Plateau structure active region debris flow development characteristic and disaster-causing mode identification method and system

Abstract

The invention discloses a plateau structure active area debris flow development characteristic and disaster-causing mode identification method and system, and relates to the technical field of debris flow prevention and control engineering, and the method comprises the steps: S10, determining the development characteristic parameters of the plateau structure active area debris flow based on remote sensing and field investigation; s20, determining a debris flow formation mechanism, and calculating a debris flow influence range; and S30, analyzing the relationship between the debris flow influence range and the position of the potential influence area so as to judge the debris flow disaster-causing mode. According to the method, on the basis of obtaining the basic parameters of the debris flow, the development characteristics are identified, then the scale of the debris flow is calculated, the debris flow disaster-causing modes are determined, and the selectable debris flow disaster-causing modes comprise impact disaster-causing modes, silting disaster-causing modes and erosion disaster-causing modes. The method has a good effect of judging the debris flow disaster-causing mode of the plateau structure active area, can identify the disaster-causing mode of the glacier and glacier lake debris flow in the plateau area, and fills the blank in the debris flow disaster-causing mode identification technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of debris flow prevention and control engineering, and particularly relates to a method and system for identifying the development characteristics and disaster-causing mode of debris flow in a plateau tectonically active area. BACKGROUND

[0002] The plateau tectonically active area has become a frequent area of debris flow disasters due to its intense geological activity, intensified glacier ablation and frequent extreme climate events. According to the inducement, the debris flow can be divided into ice lake outburst debris flow, glacier debris flow, earthquake and rainfall type debris flow and multi-mechanism coupling type debris flow. Different types of debris flow have different development characteristics and different disaster-causing processes due to the influence of the formation process. The difference in the disaster-causing mode causes the bearing body to bear different characteristics of loss. At present, the research on plateau debris flow disasters has made certain progress. In the field investigation, some debris flow disaster-causing modes can be identified by combining simple mechanical equipment, but the existing identification methods generally have the shortcomings of low identification efficiency, low precision and long cycle. However, the plateau debris flow has strong destructive and sudden nature, and it is urgent to explore a more effective method system to realize the rapid identification of the development characteristics and disaster-causing mode of the plateau tectonically active area debris flow and reduce the loss of disasters. SUMMARY

[0003] The purpose of the present application is to overcome the shortcomings of the prior art and provide a method and system for identifying the development characteristics and disaster-causing mode of debris flow in a plateau tectonically active area.

[0004] The purpose of the present application is achieved by the following technical solutions:

[0005] In a first aspect, the present application discloses a method for identifying the development characteristics and disaster-causing mode of debris flow in a plateau tectonically active area, comprising the following steps:

[0006] S10, determining the development characteristic parameters of the debris flow in the plateau tectonically active area based on remote sensing and field investigation;

[0007] S20, determining the formation mechanism of the debris flow and calculating the influence range of the debris flow;

[0008] S30, analyzing the relationship between the influence range of the debris flow and the location of the potential impact area to determine the disaster-causing mode of the debris flow.

[0009] Based on the first aspect, step S20 specifically comprises the following steps:

[0010] S21, calculating the total amount of one-time debris flow W C or debris flow flood peak flow Q c according to the existence of ice lakes and glaciers in the debris flow basin.

[0011] S22, calculating the accumulation coefficient of the debris flow, including calculating the maximum accumulation distance L of the debris flow by the formula calculating the maximum accumulation distance L of the debris flow, wherein K represents a first empirical coefficient, H represents a height difference, and S represents an average longitudinal slope, by the formula calculating the maximum width W of the debris flow accumulation fan, wherein K w represents a second empirical coefficient, by the formula calculating the accumulation area A of the debris flow; by the formula calculating the accumulation thickness T of the debris flow hi .

[0012] Based on the first aspect, if there is no ice lake and glacier in the debris flow basin in step S21, first, the peak flow Q of the debris flow is calculated by the formula B wherein represents a peak runoff coefficient, S represents a maximum 1-hour rainfall, τ represents a basin concentration time, n represents a rainfall attenuation index, and F represents a basin area; then the peak flow Q of the debris flow is calculated by the formula c wherein represents a debris flow peak flow increase coefficient, D u represents a blocking coefficient; finally, the total amount W of the one-time debris flow is calculated by the formula c wherein T represents the duration of the debris flow.

