CN114582092B - Gully debris flow early warning method based on soil moisture content - Google Patents
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Abstract
The invention discloses a gully debris flow early warning method based on soil moisture content, which belongs to the technical field of debris flow prevention engineering and is characterized by comprising the following steps of: s1, determining basic parameters of a potential debris flow basin through a Google earth or topographic map; s2, monitoring or forecasting the early rainfall and the rainfall 10 minutes before excitation of the position of the debris flow basin forming area in real time; s3, investigating the average width of a channel in a debris flow basin forming area and the particle size of particles in the debris flow basin forming area; s4, calculating a debris flow basin terrain factor T; s5, calculating a geological factor G of the debris flow basin; s6, calculating a rainfall factor R for inducing the debris flow; s7, judging the occurrence of debris flow; the method starts from a starting mechanism of the gully debris flow, directly adopts the soil moisture content as a main precondition for exciting rainfall of the debris flow, and can calculate the rainfall contribution more accurately, thereby early warning the debris flow more accurately.
Description
Technical Field
The invention relates to the technical field of debris flow prevention engineering, in particular to a gully debris flow early warning method based on soil moisture content.
Background
Debris flow is a natural disaster that occurs in mountainous areas. Water is an important condition for the formation of debris flow, and the main factors of the water source condition in rainfall type debris flow are rainfall intensity, rainfall frequency and temperature. Due to the short duration of intense rainfall, the rainfall intensity is greater than the soil infiltration capacity to form an excess seepage flow. After the super-seepage runoff converges on the slope of the hillside, the super-seepage runoff converges in the channel to form a torrent, and flood flushes and scrapes the material source in the channel to finally form a debris flow. For a bed-start valley debris flow, rainfall is a key parameter to stimulate the debris flow. The mechanism of formation of the gully-bed-started gully debris flow shows that: under the action of strong rainfall, the earth surface forms super-seepage runoff, a large amount of rainfall is collected into the debris flow channel in a runoff form to form a strong torrent, so that loose material sources in the channel are washed, and then the debris flow is lifted and uncovered to form the debris flow. When the precipitation intensity is larger than the soil permeability, the super-seepage can be formed, the soil permeability coefficient is closely related to the soil water content, and the larger the early-stage water content is, the weaker the soil permeability is, and the more easily the super-seepage is formed.
The excitation of the gully debris flow of the gully start type is related to the short-duration heavy rainfall, the rainfall of the last excitation is the key, and the average rainfall intensity, the duration of the rainfall or the total rainfall are not suitable for the early warning of the gully debris flow of the gully start type. The early-stage effective rainfall and the stimulated rainfall can well summarize rainfall conditions, wherein the stimulated rainfall is the key of debris flow early warning and is easy to understand and obtain. But the early effective rainfall is fuzzy.
Chinese patent publication No. CN105740618A, published 2016, 07, 06, discloses a rainfall segmentation method for trench-bed-start debris flow prediction, which is characterized by comprising the following processes: arranging a sensor to measure rainfall in real time, and determining whether the rainfall value of the previous 1h reaches or exceeds a rainfall critical value R0 according to the rainfall data of the area per hour: if the rainfall is smaller than the rainfall critical value R0, early rainfall is not counted, namely the early rainfall returns to 0; if the rainfall is larger than or equal to the rainfall critical value R0, the rainfall at the hour is taken as the earliest early rainfall value R1, and the rainfall at the following hours is taken as early rainfall values R2, R3, 8230 \8230; \ 8230;, rn, and the early rainfall value at the nth hour and R are obtained by overlapping the early rainfall values one by one: r = R0+ R1+ R2+ \8230; + Rn; the rainfall in this section refers to the rainfall in the last 1-hour period, namely the rainfall Rn +1 in the n + 1-hour period; after the former rainfall is finished, the later rainfall restarts to calculate the rainfall and the early rainfall; and finally, calculating a rainfall comprehensive value R x according to the early rainfall value R and the rainfall Rn +1 in the period: r = R +13.5Rn +1.
