to actual needs.

[0089] In an optional implementation, the SCS (Soil Conservation Service) runoff calculation method is used to calculate the rainfall-flood process. The SCS runoff calculation method is a method for calculating the runoff generated by rainfall. The method can simulate the runoff process through a series of parameters and formulas based on factors such as soil water storage capacity and rainfall intensity. Specifically, the step S103 includes:

[0090] The surface runoff in each time period corresponding to the designed rainfall process is determined according to the following formula:

[0091] P t =(PI a ) 2 / (PI a +S) (1)

[0092] I a =0.2S (2)

[0093] S=25400 / CN-254 (3)

[0094] Among them, P t I is expressed as the surface runoff corresponding to time t (unit: mm), P is the cumulative rainfall depth at time t (unit: mm), and the cumulative rainfall depth is determined according to the rainfall intensity at each time (unit: mm / h); a represents the initial rainfall loss (unit: mm), S represents the maximum water storage capacity of the soil in the target basin (unit: mm), CN represents the dimensionless parameter of the target basin's ability to form surface runoff, and represents the runoff curve value of the target basin's hydrological conditions, land use type, and soil type.

[0095] Specifically, the rainfall intensity at each moment can reflect the rainfall intensity per minute, hour or any other time interval. Multiplying the rainfall intensity of each time interval by the length of the time interval can get the rainfall in the time period. For each moment, the rainfall in the corresponding time period is added to the cumulative rainfall before the moment to get the cumulative rainfall depth at the moment. By traversing each moment, the cumulative rainfall depth at each moment can be obtained, and then the surface runoff corresponding to each moment can be calculated.

[0096] In the embodiment of the present invention, according to the land use type and soil type, the CN value can be determined by referring to the relevant CN value table. The CN value table is obtained based on measured data and experience summary, and provides CN values ​​corresponding to different land use types and soil types.

[0097] In the embodiment of the present invention, by using the SCS runoff calculation method, the runoff at each moment can be calculated according to the designed rainfall process. Specifically, runoff represents the part of rainfall converted into surface runoff, and surface runoff is related to flood flow and debris flow. It can be used to evaluate the runoff characteristics of the target basin, predict the time and scale of flood occurrence, and understand the potential risks of natural disasters such as debris flow.

[0098] In an optional implementation, the step S104 includes:

[0099] The debris flow rate at each moment is determined according to the following formula:

[0100] Q d = (1+λ)Q w D u (4)

[0101] Where Qd represents the debris flow, Qw represents the flood flow, Qw = P t , Du represents the channel blockage coefficient, and λ represents the flow correction coefficient.

[0102] In the embodiment of the present invention, the channel blockage coefficient can be obtained by looking up the table, and the flow correction coefficient is usually a constant and can be obtained by looking up the local hydrological manual.

[0103] In the embodiment of the present invention, the debris flow flow corresponding to time t can be determined according to the surface runoff flow corresponding to time t.

[0104] In an optional implementation, the step S105 includes:

[0105] S1051, use the following formula to determine the critical starting flow of debris flow: Among them, Q C Denotes the critical starting flow rate of debris flow, D m is the particle size of solid matter in the target watershed, θ is the channel bed gradient of the target watershed;

[0106] S1052, during the designed rainfall process, if there is a debris flow at the first moment that is greater than the critical starting flow of the debris flow, it is determined that a debris flow will occur under the designed rainfall conditions, the first moment is taken as the debris flow starting moment, the debris flow at each moment after the debris flow occurs is obtained, and the debris flow process after the debris flow starts is determined.

[0107] In the embodiment of the present invention, the particle size of solid matter in the target basin and the ditch bed gradient of the target basin can be obtained by consulting the local hydrological manual or relevant public literature, or can be determined by the following method: for the particle size of solid matter, sediment samples can be collected at different locations and depths in the target basin, and the sediment samples can be sieved using a series of sieves with different apertures, and the mass of sediment passing through each sieve is recorded to determine the particle size distribution. For more accurate particle size measurement, a microscope can be used to observe and measure the particle size. For the ditch bed gradient, a topographic map, GPS equipment or rangefinder can be used to select multiple points along the ditch bed, measure the altitude of each point, and then calculate the height difference and horizontal distance between each point to obtain the gradient. It is also possible to obtain a wide range of terrain information through drone photography or satellite image analysis, and then calculate the average gradient of the ditch bed.

