CN116955886A - Multi-scale standardized drought and flood emergency index calculation method for strength and speed coupling - Google Patents
Multi-scale standardized drought and flood emergency index calculation method for strength and speed coupling Download PDFInfo
- Publication number
- CN116955886A CN116955886A CN202310553980.7A CN202310553980A CN116955886A CN 116955886 A CN116955886 A CN 116955886A CN 202310553980 A CN202310553980 A CN 202310553980A CN 116955886 A CN116955886 A CN 116955886A
- Authority
- CN
- China
- Prior art keywords
- turning
- drought
- index
- speed
- waterlogging
- 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.)
- Granted
Links
- 238000004364 calculation method Methods 0.000 title claims abstract description 28
- 230000008878 coupling Effects 0.000 title claims abstract description 17
- 238000010168 coupling process Methods 0.000 title claims abstract description 17
- 238000005859 coupling reaction Methods 0.000 title claims abstract description 17
- 238000000034 method Methods 0.000 claims description 17
- 238000006243 chemical reaction Methods 0.000 claims description 16
- 238000011156 evaluation Methods 0.000 claims description 7
- 238000005315 distribution function Methods 0.000 claims description 6
- 238000010276 construction Methods 0.000 claims description 4
- 230000008569 process Effects 0.000 claims description 4
- 230000002301 combined effect Effects 0.000 claims 1
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000001556 precipitation Methods 0.000 description 6
- 230000002349 favourable effect Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 241000428352 Amma Species 0.000 description 1
- 101000823089 Equus caballus Alpha-1-antiproteinase 1 Proteins 0.000 description 1
- 101000823106 Equus caballus Alpha-1-antiproteinase 2 Proteins 0.000 description 1
- 101000651211 Homo sapiens Transcription factor PU.1 Proteins 0.000 description 1
- 238000007476 Maximum Likelihood Methods 0.000 description 1
- 102100027654 Transcription factor PU.1 Human genes 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 108010079923 lambda Spi-1 Proteins 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035772 mutation Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 238000011425 standardization method Methods 0.000 description 1
Classifications
-
- 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
-
- 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
- G06F17/18—Complex mathematical operations for evaluating statistical data, e.g. average values, frequency distributions, probability functions, regression analysis
-
- 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
- Y02A10/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE at coastal zones; at river basins
- Y02A10/40—Controlling or monitoring, e.g. of flood or hurricane; Forecasting, e.g. risk assessment or mapping
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Data Mining & Analysis (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Mathematical Physics (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Databases & Information Systems (AREA)
- Software Systems (AREA)
- General Engineering & Computer Science (AREA)
- Algebra (AREA)
- Life Sciences & Earth Sciences (AREA)
- Bioinformatics & Cheminformatics (AREA)
- Bioinformatics & Computational Biology (AREA)
- Evolutionary Biology (AREA)
- Operations Research (AREA)
- Probability & Statistics with Applications (AREA)
- Alarm Systems (AREA)
Abstract
The invention provides a multi-scale standardized drought and flood sharp turn index calculation method of strength and speed coupling, which comprises the steps of defining and calculating turning strength of drought and flood sharp turn; secondly, defining and calculating turning speed of drought and waterlogging, and analyzing the distribution relation of turning strength and turning speed; and finally, constructing a drainage basin multiscale standardized drought and flood sharp turn index calculation method based on the distribution relation of turning speed and turning strength and simultaneously considering the turning speed and the turning strength. The invention comprehensively considers the influence of turning speed and turning strength, can better express the characteristics of the drought and waterlogging sharp turn index compared with the common drought and waterlogging sharp turn index calculation method, can avoid misjudgment and missed judgment of the drought and waterlogging sharp turn event, and is beneficial to business application and popularization.
Description
Technical Field
The invention relates to the technical field of drainage basin drought and waterlogging disaster analysis and calculation, in particular to a multi-scale standardized drought and waterlogging emergency index calculation method with coupled strength and speed.
