CN114596689B - Shallow landslide type gully debris flow early warning method - Google Patents
Shallow landslide type gully debris flow early warning method Download PDFInfo
- Publication number
- CN114596689B CN114596689B CN202210032425.5A CN202210032425A CN114596689B CN 114596689 B CN114596689 B CN 114596689B CN 202210032425 A CN202210032425 A CN 202210032425A CN 114596689 B CN114596689 B CN 114596689B
- Authority
- CN
- China
- Prior art keywords
- soil
- debris flow
- rainfall
- area
- value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
- G08B21/02—Alarms for ensuring the safety of persons
- G08B21/10—Alarms for ensuring the safety of persons responsive to calamitous events, e.g. tornados or earthquakes
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/11—Complex mathematical operations for solving equations, e.g. nonlinear equations, general mathematical optimization problems
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/10—Numerical modelling
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Mathematical Physics (AREA)
- Data Mining & Analysis (AREA)
- Pure & Applied Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Operations Research (AREA)
- Life Sciences & Earth Sciences (AREA)
- Evolutionary Computation (AREA)
- Algebra (AREA)
- Computer Hardware Design (AREA)
- Databases & Information Systems (AREA)
- Software Systems (AREA)
- Geometry (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Pit Excavations, Shoring, Fill Or Stabilisation Of Slopes (AREA)
Abstract
The invention discloses a shallow landslide type gully debris flow early warning method, which belongs to the technical field of debris flow prevention engineering and is characterized by comprising the following steps of: a. measuring the total flow area A of the debris flow without the accumulation area; b. measuring percentage S of sensitive gradient area in total flow area of debris flow without accumulation area 0 Determining a debris flow terrain factor T according to the longitudinal gradient J of the gully bed; c. determining annual average rainfall R of debris flow channel in monitoring area 0 Rainfall variation coefficient C of debris flow channel in 1 hour v Measuring the excited rainfall It for 1 hour, determining the parent rock type of the soil, calculating a soil moisture content factor K, and determining a debris flow rainfall factor R; d. calculating an occurrence index P of the debris flow; e. and judging the occurrence of debris flow. The measuring and calculating result of the invention is more in line with the debris flow forming mechanism, the debris flow early warning accuracy is improved, and the invention has higher disaster prevention applicability.
Description
Technical Field
The invention relates to the technical field of debris flow prevention engineering, in particular to a shallow landslide type gully debris flow early warning method.
Background
The shallow surface soil landslide is one of geological disasters with the most extensive distribution, high outbreak frequency and great harmfulness in landslides. The shallow surface soil landslide is a type of landslide occurring on a loose unconsolidated cohesive soil or sandy soil slope, and has the characteristics of large void ratio, strong water permeability and obvious rock stratification of the lower layer due to loose slope body structure. The material composition is generally a matrix weathering product, and the stacking thickness is usually less than 5 meters. The slope is easy to be periodically influenced by atmospheric falling water and reservoir water level due to loose sliding bodies, and is poor in stability. When the landslide is subjected to sufficient water source and sufficient sliding surface in the gliding process, the landslide is likely to be converted into debris flow.
At present, the forecasting and forecasting of the debris flow at home and abroad are mainly established on the basis of years of observation and accumulation, and the empirical critical rainfall value is given, for example, the forecasting and forecasting of the debris flow of the Yun Najiang family ditch is established on the basis of 30 years of long-term observation. Particularly for the shallow surface soil landslide type gully debris flow, the critical rainfall for debris flow starting is mainly obtained by a method based on statistics, induction and summary of historical observation data. However, for low-frequency debris flow, no observation data is accumulated, so that an empirical method for obtaining a critical rainfall value on the basis of obtaining observation data cannot be obtained, and the occurrence of debris flow is predicted. The prevention of such low-frequency debris flow disasters requires deep understanding of the occurrence law of debris flow and prediction of the occurrence of debris flow.
Water is an important condition for forming the debris flow, and main factors of water source conditions in the rainfall type debris flow are rainfall intensity, rainfall frequency and temperature. To shallow landslide type gully debris flow, there are two aspects to the effect of rainfall: firstly, rainfall infiltration causes shallow landslide and moves into a channel to form a debris flow source; and secondly, rainfall runoff is formed, runoff is converged into mountain torrents, and solid matters in the channel are started to form debris flow. Under the condition of heavy rainfall, the rainfall intensity is greater than the soil permeability to form super-seepage runoff. After the super-seepage flow converges on the slope of the hillside, the super-seepage flow converges in the channel to form a torrential flood, and the flood washes and scrapes the source in the channel to finally form a debris flow. Rainfall is therefore a key parameter for stimulating 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.
In the current debris flow early warning model, rainfall factors mainly consider that:
1. effective rainfall and stimulated rainfall in the early stage;
2. average rainfall intensity and duration of rainfall;
3. the total rainfall.
The excitation of shallow landslide type valley debris flow is related to the finally formed torrential flood, so that the excitation related to heavy rainfall, the average rainfall intensity and the duration of rainfall, or the total rainfall, are not suitable for the early warning of the valley debris flow. 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, represents the final larger rainfall intensity, and is easier to understand and obtain. However, the early effective rainfall is fuzzy, and a plurality of calculation methods are available. One method is a daily rainfall attenuation method: the rainfall attenuation of the first 1 day is determined according to the rainfall multiplied by the attenuation coefficient, and the rainfall attenuation of the first 2 days is determined according to the rainfall multiplied by the attenuation coefficient to the power of 2. By analogy, the rainfall in the first 20 days can be obtained by the method as the early rainfall. The attenuation coefficient value is 0.8-0.9, and is determined according to the characteristics of the research area. The method is overall reliable, simple and practical, but in practical application, the possibility of exaggerating early rainfall may occur, such as: when heavy rainfall occurs in the first 3-5 days and then stops for 2 days, and the heavy rainfall occurs again, the calculated early rainfall value is large, but the actual rainfall stops for 2 days, and the previous rainfall is basically not affected, so that the early rainfall is exaggerated, and false alarm is caused.
The Chinese patent document with publication number CN106157541A and publication date 2016, 11 and 23 discloses a gully debris flow early warning method, which is characterized by comprising the following steps: measuring the specific surface area value ai of the secondary clay minerals of minerals, the content bi of the mineral components in primary minerals, calculating the total specific surface area value N of the lithologic secondary clay minerals, a clay index N, a rock firmness coefficient F, a permeability index K, a geological factor G, a watershed area A0, a full watershed area A, a full watershed area percentage S and a longitudinal specific gradient J of a trench bed, a terrain factor T, a trench annual average rainfall R0 and a 1-hour rainfall variation coefficient Cv are determined, an early rainfall B is measured, a 1-hour stimulated rainfall I is measured, a debris flow hydrological factor R is calculated, a critical value Cr is calculated, and early warning levels are classified.
The gully debris flow early warning method disclosed in the patent document needs early rainfall as a part of rainfall factors, and the definition of early rainfall is not easy to accurately express the effect of rainfall in shallow landslide and later stage torrential flood formation and finally occurring debris flow, so that the accuracy of debris flow early warning is reduced, and the disaster prevention applicability is poor.