[0013] Based on the first aspect, if there is a glacier in the debris flow basin in step S21, it is further determined whether there is an ice area in the rain season, if there is no ice in the rain season and only in the summer, the total amount W of the one-time debris flow is calculated by the formula c ; if there is ice in the rain season and in the summer, first, the glacier ablation amount M is calculated by the degree-day model, M = DDF*PDD, wherein DDF represents a degree-day factor, and PDD is a positive accumulated temperature, which is calculated by wherein T t represents the daily average temperature of the tth day, H t represents a logical variable corresponding to T t , that is, H t is 1 when T t ≥ 0℃, otherwise H t is 0; then the ablation flow Q of the glacier is converted from the ablation amount M by the formula x wherein A1 represents the area where the glacier exists; finally, the peak flow Q of the debris flow is calculated by the formula c wherein k represents an amplification coefficient.​​​​​​

[0014] Based on the first aspect, if there is an ice lake in the debris flow basin in step S21, there is no glacier, then the ice lake outburst is added to the debris flow flow, and the formula is The ice lake volume V is calculated, wherein A2 represents the ice lake area; and the formula Q K = 0.063·PE 0.42 The ice lake storage capacity and outburst flood peak flow Q K is calculated, wherein PE represents the ice lake potential, that is, the product of the ice lake volume, dam height and lake water specific weight; and finally the formula The debris flow peak flow Q c is calculated.

[0015] Based on the first aspect, if there is an ice lake and a glacier in the debris flow basin in step S21, then the formula The debris flow flood peak flow Q c is calculated.

[0016] Based on the first aspect, step S3 specifically includes:

[0017] Based on the potential impact area of the debris flow and the position of the debris flow, the position relationship parameters of the debris flow and the impact area are obtained, including the nearest vertical distance L j of the potential impact area and the debris flow ditch, the distance L h from the debris flow ditch mouth to the river, and the vertical height H j of the debris flow and the impact area and the debris flow ditch;

[0018] If L h + river width L k ≤ L, and T hi ≥ river depth H h , the debris flow disaster mode is blocking river and damming disaster;

[0019] If L j ≤ W / 2, H j < 0, and T hi - ditch depth < building height, the debris flow disaster mode is impact disaster;

[0020] If L j ≤ W / 2, H j < 0, and T hi - ditch depth ≥ building height, the debris flow disaster mode is silt disaster;

[0021] If L j ≤ W / 2, H j ≥ 0, the debris flow disaster mode is erosion disaster;

[0022] If there is an ice lake downstream of the debris flow gully, the debris flow will induce ice lake outburst flood or debris flow disaster, and the debris flow disaster mode is chain disaster.

[0023] In a second aspect, the present application discloses a system for identifying the development characteristics and disaster mode of the debris flow in the plateau tectonically active area, which is used for the method for identifying the development characteristics and disaster mode of the debris flow in the plateau tectonically active area.

[0024] The development characteristic parameter acquisition module is used for acquiring the development characteristic parameters of the debris flow in the plateau tectonically active area.

[0025] The debris flow influence range calculation module is used for determining the formation mechanism of the debris flow and calculating the influence range of the debris flow.

[0026] The debris flow disaster mode judgment module is used for analyzing the relationship between the influence range of the debris flow and the position of the potential influence area and judging the disaster mode of the debris flow.

[0027] The present application has the following beneficial effects:

[0028] 1) Based on the basic parameters of the debris flow, the development characteristics are identified, the scale of the debris flow is calculated, and the disaster mode of the debris flow is determined. If the debris flow gully is close to the river, the maximum outflow length of the debris flow is greater than the width of the river, and the accumulation thickness of the debris flow is greater than the water depth, then the disaster mode of the debris flow is blockage and outburst disaster. If the debris flow is far away from the river, but there is an ice lake downstream of the debris flow, then the disaster mode of the debris flow is chain disaster. If the debris flow is far away from the river, then the relationship between the debris flow and the potential influence area needs to be judged, and the estimated parameters of the debris flow accumulation and the parameters of the debris flow accumulation are referred to for judging the disaster mode of the debris flow. The optional disaster modes of the debris flow are impact, burial and erosion disasters. The disaster mode of the debris flow in the plateau tectonically active area can be identified, and the defects of the prior art are filled. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a step schematic diagram of the method for identifying the development characteristics and disaster mode of the debris flow in the plateau tectonically active area according to the embodiment of the present application.