Background
Compared with single drought and waterlogging disasters, when abnormal situations of precipitation are rapidly changed, the disasters of drought and waterlogging composite forms are more serious in influence, and the disasters are more prominent by rapid rotation of drought and waterlogging. For rapid rotation of drought and waterlogging, the soil is dehydrated and loosened or agglomerated and hardened due to continuous high-temperature drought in the early stage, the atmospheric energy is stored greatly, strong convection weather and concentrated short-time heavy rainfall are very easy to occur due to slight disturbance, the extreme disasters of various disaster causing factors are sudden, and great challenges are brought to the defense of drought and water disasters. In order to quantitatively evaluate the drought and flood emergency degree, an index for quantitatively describing the drought and flood emergency is firstly required to be constructed, the traditional drought and flood emergency index is mainly constructed by using a standardized meteorological and hydrologic sequence such as precipitation or runoff, and the index comprises the terms of the intensity of the drought and flood emergency, the absolute intensity of the drought and flood, the weight coefficient of the drought and flood, and the like. The traditional drought and flood emergency indexes are usually constructed based on the drought and flood emergency intensities, but for a real drought and flood emergency, besides the difference of the drought and flood intensities before and after turning, the speed of emergency has an important effect, and the influence of the speed of emergency on the emergency is not considered in the traditional drought and flood emergency indexes. In addition, the traditional index can effectively identify drought and waterlogging emergency events, but because the traditional index comprises weight items of drought and waterlogging, misjudgment and missed judgment on the drought and waterlogging emergency events can be difficult to avoid in practical application.
Disclosure of Invention
The invention aims to provide a multi-scale standardized drought and flood emergency index calculation method with coupled strength and speed aiming at the defects of the prior art.
In order to achieve the above purpose, the invention adopts the following technical scheme:
the invention provides a multi-scale standardized drought and flood emergency index calculation method of strength and speed coupling, which comprises the following steps:
s1, defining and calculating turning strength: defining drought and flood emergency turning strength based on an international drought and flood evaluation standard, and calculating corresponding drought and flood emergency turning strength by using a standardized rainfall and runoff index;
s2, turning speed definition calculation: setting turning judgment conditions of drought and waterlogging sharp turning events, defining extreme turning time, and calculating the drought and waterlogging sharp turning speed by using the extreme turning time and turning scale;
s3, determining a speed conversion relation: comparing the distribution relation of the turning strength and the turning speed, giving a conversion coefficient of the turning speed to the strength, and calculating the influence item of the final drought and waterlogging sharp turning speed;
s4, building a drought and waterlogging tight turning comprehensive index: based on the set turning speed, turning strength and conversion relation, a drainage basin multiscale standardized drought and waterlogging sharp turn index which simultaneously considers the turning strength and speed coupling is constructed.
Further, the specific steps in S1 are as follows:
s11, calculating an internationally applicable standardized rainfall or runoff index sequence, and constructing a probability density distribution function library, wherein different probability density distribution functions are selected from the function library according to the characteristics of the river basin during actual calculation due to different characteristics of different areas and elements;
s12, in order to adapt to the existing drought and flood grading evaluation standard, the intensity of drought and flood emergency is constructed by adopting the difference value of the rainfall or runoff indexes standardized before and after turning, and the calculation formula is as follows:
wherein I represents the turning strength; t (T) s A time scale representing the respective index; SVI represents the normalized rainfall or runoff index calculated in S11; i and i+1 represent the present period and the next period, respectively.