Disclosure of Invention
The invention provides a shallow-layer landslide type gully debris flow early warning method for overcoming the defects of the prior art, the method simultaneously considers the effects and mutual influences of two factors of terrain and hydrology which cause debris flow, and introduces geological factors when judging the critical value, so that the measurement and calculation result is more in line with the debris flow forming mechanism, and the debris flow early warning accuracy is improved; and a large amount of historical observation data of the debris flow are not needed, and only the topographic factors, geological features and rainfall observation data of the debris flow basin are needed to be determined, so that the early warning efficiency is higher, and the disaster prevention applicability is higher.
The invention is realized by the following technical scheme:
a shallow landslide type gully debris flow early warning method is characterized by comprising the following steps:
a. measuring the total flow area A of debris flow without an accumulation area through a high-precision topographic map;
b. measuring percentage S of sensitive gradient area in debris flow full-flow area without accumulation area through high-precision topographic map 0 And a longitudinal gradient J of the gully bed, and determining a debris flow terrain factor T according to the formula 1;
T＝S 0 J 0.3 (A/A 0 ) 0.2 formula 1
Wherein T is a debris flow topographic factor; s 0 The sensitive gradient area accounts for the percentage of the area of the debris flow full flow area without the accumulation area; j is the longitudinal gradient of the furrow bed; a is the total flow area of the debris flow without the accumulation area, km 2 ；A 0 Is unit area, 1km 2 ；
c. Looking up hydrologic manual to determine annual average rainfall R of debris flow channel in monitoring area 0 Rainfall variation coefficient C of debris flow channel in 1 hour v Measuring the excited rainfall It for 1 hour on site, determining the parent rock type of the soil, calculating a soil moisture factor K, and determining a debris flow rainfall factor R according to a formula 2;
wherein R is a debris flow rainfall factor; r is an index for stimulating rainfall, mm; r 0 The annual average rainfall of the debris flow channel is mm; c v A rainfall variation coefficient of the debris flow channel for 1 hour; k is a soil water content factor, mm; it is 1 hour triggered rainfall, mm；
d. Calculating an occurrence index P of the debris flow according to the formula 3;
P＝RT 0.45 formula 3
Wherein P is the occurrence index of the debris flow; r is a debris flow rainfall factor; t is a debris flow topographic factor;
e. judging the occurrence of debris flow according to the type of the parent rock of the soil:
when P is less than Cr1, the possibility of debris flow is low;
when Cr2 is more than P and is more than or equal to Cr1, the possibility of debris flow is moderate;
when Cr3 is more than P and is more than or equal to Cr2, the possibility of debris flow is high;
when P is more than or equal to Cr3, the possibility of debris flow is high;
when the parent rock type of the soil is granite, the value of Cr1 is 0.39; when the parent rock type of the soil is sandstone shale, the value of Cr1 is 0.40; when the parent rock type of the soil is the orthobaric rock, the value of Cr1 is 0.40; when the parent rock type of the soil is gabbro, the value of Cr1 is 0.40; when the parent rock type of the soil is sandstone, the value of Cr1 is 0.48; when the parent rock type of the soil is limestone, the value of Cr1 is 0.27;
when the parent rock type of the soil is granite, the value of Cr2 is 0.46; when the parent rock type of the soil is sandstone and shale, the value of Cr2 is 0.48; when the parent rock type of the soil is the orthobaric rock, the value of Cr2 is 0.47; when the parent rock type of the soil is gabbro, the value of Cr2 is 0.47; when the parent rock type of the soil is sandstone, the value of Cr2 is 0.56; when the parent rock type of the soil is limestone, the value of Cr2 is 0.31;
when the parent rock type of the soil is granite, the value of Cr3 is 0.53; when the parent rock type of the soil is sandstone and shale, the value of Cr3 is 0.55; when the parent rock type of the soil is the orthobaric rock, the value of Cr3 is 0.54; when the parent rock type of the soil is gabbro, the value of Cr3 is 0.54; when the parent rock type of the soil is sandstone, the value of Cr3 is 0.65; when the parent rock type of the soil is limestone, the value of Cr3 is 0.37.
In the step b, the sensitive gradient means that the gradient is 25-45 degrees.
In the step c, the soil moisture content factor K is obtained through calculation, and when the soil is in a wet area, the calculation is carried out according to the formula 4; when the soil is in the transition region, calculating according to the formula 5; when the soil is in a drought region, calculating according to the formula 6;
K＝3×10- 8 ×e 54.7S m formula 4
K＝1×10- 8 ×e 56.7S m formula 5
K＝8×10- 18 ×e 163S m formula 6
Wherein Sm is the soil moisture content, and when the soil is a wet area, the soil moisture content Sm is calculated by a formula 7; when the soil is in the transition area, the soil moisture content Sm is calculated by the formula 8; when the soil is in a drought area, the soil moisture content Sm is calculated by the formula 9; e is radix, e =2.71828;
sm = alpha (0.0168 ln (Mi) + 0.3452) formula 7
Sm =0.0168ln (Mi) +0.3452 formula 8
Sm = beta (0.0058 ln (Mi) + 0.2475) formula 9
Wherein Sm is the soil moisture content, alpha is the correction coefficient of a wetting area, 1 is taken when the daily rainfall is larger than 1mm, and 1.15 is taken when the daily rainfall is smaller than or equal to 1 mm; beta is a drought region coefficient, 1 is taken when the daily rainfall is more than 1mm, and 0.8 is taken when the daily rainfall is less than or equal to 1 mm; mi is the wetting index, calculated from equation 10;
mi = B/pe type 10
Wherein Mi is the wetting index; b is daily precipitation, mm/d; pe is the maximum latent heat evaporation, mm/d, calculated from equation 11-equation 14;
a＝0.492+1.792×10 -2 I-7.71×10 -3 I 2 +6.75×10 -7 I 3 formula 12
Wherein pe is maximum latent heat evaporation, mm/d; ta is the daily average temperature, DEG C; h is the average annual daylight length, and I is the monthly total heating index; a is an index; tm is the monthly average temperature, DEG C; i is a coefficient.
The soil is a wet area and is R 0 Not less than 1.38S-1068; the soil is a transition area which means that 1.38S-1068 is more than R 0 Not less than 1.38S-1965; the soil is arid region and refers to R 0 < 1.38S-1965; wherein R is 0 The annual average rainfall of the debris flow channel is mm; s is the average sunshine hours of many years, h.
The debris flow terrain factor T is the sum of a plurality of factors related to terrain conditions, which are beneficial to the formation of shallow landslide type gully debris flow.
The debris flow rainfall factor R is the sum of a plurality of factors related to hydrological conditions, which are beneficial to the formation of shallow landslide type valley debris flow.
The principle of the invention is as follows:
the formation of the debris flow is determined by the topographic condition, the geological condition and the precipitation condition of the debris flow, and the debris flow is formed under the combined action of the three conditions. The invention fully considers the comprehensive effects of the three conditions, unifies the effects of the terrain condition and the precipitation condition to form a judgment model, and combines the critical value determined by the geological condition to realize the organic combination of the three conditions. Through a large amount of field investigation and research, the function relation between debris flow starting critical values Cr1, cr2 and Cr3 and debris flow terrain factors T and debris flow rainfall factors R in the early warning monitoring area is analyzed and determined for a set debris flow channel on the basis of determining the debris flow range.
