Comprehensive Evaluation Method for Lightning Warning Effect Based on Lightning Monitoring Data

Abstract

The present invention discloses a comprehensive evaluation method for the lightning warning effect based on lightning monitoring data. Combining the characteristic of the aggregation of lightning activities, on the basis that the traditional lightning warning effect evaluation method only focuses on whether lightning occurs in the evaluation area, through the quality control of lightning data and combining the lightning frequency in the evaluation area, the lightning warning avoidance rate evaluation index is added. The comprehensive lightning warning effect evaluation method disclosed by the present invention can more objectively evaluate lightning warning products, so as to better carry out lightning warning services and enhance the ability to defend against lightning disasters.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning warning, and more specifically to a comprehensive evaluation method for lightning warning effects based on lightning monitoring data. Background Art

[0002] Lightning is a weather phenomenon in the atmosphere with transient large current, high voltage, and strong electromagnetic radiation, often causing major disaster accidents. Lightning disasters are one of the "ten most serious natural disasters" announced by the United Nations International Strategy for Disaster Reduction, and the International Electrotechnical Commission calls lightning "a major public hazard in the electronic era". In recent years, with the development of lightning monitoring technology, carrying out lightning nowcasting based on multi-source data has become a popular direction for reducing lightning disaster losses. By integrating monitoring data such as satellites, radars, lightning location, and atmospheric electric fields, and through algorithms such as area recognition, tracking, and extrapolation, lightning nowcasting products such as the probability of lightning occurrence and the moving trend of lightning activity areas are automatically generated, improving the accuracy of lightning monitoring and the level of warning and forecasting services, which is of great significance for ensuring the development of social economy.

[0003] However, the existing lightning nowcasting effect evaluation methods mainly evaluate the lightning warning effect from the perspective of observing and forecasting the presence or absence of lightning. Thunderstorms are strong convective phenomena with vigorous development, and lightning activities have the characteristics of clustering in time and space. Lightning often occurs concentrated in a certain period and location. Using the evaluation of presence or absence has certain defects from the perspective of lightning disaster prevention. Currently, lightning nowcasting products based on data such as radars, lightning, and atmospheric electric fields are generally updated every 6, 10, or 15 minutes, and the evaluation frequency in a day is as high as several hundred times. The existing lightning monitoring system has poor warning effects for strong lightning weather, and there will inevitably be a small number of misdetected lightning and positioning errors, which will cause certain interference to the accuracy of lightning warning and have an adverse impact on the actual evaluation of lightning warning effects.

[0004] Therefore, how to objectively reflect the evaluation of lightning warning effects so as to achieve accurate evaluation of lightning warning is an urgent problem for those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a comprehensive evaluation method for lightning warning effects based on lightning monitoring data. On the basis of the existing method, it is proposed to use the interception efficiency of the total lightning frequency to evaluate the lightning warning effect, which helps to more objectively reflect the evaluation of lightning warning effects.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A comprehensive evaluation method for lightning warning effects based on lightning monitoring data, comprising the following steps:

[0008] S1. Statistically analyze the lightning monitoring data within a certain period in the meteorological region and save the lightning monitoring data in the database;

[0009] S2. Evaluate the lightning monitoring data in the database using evaluation factors, where the evaluation factors include the lightning warning hit rate, the lightning warning false alarm rate, the lightning warning TS score, and the lightning warning avoidance rate.

[0010] Preferably, in step S2, the lightning warning avoidance rate is used to evaluate the lightning monitoring data in the database, which specifically includes:

[0011] S21. Traverse and query the lightning monitoring data stored in the database within a certain specified period;

[0012] S22. Obtain the number of lightning strikes and the lightning warning level within a specified time interval at the first starting time, and determine the lightning warning threshold;

[0013] S23. Iteratively update the number of lightning avoidance times and the number of lightning non-avoidance times within the specified period. The number of lightning avoidance times is the number of lightning strikes with a lightning warning level greater than or equal to the lightning warning threshold, and the number of lightning non-avoidance times is the number of lightning strikes with a lightning warning level less than the lightning warning threshold;

[0014] S24. Calculate the lightning warning avoidance rate within the specified period in the meteorological region based on the iteratively updated number of lightning avoidance times and the number of lightning non-avoidance times, and use the lightning warning avoidance rate to evaluate the lightning monitoring data.

[0015] Preferably, the total duration of the specified period is 30 minutes.

[0016] Preferably, the specified time interval in step S22 is 6 minutes.

[0017] Preferably, the lightning warning levels in step S22 include, from low to high, the lightning blue warning, the lightning yellow warning, the lightning orange warning, and the lightning red warning, and the lightning warning threshold is the lightning orange warning.

[0018] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a comprehensive evaluation method for lightning warning effects based on lightning monitoring data, which has the following beneficial effects:

[0019] (1) Comprehensively consider the number of lightning warnings and the lightning frequency, avoiding the errors in lightning location data and the impact of the errors on lightning warning products.