Further, the specific steps of S2 are as follows:
s21, in order to remove misjudgment and missed judgment of the traditional drought and flood emergency indexes, setting turning judgment conditions of a drought and flood emergency event, setting a flood condition when SVI is more than or equal to 0.5 and a drought condition when SVI is less than or equal to-0.5, and setting the following drought and flood emergency judgment conditions:
s22, setting a turning speed of corresponding drought and waterlogging sharp turning according to the drought and waterlogging sharp turning judgment standard, wherein the turning speed value represents the time speed from drought or waterlogging extreme value to waterlogging or drought extreme value;
when a plurality of extreme values exist in raindrop or drought, two extreme values closest to the turning point are adopted for speed calculation, and a calculation formula is as follows:
wherein V represents the turning speed; t (T) max Representing the time corresponding to the maximum value of the index SVI; t (T) min Representing the time corresponding to the minimum value of the index, wherein the difference value between the minimum value and the minimum value is 1, and the maximum value is 2 xT s -1, when the index judgment condition is a non-drought and waterlogging sharp turning event, the corresponding turning speed is 0.
Further, the specific steps of S3 are as follows:
s31, analyzing the fitting distribution relation of the turning speed and the turning strength to give a conversion coefficient alpha of the turning speed compared with the turning strength;
s32, calculating a limiting weight k of the turning speed based on a conversion coefficient alpha, and constructing a final speed influence item by using the limiting weight k;
in actual calculation, for the turning strength I, if the influence of the turning speed on the drought and waterlogging emergency is set to be not more than alpha of the I, V is obtained k ≤α；
When the turning time is shortest, the V value is the maximum of Ts; when the turning time is longest, the V value is minimum to be 1;
the limiting weight k needs to satisfy the properties:
thereby, the limiting weight k value of the calculated condition is solved as:
further, the S4 specifically is: establishing a multi-scale standardized drought and flood sharp turn index MSDFAI index by coupling the S1 to the S3:
wherein alpha is a coefficient term, T s Is the time scale of the turning event; for the intensity term, use is made of (SPI i+1 -SPI i ) And/2, comparing the index with the existing standardized rainfall and drought index to realize the standardization of the drought and drought emergency index; v is a speed item, and is divided into three types according to the type of turning event;the overall impact of the control speed on the index is within a given coefficient a as a weight term for the speed.
Further, when T s When the value is 1, the V value is 1 when the event is a traditional short-period turning event, and the corresponding MSDFAI index is only the turning intensity;
when T is s When the turning speed is more than or equal to 2, the MSDFAI index represents the comprehensive influence of the turning speed and the turning strength for the traditional long-period turning event;
because the MSDFAI index divides different types of turning speeds in construction, the MSDFAI index judges through the conditions in the S22, and when the turning is in the same drought or waterlogging state before and after turning and any non-drought or non-waterlogging state, the index is assigned to 0 so as to eliminate the interference of other events on drought and waterlogging emergency events and avoid the situation that the index is misjudged or missed in the process of judging the drought and waterlogging emergency events.
The beneficial effects of the invention are as follows: on the basis of further clarifying the definition of drought and waterlogging, theoretical analysis practice indicates the limitation of the traditional drought and waterlogging sharp turning index and the influence of the drought and waterlogging sharp turning rate on turning events, and an improved multi-scale standardized drought and waterlogging sharp turning index constructed based on standardized rainfall and runoff indexes is provided. The method can effectively overcome the misinterpretation of the drought and flood emergency, comprehensively consider the influence of turning strength and speed on the drought and flood emergency in different time scales, and can more comprehensively express the characteristics of the drought and flood emergency compared with the traditional index.
Drawings
FIG. 1 is a flow chart of a method for calculating an intensity and speed coupled multiscale standardized drought and flood sharp turn index according to the present invention;
FIG. 2 is a schematic diagram of a drought and water break time point distribution;
FIG. 3 is a graph comparing MSDFAI index with conventional drought/flood sharp turn index.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Referring to fig. 1, a method for calculating a multi-scale standardized drought and flood emergency rotation index of intensity and speed coupling includes the following steps:
s1, defining and calculating turning strength: defining drought and flood emergency turning strength based on an international drought and flood evaluation standard, and calculating corresponding drought and flood emergency turning strength by using a standardized rainfall and runoff index;
s2, turning speed definition calculation: setting turning judgment conditions of drought and waterlogging sharp turning events, defining extreme turning time, and calculating the drought and waterlogging sharp turning speed by using the extreme turning time and turning scale;
s3, determining a speed conversion relation: comparing the distribution relation of the turning strength and the turning speed, giving a conversion coefficient of the turning speed to the strength, and calculating the influence item of the final drought and waterlogging sharp turning speed;
s4, building a drought and waterlogging tight turning comprehensive index: based on the set turning speed, turning strength and conversion relation, a drainage basin multiscale standardized drought and waterlogging sharp turn index which simultaneously considers the turning strength and speed coupling is constructed.