The technical principle of judging the probability of debris flow occurrence through the threshold values of the debris flow starting critical values Cr1, cr2 and Cr3 is as follows: through field investigation of large-scale mass-produced debris flow events, determining that almost no debris flow occurs when P is less than Cr1 according to terrain and rainfall conditions of storm debris flow basins and non-storm debris flow basins and calculated judgment values; p is more than or equal to Cr1 and less than Cr2, and a small amount of debris flow occurs; p is more than or equal to Cr2 and less than Cr3, and more debris flow occurs; p is more than or equal to Cr3, and a plurality of debris flows are exposed.
The beneficial effects of the invention are mainly shown in the following aspects:
1. the method comprises the following steps that (a) the full-watershed area A of debris flow without an accumulation area is measured through a high-precision topographic map; b. measuring the percentage S of sensitive gradient area to the total flow area of debris flow without accumulation area through high-precision topographic map 0 And a longitudinal gradient J of the gully bed, and determining a debris flow terrain factor T according to the formula 1; c. looking up hydrologic manual to determine annual average rainfall R of debris flow channel in monitoring area 0 1-hour rainfall variation coefficient C of debris flow channel v Measuring the excited rainfall It for 1 hour on site, determining the parent rock type of the soil, calculating a soil moisture factor K, and determining a debris flow rainfall factor R according to a formula 2; d. calculating an occurrence index P of the debris flow according to the formula 3; e. the method comprises the steps of judging the occurrence of the debris flow according to the type of the parent rock of the soil, and as a complete technical scheme, considering the effects and mutual influences of two factors of terrain and hydrology which cause the debris flow at the same time compared with the prior art, and introducing geological factors when judging a critical value, so that a measuring and calculating result is more in line with the debris flow formation mechanism, and the debris flow early warning accuracy is improved; and a large amount of historical observation data of debris flow occurrence are not needed, and only the topographic factor, geological features and rainfall observation data of a debris flow basin need to be determined, so that the early warning efficiency is higher, and the disaster prevention applicability is higher.
2. According to the invention, the functions of two factors of terrain and hydrology which cause debris flow are considered simultaneously for measuring and calculating the critical rainfall and the geological related threshold value for debris flow starting, for a given debris flow channel, a large amount of historical observation data of debris flow generation are not needed for measuring and calculating the rainfall threshold value for debris flow starting, and as most of the debris flow channels have no long-term observation data of debris flow generation except a debris flow observation station set by scientific research, the method has higher disaster prevention applicability for debris flow forecast of the given debris flow channel.
3. The method can be used for early warning of low-frequency shallow surface soil landslide type gully debris flow in data-free areas, and is beneficial to improving the disaster prevention effect.
4. According to the method, the direct soil moisture content is used for replacing indirect early rainfall influence, a quantitative calculation method and indexes of the probability of occurrence of the shallow-layer landslide type gully debris flow are provided, and the early warning accuracy is greatly improved.
5. According to the invention, the rainfall and the evaporation in the soil wetting area, the drought area and the transition area are greatly different, so that the water content of the soil is greatly influenced, the three areas are separately calculated, the calculated water content of the soil is more accurate, and the early warning accuracy can be further ensured.
6. According to the method, the daily rainfall is taken as a basis, and all parameters of the sunshine duration, the daily temperature, the monthly average temperature and the heating index influencing the soil moisture content are fully considered, so that the calculated soil moisture content can be ensured to be more accurate.
7. According to the invention, the water content of the soil is calculated by taking the rainfall and the temperature of 24h as calculation basis, but the method is superior to the rainfall and the temperature of 24h in the general sense: 24h rainfall and temperature in the general sense, refers to a specific period of time, such as 8 days first to 8 days second; or rainfall and temperature from day 20 to day 20; the rainfall and temperature of 24 hours before the early warning is the rainfall and temperature of 24 hours before the early warning, namely, the rainfall and temperature are gradually updated and changed along with the time advance of each hour, and the rainfall and temperature are updated every hour, so that the rainfall and temperature data are updated every hour, and the data during the early warning are more accurate; the condition that rainfall and temperature data in a specific time period cannot reflect the actual condition of the early warning moment or early warning is carried out at a specific time, such as 8 hours or 20 hours of the second day, so that early warning delay is avoided.
Detailed Description
Example 1
A shallow landslide type gully debris flow early warning method comprises the following steps:
a. measuring the total flow area A of debris flow without an accumulation area through a high-precision topographic map;
b. measuring percentage S of sensitive gradient area in debris flow full-flow area without accumulation area through high-precision topographic map 0 And a longitudinal gradient J of the gully bed, and determining a debris flow terrain factor T according to the formula 1;
T＝S 0 J 0.3 (A/A 0 ) 0.2 formula 1
Wherein T is a debris flow topographic factor; s. the 0 The sensitive gradient area accounts for the percentage of the area of the debris flow full flow area without the accumulation area; j is the longitudinal gradient of the furrow bed; a is the total flow area of the debris flow without the accumulation area, km 2 ；A 0 Is unit area, 1km 2 ；
c. Looking up hydrological manual to determine annual average rainfall R of debris flow channel in monitoring area 0 Rainfall variation coefficient C of debris flow channel in 1 hour v Measuring the excited rainfall I t on site for 1 hour, determining the type of the mother rock of the soil, calculating a soil water content factor K, and determining a debris flow rainfall factor R according to a formula 2;
wherein R is a debris flow rainfall factor; r is an index of stimulated rainfall, mm; r 0 The annual average rainfall of the debris flow channel is mm; c v A rainfall variation coefficient of the debris flow channel for 1 hour; k is a soil water content factor, mm; it is 1 hour triggered rainfall, mm;
d. calculating an occurrence index P of the debris flow according to the formula 3;
P＝RT 0.45 formula 3
Wherein P is the occurrence index of the debris flow; r is a debris flow rainfall factor; t is a debris flow topographic factor;
e. judging the occurrence of debris flow according to the type of the parent rock of the soil:
when P is less than Cr1, the possibility of debris flow is low;
when Cr2 is more than P and is more than or equal to Cr1, the possibility of debris flow is moderate;
when Cr3 is more than P and is more than or equal to Cr2, the possibility of debris flow is high;
when P is more than or equal to Cr3, the possibility of debris flow is high;
when the parent rock type of the soil is granite, the value of Cr1 is 0.39; when the parent rock type of the soil is sandstone and shale, the value of Cr1 is 0.40; when the parent rock type of the soil is the orthobaric rock, the value of Cr1 is 0.40; when the parent rock type of the soil is gabbro, the value of Cr1 is 0.40; when the parent rock type of the soil is sandstone, the value of Cr1 is 0.48; when the parent rock type of the soil is limestone, the value of Cr1 is 0.27;
when the parent rock type of the soil is granite, the value of Cr2 is 0.46; when the parent rock type of the soil is sandstone and shale, the value of Cr2 is 0.48; when the parent rock type of the soil is the orthobaric rock, the value of Cr2 is 0.47; when the parent rock type of the soil is gabbro, the value of Cr2 is 0.47; when the parent rock type of the soil is sandstone, the value of Cr2 is 0.56; when the parent rock type of the soil is limestone, the value of Cr2 is 0.31;
when the type of the parent rock of the soil is granite, the value of Cr3 is 0.53; when the parent rock type of the soil is sandstone and shale, the value of Cr3 is 0.55; when the parent rock type of the soil is the orthobaric rock, the value of Cr3 is 0.54; when the parent rock type of the soil is gabbro, the value of Cr3 is 0.54; when the parent rock type of the soil is sandstone, the value of Cr3 is 0.65; when the parent rock type of the soil is limestone, the value of Cr3 is 0.37.