[0030] Figure 2 It is a flow schematic diagram of the method for identifying the development characteristics and disaster mode of the debris flow in the plateau tectonically active area according to the embodiment of the present application.

[0031] Figure 3 It is an ice lake parameter schematic diagram of the method for identifying the development characteristics and disaster mode of the debris flow in the plateau tectonically active area according to the embodiment of the present application.

[0032] Figure 4 It is a debris flow disaster mode judgment schematic diagram of the method for identifying the development characteristics and disaster mode of the debris flow in the plateau tectonically active area according to the embodiment of the present application. DETAILED DESCRIPTION

[0033] The technical solutions of the present application will be described clearly and completely below in combination with embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the present application.

[0034] The present application discloses a method for identifying development characteristics and disaster-causing modes of debris flow in a plateau tectonically active area, a schematic diagram of steps of which is shown in Figure 1 , and a flowchart thereof is shown in Figure 2 . The method specifically comprises the following steps:

[0035] S10, determining development characteristic parameters of debris flow in a plateau tectonically active area based on remote sensing and field investigation;

[0036] S20, determining a formation mechanism of debris flow and calculating an influence range of debris flow;

[0037] S30, analyzing the relationship between the influence range of debris flow and the location of a potential influence area, so as to judge a disaster-causing mode of debris flow.

[0038] Specifically, step S20 comprises the following steps:

[0039] S21, calculating a total amount W of one-time debris flow C or a flood peak flow Q c of debris flow according to the existence of ice lakes and glaciers in a debris flow basin;

[0040] S22, calculating a deposition coefficient of debris flow, including calculating a maximum deposition distance L of debris flow by a formula , wherein K represents a first empirical coefficient, the specific value of which needs to be calibrated according to similar debris flow events that have occurred in a research area, H represents an elevation, the unit of which is meters, and S represents an average longitudinal slope (dimensionless); calculating a maximum width W of a debris flow deposition fan by a formula , wherein K w represents a second empirical coefficient, the second empirical coefficient K w is related to the topographic constraints of a deposition area and the properties of debris flow, and in an open area, the value is mostly 3-10, and in a narrow area, the value is smaller, mostly 1-3; calculating a deposition area A of debris flow by a formula ; and calculating a deposition thickness T hi of debris flow by a formula .

[0041] For example, in step S21, if there are no glacial lakes or glaciers within the debris flow basin, the process is first determined using the formula... Calculate the peak flow rate Q B (Its unit is m) 3 / s), where The peak runoff coefficient is represented by S, which represents the maximum hourly rainfall (or rainfall intensity, in mm / hour), τ represents the watershed runoff time (in hours), n represents the rainfall attenuation index, and F represents the watershed area (in km²). 2 ); then through the formula Peak flow rate Q of debris flow c The calculation is performed, and the unit is m. 3 / s, where D represents the coefficient of increase in peak flow rate of debris flow. u Represents the congestion coefficient; finally, it is expressed by the formula. Calculate the total ejecta W of a single debris flow c Its unit is m 3 , where T represents the duration of the debris flow.

[0042] For example, in step S21, if there is a glacier in the debris flow basin, the area of ​​the glacier during the rainy season is further determined. If there is no glacier during the rainy season, and glaciers only exist in summer, the area is determined using the formula. Calculate the total ejecta W of a single debris flow c If glaciers exist during both the rainy and summer seasons, the glacier ablation M is first calculated using a day-degree model. M = DDF * PDD, with units of millimeters. DDF represents the day-degree factor, reflecting the ablation intensity per unit positive accumulated temperature, and PDD is the positive accumulated temperature, calculated as follows: Its unit is Celsius-day, where T t This represents the average daily temperature on day t, expressed in degrees Celsius (H). t T represents t The corresponding logical variable, namely T t At ≥0℃, H t H is 1, otherwise H t It is 0; then it is calculated using the formula. Convert glacial ablation M into ablation flow rate Q x Its unit is m 3 / s, where A1 represents the area where the glacier exists; finally, the formula is used... Calculate the peak flow rate Q of debris flow c , where k represents the amplification factor. During rainfall, due to the latent heat of rainwater and heat conduction, the amplification factor k needs to be introduced. The value of k is positively correlated with the area k of the glacier, and the value ranges from 1.3 to 2.5.