The specific steps in the step S1 are as follows:
s11, calculating an internationally applicable standardized rainfall or runoff index sequence, constructing a probability density distribution function library, and selecting different probability density distribution functions from the function library according to the characteristics of the river basin in actual calculation due to different characteristics of different areas and elements, wherein the distribution is as follows:
s12, in order to adapt to the existing drought and flood grading evaluation standard, the intensity of drought and flood emergency is constructed by adopting the difference value of the rainfall or runoff indexes standardized before and after turning, and the calculation formula is as follows:
wherein I represents the turning strength; t (T) s A time scale representing the respective index; SVI represents the normalized rainfall or runoff index calculated in S11; i and i+1 represent the present period and the next period, respectively.
In the present embodiment, G is usedThe amma distribution calculates the standardized rainfall SPI index of the Yangtze river basin, and sets T s =2, i.e. the SVI index in this embodiment specifically refers to the SPI index, and assuming that the precipitation amount at a certain time scale is x, the probability density function of the Gamma distribution is:
wherein, alpha and beta are shape parameters and scale parameters respectively; Γ (α) is a gamma function.
The alpha and beta values are estimated using a maximum likelihood method, namely:
in the method, in the process of the invention,is climate average value, n is sequence length, A is intermediate parameter variable, x i Is the rainfall value of the i-th period.
Since the gamma function does not include x=0, and the actual precipitation may be 0, the gamma function is not limited to the aboveShould be the mean of non-0 items in the precipitation train. If the number of terms in the precipitation series is 0 is m and q=m/n, the cumulative probability is calculated as follows:
H(x)＝q+(1-q)G(x)
wherein:namely +.>
And then the accumulated probability distribution H (x) is converted into standard normal distribution to obtain corresponding SPI values:
when H (x) is more than 0 and less than or equal to 0.5,
when 0.5 < H (x) < 1,
wherein c 0 ＝2.515、c 1 ＝0.802853、c 0 ＝0.010328、d 1 ＝1.432788、d 2 ＝0.189269、d 3 ＝0.001308。
The specific steps of the S2 are as follows:
s21, in order to remove misjudgment and missed judgment of the traditional drought and flood emergency indexes, setting turning judgment conditions of a drought and flood emergency event, setting a flood condition when SVI is more than or equal to 0.5 and a drought condition when SVI is less than or equal to-0.5, and setting the following drought and flood emergency judgment conditions:
to calculate the turning rate, the SVI index of minimum time granularity, T, is further calculated s SVI index at=1, abbreviated as SVI1. And determining a turning time point from the drought/waterlogging extreme value to the waterlogging or the drought extreme value by utilizing the SVI1 index, and taking two extreme values closest to the turning point as the turning time point when a plurality of extreme values exist in the waterlogging/drought.
For drought and flood emergency situations, i.e., SVI (T) s ) i ≤-0.5∩SVI(T s ) i+1 The turning time point is calculated as follows:
for drought and flood emergency situations, i.e., SVI (T) s ) i ≥0.5∩SVI(T s ) i+1 The turning time point is calculated as follows, wherein the turning time point is less than or equal to-0.5:
wherein T represents SVI (T) s ) i ～SVI(T s ) i+1 A minimum time interval between, whereinRepresenting the minimum granularity time distribution of the previous period,/->Representing the minimum particle size time distribution for the latter period. tt represents the time series found to meet the preliminary condition, T min Represents drought extreme point, T max And (5) representing the extreme points of raindrop.