The embodiment is the most basic implementation mode, simultaneously considers the functions and mutual influences of two factors of topography and hydrology causing the debris flow, and introduces geological factors when judging the critical value, so that the measuring and calculating result is more consistent with the debris flow forming mechanism, and the debris flow early warning accuracy is improved; and a large amount of historical observation data of the debris flow are not needed, and only the topographic factors, geological features and rainfall observation data of the debris flow basin are needed to be determined, so that the early warning efficiency is higher, and the disaster prevention applicability is higher.
Example 2
A shallow landslide type gully debris flow early warning method comprises the following steps:
a. measuring the total flow area A of debris flow without an accumulation area through a high-precision topographic map;
b. measuring percentage S of sensitive gradient area in debris flow full-flow area without accumulation area through high-precision topographic map 0 And a longitudinal gradient J of the gully bed, and determining a debris flow terrain factor T according to the formula 1;
T＝S 0 J 0.3 (A/A 0 ) 0.2 formula 1
Wherein T is a debris flow topographic factor; s. the 0 The sensitive gradient area accounts for the percentage of the total flow area of the debris flow without the accumulation area; j is the longitudinal gradient of the furrow bed; a is the total flow area of the debris flow without the accumulation area, km 2 ；A 0 Is unit area, 1km 2 ；
c. Looking up hydrologic manual to determine annual average rainfall R of debris flow channel in monitoring area 0 1-hour rainfall variation coefficient C of debris flow channel v Measuring the excited rainfall It for 1 hour on site, determining the parent rock type of the soil, calculating a soil moisture factor K, and determining a debris flow rainfall factor R according to a formula 2;
wherein R is a debris flow rainfall factor; r is an index of stimulated rainfall, mm; r 0 The annual average rainfall of the debris flow channel is mm; c v A rainfall variation coefficient of the debris flow channel for 1 hour; k is a soil water content factor, mm; it is 1 hour triggered rainfall, mm;
d. calculating an occurrence index P of the debris flow according to the formula 3;
P＝RT 0.45 formula 3
Wherein P is the occurrence index of the debris flow; r is a debris flow rainfall factor; t is a debris flow topographic factor;
e. judging the occurrence of debris flow according to the type of the parent rock of the soil:
when P is less than Cr1, the possibility of debris flow is low;
when Cr2 is more than P and is more than or equal to Cr1, the possibility of debris flow is moderate;
when Cr3 is more than P and is more than or equal to Cr2, the possibility of debris flow is high;
when P is more than or equal to Cr3, the possibility of debris flow is high;
when the type of the parent rock of the soil is granite, the value of Cr1 is 0.39; when the parent rock type of the soil is sandstone shale, the value of Cr1 is 0.40; when the parent rock type of the soil is the orthobaric rock, the value of Cr1 is 0.40; when the parent rock type of the soil is gabbro, the value of Cr1 is 0.40; when the parent rock type of the soil is sandstone, the value of Cr1 is 0.48; when the parent rock type of the soil is limestone, the value of Cr1 is 0.27;
when the parent rock type of the soil is granite, the value of Cr2 is 0.46; when the parent rock type of the soil is sandstone and shale, the value of Cr2 is 0.48; when the parent rock type of the soil is the orthobaric rock, the value of Cr2 is 0.47; when the parent rock type of the soil is gabbro, the value of Cr2 is 0.47; when the parent rock type of the soil is sandstone, the value of Cr2 is 0.56; when the parent rock type of the soil is limestone, the value of Cr2 is 0.31;
when the parent rock type of the soil is granite, the value of Cr3 is 0.53; when the parent rock type of the soil is sandstone and shale, the value of Cr3 is 0.55; when the parent rock type of the soil is the orthobaric rock, the value of Cr3 is 0.54; when the parent rock type of the soil is gabbro, the value of Cr3 is 0.54; when the parent rock type of the soil is sandstone, the value of Cr3 is 0.65; when the parent rock type of the soil is limestone, the value of Cr3 is 0.37.
In the step b, the sensitive gradient means that the gradient is 25-45 degrees.
In the step c, the soil moisture content factor K is obtained through calculation, and when the soil is in a wet area, the calculation is carried out according to the formula 4; when the soil is in a transition region, calculating according to the formula 5; when the soil is in a drought region, calculating according to the formula 6;
K＝3×10 -8 ×e 54.7Sm formula 4
K＝1×10 -8 ×e 56.7Sm Formula 5
K＝8×10 -18 ×e 163Sm Formula 6
Wherein Sm is the soil moisture content, and when the soil is a wet area, the soil moisture content Sm is calculated by a formula 7; when the soil is in the transition area, the soil moisture content Sm is calculated by the formula 8; when the soil is in a drought area, the soil moisture content Sm is calculated by the formula 9; e is radix, e =2.71828;
sm = alpha (0.0168 ln (Mi) + 0.3452) formula 7
Sm =0.0168ln (Mi) +0.3452 formula 8
Sm = beta (0.0058 ln (Mi) + 0.2475) formula 9
Wherein Sm is the soil moisture content, alpha is the correction coefficient of a wetting area, 1 is taken when the daily rainfall is larger than 1mm, and 1.15 is taken when the daily rainfall is smaller than or equal to 1 mm; beta is a drought region coefficient, 1 is taken when the daily rainfall is more than 1mm, and 0.8 is taken when the daily rainfall is less than or equal to 1 mm; mi is the wetting index, calculated from equation 10;
mi = B/pe type 10
Wherein Mi is the wetting index; b is daily precipitation, mm/d; pe is the maximum latent heat evaporation, mm/d, calculated from equation 11-equation 14;
a＝(1.492+1.792×10 -2 I-7.71×10 -3 I 2 +6.75×10 -7 I 3 formula 12
Wherein pe is maximum latent heat evaporation, mm/d; ta is the daily average temperature, DEG C; h is the average annual daylight length, and I is the monthly total heating index; a is an index; tm is the monthly average temperature, DEG C; i is a coefficient.
The embodiment is a better implementation mode, the effect of two factors of terrain and hydrology causing debris flow is considered simultaneously for measuring and calculating the critical rainfall and the geological related threshold value of debris flow starting, for a given debris flow channel, a large amount of historical observation data of debris flow occurrence are not needed for measuring and calculating the rainfall threshold value of debris flow starting, and except for a debris flow observation station set by scientific research, most of the debris flow channels have no long-term observation data of debris flow occurrence, so that the method has higher disaster prevention applicability for debris flow forecast of the given debris flow channel.