[0108] In the embodiment of the present invention, after obtaining the debris flow starting flow, it can be determined whether there is a debris flow at a certain moment among the debris flow at each moment determined in step S104 that is greater than the debris flow starting flow. If it is greater, it means that a debris flow disaster will occur.

[0109] In the embodiment of the present invention, the smaller the granularity of dividing each moment in step S102, the more accurate the time point of debris flow disaster occurrence can be obtained in step S105. For example, if each minute is used as a time period in step S102 and the start time of each minute is used as each moment, the time point of debris flow disaster occurrence can be obtained with accuracy to the minute. In the actual application process, the granularity of dividing each moment in step S102 can be determined according to actual needs to obtain the time point of debris flow disaster occurrence with the required accuracy.

[0110] In an optional embodiment, the rainfall types include: strong first then weak type, weak first then strong type and center type, and the step S102 includes: flattening the maximum rainfall values ​​in different time periods according to the rainfall types to obtain a first designed rainfall process corresponding to the strong first then weak type, a second designed rainfall process corresponding to the weak first then strong type, and a third designed rainfall process corresponding to the center type.

[0111] In this embodiment, the step S103 includes: according to the first designed rainfall process, the second designed rainfall process and the third designed rainfall process, respectively combining land parameters and hydrological calculations to determine the surface runoff at each moment corresponding to each of the three designed rainfall processes.

[0112] In the embodiment of the present invention, the rainfall is flattened according to the maximum rainfall values ​​in different time periods (such as 1h, 6h, 24h) and three different rainfall types to obtain the designed rainfall processes of different rainfall types.

[0113] In an embodiment of the present invention, the design rainfall parameters can be analyzed respectively for different rainfall types, and finally debris flow forecasts under various rainfall types can be obtained. Therefore, by taking the rainfall type as one of the consideration parameters for debris flow forecast, a debris flow forecast that is more in line with the actual situation can be obtained.

[0114] According to the embodiment of the present invention, when it is determined that a debris flow disaster has occurred, the flood process in the time period when no debris flow occurs and the debris flow process when the debris flow occurs can be combined to obtain the flow process of the debris flow, thereby predicting the time and scale of the debris flow.

[0115] In an optional implementation, the step S106 includes:

[0116] S1061, obtaining a flood process line according to the surface runoff at each time;

[0117] S1062, obtaining a debris flow process line according to the debris flow rate at each moment;

[0118] S1063, superimposing the flood process line and the debris flow process line according to time to obtain a flood-debris flow process line;

[0119] S1064, outputting whether a debris flow occurs, the debris flow start time and the flood-debris flow process line.

[0120] In the embodiment of the present invention, the flood process line and the debris flow process line are obtained respectively, and the flood-debris flow process line is superimposed to obtain the debris flow process line, which is displayed as a debris flow forecast, so that relevant personnel can analyze the debris flow disaster more intuitively and conveniently.

[0121] For ease of understanding, an exemplary embodiment is also provided in the embodiments of the present invention:

[0122] Specifically, the target watershed is located in Ergou along the Duwen Highway, such as Figure 2 As shown, it shows a schematic diagram of the target watershed in the exemplary embodiment provided by the embodiment of the present invention. Ergou is located in the central and eastern part of Wenchuan County, Sichuan Province. It is a first-level tributary on the right bank of the upper reaches of the Minjiang River. The watershed area is about 39.4km2, the main ditch is about 14km long, and the mouth of the ditch is about 6km away from Yingxiu Town, the epicenter of the Wenchuan earthquake. It is a typical high mountain canyon landform, with an altitude of 930m at the mouth of the ditch, and the highest point of the watershed is 4140m above sea level, with a drop of 3210m and a vertical drop of 147‰. Ergou belongs to the subtropical humid monsoon climate zone on the edge of the Sichuan Basin. It is hot and rainy in summer, with an annual regional rainfall of about 1000-1200mm, and secondary disasters such as mountain torrents, landslides, mud-rock flows and collapses occur frequently.

[0123] In the embodiment of the present invention, according to the Sichuan Province Hydrological Manual, the design rainfall values ​​for the basin once in 20 years are determined to be: 58.5 mm in 1 hour, 139.3 mm in 6 hours and 264 mm in 24 hours.

[0124] In the embodiment of the present invention, three rainfall types (strong first then weak, weak first then strong, and center type) are set. Figure 3 As shown, which shows a schematic diagram of the rainfall process for three rainfall types), the designed rainfall process for different rainfall types is obtained.