In the present embodiment, T is adopted s Long period drought and flood emergency event of=2, the minimum time granularity is 1 month, the outside frame line represents the SPI index of 2 months (indicated by SPI 2), the column in the box represents the SPI index of month (indicated by SPI 1), and when the SPI2 before and after turning is the same, there are at least three distribution conditions of SPI1 in the box as shown in fig. 2.
For fig. 2 (a), the turn time from the peak of rain to the peak of drought is fastest, taking 2 months;
for fig. 2 (b), the turn time is centered, taking 3 months;
for fig. 2 (c), the turn time is the slowest, taking 4 months.
S22, setting a turning speed of corresponding drought and waterlogging sharp turning according to the drought and waterlogging sharp turning judgment standard, wherein the turning speed value represents the time speed from drought or waterlogging extreme value to waterlogging or drought extreme value;
when a plurality of extreme values exist in raindrop or drought, two extreme values closest to the turning point are adopted for speed calculation, and a calculation formula is as follows:
wherein V represents a rotationFolding speed; t (T) max Representing the time corresponding to the maximum value of the index SVI; t (T) min Representing the time corresponding to the minimum value of the index, wherein the difference value between the minimum value and the minimum value is 1, and the maximum value is 2 xT s -1, when the index judgment condition is a non-drought and waterlogging sharp turning event, the corresponding turning speed is 0.
The specific steps of the S3 are as follows:
s31, analyzing the fitting distribution relation of the turning speed and the turning strength to give a conversion coefficient alpha of the turning speed compared with the turning strength;
given the conversion coefficient α=1.5 in the present embodiment, this is distinguished by taking the drought/flood classification into consideration with 0.5 as a standard, and when the unit turning strength is 1, the influence of the turning rate calculated therefrom on the index can be controlled within the range of 1.5.
S32, calculating a limiting weight k of the turning speed based on a conversion coefficient alpha, and constructing a final speed influence item by using the limiting weight k;
in actual calculation, for the turning strength I, if the influence of the turning speed on the drought and waterlogging emergency is set to be not more than alpha of the I, V is obtained k ≤α；
When the turning time is shortest, the V value is the maximum of Ts; when the turning time is longest, the V value is minimum to be 1;
the limiting weight k needs to satisfy the properties:
thereby, the limiting weight k value of the calculated condition is solved as:
the step S4 specifically comprises the following steps: establishing a multi-scale standardized drought and flood sharp turn index MSDFAI index by coupling the S1 to the S3:
wherein alpha is a coefficient term, T s Is the time scale of the turning event; for the intensity term, use is made of (SPI i+1 -SPI i ) And/2, comparing the index with the existing standardized rainfall and drought index to realize the standardization of the drought and drought emergency index; v is a speed item, and is divided into three types according to the type of turning event;the overall impact of the control speed on the index is within a given coefficient a as a weight term for the speed.
When T is s When the value is 1, the V value is 1 when the event is a traditional short-period turning event, and the corresponding MSDFAI index is only the turning intensity;
when T is s When the turning speed is more than or equal to 2, the MSDFAI index represents the comprehensive influence of the turning speed and the turning strength for the traditional long-period turning event;
because the MSDFAI index divides different types of turning speeds in construction, the MSDFAI index judges through the conditions in the S22, and when the turning is in the same drought or waterlogging state before and after turning and any non-drought or non-waterlogging state, the index is assigned to 0 so as to eliminate the interference of other events on drought and waterlogging emergency events and avoid the situation that the index is misjudged or missed in the process of judging the drought and waterlogging emergency events.
The corresponding drought and flood turning event grading standard can be given according to the constructed MSDFAI index, and is shown in table 1. The grade can be consistent with the international grade division standard of drought and waterlogging events, and is favorable for unification of a drought and waterlogging event evaluation system.