Example 3
A shallow landslide type gully debris flow early warning method comprises the following steps:
a. measuring the total flow area A of debris flow without an accumulation area through a high-precision topographic map;
b. measuring percentage S of sensitive gradient area in debris flow full-flow area without accumulation area through high-precision topographic map 0 And a longitudinal gradient J of the gully bed, and determining a debris flow terrain factor T according to the formula 1;
T＝S 0 J 0.3 (A/A 0 ) 0.2 formula 1
Wherein T is a debris flow topographic factor; s 0 The sensitive gradient area accounts for the percentage of the total flow area of the debris flow without the accumulation area; j is the longitudinal gradient of the furrow bed; a is the total flow area of debris flow without accumulation area, km 2 ；A 0 Is unit area, 1km 2 ；
c. Looking up hydrologic manual to determine annual average rainfall R of debris flow channel in monitoring area 0 Rainfall variation coefficient C of debris flow channel in 1 hour v Measuring the excited rainfall It for 1 hour on site, determining the parent rock type of the soil, calculating a soil moisture factor K, and determining a debris flow rainfall factor R according to a formula 2;
wherein R is a debris flow rainfall factor; r is an index of stimulated rainfall, mm; r is 0 The annual average rainfall of the debris flow channel is mm; c v A rainfall variation coefficient of the debris flow channel for 1 hour; k is a soil water content factor, mm; it is 1 hour excitation rainfall, mm;
d. calculating an occurrence index P of the debris flow according to the formula 3;
P＝RT 0.45 formula 3
Wherein P is the occurrence index of the debris flow; r is a debris flow rainfall factor; t is a debris flow topographic factor;
e. judging the occurrence of debris flow according to the type of the parent rock of the soil:
when P is less than Cr1, the possibility of debris flow is low;
when Cr2 is more than P and is more than or equal to Cr1, the possibility of debris flow is moderate;
when Cr3 is more than P and is more than or equal to Cr2, the possibility of debris flow is high;
when P is more than or equal to Cr3, the possibility of debris flow is high;
when the parent rock type of the soil is granite, the value of Cr1 is 0.39; when the parent rock type of the soil is sandstone and shale, the value of Cr1 is 0.40; when the parent rock type of the soil is the orthobaric rock, the value of Cr1 is 0.40; when the parent rock type of the soil is gabbro, the value of Cr1 is 0.40; when the parent rock type of the soil is sandstone, the value of Cr1 is 0.48; when the parent rock type of the soil is limestone, the value of Cr1 is 0.27;
when the parent rock type of the soil is granite, the value of Cr2 is 0.46; when the parent rock type of the soil is sandstone and shale, the value of Cr2 is 0.48; when the parent rock type of the soil is the orthobaric rock, the value of Cr2 is 0.47; when the parent rock type of the soil is gabbro, the value of Cr2 is 0.47; when the parent rock type of the soil is sandstone, the value of Cr2 is 0.56; when the parent rock type of the soil is limestone, the value of Cr2 is 0.31;
when the parent rock type of the soil is granite, the value of Cr3 is 0.53; when the parent rock type of the soil is sandstone and shale, the value of Cr3 is 0.55; when the parent rock type of the soil is the orthobaric rock, the value of Cr3 is 0.54; when the parent rock type of the soil is gabbro, the value of Cr3 is 0.54; when the parent rock type of the soil is sandstone, the value of Cr3 is 0.65; when the parent rock type of the soil is limestone, the value of Cr3 is 0.37.
In the step b, the sensitive gradient refers to the gradient of 25-45 degrees.
In the step c, the soil moisture content factor K is obtained through calculation, and when the soil is in a wet area, the calculation is carried out according to the formula 4; when the soil is in a transition region, calculating according to the formula 5; when the soil is in a drought region, calculating according to the formula 6;
K＝3×10 -8 ×e 54.7Sm formula 4
K＝1×10 -8 ×e 56.7Sm Formula 5
K＝8×10 -18 ×e 163Sm Formula 6
Wherein Sm is the soil moisture content, and when the soil is a wet area, the soil moisture content Sm is calculated by a formula 7; when the soil is in the transition area, the soil moisture content Sm is calculated by the formula 8; when the soil is in a drought area, the soil moisture content Sm is calculated by the formula 9; e is radix, e =2.71828;
sm = alpha (0.0168 ln (Mi) + 0.3452) formula 7
Sm =0.0168ln (Mi) +0.3452 formula 8
Sm = beta (0.0058 ln (Mi) + 0.2475) formula 9
Wherein Sm is the soil moisture content, alpha is the correction coefficient of a wetting area, 1 is taken when the daily rainfall is larger than 1mm, and 1.15 is taken when the daily rainfall is smaller than or equal to 1 mm; beta is a drought region coefficient, 1 is taken when the daily rainfall is more than 1mm, and 0.8 is taken when the daily rainfall is less than or equal to 1 mm; mi is the wetting index, calculated from equation 10;
mi = B/pe type 10
Wherein Mi is the wetting index; b is daily precipitation, mm/d; pe is the maximum latent heat evaporation, mm/d, calculated from equation 11-equation 14;
a＝0.492+1.792×10 -2 I-7.71×10 -5 I 2 +6.75×10 -7 I 3 formula 12
Wherein pe is maximum latent heat evaporation, mm/d; ta is the daily average temperature, DEG C; h is the average annual daylight length, and I is the monthly total heating index; a is an index; tm is the monthly average temperature, DEG C; i is a coefficient.
This embodiment is another preferred embodiment, and can be used for early warning of low-frequency shallow-surface soil landslide type gully debris flow in non-data areas, which is beneficial to improving disaster prevention effect.
Example 4
A shallow landslide type gully debris flow early warning method comprises the following steps:
a. measuring the total flow area A of debris flow without an accumulation area through a high-precision topographic map;
b. measuring percentage S of sensitive gradient area in debris flow full-flow area without accumulation area through high-precision topographic map 0 And a longitudinal gradient J of the gully bed, and determining a debris flow terrain factor T according to the formula 1;
T＝S 0 J 0.3 (A/A 0 ) 0.2 formula 1
Wherein T is a debris flow topographic factor; s. the 0 The sensitive gradient area accounts for the percentage of the total flow area of the debris flow without the accumulation area; j is the longitudinal gradient of the furrow bed; a is the total flow area of debris flow without accumulation area, km 2 ；A 0 Is unit area, 1km 2 ；
c. Looking up hydrologic manual to determine annual average rainfall R of debris flow channel in monitoring area 0 1 hour from debris flow channelCoefficient of rain variation C v Measuring the excited rainfall It for 1 hour on site, determining the parent rock type of the soil, calculating a soil moisture factor K, and determining a debris flow rainfall factor R according to a formula 2;
wherein R is a debris flow rainfall factor; r is an index for stimulating rainfall, mm; r 0 The annual average rainfall of the debris flow channel is mm; c v A rainfall variation coefficient of the debris flow channel for 1 hour; k is a soil water content factor, mm; it is 1 hour excitation rainfall, mm;
d. calculating an occurrence index P of the debris flow according to the formula 3;
P＝RT 0.45 formula 3
Wherein P is the occurrence index of the debris flow; r is a debris flow rainfall factor; t is a debris flow topographic factor;
e. judging the occurrence of debris flow according to the type of the parent rock of the soil:
when P is less than Cr1, the possibility of debris flow is low;
when Cr2 is more than P and is more than or equal to Cr1, the possibility of debris flow is moderate;
when Cr3 is more than P and is more than or equal to Cr2, the possibility of debris flow is high;
when P is more than or equal to Cr3, the possibility of debris flow is high;
when the parent rock type of the soil is granite, the value of Cr1 is 0.39; when the parent rock type of the soil is sandstone and shale, the value of Cr1 is 0.40; when the parent rock type of the soil is the orthobaric rock, the value of Cr1 is 0.40; when the parent rock type of the soil is gabbro, the value of Cr1 is 0.40; when the parent rock type of the soil is sandstone, the value of Cr1 is 0.48; when the parent rock type of the soil is limestone, the value of Cr1 is 0.27;
when the parent rock type of the soil is granite, the value of Cr2 is 0.46; when the parent rock type of the soil is sandstone and shale, the value of Cr2 is 0.48; when the parent rock type of the soil is the orthobaric rock, the value of Cr2 is 0.47; when the parent rock type of the soil is gabbro, the value of Cr2 is 0.47; when the parent rock type of the soil is sandstone, the value of Cr2 is 0.56; when the parent rock type of the soil is limestone, the value of Cr2 is 0.31;
when the parent rock type of the soil is granite, the value of Cr3 is 0.53; when the parent rock type of the soil is sandstone shale, the value of Cr3 is 0.55; when the parent rock type of the soil is the orthobaric rock, the value of Cr3 is 0.54; when the parent rock type of the soil is gabbro, the value of Cr3 is 0.54; when the parent rock type of the soil is sandstone, the value of Cr3 is 0.65; when the parent rock type of the soil is limestone, the value of Cr3 is 0.37.