[0125] In the embodiment of the present invention, according to the above three designed rainfall processes, the SCS runoff calculation method formulas (1), (2), and (3) are used to calculate the rainfall-flood process and realize the calculation of the surface runoff process (such as Figure 4 As shown, it shows a schematic diagram of the surface runoff process corresponding to three rainfall types in an embodiment of the present invention).

[0126] In the embodiment of the present invention, formula (4) is further used to calculate the debris flow process, and formula (5) is used to determine the debris flow conditions for the occurrence of debris flow disasters. The calculated schematic diagram of the flood-debris flow process with a return period of 20 years and the forecast results are shown in the figure. Figure 5 shown.

[0127] In the embodiment of the present invention, through hydrological calculation and debris flow formation process analysis, a forecasting method based on flood flow calculation and debris flow flow calculation is realized, which can simultaneously forecast a full range of parameters such as whether a debris flow will occur, the occurrence time period and the flow process, thereby enriching the debris flow forecasting parameters.

[0128] In addition, in the embodiment of the present invention, by introducing the design rainfall parameters, the design rainfall parameters and the rainfall type are combined to obtain the design rainfall process, and at the same time combined with the hydrological calculation method, the judgment of whether the debris flow occurs and the calculation of the flow process line are realized.

[0129] It can be seen that in the embodiment of the present invention, the prediction method based on a series of debris flow formation processes, namely rainfall process-surface runoff flow process-debris flow flow process, breaks through the traditional statistical method using rainfall as an indicator and provides a new idea for debris flow prediction.

[0130] Based on the same inventive concept, the embodiment of the present invention also provides a multi-parameter forecasting device for hydraulic debris flow in a small watershed, such as Figure 6 As shown, it shows a structural block diagram of a multi-parameter forecasting device for hydraulic debris flow in a small watershed provided by an embodiment of the present invention. Specifically, the device includes:

[0131] The parameter acquisition module 601 is used to acquire the design rainfall parameters and land parameters of the target watershed, wherein the design rainfall parameters include: the maximum rainfall value of different rainfall return periods, and the land parameters include: land use type and soil type;

[0132] A rainfall process determination module 602 is used to determine a designed rainfall process according to the designed rainfall parameters and rainfall type;

[0133] A surface runoff determination module 603 is used to calculate and determine the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process, land parameters and hydrological conditions;

[0134] The debris flow flow determination module 604 is used to determine the debris flow flow at each moment according to the surface runoff at each moment;

[0135] The debris flow process determination module 605 is used to determine whether a debris flow occurs, the debris flow start time and the debris flow process after the debris flow starts according to the debris flow flow at each moment;

[0136] The prediction module 606 is used to output debris flow prediction parameters, which include whether a debris flow occurs, the debris flow start time, and the debris flow flow process parameters after the start.

[0137] Based on the same inventive concept, an embodiment of the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes, the steps in the multi-parameter prediction method for hydraulic debris flows in a small watershed are implemented as described in any of the above embodiments.

[0138] Based on the same inventive concept, an embodiment of the present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps in the multi-parameter prediction method for hydraulic debris flows in a small watershed described in any of the above embodiments are implemented.

[0139] Based on the same inventive concept, an embodiment of the present invention provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps in the multi-parameter prediction method for hydraulic debris flows in a small watershed described in any of the above embodiments.

[0140] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0141] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0142] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0143] The above is a detailed introduction to a multi-parameter prediction method for hydraulic debris flows in a small watershed provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for general technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A multi-parameter prediction method for hydraulic debris flow in a small watershed, characterized in that: The method comprises: Acquire design rainfall parameters and land parameters of the target watershed, wherein the design rainfall parameters include: maximum rainfall values ​​at different rainfall recurrence periods, and the land parameters include: land use type and soil type; Determining a design rainfall process according to the design rainfall parameters and rainfall type; Calculate and determine the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process, land parameters and hydrological conditions; Determine the debris flow rate at each moment according to the surface runoff at each moment; Determine whether a debris flow occurs, the debris flow start time, and the debris flow process after the debris flow starts based on the debris flow flow at each moment; Output debris flow prediction parameters, the debris flow prediction parameters including: whether a debris flow occurs, the debris flow start time and the debris flow flow process parameters after the start.