TABLE 1 drought/flood emergency event class classification criteria based on MSDFAI index
Fig. 3 shows a comparison of the MSDFAI index and the conventional drought/flood emergency index, and it can be seen that when the conventional index is used for identifying long-period drought/flood mutation events, the conventional index still judges that drought/flood emergency events occur for a number of MSDFAI indexes of 0 items, and overestimates the proportion of drought/flood events, thereby causing a large number of missed judgment and misjudgment events. In addition, the range of the long-period traditional index is between-30 and 30, and due to different index standardization methods and different values of weighting parameters, a scientific and objective threshold value is difficult to set for drought and waterlogging emergency events, so that unified drought and waterlogging disaster assessment is not facilitated. The span range of the MSDFAI is-5, and the non-drought and waterlogging disaster emergency alternate event is represented by 0 value, so that the grade of the drought and waterlogging disaster emergency alternate event can be clearly judged, and the grade corresponds to the existing drought and waterlogging disaster grade.
In summary, the invention provides an improved multi-scale standardized drought and flood emergency index based on standardized rainfall and runoff index construction by a multi-scale standardized drought and flood emergency index calculation method coupled with strength and speed, and theoretical analysis practice indicates the limitation of the traditional drought and flood emergency index and the influence of the drought and flood emergency rate on turning events on the basis of further defining the definition of the drought and flood emergency. The method can effectively overcome the misinterpretation of drought and waterlogging emergency, comprehensively consider the influence of turning strength and speed on the drought and waterlogging emergency in different time scales, is consistent with the classification of the existing drought and waterlogging disasters, and is favorable for the application and popularization of business.
The foregoing examples merely illustrate embodiments of the invention and are described in more detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present patent is to be determined by the appended claims.
Claims (6)
1. A method for calculating a multi-scale standardized drought and flood emergency rotation index of intensity and speed coupling is characterized by comprising the following steps:
s1, defining and calculating turning strength: defining drought and flood emergency turning strength based on an international drought and flood evaluation standard, and calculating corresponding drought and flood emergency turning strength by using a standardized rainfall and runoff index;
s2, turning speed definition calculation: setting turning judgment conditions of drought and waterlogging sharp turning events, defining extreme turning time, and calculating the drought and waterlogging sharp turning speed by using the extreme turning time and turning scale;
s3, determining a speed conversion relation: comparing the distribution relation of the turning strength and the turning speed, giving a conversion coefficient of the turning speed to the strength, and calculating the influence item of the final drought and waterlogging sharp turning speed;
s4, building a drought and waterlogging tight turning comprehensive index: based on the set turning speed, turning strength and conversion relation, a drainage basin multiscale standardized drought and waterlogging sharp turn index which simultaneously considers the turning strength and speed coupling is constructed.
2. The method for calculating the multi-scale standardized drought and flood emergency rotation index of the intensity and speed coupling according to claim 1, wherein the specific steps in the step S1 are as follows:
s11, calculating an internationally applicable standardized rainfall or runoff index sequence, and constructing a probability density distribution function library, wherein different probability density distribution functions are selected from the function library according to the characteristics of the river basin during actual calculation due to different characteristics of different areas and elements;
s12, in order to adapt to the existing drought and flood grading evaluation standard, the intensity of drought and flood emergency is constructed by adopting the difference value of the rainfall or runoff indexes standardized before and after turning, and the calculation formula is as follows:
wherein I represents the turning strength; t (T) s A time scale representing the respective index; SVI represents the normalized rainfall or runoff index calculated in S11; i and i+1 represent the present period and the next period, respectively.
3. The method for calculating the multi-scale standardized drought and flood emergency rotation index of the intensity and speed coupling according to claim 1, wherein the specific steps of S2 are as follows:
s21, in order to remove misjudgment and missed judgment of the traditional drought and flood emergency indexes, setting turning judgment conditions of a drought and flood emergency event, setting a flood condition when SVI is more than or equal to 0.5 and a drought condition when SVI is less than or equal to-0.5, and setting the following drought and flood emergency judgment conditions:
s22, setting a turning speed of corresponding drought and waterlogging sharp turning according to the drought and waterlogging sharp turning judgment standard, wherein the turning speed value represents the time speed from drought or waterlogging extreme value to waterlogging or drought extreme value;
when a plurality of extreme values exist in raindrop or drought, two extreme values closest to the turning point are adopted for speed calculation, and a calculation formula is as follows:
wherein V represents the turning speed; t (T) max Representing the time corresponding to the maximum value of the index SVI; t (T) min Representing the time corresponding to the minimum value of the index, wherein the difference value between the minimum value and the minimum value is 1, and the maximum value is 2 xT s -1, when the index judgment condition is a non-drought and waterlogging sharp turning event, the corresponding turning speed is 0.