The rainfall segmentation method for predicting the gully-bed starting type debris flow disclosed by the patent document determines a calculation method of a rainfall process through rainfall intensity and rainfall interval time, and further calculates rainfall capacity in an early period, and is an indirect method, namely, influence of rainfall conditions on subsequent stimulated rainfall is assumed through rainfall segmentation; however, after the rainfall stops for 6 hours or 12 hours, the method does not consider the influence of the previous rainfall; in fact, the rainfall stops for 6 hours or 12 hours, and the soil still retains part of water, namely the former rainfall has functions and influences, so that the condition of underestimating early rainfall can occur, the report is missed, and the early warning accuracy of the debris flow is influenced.
Disclosure of Invention
The invention provides a gully debris flow early warning method based on soil moisture content, which is based on the starting mechanism of gully debris flow, fully considers the premise condition that the soil moisture content is the rainfall over-seepage flow, confluence, mountain torrents formation and debris flow starting, directly adopts the soil moisture content as a main premise condition for exciting the rainfall of the debris flow, and can calculate the contribution of rainfall more accurately, thereby early warning the debris flow more accurately.
The invention is realized by the following technical scheme:
a gully debris flow early warning method based on soil water content is characterized by comprising the following steps:
s1, determining basic parameters of a potential debris flow basin through a Google earth or topographic map, wherein the basic parameters comprise the area of a debris flow basin forming area, the shape coefficient of the debris flow basin forming area, the length of a debris flow basin forming area ditch and the longitudinal gradient of a debris flow basin forming area ditch bed;
s2, consulting hydrologic manual data to obtain annual average rainfall capacity of a debris flow basin forming area and a rainfall 10-minute variation coefficient of the debris flow basin forming area, and monitoring or forecasting early rainfall capacity and rainfall capacity 10 minutes before excitation of the position of the debris flow basin forming area in real time;
s3, investigating the average width of a channel in a debris flow basin forming area and the particle size of particles in the debris flow basin forming area on site;
s4, calculating a debris flow basin terrain factor T through the formula 1;
in the formula:
t-debris flow basin terrain factor;
f, the shape coefficient of a debris flow basin forming area;
j-longitudinal gradient of a trench bed in a debris flow basin forming area;
a-the area of a debris flow basin forming area;
w is the average width of the channels in the debris flow basin forming area;
l represents the channel length of the debris flow basin forming area;
s5, calculating a geological factor G of the debris flow basin by the following formula 2:
G＝D/D 0 formula 2
In the formula:
g is geological factor of debris flow basin;
d, the particle size of the debris flow basin forming area is the average particle size of the surface of loose solid matters in the forming area;
D 0 -the particle size of the coarse particles is 2mm;
s6, calculating a rainfall factor R for inducing the debris flow through a formula 3;
in the formula:
r-rainfall factor inducing debris flow;
r-measures of stimulated rainfall;
R 0 -annual average rainfall of the debris flow basin forming area;
C V rainfall 10 minutes in the debris flow basin forming area is changed by a coefficient;
k is a soil moisture content factor before the debris flow occurs, and is calculated by a formula 4-a formula 6;
it-rainfall 10 minutes before excitation;
if the soil is a wet area, K =3 × 10 -8 ×e 54.7Sm Formula 4
If the soil is a transition zone, K =1 × 10 -8 ×e 56.7Sm Formula 5
Soil sampleThe soil is arid region, K =8 × 10 -18 ×e 163Sm Formula 6
In the formula: sm-soil moisture content; e is radix, e =2.71828;
s7, calculating an early warning index P of the debris flow by the formula 7, and judging the occurrence of the debris flow;
in the formula:
p is the early warning index of debris flow;
r-rainfall factor inducing debris flow;
t-debris flow basin terrain factor;
g is geological factor of debris flow basin;
when P is less than 0.052, the possibility of debris flow is low;
when P is more than 0.068 and more than or equal to 0.052, the possibility of debris flow is moderate;
when P is 0.068 or more, the possibility of occurrence of debris flow is high.