2. The multi-parameter prediction method for hydraulic debris flow in a small watershed according to claim 1 is characterized in that: Determining the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process, land parameters and hydrological calculations, including: The surface runoff in each time period corresponding to the designed rainfall process is determined according to the following formula: P t =(P-I a ) 2 / (P-I a +S); I a =0.2S; S = 25400 / CN-254; Among them, P t I is the surface runoff corresponding to time t, P is the cumulative rainfall depth at time t, and the cumulative rainfall depth is determined according to the rainfall intensity at each time; a represents the initial rainfall loss, S represents the maximum water storage capacity of the soil in the target basin, CN represents the dimensionless parameter of the target basin's ability to form surface runoff, and represents the runoff curve value of the target basin's hydrological conditions, land use type, and soil type.

3. The multi-parameter prediction method for hydraulic debris flow in a small watershed according to claim 2 is characterized in that: Determining the debris flow at each moment according to the surface runoff at each moment includes: The debris flow rate at each moment is determined according to the following formula: Q d =(1+λ)Q w D u ; Where Qd represents the debris flow, Qw represents the flood flow, Qw = P t , Du represents the channel blockage coefficient, and λ represents the flow correction coefficient.

4. The multi-parameter prediction method for hydraulic debris flow in a small watershed according to claim 3 is characterized in that: Determine whether a debris flow occurs, the debris flow start time, and the debris flow process after the debris flow starts based on the debris flow flow at each moment, including: The critical starting flow rate of debris flow is determined by the following formula: Among them, Q C Denotes the critical starting flow rate of debris flow, D m is the particle size of solid matter in the target watershed, θ is the channel bed gradient of the target watershed; During the designed rainfall process, if the debris flow rate at the first moment is greater than the critical flow rate for starting the debris flow, it is determined that a debris flow will occur under the designed rainfall conditions, and the first moment is taken as the debris flow starting moment. The debris flow rates at various moments after the debris flow occurs are obtained, and the debris flow process after the debris flow starts is determined.

5. The multi-parameter prediction method for hydraulic debris flow in a small watershed according to claim 1 is characterized in that: The rainfall types include: first strong then weak, first weak then strong, and center-front. According to the design rainfall parameters and rainfall types, the design rainfall process is determined, including: According to the rainfall type, the maximum rainfall values ​​in different time periods are flattened to obtain the first design rainfall process corresponding to the first strong then weak type, the second design rainfall process corresponding to the first weak then strong type, and the third design rainfall process corresponding to the center type; Determining the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process, land parameters and hydrological calculations, including: According to the first designed rainfall process, the second designed rainfall process and the third designed rainfall process, the surface runoff at each moment corresponding to each of the three designed rainfall processes is determined in combination with land parameters and hydrological calculations.

6. The multi-parameter prediction method for hydraulic debris flow in a small watershed according to claim 1 is characterized in that: Whether a debris flow occurs, the debris flow start time, and the debris flow flow process after the debris flow starts are determined as debris flow prediction parameters, and the debris flow prediction is output, including: Obtaining a flood process line according to the surface runoff at each time; Obtaining a debris flow process line according to the debris flow flow at each moment; Superimposing the flood process line and the debris flow process line at different times to obtain a flood-debris flow process line; Output whether a debris flow occurs, the debris flow start time and the flood-debris flow process line.

7. A multi-parameter forecasting device for hydraulic debris flow in a small watershed, characterized in that: The device comprises: A parameter acquisition module, used to acquire the design rainfall parameters and land parameters of the target watershed, wherein the design rainfall parameters include: maximum rainfall values ​​of different rainfall recurrence periods, and the land parameters include: land use type and soil type; A rainfall process determination module, used to determine the designed rainfall process according to the designed rainfall parameters and rainfall type; A surface runoff determination module, used to calculate and determine the surface runoff at each moment corresponding to the designed rainfall process according to the designed rainfall process, land parameters and hydrological conditions; A debris flow flow determination module, used to determine the debris flow flow at each moment according to the surface runoff at each moment; A debris flow process determination module is used to determine whether a debris flow occurs, the debris flow start time, and the debris flow flow process after the debris flow starts according to the debris flow flow at each moment; The prediction module is used to output debris flow prediction parameters, which include: whether a debris flow occurs, the debris flow starting time, and the debris flow flow process parameters after starting.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the multi-parameter prediction method for hydraulic debris flow in a small watershed as described in any one of claims 1-6 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the multi-parameter prediction method for hydraulic debris flow in a small watershed as described in any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps in the multi-parameter prediction method for hydraulic debris flow in a small watershed as described in any one of claims 1-6 are implemented.

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