[0020] (2) The evaluation of the lightning warning avoidance rate is added, which can more objectively reflect the effectiveness of the lightning approaching warning products. The evaluation factors include POD: the hit rate of lightning warnings in a meteorological area during a certain period; FAR: the false alarm rate of lightning warnings in a meteorological area during a certain period; TS: the TS score of lightning warnings in a meteorological area during a certain period; ER: the lightning warning avoidance rate in a meteorological area during a certain period. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0022] Figure 1 It is a schematic diagram of the lightning warning evaluation process using POD / FAR / TS provided by the present invention;

[0023] Figure 2 It is a schematic diagram of the lightning warning evaluation process using the lightning warning avoidance rate provided by the present invention. Detailed Embodiments

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0025] At present, the lightning approaching warning levels are divided into four levels, which are set as blue, yellow, orange and red from low to high in sequence. In this example, orange is selected as the evaluation threshold, and the warning duration is 0 - 30 minutes. For lightning warning products with other levels and durations, this method can be referred to.

[0026] Based on the traditional lightning warning evaluation method, the present invention adds the evaluation of the lightning warning avoidance rate to form a comprehensive lightning warning effect evaluation method, which not only considers whether lightning occurs in the target area (traditional method), but also considers the frequency of lightning occurrence in the target area (lightning warning avoidance rate). It fully combines the clustering characteristics of lightning activities, reduces the influence of lightning monitoring data (a small amount of mismeasurement and positioning error) on lightning warning products, and more objectively reflects the lightning warning effect.

[0027] An embodiment of the present invention discloses a comprehensive evaluation method for lightning warning effects based on lightning monitoring data. By adding an evaluation of the lightning warning avoidance rate on the basis of traditional lightning warning evaluations (POD / FAR / TS), the effectiveness of lightning approaching warning products can be more objectively reflected, including the following steps:

[0028] S1. Statistically analyze the lightning monitoring data within a certain time period in key meteorological region A and save the lightning monitoring data in a database;

[0029] S2. Evaluate the lightning monitoring data in the database using evaluation factors, where the evaluation factors include the lightning warning hit rate (POD), the lightning warning false alarm rate (FAR), the lightning warning TS score, and the lightning warning avoidance rate (ER).

[0030] Specifically, as Figure 1 shown, in step S2, when evaluating the lightning monitoring data in the database using the lightning warning hit rate (POD), the lightning warning false alarm rate (FAR), and the lightning warning TS score, the following steps can be adopted:

[0031] a1: Traverse the lightning monitoring data with different starting times in key meteorological region A at a certain time period from the database.

[0032] a2: Judge the number (after screening) n of cloud-to-ground flashes occurring in the next 30 minutes predicted at the first starting time in key region A and the warning level p, and set the evaluation threshold level of key region A as the orange warning.

[0033] a3: When further determining that the warning level is greater than or equal to the orange threshold, for the number n of cloud-to-ground flashes occurring within 15 minutes, if n>0, it means that lightning occurs within 15 minutes, and the number of accurate forecasts is incremented by 1; if n<0, it means that no lightning occurs within 15 minutes, and the number of false alarms is incremented by 1.

[0034] When determining that the warning level is less than the orange level threshold, if n>0, the number of missed alarms is incremented by 1.

[0035] a4: After calculating the situation of this evaluation and inspection, determine whether the calculation is completed. If not, then re-enter step a2. If the calculation is completed, then calculate the hit rate POD, false alarm rate FAR, and TS score of lightning warning in key meteorological region A within a certain time period

[0036] POD = (Nc) / (Nc + Nm)*100%

[0037] FAR = (Nf) / (Nf + Nc)*100%

[0038] TS = (Nc) / (Nm + Nc + Nf)*100%

[0039] Nc: The number of accurate forecasts of lightning warnings in a certain key area during a certain period

[0040] Nm: The number of missed reports of lightning warnings in a certain key area during a certain period

[0041] Nf: The number of false alarms of lightning warnings in a certain key area during a certain period

[0042] POD: The hit rate of lightning warnings in a certain key area during a certain period

[0043] FAR: The false alarm rate of lightning warnings in a certain key area during a certain period

[0044] TS: The TS score of lightning warnings in a certain key area during a certain period

[0045] Using the hit rate (POD) of lightning warnings, the false alarm rate (FAR) of lightning warnings, and the TS score of lightning warnings to evaluate the lightning monitoring data in the database, only need to judge whether lightning occurs during this period, without paying attention to the specific number and frequency of lightning occurrences.

[0046] Such as Figure 2 As shown, on the basis of the above evaluation of lightning warnings using the hit rate (POD) of lightning warnings, the false alarm rate (FAR) of lightning warnings, and the TS score of lightning warnings, the present invention adds an evaluation of the lightning warning avoidance rate. The evaluation of the lightning warning avoidance rate specifically includes the following steps:

[0047] b1: Traverse the lightning monitoring data of different starting times stored in the A key meteorological area within a certain 30 - minute period from the database.