The debris flow basin forming area specifically refers to a debris flow circulation passing area and an area above a debris flow accumulation fan.
And when the debris flow basin forming area is provided with a main ditch and at least one branch ditch, the maximum P value is used as a judgment index to judge the possibility of debris flow.
When the branch ditches are multiple, when several branch ditches are in the debris flow basin forming area, the branch ditch basin is the branch ditch forming area.
In the step S6, the soil moisture content Sm is obtained by actually measuring the moisture content at a depth of 20cm below the soil surface.
The basic principle of the invention is as follows:
the formation of the debris flow is initiated by the torrential flood caused by rainfall flushing loose solid matter from the debris flow formation area. If the probability of occurrence is too small, such as P < 0.052, the sand carrying capacity of the torrential flood caused by rainfall is insufficient, solid substances in the channel of the formation area are difficult to start, and the probability of occurrence is small; otherwise, the probability of occurrence is high. The reasons why the occurrence of debris flow may be too small include three aspects:
firstly, the debris flow basin terrain factor is too small: if the area of the debris flow basin forming area is too small, the catchment is too little, large-flow torrential flood cannot be formed, and solid substances are difficult to start; the longitudinal gradient of the ditch bed in the debris flow basin forming area is too small, and solid matters are difficult to start; the shape coefficient of a debris flow basin forming area is too small, so that the debris flow basin cannot converge to form a torrential flood with larger flow, and solid matters are difficult to start; the average width of the channel in the debris flow basin forming area is too large, so that the water flow of the torrential flood in the forming area is dispersed, the sand carrying capacity is reduced, and the debris flow forming condition is higher.
Secondly, the geological factor of the debris flow basin is too large, the particle size of particles in a debris flow basin forming area is too large, and solid matters are difficult to start in torrential flood.
Thirdly, the rainfall factor inducing the debris flow is too small: the water content of the soil is too small, the permeability coefficient of the soil is too large, the rainfall intensity required for generating the super-seepage runoff is too large, the rainfall intensity required for forming the rainfall runoff is large, large rainfall runoff cannot be generated, torrential flood with large flow cannot be formed, and the loose solid source of the ditch bed is difficult to start; the rainfall amount is too small 10 minutes before the excitation, the formed rainfall runoff yield is too small, the formed torrential flood flow is too small, and the loose solid source of the ditch bed is difficult to start.
The beneficial effects of the invention are mainly shown in the following aspects:
1. according to the method, starting from a starting mechanism of the gully debris flow, the water content of the soil is fully considered to be a precondition for causing rainfall over-seepage, converging, forming a torrential flood and starting the debris flow, the water content of the soil is directly adopted as a main precondition for exciting rainfall of the debris flow, and rainfall contribution can be calculated more accurately, so that the debris flow is warned more accurately.
2. The invention provides a quantitative method and an index for calculating the probability of the gully debris flow by researching the mountain torrents and the slope convergence required by the debris flow and replacing an indirect rainfall daily decay method and a rainfall segmentation method with direct soil moisture content.
3. According to the invention, by researching the influence of the probability judgment index of the debris flow on the debris flow, a debris flow probability calculation method and a critical value are provided, so that the debris flow early warning is more accurate.
4. According to the invention, the occurrence of the excess seepage runoff, confluence runoff, torrential flood and debris runoff can be judged better by calculating the soil water content and the soil water content factor before the debris runoff occurs and combining the stimulated rainfall of the debris runoff, and a fine calculation index is given, so that the early warning of the debris runoff is more accurate.
5. According to the invention, the research is carried out on the soil moisture content of the debris flow before rainfall excitation, quantitative rainfall parameters are accurately calculated, and the influence factors of the area of a debris flow basin forming area, the shape coefficient of the debris flow basin forming area, the channel length of the debris flow basin forming area, the channel bed longitudinal gradient of the debris flow basin forming area, the average width of the channel of the debris flow basin forming area, the particle size of the debris flow basin forming area, the annual average rainfall of the debris flow basin forming area, the rainfall 10-minute variation coefficient of the debris flow basin forming area and the rainfall 10 minutes before the excitation are organically combined, so that the debris flow early warning accuracy is greatly improved.