In the step b, the sensitive gradient means that the gradient is 25-45 degrees.
In the step c, the soil moisture content factor K is obtained through calculation, and when the soil is in a wet area, the calculation is carried out according to the formula 4; when the soil is in a transition region, calculating according to the formula 5; when the soil is in a drought region, calculating according to the formula 6;
K＝3×10 -8 ×e 54.7Sm formula 4
K＝1×10 -8 ×e 56.7Sm Formula 5
K＝8×10 -18 ×e 163Sm Formula 6
Wherein Sm is the soil moisture content, and when the soil is a wet area, the soil moisture content Sm is calculated by a formula 7; when the soil is in the transition area, the soil moisture content Sm is calculated by the formula 8; when the soil is in a drought area, the soil moisture content Sm is calculated by the formula 9; e is radix, e =2.71828;
sm = alpha (0.0168 ln (Mi) + 0.3452) formula 7
Sm =0.0168ln (Mi) +0.3452 formula 8
Sm = beta (0.0058 ln (Mi) + 0.2475) formula 9
Wherein Sm is the soil moisture content, alpha is the correction coefficient of a wetting area, 1 is taken when the daily rainfall is larger than 1mm, and 1.15 is taken when the daily rainfall is smaller than or equal to 1 mm; beta is a drought region coefficient, 1 is taken when the daily rainfall is more than 1mm, and 0.8 is taken when the daily rainfall is less than or equal to 1 mm; mi is the wetting index, calculated from equation 10;
mi = B/pe type 10
Wherein Mi is the wetting index; b is daily precipitation, mm/d; pe is the maximum latent heat evaporation, mm/d, calculated from equation 11-equation 14;
a＝0.492+1.792×10 -2 I-7.71×10 -5 I 2 +6.75×10 -7 I 3 formula 12
Wherein pe is maximum latent heat evaporation, mm/d; ta is the daily average temperature, DEG C; h is the average annual daylight length, and I is the monthly total heating index; a is an index; tm is the monthly average temperature, DEG C; i is a coefficient.
The soil is a wet area and refers to R 0 Not less than 1.38S-1068; the soil is a transition zone which means that the soil is 1.38S-1068 > R 0 Not less than 1.38S-1965; the soil is arid region and refers to R 0 < 1.38S-1965; wherein R is 0 The annual average rainfall of the debris flow channel is mm; s is the average sunshine hours of many years, h.
The embodiment is the best implementation mode, the influence of indirect early rainfall is replaced by direct soil moisture content, a quantitative calculation method and indexes of the probability of occurrence of shallow-layer landslide type gully debris flow are provided, and early warning accuracy is greatly improved.
The rainfall and the evaporation in the soil wetting area, the arid area and the transition area are greatly different, the moisture content of the soil is greatly influenced, the three areas are separately calculated, the calculated moisture content of the soil is more accurate, and the early warning accuracy can be guaranteed.
On the basis of daily rainfall, all parameters influencing the soil moisture content by sunshine time, daily temperature, monthly average temperature and heating index are fully considered, and the calculated soil moisture content can be ensured to be more accurate.
The water content of the soil is calculated by taking the rainfall and the temperature of 24 hours as calculation basis, but the method is superior to the rainfall and the temperature of 24 hours in the general sense: 24h rainfall and temperature in the general sense, refers to a specific period of time, such as 8 days first to 8 days second; or rainfall and temperature from day 20 to day 20; the rainfall and temperature of 24 hours before the early warning is the rainfall and temperature of 24 hours before the early warning, namely, the rainfall and temperature are gradually updated and changed along with the time advance of each hour, and the rainfall and temperature are updated every hour, so that the rainfall and temperature data are updated every hour, and the data during the early warning are more accurate; the condition that rainfall and temperature data in a specific time period cannot reflect the actual condition of the early warning moment or early warning is carried out at a specific time, such as 8 hours or 20 hours of the second day, so that early warning delay is avoided.
The present invention will be described in detail with reference to specific examples.
In 2011, when 5 nights to 6 nights in 6 nights, the rain falls in short duration in most regions in the middle of the nome county under the influence of high-altitude wind shear and cold air, the rainstorm in the regions gradually develops from easy town to south in the regions with extra-large rainstorm in some regions, and the rainfall intensity gradually decreases from south to north. The parent rock type of the soil in the area is sandstone-shale, and the area is provided with 75 ditches in total, wherein shallow-layer landslide type gully mud-rock flow occurs in 29 ditches, and shallow-layer landslide type gully mud-rock flow does not occur in 46 ditches.
The invention is adopted to carry out early warning on the 75 debris flow basins.
Firstly, measuring the total area A of debris flow without an accumulation area, the percentage S0 of the sensitive slope area in the total area A of debris flow without the accumulation area and the longitudinal gradient J of a gully bed by using a high-precision topographic map; then according to the Cr1, cr2 and Cr3 values corresponding to the sandstone shale in Table 1, respectively: 0.40, 0.48 and 0.55.
