This achievement is a systematic analysis and summary of the research and service of meteorological early warning and prediction of geological disasters in the past nine years. Three methods of regional early warning of geological disasters are put forward, including implicit statistical prediction method, explicit statistical prediction method and dynamic prediction method, and the research and application of two generations of regional meteorological early warning technologies of geological disasters (implicit statistical prediction method and explicit statistical prediction method) are systematically carried out. Throughout the country, the occurrence regularity of geological disasters under different strata, structures, climate and other conditions was studied in different regions, and an early warning model of geological disasters was established. Significant progress and innovative achievements have been made in the study of regional meteorological early warning methods for geological disasters, which has created a precedent for meteorological early warning of geological disasters in Chinese mainland, provided technical guidance and reference for meteorological early warning of geological disasters at the provincial level, and has been recognized by governments at all levels and the public.
1. Regional Early Warning Principles for Geological Disasters
This paper puts forward three divisions of geological disaster regional implicit statistical prediction, explicit statistical prediction and dynamic prediction, and designs and develops two systems of implicit statistical prediction and explicit statistical early warning of geological disasters.
(1) implicit statistical prediction method
Implicit statistical forecasting method implies the role of geological environment factors in rainfall parameters, and only the critical rainfall parameters are considered in the early warning criterion of a certain area to establish the model. Implicit statistical method can be called the first generation prediction method, which is more suitable for small areas with simple geological environment model. Using this method, the first generation national geological disaster early warning system was designed and implemented, and it was applied in 2003 ~ 2007.
(2) Explicit statistical prediction method
Explicit statistical prediction method is a method to establish early warning criterion model considering geological environment change and rainfall parameter superposition. It is transformed from geological disaster risk zoning and spatial prediction. This method can fully reflect the changes of geological environment elements in the early warning area, and with the improvement of investigation and research accuracy, the spatial early warning accuracy of geological disasters can be improved. Explicit statistical method can be called the second generation prediction method, which is more suitable for large areas with complex geological environment models. Based on the spatial analysis of geological environment, combined with the results of unit analysis, this method is realized by gridding the "potential" of geological disasters in units and divisions, which overcomes the limitation of relying only on a single critical rainfall index, and can be further upgraded in the expression of critical inducing factors, the selection of early warning indicators and quantitative grading. Using this method, the second generation national geological disaster early warning system is designed and implemented, and it has been applied since 2008.
(3) Dynamic prediction method
Dynamic prediction method is a method of establishing early warning criterion equation considering the dynamic change process of soil mass under the coupling effect of ground and atmosphere during rainfall, which is essentially an analytical method. The prediction result of dynamic method is deterministic, which can be called the third generation prediction method. At present, this method is only suitable for a single test area or a local area that is particularly important because of the need for precision instrument detection. Based on the transformation mechanism of rainfall infiltration in slope before, during and after rainfall, this method specifically describes the corresponding relationship between the change of groundwater dynamic action in slope and the change of slope stability in the whole process. The first person who completed the achievement established the first experimental area in Ya 'an, Sichuan.
2. The first generation of national geological disaster early warning system
Early warning zoning: according to the statistical analysis results of the national geomorphological pattern, geological environment characteristics and their relationship with rainfall-induced landslide geological disasters, based on the national river basins, climatic zones, structural units and regional geological environment conditions, the first-level zoning is carried out; According to the distribution density, topographical features, stratigraphic lithology, geological structure and neotectonic movement, and annual average rainfall distribution of regional watersheds, historical landslides and debris flows, the secondary zoning is carried out. The whole country is divided into 7 early warning zones and 74 early warning zones.
Criterion of critical rainfall: The relationship between landslide and debris flow and rainfall is studied by statistical analysis method, and the scatter diagram of the relationship between landslide and debris flow and critical rainfall in different periods is made. Scattered points are concentrated into bands, and the upper bound can be expressed by β line and the lower bound by α line. Based on the rainfall of 1, 2, 4, 7, 10 and 15, the model diagram of geological disaster early warning criterion is established as the critical rainfall criterion.
Special symbol for early warning: A special "symbol" for meteorological early warning and forecasting of geological disasters was designed and produced. Since 2005, CCTV has released pictures of geological disaster meteorological early warning information, at the same time, it also distributed animations of collapse, landslide and debris flow, which enhanced the visual impact of geological disaster early warning information, and also improved the social influence of geological disaster meteorological early warning and the national awareness of disaster prevention.
Early warning software system: From 2003 to 2006, the model adopted the first generation critical rainfall standard method, and developed the early warning and forecasting software based on C language. In 2007, the model still adopted the first generation of critical rainfall standard method, and developed the second set of early warning and forecasting software based on ArcGIS.
3. The second generation national geological disaster early warning system
The establishment process of early warning model: ① geological disaster early warning zoning, which divides the whole country into seven early warning regions and establishes early warning models by regions; (2) The compilation of meteorological early warning information layer of geological disasters should fully consider the basic information of geological environment and the historical occurrence of geological disasters. * * * 30 early warning information layers have been compiled, and a relatively complete national meteorological early warning and forecasting information system for geological disasters has been established. The accuracy of main layers has been improved from1:6 million in the first generation to1:kloc-0/10,000; ③ Calculation of geological hazard potential; ④ Establish a statistical early warning model.
(1) explicit statistical early warning model method
According to the theory of regional early warning and forecasting of geological disasters, the explicit statistical early warning method comprehensively considers geological environment factors and rainfall factors, that is, different from the critical rainfall template method, the early warning model should not only consider the role of rainfall factors, but also include indicators of geological environment factors. Geological environment factors are complex and diverse, so it is measured by a comprehensive index, and rainfall factors are measured by two indexes.