Detailed Description
Example 1
A gully debris flow early warning method based on soil moisture content comprises the following steps:
s1, determining basic parameters of a potential debris flow basin through a Google earth or topographic map, wherein the basic parameters comprise the area of a debris flow basin forming area, the shape coefficient of the debris flow basin forming area, the length of a gully of the debris flow basin forming area and the longitudinal gradient of a gully bed of the debris flow basin forming area;
s2, consulting hydrologic manual data to obtain annual average rainfall capacity of a debris flow basin forming area and a rainfall 10-minute variation coefficient of the debris flow basin forming area, and monitoring or forecasting early rainfall capacity and rainfall capacity 10 minutes before excitation of the position of the debris flow basin forming area in real time;
s3, investigating the average width of a channel in a debris flow basin forming area and the particle size of particles in the debris flow basin forming area on site;
s4, calculating a debris flow basin terrain factor T through the formula 1;
in the formula:
t-debris flow basin terrain factor;
f, the shape coefficient of a debris flow basin forming area;
j-longitudinal gradient of a gully bed in a debris flow basin forming area;
a is the area of a debris flow basin forming area;
w is the average width of the channel in the debris flow basin forming area;
l is the channel length of the debris flow basin forming area;
s5, calculating a geological factor G of the debris flow basin according to the formula 2:
G＝D/D 0 formula 2
In the formula:
g is a geological factor of the debris flow basin;
d, the particle size of the debris flow basin forming area is the average particle size of the surface of loose solid matters in the forming area;
D 0 -the particle size of the coarse particles is 2mm;
s6, calculating a rainfall factor R for inducing the debris flow through a formula 3;
in the formula:
r-rainfall factor inducing debris flow;
r-arouses the rainfall index;
R 0 -annual average rainfall of the debris flow basin forming area;
C V the coefficient of variation of rainfall in the debris flow basin forming area for 10 minutes;
k is a soil moisture content factor before the debris flow occurs, and is calculated by a formula 4-a formula 6;
it-rainfall 10 minutes before excitation;
if the soil is a wet area, K =3 × 10 -8 ×e 54.7Sm Formula 4
If the soil is a transition zone, K =1 × 10 -8 ×e 56.7Sm Formula 5
If the soil is a arid region, K =8 × 10 -18 ×e 163Sm Formula 6
In the formula: sm is soil moisture content; e is radix, e =2.71828;
s7, calculating an early warning index P of the debris flow through the formula 7, and judging the occurrence of the debris flow;
in the formula:
p is the early warning index of the debris flow;
r-rainfall factor inducing debris flow;
t-debris flow basin terrain factor;
g is a geological factor of the debris flow basin;
when P is less than 0.052, the possibility of debris flow is low;
when P is more than 0.068 and more than or equal to 0.052, the possibility of debris flow is moderate;
when P is 0.068 or more, the possibility of occurrence of debris flow is high.
From the starting mechanism of the gully debris flow, the precondition that the soil moisture content is the rainfall over-seepage flow, confluence, mountain torrents formation and debris flow starting is fully considered, the soil moisture content is directly adopted as a main precondition for exciting rainfall of the debris flow, the rainfall contribution can be calculated more accurately, and therefore the debris flow is early warned more accurately.