TABLE 1
| Lithology | Cr1 | Cr2 | Cr3 |
| Granite | 0.39 | 0.46 | 0.53 |
| Sandstone-sandwiched shale | 0.40 | 0.48 | 0.55 |
| Positive long rock | 0.40 | 0.47 | 0.54 |
| Gabby rock | 0.40 | 0.47 | 0.54 |
| Sandstone | 0.48 | 0.56 | 0.65 |
| Limestone | 0.27 | 0.31 | 0.37 |
And determining local climate divisions according to the annual average sunshine hours S and annual average rainfall of the plan of the mudstone flow, calculating to obtain the maximum latent heat evaporation pe of the mudstone flow at the current day according to the temperature data obtained by actual monitoring of the mud-stone flow basin, calculating to obtain the wetness index Mi of the environment at the time of the mudstone flow by using the daily rainfall B and the maximum latent heat evaporation pe obtained by monitoring, calculating to obtain the soil water content Sm according to the wetness index Mi, and finally calculating to obtain the soil water content factor K when the mudstone flow occurs according to the soil water content Sm at the time of the mudstone flow. Looking up the hydrologic manual to obtain the 1-hour rainfall variation coefficient C of the debris flow channel v And =0.4, acquiring the 1-hour stimulated rainfall of the position of the drainage basin of the debris flow forming area according to actual monitoring, calculating a rainfall index and a debris flow rainfall factor R by combining the soil water content factor K, and calculating to acquire an occurrence index P of the debris flow.
The parameters of the 75 debris flow basins, the calculated debris flow occurrence index P and the actual debris flow occurrence are shown in table 2.
TABLE 2
Early warning is carried out according to the occurrence index P of the debris flow: when P is more than or equal to 0.55, the possibility of debris flow is high; when P is more than or equal to 0.48 and less than 0.58, the possibility of debris flow is high; when P is more than or equal to 0.40 and less than 0.48, the possibility of debris flow is moderate; when P < 0.40, the possibility of occurrence of debris flow is small.
In table 2, it is judged that 11 debris flows have a high possibility of occurring, and all the debris flows occur; the probability of the occurrence of the debris flow is 23, wherein 14 of the debris flows occur, and 9 of the debris flows do not occur; the mud-rock flow occurrence probability is medium, 32 mud-rock flows occur, 4 mud-rock flows occur, and 28 mud-rock flows do not occur; the probability of occurrence of debris flow is small, 9 debris flows do not occur.
In conclusion, the early warning accuracy of the shallow landslide type gully debris flow is high by applying the method provided by the invention.
Claims (4)
1. A shallow landslide type gully debris flow early warning method is characterized by comprising the following steps:
a. measuring the total flow area A of debris flow without an accumulation area through a high-precision topographic map;
b. measuring the percentage S of sensitive gradient area to the total flow area of debris flow without accumulation area through high-precision topographic map 0 And a longitudinal gradient J of the gully bed, and determining a debris flow terrain factor T according to the formula 1;
T＝S 0 J 0.3 (A/A 0 ) 0.2 formula 1
Wherein T is a debris flow topographic factor; s 0 The sensitive gradient area accounts for the percentage of the total flow area of the debris flow without the accumulation area; j is the longitudinal gradient of the furrow bed; a is the total flow area of the debris flow without the accumulation area, km 2 ；A 0 Is unit area, 1km 2 ；
c. Looking up hydrologic manual to determine annual average rainfall R of debris flow channel in monitoring area 0 Rainfall variation coefficient C of debris flow channel in 1 hour v Measuring the excited rainfall It for 1 hour on site, determining the parent rock type of the soil, calculating a soil moisture factor K, and determining a debris flow rainfall factor R according to a formula 2;
wherein R is debris flow rainfall causeA seed; r is an index for stimulating rainfall, mm; r 0 The annual average rainfall of the debris flow channel is mm; c v A rainfall variation coefficient of the debris flow channel for 1 hour; k is a soil water content factor, mm; it is 1 hour excitation rainfall, mm;
d. calculating an occurrence index P of the debris flow according to the formula 3;
P＝RT 0.45 formula 3
Wherein P is the occurrence index of the debris flow; r is a debris flow rainfall factor; t is a debris flow topographic factor;
e. judging the occurrence of debris flow according to the type of the parent rock of the soil:
when P is less than Cr1, the possibility of debris flow is low;
when Cr2 is more than P and is more than or equal to Cr1, the possibility of debris flow is moderate;
when Cr3 is more than P and is more than or equal to Cr2, the possibility of debris flow is high;
when P is more than or equal to Cr3, the possibility of debris flow is high;
when the parent rock type of the soil is granite, the value of Cr1 is 0.39; when the parent rock type of the soil is sandstone and shale, the value of Cr1 is 0.40; when the parent rock type of the soil is the orthobaric rock, the value of Cr1 is 0.40; when the parent rock type of the soil is gabbro, the value of Cr1 is 0.40; when the parent rock type of the soil is sandstone, the value of Cr1 is 0.48; when the parent rock type of the soil is limestone, the value of Cr1 is 0.27;
when the parent rock type of the soil is granite, the value of Cr2 is 0.46; when the parent rock type of the soil is sandstone and shale, the value of Cr2 is 0.48; when the parent rock type of the soil is the orthobaric rock, the value of Cr2 is 0.47; when the parent rock type of the soil is gabbro, the value of Cr2 is 0.47; when the parent rock type of the soil is sandstone, the value of Cr2 is 0.56; when the parent rock type of the soil is limestone, the value of Cr2 is 0.31;
when the parent rock type of the soil is granite, the value of Cr3 is 0.53; when the parent rock type of the soil is sandstone and shale, the value of Cr3 is 0.55; when the parent rock type of the soil is the orthobaric rock, the value of Cr3 is 0.54; when the parent rock type of the soil is gabbro, the value of Cr3 is 0.54; when the parent rock type of the soil is sandstone, the value of Cr3 is 0.65; when the parent rock type of the soil is limestone, the value of Cr3 is 0.37.
2. The shallow landslide type gully debris flow early warning method according to claim 1, wherein: in the step b, the sensitive gradient means that the gradient is 25-45 degrees.
3. The shallow landslide type gully debris flow early warning method according to claim 1, wherein: in the step c, the soil moisture content factor K is obtained through calculation, and when the soil is in a wet area, the calculation is carried out according to the formula 4; when the soil is in the transition region, calculating according to the formula 5; when the soil is in a drought region, calculating according to the formula 6;
K＝3×10 -8 ×e 54.7Sm formula 4
K＝1×10 -8 ×e 56.7Sm Formula 5
K＝8×10 -18 ×e 163Sm Formula 6
Wherein Sm is the soil moisture content, and when the soil is a wet area, the soil moisture content Sm is calculated by a formula 7; when the soil is in the transition area, the soil moisture content Sm is calculated by the formula 8; when the soil is in a drought area, the soil moisture content Sm is calculated by the formula 9; e is radix, e =2.71828;
sm = alpha (0.0168 ln (Mi) + 0.3452) formula 7
Sm =0.0168ln (Mi) +0.3452 formula 8
Sm = beta (0.0058 ln (Mi) + 0.2475) formula 9
Wherein Sm is the soil moisture content, alpha is the correction coefficient of a wetting area, 1 is taken when the daily rainfall is larger than 1mm, and 1.15 is taken when the daily rainfall is smaller than or equal to 1 mm; beta is a drought region coefficient, 1 is taken when the daily rainfall is more than 1mm, and 0.8 is taken when the daily rainfall is less than or equal to 1 mm; mi is the wetting index, calculated from equation 10;
mi = B/pe type 10
Wherein Mi is the wetting index; b is daily precipitation, mm/d; pe is the maximum latent heat evaporation, mm/d, calculated from equation 11-equation 14;
a＝0.492+1.792×10 -2 I-7.71×10 -5 I 2 +6.75×10 -7 I 3 formula 12
Wherein pe is maximum latent heat evaporation, mm/d; ta is the daily average temperature, DEG C; h is the average annual daylight length, and I is the monthly total heating index; a is an index; tm is the monthly average temperature, DEG C; i is a coefficient.