4. The method for calculating the multi-scale standardized drought and flood emergency rotation index of the intensity and speed coupling according to claim 3, wherein the specific steps of S3 are as follows:
s31, analyzing the fitting distribution relation of the turning speed and the turning strength to give a conversion coefficient alpha of the turning speed compared with the turning strength;
s32, calculating a limiting weight k of the turning speed based on a conversion coefficient alpha, and constructing a final speed influence item by using the limiting weight k;
in actual calculation, for the turning strength I, if the influence of the turning speed on the drought and waterlogging emergency is set to be not more than alpha of the I, V is obtained k ≤α；
When the turning time is shortest, the V value is the maximum of Ts; when the turning time is longest, the V value is minimum to be 1;
the limiting weight k needs to satisfy the properties:
thereby, the limiting weight k value of the calculated condition is solved as:
5. the method for calculating the multi-scale standardized drought and flood emergency rotation index of the intensity and speed coupling according to claim 4, wherein the step S4 is specifically: establishing a multi-scale standardized drought and flood emergency index MSDFAI by coupling the S1 to the S3:
wherein alpha is a coefficient term, T s Is the time scale of the turning event; for the intensity term, use is made of (SPI i+1 -SPI i ) And/2, comparing the index with the existing standardized rainfall and drought index to realize the standardization of the drought and drought emergency index; v is a speed item, and is divided into three types according to the type of turning event;the overall impact of the control speed on the index is within a given coefficient a as a weight term for the speed.
6. The method for calculating the multi-scale standardized drought and flood emergency rotation index of the intensity and speed coupling according to claim 5, wherein the method comprises the following steps of:
when T is s When the value is 1, the V value is 1 when the event is a traditional short-period turning event, and the corresponding MSDFAI index is only the turning intensity;
when T is s When not less than 2, it is a transmissionThe MSDFAI index represents the combined effect of turning speed and turning strength;
because the MSDFAI index divides different types of turning speeds in construction, the MSDFAI index judges through the conditions in the S22, and when the turning is in the same drought or waterlogging state before and after turning and any non-drought or non-waterlogging state, the index is assigned to 0 so as to eliminate the interference of other events on drought and waterlogging emergency events and avoid the situation that the index is misjudged or missed in the process of judging the drought and waterlogging emergency events.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310553980.7A CN116955886B (en) | 2023-05-17 | 2023-05-17 | Multi-scale standardized drought and flood emergency index calculation method for strength and speed coupling |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310553980.7A CN116955886B (en) | 2023-05-17 | 2023-05-17 | Multi-scale standardized drought and flood emergency index calculation method for strength and speed coupling |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116955886A true CN116955886A (en) | 2023-10-27 |
| CN116955886B CN116955886B (en) | 2024-03-26 |
Family
ID=88445080
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310553980.7A Active CN116955886B (en) | 2023-05-17 | 2023-05-17 | Multi-scale standardized drought and flood emergency index calculation method for strength and speed coupling |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116955886B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103678885A (en) * | 2013-11-22 | 2014-03-26 | 河海大学 | Method for establishing and analyzing drought index based on gravity satellite |
| KR20160057911A (en) * | 2014-11-14 | 2016-05-24 | 사단법인 한국농림기상학회 | System for deducting agricultural drought index and method therefor |
| CN110334404A (en) * | 2019-06-10 | 2019-10-15 | 淮阴师范学院 | A kind of rapid dry accurate recognition methods of drought of Watershed Scale |
