Risk-based Warning and Services of Meteorological Disasters In China
Wei Li
National Meteorological Center of CMA
September,2016
Page 1 Page 2 Multi-hazard Risk Analysis and Assessment
Weather event
typhoon
rain storm
lightning …… Low Middle high Construction sites Electrical facilities Railway transport Exposure Weather Telecommunication facilities events ……
Vulnerability Disaster Risk Exposure Vulnerability
Page 3 页 面 2018-10-30 3 Major Meteorological Hazards in China
§ Almost all the meteorological Drought disasters happen in China. § 71% of all natural disasters Flood are meteorological disasters in China. § The major meteorological disasters are drought, flood, typhoon, etc. Heat wave Drought Hail & Gale Typhoon
Typhoon Sand/dust storm Gale Flood
Page 4 4 Increasing Risks of Meteorological Hazards l River and mountain floods caused 2/3 of the total death toll related to meteorological hazards, and 70% or 80% of the total economic losses. l Starting from 2008, each year would see waterlogging and urban floods occurring in more than 130 cities. In 2010, 258 cities reported waterlogging incidences. (CSREX, 2014)
Mountain Floods Basin Floods
Mega Cities Ex Waterlogging trem Landslides e ev ents Mud Flow
Page 5 CASES OF HAZARD IMPACTS Mountain Floods and Waterlogging Induced by heavy rainfall from 18 to 21 July,2016, Taihang mountain region, Hebei Province
Mud Flow
l Maximum precipitation reached 785mm from 18 to 21 July, Cixian county lThe maximum precipitation in 24 hours
City Waterlogging reached 433mm in Jing Jing county, 314 mm in Shijiazhuang city lInduced floods, landslides , mud flow in mountain areas and waterlogging in urban areas
Page 6 CASES OF HAZARD IMPACTS Catastrophic Heavy Rainfall and Floods in Beijing, July 21, 2012
l Maximum precipitation reached 460mm ( comparing to annual rainfall of 546mm) l Hourly maximum precipitation reached 100 mm l Induced floods and waterlogging in urban areas and landslides in suburban areas lLPaegfet 7 a death toll of 78 people. • CMA has put risk assessment and risk-based warning of meteorological disaster as key priorities of public meteorological service. • Up to now, an operational system of risk- based warning has been established, covering risk survey, identification, warning, and assessment.
Page 8 1. Risk Survey RISK Hazard Exposure Vulnerability
l Weather factors l Geographic settings l Losses l Inundation l Climate factors l Socioeconomic l Demographic information information l Hydrological factors l Susceptibility l Geological context l GIS for exposure l Resilience
Survey Flood Risk Survey
Since 2012, CMA, in cooperation with DMAs, has carried out risk surveys on floods, flash floods, landslides and mud flows induced by heavy rainfall in small and medium-sized river basins. This task has come to an end in 2190 counties in China, covering 5860 small and medium-sized river basins, 17759 flash flood sites, 12438 mud flow sites, and 53589 landslide sites. Totally, more than 1,1P6a0ge, 0900 records have been collected. 2. Risk Database
• A database on historical meteorological disasters in China has been set up. • It covers more than 2000 counties and spans nearly 30 years. • It includes information on 28 types of disasters, such as drought, flood, typhoon, frost, heat wave, heavy snow, etc. • It also includes impact information from different sectors, such as society, agriculture, animal husbandry, irrigation, industry, forestry, fishery, transportation, power generation, telecommunication, Infrastructure, commerce and other industries.
Page 10 3. Thresholds of Disaster
• The correlation between precipitation and disaster is identified and the precipitation thresholds leading to disaster with different time scales and levels are calculated by using statistical analysis methods and hydrological models
• For each river and potential sites of flash food, landslide and mud flow. . Four risk levels are implemented with distinct colours, i.e. blue (low risk), yellow (medium risk), orange (high risk) and red (extremely high risk).
• These risk levels are coupled with different time scales corresponding to certain rainfall duration (48h, 24h, 12h, 6h, 3h and 1h).
• A total of 120040 threshold values have been developed up to now.