Example 2
A gully debris flow early warning method based on soil moisture content comprises the following steps:
s1, determining basic parameters of a potential debris flow basin through a Google earth or topographic map, wherein the basic parameters comprise the area of a debris flow basin forming area, the shape coefficient of the debris flow basin forming area, the length of a gully of the debris flow basin forming area and the longitudinal gradient of a gully bed of the debris flow basin forming area;
s2, consulting hydrologic manual data to obtain annual average rainfall capacity of a debris flow basin forming area and a rainfall 10-minute variation coefficient of the debris flow basin forming area, and monitoring or forecasting early rainfall capacity and rainfall capacity 10 minutes before excitation of the position of the debris flow basin forming area in real time;
s3, investigating the average width of a channel in a debris flow basin forming area and the particle size of particles in the debris flow basin forming area on site;
s4, calculating a debris flow basin terrain factor T through the formula 1;
in the formula:
t-debris flow basin terrain factor;
f, the shape coefficient of a debris flow basin forming area;
j-longitudinal gradient of a gully bed in a debris flow basin forming area;
a is the area of a debris flow basin forming area;
w is the average width of the channels in the debris flow basin forming area;
l represents the channel length of the debris flow basin forming area;
s5, calculating a geological factor G of the debris flow basin by the following formula 2:
G＝D/D 0 formula 2
In the formula:
g is a geological factor of the debris flow basin;
d, the particle size of the debris flow basin forming area is the average particle size of the surface of loose solid matters in the forming area;
D 0 -the particle size of the coarse particles is 2mm;
s6, calculating a rainfall factor R for inducing the debris flow through a formula 3;
in the formula:
r-rainfall factor inducing debris flow;
r-arouses the rainfall index;
R 0 -annual average rainfall of the debris flow basin forming area;
C V the coefficient of variation of rainfall in the debris flow basin forming area for 10 minutes;
k is a soil moisture content factor before the debris flow occurs, and is calculated by a formula 4-a formula 6;
it-rainfall 10 minutes before excitation;
if the soil is a wet area, K =3 × 10 -8 ×e 54.7Sm Formula 4
If the soil is a transition zone, K =1 × 10 -8 ×e 56.7Sm Formula 5
If the soil is a arid region, K =8 × 10 -18 ×e 163Sm Formula 6
In the formula: sm-soil moisture content; e is radix, e =2.71828;
s7, calculating an early warning index P of the debris flow through the formula 7, and judging the occurrence of the debris flow;
in the formula:
p is the early warning index of debris flow;
r-rainfall factor inducing debris flow;
t is a debris flow basin terrain factor;
g is a geological factor of the debris flow basin;
when P is less than 0.052, the possibility of debris flow is low;
when P is more than 0.068 and more than or equal to 0.052, the possibility of debris flow is moderate;
when P is 0.068 or more, the possibility of occurrence of debris flow is high.
The debris flow basin forming area specifically refers to a debris flow circulation passing area and an area above a debris flow accumulation fan.
And when the debris flow basin forming area is provided with a main ditch and at least one branch ditch, the maximum P value is used as a judgment index to judge the possibility of debris flow.
Through researching mountain torrents and slope convergence required by debris flow, and replacing an indirect rainfall daily attenuation method and a rainfall segmentation method with direct soil moisture content, a quantitative gully debris flow occurrence possibility calculation method and index are provided.
Example 3
A gully debris flow early warning method based on soil water content comprises the following steps:
s1, determining basic parameters of a potential debris flow basin through a Google earth or topographic map, wherein the basic parameters comprise the area of a debris flow basin forming area, the shape coefficient of the debris flow basin forming area, the length of a debris flow basin forming area ditch and the longitudinal gradient of a debris flow basin forming area ditch bed;
s2, looking up hydrologic manual data to obtain annual average rainfall capacity of a debris flow basin forming area and a rainfall 10-minute variation coefficient of the debris flow basin forming area, and monitoring or forecasting early rainfall capacity of the position of the debris flow basin forming area and rainfall capacity of 10 minutes before excitation in real time;
s3, investigating the average width of a channel in a debris flow basin forming area and the particle size of particles in the debris flow basin forming area on site;
s4, calculating a debris flow basin terrain factor T through the formula 1;
in the formula:
t-debris flow basin terrain factor;
f, the shape coefficient of a debris flow basin forming area;