[0048] b2: Obtain the number n of cloud - to - ground lightning occurrences and the warning level p within a 6 - minute time interval in the A key meteorological area at the first starting time, and determine the lightning warning threshold.

[0049] Preferably, in this embodiment, the orange lightning warning is used as the lightning warning threshold, and the method using other lightning warning levels as the level threshold has the same principle as the method described in this embodiment.

[0050] The starting time refers to the time when a lightning warning product, such as an orange lightning warning, is generated. For example, 8:00 is set as the starting time. If the orange lightning warning is updated at a frequency of once every 6 minutes, then 8:06, 8:12... are all starting times.

[0051] b3: Define the number of lightning strikes when the lightning warning level in a certain period is greater than or equal to the lightning warning threshold as the lightning avoidance count ERC, and iteratively update the lightning avoidance count in the 30 - minute time period of the A key area:

[0052] ERC = ERC + n1, where n1 represents the number of times when the lightning warning level is greater than or equal to the orange lightning warning within a certain 6 - minute time interval.

[0053] Similarly, the number of lightning strikes when the lightning warning level is less than the lightning warning threshold within a certain period is defined as the number of un - avoided lightning strikes ERNC. Similarly, the number of lightning - avoided times in the 30 - minute time period of Area A is iteratively updated: ERNC = ERNC + n2, where n2 represents the number of times when the lightning warning level is less than the orange lightning warning within a certain 6 - minute time interval.

[0054] ERC and ERNC are iteratively updated with the update frequency of the lightning warning product. Specifically, it depends on the determination of the lightning warning level. If the lightning warning level in Area A exceeds (is greater than or equal to) the lightning warning threshold, the number of lightning - avoided times ERC will continuously increase. If the lightning warning level in Area A does not exceed the lightning warning threshold, the number of un - avoided lightning strikes ERNC will increase.

[0055] b4: After calculating the situation of this evaluation and inspection, determine whether the calculation is complete. If not, then re - enter step b2. If the calculation is complete, then calculate the avoidance rate ER of the lightning warning in Area A within a certain period according to the finally updated number of lightning - avoided times and the number of un - avoided lightning strikes:

[0056] ER=(ERC) / (ERC + ERNC)*100%

[0057] In this embodiment, lightning data can be obtained by lightning locators deployed outdoors. The acquisition of lightning frequency is calculated after determining the warning level and threshold. Finally, the lightning frequencies within a certain period are accumulated. During the effective warning period, the higher the proportion of the number of lightning - avoided times, the better the warning effect. Warning about lightning in future periods according to the warning evaluation results obtained by the method of the present invention can effectively improve the accuracy of lightning warning on the basis of the existing technology.

[0058] Each embodiment in this specification is described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0059] The foregoing description of the disclosed embodiments enables those skilled in the art to practice or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A comprehensive evaluation method for lightning warning effects based on lightning monitoring data, characterized in that The method includes the following steps: S1. Stat the lightning monitoring data within a certain period in the meteorological region, and save the lightning monitoring data in the database; S2. Evaluate the lightning monitoring data in the database by using evaluation factors, where the evaluation factors include lightning warning hit rate, lightning warning false alarm rate, lightning warning TS score, and lightning warning avoidance rate; Evaluate the lightning monitoring data in the database by using the lightning warning avoidance rate, specifically including: S21. Traverse and query the lightning monitoring data stored in the database within a certain specified period; S22. Obtain the number of lightning strikes and the lightning warning level within a specified time interval at the first starting time of reporting, and determine the lightning warning threshold; S23. Iteratively update the number of lightning avoidance times and the number of non-lightning avoidance times within the specified period. The number of lightning avoidance times is the number of lightning strikes with a lightning warning level greater than or equal to the lightning warning threshold, and the number of non-lightning avoidance times is the number of lightning strikes with a lightning warning level less than the lightning warning threshold; S24. Calculate the lightning warning avoidance rate of the meteorological region within the specified period according to the iteratively updated number of lightning avoidance times and the number of non-lightning avoidance times, and evaluate the lightning monitoring data by using the lightning warning avoidance rate; the calculation formula is as follows: ER = (ERC) / (ERC + ERNC) * 100%; where ER represents the lightning warning avoidance rate, ERC represents the number of lightning avoidance times, and ERNC represents the number of non-lightning avoidance times.

2. The comprehensive evaluation method for lightning warning effect based on lightning monitoring data according to claim 1, characterized in that The total duration of the specified period is 30 min.

3. The comprehensive evaluation method for lightning warning effect based on lightning monitoring data according to claim 1, characterized in that The specified time interval in step S22 is 6 min.

4. The comprehensive evaluation method for lightning warning effect based on lightning monitoring data according to claim 1, wherein The lightning warning levels in step S22 include, from low to high, lightning blue warning, lightning yellow warning, lightning orange warning, and lightning red warning in sequence, and the lightning warning threshold is the lightning orange warning.

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