Select "potential degree of geological disasters" (g) as a comprehensive index of geological environment factors; Daily rainfall (Rd) and previous rainfall (Rp) are used as indicators of rainfall inducing factors. Taking G, Rd and Rp as input and the actual occurrence of historical geological disasters as output, statistical analysis is made and an explicit statistical early warning model is established. The general functions are as follows:
T=G+Rd+Rp
Where: t is the early warning index, and the meteorological early warning level of geological disasters is determined accordingly; G is the potential degree of geological disasters and a quantitative index of geological environmental conditions; Rd is the daily rainfall, which is the rainfall on the day of geological disasters, and the forecast rainfall is used for early warning analysis; Rp is the previous cumulative rainfall, which is the cumulative rainfall before the geological disaster.
(2) Special early warning symbols
The second generation of early warning animation symbols are designed. When CCTV- 1 released the pictures of early warning products, the animation of early warning symbols and the broadcast form of announcers were distributed at the same time, which significantly improved the realism and aesthetic effect of the second generation of early warning symbols.
(3) Early warning software system
The second generation national geological disaster early warning system is based on Microsoft Windows operating system, Office system and Map-GIS platform, which has the functions of convenient layer management, early warning calculation and automatic zoning. It can realize the automatic service of daily early warning and forecasting, and integrate two generations of model methods, geological environment background, rainfall data and other real-time queries and convenient interactive operations.
Second, the scope of application and application examples
From 2003 to 20 1 1, the first and second generation national geological disaster forecasting and early warning systems have been applied to the national geological disaster meteorological forecasting and early warning work for 9 years, and the geological disaster early warning information was released on CCTV for 639 times, on China Geological Environment Information Network for1/kloc-0 for 33 times and in china national radio for/kloc-0. The national meteorological early warning of geological disasters also provided targeted early warning and forecasting services for the rescue and relief of Wenchuan earthquake in May 2008, Yushu earthquake in April 20 10 and Zhouqu catastrophic mountain torrents and mudslides in August 20 10.
The meteorological early warning system of geological disasters has been developed and served for 9 years, which has obviously improved the public's awareness of prevention in areas prone to sudden geological disasters. In particular, it has played an important role in reducing economic losses caused by geological disasters, reducing casualties, raising people's awareness of disaster prevention and mitigation, promoting social stability and protecting important infrastructure, and has been widely recognized by all walks of life. This work has also been affirmed and appreciated by the Prime Minister, Vice Premier Zeng, Vice Premier Hui Liangyu, Minister Sun Wensheng and Minister Xu.
Typical inspection example:
On August 19, 2007, the results of rainfall forecast by the National Meteorological Center showed that there was a rainstorm (50 mm) in southern Zhejiang, the whole of Fujian and the northeast of Guangdong. Among them, there are heavy rains (100mm) in southern Zhejiang, most of Fujian and northeastern Guangdong, and heavy rains (250mm) in eastern Fujian. After comprehensively analyzing the "potential degree" of geological disasters, meteorological forecast rainfall and actual rainfall in the early meteorological period, the national geological disaster prediction and early warning software is used to predict and automatically generate early warning results.
According to the feedback of geological disasters, there were a total of major geological disasters 105 in China during this early warning period, including 80 in Fujian, 5 in Yunnan and 0/0 in Hunan. Among them, 90 disasters are within the scope of level 5 early warning zone, 3 disasters are within the scope of level 4 early warning zone, 6 disasters are within the scope of level 3 early warning zone and 6 disasters are outside the scope of early warning zone.
Third, promote the transformation mode.
He has published many research papers in core, EI and other journals, and held many academic conferences. Published the monograph "Regional Early Warning Method and Application of Geological Disasters in China", and the second generation national geological disaster early warning software system and publishing system based on explicit statistical early warning model obtained two computer software copyright registration certificates.
Since 2003, the related research results of the theory and method of meteorological early warning and forecasting of geological disasters have been successfully applied to the meteorological early warning and forecasting of geological disasters jointly carried out by the Ministry of Land and Resources and China Meteorological Bureau. Driven by the cooperative demonstration of the Ministry of Land and Resources and the China Meteorological Bureau, the meteorological early warning and forecasting of geological disasters has been carried out in 30 provinces, 223 cities and 1035 counties. From June 2003 to 20 10, through the combination of meteorological early warning and forecasting of geological disasters, geological disaster investigation and group monitoring and prevention, 5,356 geological disasters were successfully avoided throughout the country, avoiding casualties of 29180,000 people and property losses of 3.77 billion yuan. In view of the remarkable achievements made in disaster prevention and mitigation in the past eight years and social recognition, the Ministry of Land and Resources and the China Meteorological Bureau signed the Cooperation Framework Agreement on Deepening Meteorological Early Warning and Forecasting of Geological Disasters on June 4th, 20 10.
Therefore, with the increasing demand for meteorological early warning and forecasting of geological disasters, the related research results of meteorological early warning and forecasting theories and methods of geological disasters will be further studied and applied, and will play a greater role in the prevention and control of geological disasters.
Technical support unit: China Geological Environment Monitoring Institute (Geological Disaster Emergency Technical Guidance Center of Ministry of Land and Resources).
Contact: Liu Yanhui
Mailing address: No.20 Dahuisi, Haidian District, Beijing
Postal code: 10008 1
Tel: 010-62192513.
E-mail :liuyh@mail.cigem.gov.cn