j-longitudinal gradient of a gully bed in a debris flow basin forming area;
a-the area of a debris flow basin forming area;
w is the average width of the channels in the debris flow basin forming area;
l is the channel length of the debris flow basin forming area;
s5, calculating a geological factor G of the debris flow basin by the following formula 2:
G＝D/D 0 formula 2
In the formula:
g is a geological factor of the debris flow basin;
d, the particle size of the debris flow basin forming area is the average particle size of the surface of loose solid matters in the forming area;
D 0 -the particle size of the coarse particles is 2mm;
s6, calculating a rainfall factor R for inducing the debris flow through a formula 3;
in the formula:
r-rainfall factor inducing debris flow;
r-arouses the rainfall index;
R 0 -annual average rainfall in the debris flow basin forming area;
C V the coefficient of variation of rainfall in the debris flow basin forming area for 10 minutes;
k is a soil moisture content factor before the debris flow occurs, and is calculated by a formula 4-a formula 6;
it-rainfall 10 minutes before excitation;
if the soil is a wet area, K =3 × 10 -8 ×e 54.7Sm Formula 4
If the soil is a transition zone, K =1 × 10 -8 ×e 56.7Sm Formula 5
If the soil is in arid region, K =8 × 10 -18 ×e 163Sm Formula 6
In the formula: sm-soil moisture content; e is radix, e =2.71828;
s7, calculating an early warning index P of the debris flow through the formula 7, and judging the occurrence of the debris flow;
in the formula:
p is the early warning index of the debris flow;
r-rainfall factor inducing debris flow;
t-debris flow basin terrain factor;
g is geological factor of debris flow basin;
when P is less than 0.052, the possibility of debris flow is low;
when P is more than 0.068 and more than or equal to 0.052, the possibility of debris flow is moderate;
when P is more than or equal to 0.068, the possibility of debris flow is high.
The debris flow basin forming area specifically refers to a debris flow circulation passing area and an area above a debris flow accumulation fan.
And when the debris flow basin forming area is provided with a main ditch and at least one branch ditch, judging the possibility of debris flow by taking the maximum P value as a judgment index.
When the branch ditches are multiple, when a plurality of branch ditches are in the debris flow basin forming area, the branch ditch basin is the branch ditch forming area.
In the step S6, the soil moisture content Sm is obtained by actually measuring the moisture content at a depth of 20cm below the soil surface.
The influence of the probability judgment index of the debris flow on the debris flow formation is researched, and a debris flow probability calculation method and a critical value are provided, so that the debris flow early warning is more accurate.
Through the calculation of the soil moisture content and the soil moisture content factor before the debris flow occurs, the occurrence of the super-seepage runoff, the confluence runoff, the torrential flood and the debris flow can be better judged by combining the stimulated rainfall of the debris flow, the fine calculation index is given, and the early warning of the debris flow is more accurate.
The method comprises the steps of researching soil moisture content of debris flow before rainfall excitation, accurately calculating quantitative rainfall parameters, and organically combining the influence factors of the area of a debris flow basin forming area, the shape coefficient of the debris flow basin forming area, the channel length of the debris flow basin forming area, the longitudinal gradient of a channel bed of the debris flow basin forming area, the average width of a channel of the debris flow basin forming area, the particle size of a particle in the debris flow basin forming area, the annual average rainfall of the debris flow basin forming area, the rainfall 10-minute variation coefficient of the debris flow basin forming area and the rainfall 10 minutes before excitation, so that debris flow early warning accuracy is greatly improved.
The early warning method of the present invention is described in detail below with reference to specific examples.
In 2011, 5 nights to 6 nights in 6 morning, the influence of high-altitude wind shear and cold air causes short-duration strong rainfall in the middle north of the nome county and extra-large heavy rainstorm in some regions. The rainstorm center in the area gradually develops from easy town to south, and the rainfall intensity gradually decreases from south to north. The rainfall starts from 5 days and 22 nights in 6 months to end at 8-9 days, the whole duration time is short, the rainfall intensity is high, the maximum hour rainfall reaches 105.9mm, the accumulated total rainfall reaches 315mm, and the rainfall is the extra-large rainstorm which is not met by the hope county in one hundred years historically. The rainfall induces mass-produced debris flow, and 25 debris flows are produced in the total quantity from the rainfall to the new station.