| CN113961880A (en) * | 2021-11-01 | 2022-01-21 | 西安理工大学 | Diagnosis method for hydrologic drought duration and intensity dependent structural variation |
| CN113988673A (en) * | 2021-11-02 | 2022-01-28 | 中山大学 | Drought and waterlogging sudden turning evaluation method |
| CN115409340A (en) * | 2022-08-17 | 2022-11-29 | 西北农林科技大学 | Short-period drought and waterlogging rush index construction method and system |
-
2023
- 2023-05-17 CN CN202310553980.7A patent/CN116955886B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103678885A (en) * | 2013-11-22 | 2014-03-26 | 河海大学 | Method for establishing and analyzing drought index based on gravity satellite |
| KR20160057911A (en) * | 2014-11-14 | 2016-05-24 | 사단법인 한국농림기상학회 | System for deducting agricultural drought index and method therefor |
| CN110334404A (en) * | 2019-06-10 | 2019-10-15 | 淮阴师范学院 | A kind of rapid dry accurate recognition methods of drought of Watershed Scale |
| CN113961880A (en) * | 2021-11-01 | 2022-01-21 | 西安理工大学 | Diagnosis method for hydrologic drought duration and intensity dependent structural variation |
| CN113988673A (en) * | 2021-11-02 | 2022-01-28 | 中山大学 | Drought and waterlogging sudden turning evaluation method |
| CN115409340A (en) * | 2022-08-17 | 2022-11-29 | 西北农林科技大学 | Short-period drought and waterlogging rush index construction method and system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116955886B (en) | 2024-03-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Gao et al. | Simulation and design of joint distribution of rainfall and tide level in Wuchengxiyu Region, China | |
| CN109242336B (en) | Critical rainfall early warning method for torrential flood disasters in multi-scenario mode | |
| CN112348237B (en) | Abnormal trend detection method for dynamic drilling data | |
| CN113298305B (en) | Double-threshold rainstorm mountain torrent flood disaster early warning method based on different rainfall time-course characteristics | |
| CN102831752B (en) | Glacial lake burst early-warning method | |
| CN111191936B (en) | Typhoon, wind and rain comprehensive influence index calculation method and storage device | |
| CN104090974B (en) | The Application of Data Mining of the follow-up water of extension reservoir and system | |
| CN114442198B (en) | Forest fire weather grade forecasting method based on weighting algorithm | |
| CN107180270A (en) | Passenger flow forecasting and system | |
| CN113723824B (en) | Storm disaster risk assessment method | |
| CN115188163B (en) | Flood early warning method and system based on storm and flood similarity | |
| CN111325947A (en) | Storm surge flood early warning method and system based on long-term and short-term memory network | |
| CN114022307A (en) | Method for analyzing abnormal change of power consumption of solitary old people in grading and time-sharing manner | |
| CN114897242A (en) | Method for adaptively segmenting rainfall runoff in time period field | |
| CN115630337A (en) | Quantitative evaluation method and system for extreme rainfall attribution based on large-scale climate remote correlation | |
| CN116955886B (en) | Multi-scale standardized drought and flood emergency index calculation method for strength and speed coupling | |
| CN115859577A (en) | Water bloom early warning method, device, medium and equipment based on weather forecast | |
| CN109118721B (en) | Method and device for calculating composite early warning index based on critical rainfall and early warning method | |
| CN109902265B (en) | Underground early warning method based on hidden Markov model | |
| CN113946796A (en) | Drought propagation time calculation method based on conditional probability high space-time resolution | |
| CN114170761A (en) | Slope state monitoring system and method based on big data | |
| CN117870943A (en) | Multi-sensor-based data optimization acquisition system in grouting process | |
| CN111339155B (en) | Correlation analysis system | |
| CN116341994A (en) | River water ecological treatment method and system based on passenger water diversion | |
| CN113704849B (en) | Evaluation method for power transmission and transformation project slope instability risk degree |
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 |