[0043] Exemplarily, the ice lake parameter schematic diagram is as shown in Figure 3 As shown in the figure, if there is an ice lake and no glacier in the debris flow basin in step S21, the ice lake breaching superimposed debris flow discharge is judged, and the formula is used to calculate the ice lake volume V, wherein A2 represents the ice lake area, and the unit is km 2 ; the ice lake storage capacity and breaching flood peak flow Q K is calculated by the formula Q 0.42 = 0.063·PE K , wherein PE represents the ice lake potential, that is, the product of the ice lake volume, dam height and water density; and finally the debris flow peak flow Q c is calculated by the formula .

[0044] Exemplarily, if there is an ice lake and a glacier in the debris flow basin in step S21, the debris flow flood peak flow Q c is calculated by the formula .

[0045] Specifically, the debris flow disaster mode judgment schematic diagram is as shown in Figure 4 The step S3 includes:

[0046] Based on the potential influence area of the debris flow and the position of the debris flow, the position relationship parameters of the debris flow and the influence area are obtained, including the nearest vertical distance L j between the potential influence area and the debris flow ditch, the distance L h from the debris flow ditch to the river, and the vertical height H j between the debris flow and the influence area and the debris flow ditch;

[0047] If L h + river width L k ≤ L, and T hi ≥ river depth H h , the debris flow disaster mode is blocking river and damming disaster;

[0048] If L j ≤ W / 2, H j < 0, and T hi - ditch depth ≥ building height, the debris flow disaster mode is impact disaster;

[0049] If L j ≤ W / 2, H j < 0, and T hi - ditch depth ≥ building height, the debris flow disaster mode is impact disaster;

[0050] If L j ≤ W / 2, H j≥ 0, the mud flow disaster mode is erosion disaster;

[0051] If there is an ice lake downstream of the mud flow valley, the mud flow disaster mode is chain disaster if the ice lake outburst flood or mud flow is induced.

[0052] The application further discloses a mud flow development characteristic and disaster mode identification system in a plateau tectonically active area.

[0053] The development characteristic parameter acquisition module is configured to acquire the development characteristic parameters of the mud flow in the plateau tectonically active area.

[0054] The mud flow influence range calculation module is configured to determine the mud flow formation mechanism and calculate the mud flow influence range.

[0055] The mud flow disaster mode judgment module is configured to analyze the relationship between the mud flow influence range and the potential influence area position and determine the mud flow disaster mode.

[0056] In summary, the application discloses a mud flow development characteristic and disaster mode identification method and system in a plateau tectonically active area, which has good effects on mud flow disaster mode judgment in the plateau tectonically active area, can identify the mud flow disaster mode of the ice lake in the plateau area, and fills the blank in the field of mud flow disaster mode identification. Based on the mud flow basic parameters, the development characteristic is identified, the mud flow scale is calculated, and then the mud flow disaster mode is determined. If the mud flow valley is close to the river, the maximum mud flow outflow length is greater than the river width, and the mud flow accumulation thickness is greater than the water depth, the mud flow disaster mode is outburst disaster caused by blockage. If the mud flow is far away from the river, but there is an ice lake downstream of the mud flow, the mud flow disaster mode is chain disaster. If the mud flow is far away from the river, the relationship between the mud flow and the potential influence area position needs to be determined, the mud flow accumulation estimation parameters and the mud flow accumulation parameters are referred to, and the mud flow disaster mode is determined. The mud flow disaster mode can be impact, buried, and erosion disaster. The application can identify the mud flow disaster mode in the plateau tectonically active area, and fills the defects of the prior art.

[0057] The above only describes the preferred embodiments of the application, and it should be understood that the application is not limited to the forms disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concepts described herein by the above-mentioned teaching or related art or knowledge. The modifications and changes made by those skilled in the art without departing from the spirit and scope of the application should be within the protection scope of the appended claims of the application.

Claims

1. A method for identifying the development characteristics and disaster-causing mode of debris flow in a plateau tectonically active area, characterized in that, The method comprises the following steps: S10, determining the development characteristic parameters of the debris flow in the plateau tectonic active area based on remote sensing and field investigation; S20, determining the formation mechanism of the debris flow and calculating the influence range of the debris flow; S30, analyzing the relationship between the influence range of the debris flow and the location of the potential influence area, thereby judging the disaster-causing mode of the debris flow.

2. The method according to claim 1, wherein, The step S20 specifically comprises the following steps: S21, according to the existence of glacial lake and glacier in the debris flow basin, calculate the total amount of one-time debris flow W C or debris flow flood peak flow Q c ; S22, calculating the accumulation coefficient of the debris flow, including calculating the maximum accumulation distance L of the debris flow by a formula calculating the maximum accumulation distance L of the debris flow, wherein K represents a first empirical coefficient, H represents a height difference, and S represents an average longitudinal slope, by a formula calculating the maximum width W of the debris flow accumulation fan, wherein K w represents a second empirical coefficient, by a formula calculating the accumulation area A of the debris flow; and calculating the accumulation thickness T of the debris flow by a formula hi .

3. The method according to claim 2, wherein the method is characterized by: If there is no ice lake and glacier in the debris flow basin in step S21, first, the peak flow Q is calculated by the formula B wherein represents the peak runoff coefficient, S represents the maximum 1-hour rainfall, τ represents the basin confluence time, n represents the rainfall attenuation index, and F represents the basin area; then the peak flow Q of the debris flow is calculated by the formula c wherein represents the peak flow increase coefficient of the debris flow, D u represents the blockage coefficient; finally, the total amount W c of the one-time debris flow is calculated by the formula wherein T represents the duration of the debris flow.

4. The method according to claim 3, wherein the method is characterized by: If there is a glacier in the debris flow basin in step S21, the area of the glacier in the rainy season is further determined. If there is no glacier in the rainy season and only a glacier in the summer, the total amount of the one-time debris flow is calculated by the formula W = Q * T c If there is a glacier in the rainy season and the summer, the glacier ablation amount M is first calculated by the degree-day model, M = DDF * PDD, where DDF represents the degree-day factor and PDD is the positive accumulated temperature, which is calculated by where T t represents the daily average temperature on the tth day, H t represents the logical variable corresponding to T t , that is, H t is 1 when T t ≥ 0℃, otherwise H t is 0; then the glacier ablation amount M is converted into the ablation flow Q x by the formula where A1 represents the area where the glacier exists; finally, the debris flow peak flow Q c is calculated by the formula where k represents the amplification factor.

5. The method according to claim 4, wherein, If there is an ice lake but no glacier in the debris flow basin, the ice lake outburst is added to the debris flow discharge in step S21, and the formula is used to calculate the ice lake volume V, where A2 represents the ice lake area; the formula Q K = 0.063·PE 0.42 is used to calculate the ice lake storage capacity and outburst flood peak discharge Q K , where PE represents the ice lake potential, i.e., the product of the ice lake volume, dam height, and lake water specific weight; and finally, the formula is used to calculate the debris flow peak discharge Q c .

6. The method according to claim 5, wherein, If there are both ice lakes and glaciers in the debris flow basin in step S21, the formula is used to calculate the debris flow flood peak flow Q c .

7. The method according to claim 6, wherein, The step S3 specifically comprises: Obtaining the relationship parameter between the debris flow and the position of the influence area based on the potential influence area of the debris flow and the position of the debris flow, including the nearest vertical distance L between the potential influence area and the debris flow ditch j , the distance L between the debris flow ditch mouth and the river h , the vertical height H between the debris flow and the influence area and the debris flow ditch j ; If L h + river width L k ≤ L, and T hi ≥ river depth H h , then the debris flow disaster mode is river blocking and damming disaster. If L j ≤ W / 2, H j < 0, and T hi - the channel depth < building height, the debris flow disaster mode is impact disaster; If L j ≤ W / 2, H j < 0, and T hi - the channel depth ≥ the building height, then the debris flow disaster mode is siltation disaster; If L j ≤ W / 2, H j ≥ 0, the debris flow disaster mode is erosion disaster; If there is an ice lake downstream of the debris flow gully, the disaster is caused by the induced ice lake outburst flood or debris flow, and the disaster-causing mode of the debris flow is chain disaster.

8. A system for identifying the development characteristics and disaster-causing modes of debris flow in a plateau tectonically active area, for use in a method for identifying the development characteristics and disaster-causing modes of debris flow in a plateau tectonically active area according to any one of claims 1-7, characterized in that, It comprises: A development characteristic parameter acquisition module is configured to acquire the development characteristic parameters of the debris flow in the plateau tectonic active area; A debris flow influence range calculation module is configured to determine the formation mechanism of the debris flow and calculate the influence range of the debris flow; A debris flow disaster-causing mode judgment module is configured to analyze the relationship between the influence range of the debris flow and the location of the potential influence area, thereby judging the disaster-causing mode of the debris flow.

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