The method is adopted to carry out early warning on the 25 debris flows, and the parameters of the 25 debris flows, the early warning index P of the debris flows and the actual occurrence condition of the debris flows are shown in the table 1.
TABLE 1
According to the early warning index P of the debris flow, when P is less than 0.052, the possibility of the debris flow is low; when P is more than 0.068 and more than or equal to 0.052, the possibility of debris flow is moderate; when P is more than or equal to 0.068, the possibility of debris flow is high.
In table 1, 25 actual debris flow fields occur, 22 of them are judged by the invention to have high debris flow occurrence probability, and 3 are judged by the invention to have medium debris flow occurrence probability.
Therefore, the early warning method has high accuracy in early warning of the debris flow.
Claims (5)
1. A gully debris flow early warning method based on soil water content is characterized by comprising the following steps:
s1, determining basic parameters of a potential debris flow basin through a Google earth or topographic map, wherein the basic parameters comprise the area of a debris flow basin forming area, the shape coefficient of the debris flow basin forming area, the length of a gully of the debris flow basin forming area and the longitudinal gradient of a gully bed of the debris flow basin forming area;
s2, consulting hydrologic manual data to obtain annual average rainfall capacity of a debris flow basin forming area and a rainfall 10-minute variation coefficient of the debris flow basin forming area, and monitoring or forecasting early rainfall capacity and rainfall capacity 10 minutes before excitation of the position of the debris flow basin forming area in real time;
s3, investigating the average width of a channel in a debris flow basin forming area and the particle size of particles in the debris flow basin forming area on site;
s4, calculating a debris flow basin terrain factor T through the formula 1;
In the formula:
t is a debris flow basin terrain factor;
f, the shape coefficient of a debris flow basin forming area;
j-longitudinal gradient of a gully bed in a debris flow basin forming area;
a-the area of a debris flow basin forming area;
w is the average width of the channel in the debris flow basin forming area;
l is the channel length of the debris flow basin forming area;
s5, calculating a geological factor G of the debris flow basin according to the formula 2:
G=D/D 0 formula 2
In the formula:
g is geological factor of debris flow basin;
d, the particle size of the debris flow basin forming area is the average particle size of the surface of loose solid matters in the forming area;
D 0 -the particle size of the coarse particles is 2mm;
s6, calculating a rainfall factor R for inducing the debris flow through a formula 3;
In the formula:
r-rainfall factor inducing debris flow;
r-arouses the rainfall index;
R 0 -annual average rainfall of the debris flow basin forming area;
C V rainfall 10 minutes in the debris flow basin forming area is changed by a coefficient;
k is a soil moisture content factor before the debris flow occurs, and is calculated by a formula 4-a formula 6;
it-rainfall 10 minutes before excitation;
if the soil is a wet area, K =3 × 10 -8 ×e 54.7Sm Formula 4
If the soil is a transition zone, K =1 × 10 -8 ×e 56.7Sm Formula 5
If the soil is in arid region, K =8 × 10 -18 ×e 163Sm Formula 6
In the formula: sm-soil moisture content; e is radix, e =2.71828;
s7, calculating an early warning index P of the debris flow through the formula 7, and judging the occurrence of the debris flow;
In the formula:
p is the early warning index of debris flow;
r-rainfall factor inducing debris flow;
t-debris flow basin terrain factor;
g is geological factor of debris flow basin;
when P is less than 0.052, the possibility of debris flow is low;
when P is more than 0.068 and more than or equal to 0.052, the possibility of debris flow is moderate;
when P is 0.068 or more, the possibility of occurrence of debris flow is high.
2. The gully debris flow early warning method based on soil moisture content as claimed in claim 1, wherein: the debris flow basin forming area specifically refers to a debris flow circulation passing area and an area above a debris flow accumulation fan.
3. The gully debris flow early warning method based on the water content of the soil as claimed in claim 2, wherein: and when the debris flow basin forming area is provided with a main ditch and at least one branch ditch, the maximum P value is used as a judgment index to judge the possibility of debris flow.
4. The gully debris flow early warning method based on soil moisture content as claimed in claim 3, wherein: when there are 3 branch ditches in the debris flow basin forming area, the branch ditch basin is the branch ditch forming area.
5. The gully debris flow early warning method based on soil moisture content as claimed in claim 1, wherein: in the step S6, the soil moisture content Sm is obtained by actually measuring the moisture content at a depth of 20cm below the soil surface.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102902870A (en) * | 2012-06-13 | 2013-01-30 | 中国科学院水利部成都山地灾害与环境研究所 | Debris flow forecasting method based on water and soil coupling in drainage basin |
| CN103197046A (en) * | 2013-04-04 | 2013-07-10 | 中国科学院、水利部成都山地灾害与环境研究所 | Method for measuring volume water content of debris flow critical soil body and debris flow pre-warning method |
| US20140324351A1 (en) * | 2008-11-13 | 2014-10-30 | Saint Louis University | Apparatus and method for providing environmental predictive indicators to emergency response managers |
| CN104318717A (en) * | 2014-10-21 | 2015-01-28 | 四川大学 | Rainstorm debris flow early warning method under shortage conditions of historical data |
| CN106652361A (en) * | 2017-03-16 | 2017-05-10 | 中国科学院、水利部成都山地灾害与环境研究所 | Mud-rock flow early warning method based on rainfall-probability |
| US20180045853A1 (en) * | 2016-08-15 | 2018-02-15 | U.S.A. As Represented By The Administrator Of The National Aeronautics And Space Administration | Landslide hazard assessment system and method |
| US20180252694A1 (en) * | 2015-09-14 | 2018-09-06 | Nec Corporation | Disaster prediction system, moisture prediction device, disaster prediction method, and program recording medium |
| CN109166279A (en) * | 2018-09-29 | 2019-01-08 | 成都理工大学 | A kind of mud-rock flow fining method for early warning and application based on rainfall in ten minutes |
-
2022
- 2022-01-12 CN CN202210031474.7A patent/CN114582092B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140324351A1 (en) * | 2008-11-13 | 2014-10-30 | Saint Louis University | Apparatus and method for providing environmental predictive indicators to emergency response managers |
| CN102902870A (en) * | 2012-06-13 | 2013-01-30 | 中国科学院水利部成都山地灾害与环境研究所 | Debris flow forecasting method based on water and soil coupling in drainage basin |
| CN103197046A (en) * | 2013-04-04 | 2013-07-10 | 中国科学院、水利部成都山地灾害与环境研究所 | Method for measuring volume water content of debris flow critical soil body and debris flow pre-warning method |
| CN104318717A (en) * | 2014-10-21 | 2015-01-28 | 四川大学 | Rainstorm debris flow early warning method under shortage conditions of historical data |
| US20180252694A1 (en) * | 2015-09-14 | 2018-09-06 | Nec Corporation | Disaster prediction system, moisture prediction device, disaster prediction method, and program recording medium |
| US20180045853A1 (en) * | 2016-08-15 | 2018-02-15 | U.S.A. As Represented By The Administrator Of The National Aeronautics And Space Administration | Landslide hazard assessment system and method |
| CN106652361A (en) * | 2017-03-16 | 2017-05-10 | 中国科学院、水利部成都山地灾害与环境研究所 | Mud-rock flow early warning method based on rainfall-probability |
| CN109166279A (en) * | 2018-09-29 | 2019-01-08 | 成都理工大学 | A kind of mud-rock flow fining method for early warning and application based on rainfall in ten minutes |
Non-Patent Citations (3)
| Title |
|---|
| 三明市后山冲沟泥石流易发性评价及预报;赵宾杰 等;《科学技术与工程》;20210518;第21卷(第14期);第5719-5726页 * |
| 沟床起动型泥石流的10 min 降雨预报模型;余斌 等;《水科学进展》;20150530;第26卷(第3期);第347-355页 * |
| 粘性泥石流体阵性流形成机理研究;王裕宜 等;《自然灾害学报》;20020530;第11卷(第2期);第46-50页 * |
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