4. The shallow landslide type gully debris flow early warning method according to claim 3, wherein: the soil is a wet area and is R 0 Not less than 1.38S-1068; the soil is a transition zone which means that the soil is 1.38S-1068 > R 0 Not less than 1.38S-1965; the soil is arid region and refers to R 0 < 1.38S-1965; wherein R is 0 The annual average rainfall of the debris flow channel is mm; s is the average sunshine hours of many years, h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210032425.5A CN114596689B (en) | 2022-01-12 | 2022-01-12 | Shallow landslide type gully debris flow early warning method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210032425.5A CN114596689B (en) | 2022-01-12 | 2022-01-12 | Shallow landslide type gully debris flow early warning method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114596689A CN114596689A (en) | 2022-06-07 |
| CN114596689B true CN114596689B (en) | 2023-02-24 |
Family
ID=81803409
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210032425.5A Active CN114596689B (en) | 2022-01-12 | 2022-01-12 | Shallow landslide type gully debris flow early warning method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114596689B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116189387B (en) * | 2022-12-30 | 2024-02-06 | 成都理工大学 | Post-fire debris flow early warning method |
| CN117495086B (en) * | 2023-10-31 | 2024-07-05 | 成都理工大学 | Shallow soil landslide early warning method based on precipitation and soil moisture content |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002022690A (en) * | 2000-07-13 | 2002-01-23 | Natl Research Inst For Disaster Prevention | Electrode rod for measuring conductivity and resistivity |
| CN102968883A (en) * | 2012-11-13 | 2013-03-13 | 成都市知用科技有限公司 | Self-adaptation mud-rock flow early-warning method |
| CN106157541A (en) * | 2016-07-19 | 2016-11-23 | 成都理工大学 | A kind of Debris Flow method for early warning and application thereof |
| 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 |
| CN106645651A (en) * | 2017-02-20 | 2017-05-10 | 长沙市玖车测控技术有限公司 | Monitoring and early-warning system for water loss and soil erosion |
| CN109035709A (en) * | 2018-09-13 | 2018-12-18 | 中国科学院、水利部成都山地灾害与环境研究所 | A kind of method for early warning, the apparatus and system of mountain torrents mud-rock flow |
| CN110298480A (en) * | 2019-05-20 | 2019-10-01 | 济南大学 | A kind of mountain flood Critical Rainfall index calculating method and system |
-
2022
- 2022-01-12 CN CN202210032425.5A patent/CN114596689B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002022690A (en) * | 2000-07-13 | 2002-01-23 | Natl Research Inst For Disaster Prevention | Electrode rod for measuring conductivity and resistivity |
| CN102968883A (en) * | 2012-11-13 | 2013-03-13 | 成都市知用科技有限公司 | Self-adaptation mud-rock flow early-warning method |
| CN106157541A (en) * | 2016-07-19 | 2016-11-23 | 成都理工大学 | A kind of Debris Flow method for early warning and application thereof |
| CN106645651A (en) * | 2017-02-20 | 2017-05-10 | 长沙市玖车测控技术有限公司 | Monitoring and early-warning system for water loss and soil erosion |
| 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 |
| CN109035709A (en) * | 2018-09-13 | 2018-12-18 | 中国科学院、水利部成都山地灾害与环境研究所 | A kind of method for early warning, the apparatus and system of mountain torrents mud-rock flow |
| CN110298480A (en) * | 2019-05-20 | 2019-10-01 | 济南大学 | A kind of mountain flood Critical Rainfall index calculating method and system |
Non-Patent Citations (1)
| Title |
|---|
| 三明市后山冲沟泥石流易发性评价及预报;赵宾杰;《科学技术与工程》;20210518;第21卷(第14期);第1-7页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114596689A (en) | 2022-06-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Krisnayanti et al. | Curve number estimation for ungauged watershed in semi-arid region | |
| Cai et al. | Analysis of groundwater-level response to rainfall and estimation of annual recharge in fractured hard rock aquifers, NW Ireland | |
| Ali et al. | Spatial patterns and variation of suspended sediment yield in the upper Indus River basin, northern Pakistan | |
| CN114596689B (en) | Shallow landslide type gully debris flow early warning method | |
| Hayashi et al. | Watershed-scale response of groundwater recharge to inter-annual and inter-decadal variability in precipitation (Alberta, Canada) | |
| Saadi et al. | Application of remote sensing data and geographic information system for identifying potential areas of groundwater storage in middle Moulouya Basin of Morocco | |
| Li et al. | Correlating check dam sedimentation and rainstorm characteristics on the Loess Plateau, China | |
| Guo et al. | The impact of concentrated flow and slope on unpaved loess‐road erosion on the Chinese Loess Plateau | |
| Moeyersons et al. | Site-and rainfall-specific runoff coefficients and critical rainfall for mega-gully development in Kinshasa (DR Congo) | |
| El-Fakharany et al. | Morphometric analysis and flash floods hazards assessment for Wadi Al Aawag drainage Basins, southwest Sinai, Egypt | |
| Pietsch et al. | Late Quaternary changes in flow-regime on the Gwydir distributive fluvial system, southeastern Australia | |
| Hall et al. | Using multiple lines of evidence to map groundwater recharge in a rapidly urbanising catchment: Implications for future land and water management | |
| Boumaiza et al. | Assessing response times of an alluvial aquifer experiencing seasonally variable meteorological inputs | |
| Souei et al. | Using statistical models and GIS to delimit the groundwater recharge potential areas and to estimate the infiltration rate: A case study of Nadhour-Sisseb-El Alem Basin, Tunisia | |
| Houben et al. | Hydrogeology of the Kabul Basin (Afghanistan), part I: aquifers and hydrology | |
| Soleimani-Motlagh et al. | Groundwater budget deficit caused by drought and overexploitation | |
| Iqbal et al. | Hydrological Assessment of Surface and Groundwater Resources of Islamabad, Pakistan | |
| Thein | Modelling of short duration rainfall IDF equation for Sagaing region, Myanmar | |
| CN114582092B (en) | Gully debris flow early warning method based on soil moisture content | |
| Khayyun et al. | Hydrological model for Derbendi-Khan Dam reservoir watershed using SWAT model | |
| Lange et al. | Surface runoff and sediment dynamics in arid and semi-arid regions | |
| Thompson et al. | Hydrology and hydric soil extent within a Mollisol catena in southeastern Minnesota | |
| Upadhayay et al. | Hydro-Geological Status of the Core and Buffer Zone of Beekay Steel Industries Limited, Adityapur Industrial Area, Saraikela, Kharsawan, Jharkhand | |
| Bonta et al. | Experimental watersheds at Coshocton, Ohio, USA: Experiences and establishing new experimental watersheds | |
| Woldu et al. | Spatiotemporal recharge estimation in the upper Awash sub-basin, central Ethiopia |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |