Adjust the rainstorm warning signal-run out of the early warning ＂acceleration＂

Since March 30th, based on the pilot work in Liaoning, Zhejiang, Anhui, Hunan, Guangdong, Sichuan and Shaanxi provinces in 2022, China Meteorological Bureau has carried out the adjustment of rainstorm warning signals in an all-round way. China Meteorological News specially selected pilot units to explore and form a series of good practices and experiences for centralized display, with a view to promoting exchanges and promoting improvement.

Liaoning: Strengthening the scientificity of rainstorm warning signal

Liaoning Meteorological Bureau will incorporate the pilot work of rainstorm warning signal adjustment into the key task of "Quality Improvement Year" in 2022, and deploy it quickly and carry it out in a down-to-earth manner. On April 15, 2022, a leading group and a technical group were set up, followed by a work kick-off meeting and technical seminar, and a work plan and technical plan were issued. By comprehensively considering the characteristics of rainstorm weather and climate, urban meteorological disaster prevention and mitigation needs, Shenyang, Dandong, Jinpu New District of Dalian, Xiuyan Manchu Autonomous County of Anshan, Changtu County of Tieling and Jianping County of Chaoyang were finally selected as pilots to promote the integrated adjustment of rainstorm early warning business in the whole province.

In the adjustment of rainstorm warning signal, the meteorological department of Liaoning Province has constructed a historical rainfall data set with high temporal and spatial resolution. Carry out the analysis of the historical extreme value characteristics of short-term heavy rainfall times and hourly rainfall intensity in each pilot; Based on percentile statistical method, the characteristics of maximum rainfall intensity in each pilot hour are analyzed. Calculate the occurrence probability of the newly added hourly rain intensity warning standard; Each pilot and the local disaster prevention linkage unit meet the needs, find problems, revise and improve, and carry out evaluation; Docking local meteorological disaster prevention plans to better play the leading role of early warning information; Add meteorological risk warning in the release content of early warning signal and improve the defense guide; Accurately describe the release time, disaster type, early warning signal level, actual situation and development trend, influence scope, and the influence area is as fine as township (town, street).

After the inspection in the flood season of 2022, the adjusted rainstorm warning signal is scientific and practical. Taking Dandong as an example, after the standard adjustment, the number of early warning signals decreased by 14% on average compared with the past three years, and there was no "disaster without early warning"; The average number of people transferred from threatened areas decreased by 3091 compared with 2009 to 2021; The direct economic losses caused by meteorological disasters decreased by 86% compared with the same period in 2021, effectively saving the related manpower, material resources and financial resources caused by a large number of transferred personnel.

In the next step, the Liaoning Meteorological Bureau will investigate the application benefits of the revised rainstorm warning signal in disaster prevention and mitigation for local party committees and governments and disaster-related industry authorities; Make full use of the experience of pilot cities and counties, comprehensively carry out the adjustment of rainstorm early warning signals in cities and counties in the province, and divide four regions to adjust rainstorm early warning signals in combination with the characteristics of precipitation and disasters and the characteristics of meteorological support services in big cities; Evaluate the quality of the new standard rainstorm warning signal, and compare and analyze the number, accuracy, advance and effectiveness of rainstorm warning signals issued by cities and counties before and after the revision of the standard. (Ma Donglei Cai Kuizhi Sun Xiubo)

Hunan:Integrated rainstorm early warning service

On the basis of the original progressive early warning service model, in 2022, Hunan Meteorological Bureau selected Changsha City, Jiahe County of Chenzhou City, Anhua County of Yiyang City, Xiangyin County of Yueyang City and hongjiang city as pilots in accordance with the requirements of "multi-level collaboration and pilot first", and combined with more than 20 disaster-related industry authorities, adopted the working method of "pilot, application and improvement" to promote the pilot work in an integrated way; By improving the early warning business chain and early warning signal standards, the "631" progressive rainstorm early warning service will be innovated to help improve the defense and support capabilities of major meteorological disasters.

Hunan Meteorological Bureau subdivided the rainstorm warning in cities and counties into early warning signals and impending disaster warnings, and added the standards of one-hour rainfall intensity and accumulated rainfall, including clarifying the responsibilities of rainstorm warning signals and impending disaster warnings, and formulating the standards of rainstorm impending disaster warnings, which solved the problem of "who to transfer and when to transfer" and the disastrous problems of one-hour rainfall intensity and accumulated rainfall. By comparing and analyzing the rainstorm warning signals issued by pilot cities and counties in 2021 and 2022, it is found that the accuracy of early warning signals in pilot cities and counties can basically remain unchanged, and the advance of early warning signals is greatly improved.

Adjust the release standard of rainstorm warning signal, including canceling rainstorm blue warning signal, adjusting rainstorm orange warning signal standard, increasing rainstorm warning signal upgrade standard and increasing thunderstorm gale warning signal. The Provincial Meteorological Observatory releases the forecast of rainstorm falling area accurately to the county in the next 12 hours every 6 hours, and replaces the blue warning signal, which effectively improves the ability of the city and county meteorological bureaus to issue blue warning signals, and solves the problems of too many orange warning signals of rainstorm, low start-up conditions of emergency linkage, and the disaster caused by continuous heavy rainfall.

Optimizing the content and strategy of rainstorm warning signal release, including formulating rainstorm warning signal content templates according to initial release, continuous release and upgrade release respectively, and refining the recipients of warning signals according to their level responsibilities and industries, is beneficial for flood control responsible persons at all levels to accurately understand the content of warning information and comprehensively grasp the flood control situation. According to the analysis of the release of rainstorm warning signals in 2021, all users received a total of 3546 rainstorm warning signals before the strategy adjustment, and only 267 key decision-making users need to receive them after the adjustment, and the number of rainstorm warning signals received before and after the adjustment decreased by 92.5%.

In the next step, Hunan Meteorological Bureau will further improve the integrated platform of meteorological disaster early warning service and the early warning signal inspection and evaluation system in Hunan Province, and organize the implementation and evaluation in the whole province. (Dai shuairu)

Zhejiang:Explore the scientific connection of "early, accurate and fast"

Since China Meteorological Bureau identified Zhejiang as the pilot of rainstorm warning signal adjustment in April, 2022, Zhejiang Meteorological Bureau has made a plan by comprehensively considering the impact characteristics of meteorological disasters, and selected Xiaoshan District of Hangzhou, Haishu District of Ningbo, Pingyang County of Wenzhou, Xinchang County of Shaoxing and Jiangshan City as the pilots to carry out the pilot work of localization release of rainstorm warning signals based on the new standards.

According to the problem-oriented principle, the newly revised rainstorm warning signal fully considers the significant impact of short-duration heavy rainfall, and incorporates the one-hour rainfall intensity standard into the threshold standard, while adding a 12-hour threshold standard for the long-term stable systematic precipitation impact. In addition, the warning time limit of high-level rainstorm warning signal was extended from 3 hours to 12 hours. The formulation of the new standard fully applies the comprehensive risk survey results of meteorological disasters, and adopts the opinions of relevant departments such as agriculture, rural areas, water conservancy and emergency management, highlighting the disastrous rainstorm process that needs to be focused on prevention.

By the end of last year, the accuracy of the pilot rainstorm warning signal was 86%, and there was no omission, with an early aging time of 112 minutes; The accuracy of thunderstorm gale warning signal is 44%, and the early aging time is 63 minutes. During the influence of Typhoon Meihua in 2022, Haishu Meteorological Bureau issued an orange rainstorm warning signal 557 minutes in advance by applying the new standard, effectively warning the typhoon persistent rainstorm, and winning time for emergency linkage of relevant departments and grassroots disaster prevention and mitigation.

In order to give full play to the role of early warning signal as a "starting gun", Zhejiang has comprehensively strengthened its early warning signal publishing technology, and the province’s short-term and imminent weather forecast and early warning business system has been put into operation, realizing the second-level push of early warning guidance information and fine delivery to townships (towns, streets). All pilot cities and counties have targeted early warning signals and called grass-roots grid workers.

Moreover, the meteorological department of Zhejiang Province insists on the overall planning of business platform construction, and through iterative upgrading of the integrated short-term and imminent business platform of provinces, cities and counties, it improves the seamless and digital short-term monitoring and early warning product system covering live-approaching-short-term-potential, and establishes an objective and intelligent business process for the production and release of fine early warning signals to townships (towns and streets) to realize automatic generation, convenient interaction, information collaboration and one-click distribution of early warning signals. The platform won the third prize of the first integrated platform for short-term and imminent forecasting and early warning services of provinces, cities and counties in China Meteorological Bureau.

In the next step, the meteorological department of Zhejiang Province will continue to promote the adjustment and optimization of early warning signals, improve the inspection and evaluation mechanism of early warning signals, and build more scientific early warning signal indicators based on terrain and climate characteristics; At the same time, we will further improve the intelligence level of the integrated short-term and imminent forecasting and early warning business platform of provinces, cities and counties, and continue to promote and improve the emergency linkage mechanism with early warning signals as the guide. (Edward Zhang)

Guangdong:Optimize and adjust the publishing standards, terms and contents.

Xinyi City, Guangdong Province experienced a heavy precipitation process from June 7 to 11, 2022, with the maximum cumulative rainfall of 515mm and the maximum daily rainfall of 209mm. There were 33 landslides and no casualties.

This is the result of the adjustment of Xinyi rainstorm warning signal, and the rain intensity of one hour is included in the early warning standard, nearly 30 minutes earlier than usual; The rainstorm warning language is more standardized and more people-friendly, and disaster prevention and mitigation workers at all levels can read the warning information in the first time and carry out their work quickly and pertinently.

Based on the characteristics of Guangdong’s "rain nest", rainstorm-prone areas and highly sensitive areas of meteorological disasters, Guangdong Meteorological Bureau selected four representative cities and counties, including Shenzhen, Longmen County of Huizhou City, Xinyi City and Huilai County of Jieyang City, as the pilot projects for the accurate release of rainstorm warning signals in Guangdong, and carried out the adjustment of meteorological disaster (rainstorm) warning signals in the whole province from three aspects: release standards, release terms and release contents.

By calculating the historical data of the past 18 years, combined with the results of meteorological disaster risk survey in pilot cities and counties, the release thresholds of rainstorm warning signals at yellow, orange and red levels corresponding to one-hour rainfall intensity are determined. The frequency of issuing early warning signals by using the new threshold in the past ten years was analyzed. At the same time, compared with the release of rainstorm early warning signals in 2021 and 2022, the release advance was generally 5 to 15 minutes earlier.

After the early warning signal business was revised in 2019, and the release rules were formulated, the Guangdong Meteorological Bureau standardized the basic composition and release unit of the early warning signal release content. This year, the risk warning content will be added in the early warning signal that goes to villages and towns and high-impact and high-risk early warning; Further standardize the language through the functions of modular editing and combination in the early warning signal publishing platform; Analyzing examples of training early warning signals to improve the effectiveness of early warning signal release terms.

Guangdong Meteorological Bureau has formulated detailed defense guidelines for the public and industry, and given short impact and disaster risk reminders in the release content of early warning signals. The Guangdong Meteorological Bureau and the Guangdong Provincial Department of Housing and Urban-Rural Development jointly issued the Notice on Establishing and Improving the Cooperative Working Mechanism for Building Sites to Respond to Meteorological Disasters such as Thunderstorms, Gales and Rainstorms; The Shenzhen Meteorological Bureau, together with the Municipal Emergency Management Bureau and the Water Affairs Bureau, issued the Guidelines for Public Defense of Meteorological Disasters in Shenzhen, etc., and supplemented the high-impact risk tips for various districts and major industry authorities; Huizhou and Jieyang signed a suspension mechanism with many departments according to the regulations on early warning signal release, and made clear the industry defense suggestions. (Qu Fengqiu Zhang Xingling Lai Jianming)

Sichuan:Standard adjustment has strong connotation and heavy effect.

Sichuan Meteorological Bureau has carried out the problem-oriented adjustment of meteorological disaster (rainstorm) early warning signal, focusing on solving the problems that the unified standard of early warning signal is not suitable for local disaster prevention and mitigation needs, and the terminology is not standardized.

Sichuan Meteorological Bureau issued a work plan for the adjustment of meteorological disaster (rainstorm) early warning signals in the whole province, set up a leading group and a technical group for the adjustment of early warning signals, and extensively collected opinions and suggestions from cities (states) and provincial departments in the whole province. On the basis of fully considering the impact of urban waterlogging, mountain torrents, geological disasters, floods in small and medium-sized rivers and other disasters that may be caused by short-term heavy rainfall, the technical team established the threshold standard for fine zoning of rainstorm warning signals. The division of rainstorm warning signals in Sichuan Province was adjusted from two to three, and the rainstorm warning signal standards in Xuanying area of Liangshan Yi Autonomous Prefecture, Panzhihua City and Aba Tibetan and Qiang Autonomous Prefecture were added, and the hourly rainfall thresholds of rainstorm warning signals in three divisions were established to enhance the early warning of short-term heavy precipitation. The adjusted new standard of rainstorm warning signal is more in line with the standards of geological disaster risk and flood disaster risk.

Not only that, the pilot cities and counties used the phased results of the comprehensive risk survey of local meteorological disasters and solicited opinions from local departments, and established new standards for the territorial release of rainstorm warning signals.

In August 2022, a new standard for localization of rainstorm warning signals was officially launched. The new standards are integrated into local emergency plans to effectively improve departmental linkage. In the early warning services of heavy precipitation weather processes such as "August 28" in Suzhou and "August 29" in Jintang, the hourly rainfall standard was added and the warning signal level was upgraded in time, which achieved good service results. After the rainstorm warning signal reaches the township, the rainstorm warning advance of the pilot cities and counties will be increased by 5 minutes.

In order to improve the ability of accurate targeted release, Sichuan Meteorological Bureau also cooperated deeply with the Emergency Broadcasting Center of Sichuan Radio and Television Bureau, upgraded and improved the "Meteorological Service System for Key Industries" based on the "Early Warning Service Platform for Grassroots Meteorological Disasters in Sichuan Province", and realized early warning targeted release based on electronic fence technology by docking with the big data platform of mobile companies.

In the next step, Sichuan Meteorological Bureau will continue to carry out the calculation and objective evaluation of the new standard of rainstorm warning signal, and further improve the scientific and operability of the new standard. At the same time, by promoting the research of provincial short-term and imminent forecasting and early warning technology, speeding up the construction of grassroots meteorological disaster early warning service platform in Sichuan Province, and strengthening the research and development of objective early warning signal products with new localization standards, the support for grassroots short-term and imminent forecasting and early warning will be improved. (Zhou Tianhua Wang Yue)

Anhui:Data first support targeted release

A few days ago, the Anhui Provincial Emergency Management Department sent a thank-you letter to the Provincial Meteorological Bureau, saying that the Provincial Meteorological Bureau has continuously strengthened the monitoring, early warning and forecasting of severe weather, providing a solid meteorological service guarantee for safe production and emergency management. Huang Yong, director of Science, Technology and Forecasting Department of Anhui Meteorological Bureau, said that in the past year, the phenomenon of "flooding" of meteorological disaster warning signals was significantly reduced through the pilot work of adjusting rainstorm warning signals, and the pertinence and effectiveness of early warning information were further enhanced.

Business reform, data first. Anhui Meteorological Bureau constructed historical rainfall data sets of national meteorological stations and regional meteorological stations with different aging. The accumulated rainfall data sets and grading threshold data sets of rolling stations for 1 hour, 3 hours, 6 hours and 12 hours are established. At the same time, based on the rainstorm disaster data questionnaire of 105 counties (cities, districts) in the province from 1978 to 2020, the rainstorm disaster risk data set of the whole province is constructed.

In view of the difference of rainstorm disasters caused by different climatic backgrounds in mountainous areas and non-mountainous areas, Anhui Meteorological Bureau calculated the grading thresholds of 1-hour and 6-hour rainfall respectively by using statistical methods such as percentile, forming a new rainstorm warning signal standard. Based on the results of storm disaster risk survey, according to the difference of storm disaster risk between mountainous and non-mountainous areas, a new standard of rainstorm early warning signal is formed to distinguish mountainous and non-mountainous areas, so that the defense work is more targeted; Combine all kinds of meteorological disasters caused by short-term heavy precipitation, hail, tornado and other strong convective weather as strong convective disasters, formulate early warning and early warning signal standards for strong convective disasters, and realize targeted release of early warning information to towns and villages.

Since the launch of the new threshold standard, the average release times of rainstorm warning signals in pilot cities and counties have decreased by 79% compared with the past three years, and the average release times of severe convective weather warning signals have decreased by 93%. The early warning signal realizes accurate targeted release, and the average production and release time is reduced by 9 minutes. After the pilot cities and counties adopted the new early warning signal publishing platform, the error-free proportion of early warning signals increased from 99.7% to 100%, and the proportion of fine early warning signals to villages and towns increased from 94% to 99.8%.

Looking forward to the future, Anhui Meteorological Bureau will strengthen the collection of feedback effect and the inspection and analysis of the old and new early warning threshold standards, and further revise the release standards; In-depth cooperation with the competent departments of disaster-related industries, docking the contents of early warning and early warning signals such as heavy rain and strong convection into meteorological disaster prevention laws and regulations and local government emergency plans; At the same time, the "cloud+terminal" digital intelligent idea is applied to optimize the early warning business process, improve the integrated platform of short-term and imminent forecasting in provinces, cities and counties, and enhance the standardization of early warning business. (Wang Bing Li Yuanni)

Shaanxi:Multi-level linkage adds new impetus to early warning service

Shaanxi Meteorological Bureau put forward the working goal of "reflecting the characteristics of heavy rain in the north and south, highlighting the early warning threshold of rain intensity, constructing fine early warning strategy and smoothly transitioning the old and new standards", and according to the working idea of "scientific formulation at the provincial level, actual revision at the municipal level and trial improvement at the county level", four pilot cities, including Yan ‘an, Baoji, Hanzhong and Xi ‘an, were selected to set up a joint technical team of provinces and cities to develop new threshold standards for early warning signals of heavy rain.

According to the results of meteorological disaster risk survey in three major terrain areas and big cities, the pilot municipal bureau has formed a new standard system of rainstorm warning signals by geographical region, rainfall type and disaster impact, formulated supporting refined release terms and strategies, and set up "one county, one policy" risk warning terms and defense guidelines that reflect the differences between urban and rural areas and geographical conditions.

At present, Shaanxi has successfully completed the adjustment and pilot release of rainstorm warning signal standards, highlighting the four characteristics of rainstorm and secondary disasters in Shaanxi. The threshold standards of 12-hour, 6-hour and 3-hour reflect the overall equivalent characteristics of precipitation in the rainstorm process in the three regions of North, South and Central China. The 1-hour threshold standard reflects the ladder-like characteristics of the disaster-bearing capacity of extreme rainfall intensity in the north, south and central regions; The threshold standard of continuous rain reflects the actual situation that the intensity of autumn rain is moderate but lasts for a long time and the risk of disaster is high. The threshold standard of rainstorm in big cities in Xi ‘an is connected with the standard of waterlogging intensity in municipal departments.

Not only that, the pilot work has also formulated a refined early warning signal release template, adding early warning terms and defense guidelines for different geographical environments. At the same time, the new standard adds a one-hour threshold standard to fill the gap of short-term rainstorm warning; Increase the content of risk warning and strengthen the pertinence of disaster early warning; Distinguishing the release terms of different township early warning levels has strengthened the directivity of disaster response. Grass-roots government departments generally said that accurate and meticulous meteorological early warning provided a strong guarantee for the county flood control headquarters to carry out targeted emergency work, especially in guiding relevant towns and villages to carry out emergency evacuation work.

In the future, Shaanxi Province will continue to strengthen grass-roots business personnel’s application study of national scientific and technological achievements, research and development of provincial short-term and imminent forecasting technology and upgrade of business systems, further adjust the workflow of early warning signal release and dissemination, continuously improve and develop the linkage mechanism between local departments, and carry out popular science propaganda of new standard rainstorm warning signals and declaration of local standards. (Tang yukun)

(Editor: Zhang Lin)