Page 11 Thresholds-based risk assessment and warning Four Levels of Warnings Level-1 Levee height 120cm Flood path +1.8m
Level-2 Guard line 60cm Flood path +1.2m
Level-3 Guard line 20cm Flood path +0.6m
Level-4 Guard line Flood path 5cm water level
Urban areas Rural areas Small and medium river flood Urban waterlogging Mountain flood
Page 12 Methodology 1: Modeling
Vulnerable sites: flood path Field trip
Vulnerable site Modeling a rainfall- flood process
Different levels of rainfall thresholds
Relationship of Submerged Depth with Rainfall Technical tips 1. Field trip to typical sites of floods, collecting geographical data; 2. Simulating typical mountain flood event to derive the relationship between rainfall and submerged depth; 3. Defining rainfall thresholds according to Page 13 submerged depths. Methodology 2: Analogy
Similar Mountain Valleys Target Mountain Valleys Rainfall scenarios and Flood Modeling
Warning Site
Technical tips: Rainfall Thresholds for In case of no geographic data, use data of Different Submerging mountain areas with similar topography. Scenario
Page 14 Methodology 3: Statistics
Hourly water level and rainfall
Water Level Obsevation
Rainfall Thresholds for Warning Water Level Rise W1小ate时r L上ev涨el水 Ri位se Rainfall i n Hours （(M米/h）) (MM/3h)
1 75.3 1.5 106.8 2 138.4 3 201.5 4 264.6 Technical tips: 1. Establish the correlation between area precipitation volume and water level rise Page 15 2. Estimate water level rises based on the rainfall forecast. Methodology 4: Hydrological Model
Met eorology
QPE QPF
Runoff generation and routing Runoff depth Hy drology Surface Runoff Underground Runoff and channel flow
waterstage Discharge Water-soil coupling mechanism Soil mechanics
Technology flow chart
Geologic hazard （Landslides and mud flow） warning
Page 16 4. Refined Quantitative Precipitation Estimation (QPE) and Forecast (QPF) QPE/QPF system has been established by CMA. This has provided operational support for risk-based warning. Q P E
Satellite Surface Radar data observations Echoes Q P High-resolution NWP F products
Gridded QPF products P with high resolution Q Ensemble P Predictions F
Ensemble quantitative precipitation probability Page 17 forecast ：24HR PQRF >=0.10mm 5. Meteorological Risk Assessment
• Based on meteorological forecast and historical loss data, this risk assessment can provide necessary information of e.g. the spatial coverage, depth, and duration of a precipitation triggered inundation and can estimate possible losses of the disaster.
Flash Flood Risk Map in Meixi Watershed in Fujian Province of China Page 18 -
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6. Oper rational System y i e
a n B T i h R m r b R r e R o / s f t - U W i a l B m p I -
QPE n e o o
s i e t Policy s t a i t a e n D a maker m d
l l a a c i c d - i r r QPF r o o r o t o e t c o d s f s i s y e i n a i h H General R b H public Monitoring and forecasting
Early warming Evaluation
Risk Warning Operation Platform
• The system now includes the following components: monitoring, real-time data, threshold-based warning, man-computer interaction warning revision, warning approval and issuing, etc. • Using this system, forecasters can determine the risk level and can produce risk-based warning service products. • Currently, the system has been applied through meteorological bureaus for more than Page 13900 cities and 2000 counties within 31 provinces. 7.Real-Time Services
• Real-time services of risk-based warning have been carried out at national, provincial, city, and county levels. • Geological hazard warning is jointly disseminated by the Ministry of Land Resources and CMA. • Flash flood warning is jointly disseminated by Ministry of Water Resources and CMA. • The production, correction and dissemination of the warning products are the responsibilities of the meteorological services at provincial, city and county level.
Page 20 CASE 1: MOUNTAIN FLOOD WARNING FOR TOWNSHIP (Fujian Provence) Predicted rainfall Flood in on June 19, 2014 Dengfangxi
Flood Depth: 1.8m Observed rainfall Rainfall: 92mm Affected Villages: 3 Dengfang Chawei Chenfang
Page 21 CASE 2: RIVER FLOOD WARNING FOR BASINS (Anhui Provence)
Predicted Rainfall for July 5, 2013
Site Estimated Submerging Depth(M) Muzheng 1.2 Rongcheng 0.7 Dingqiao 1.1 Maotan 0.3 Xinqiao Datong River Basin Rainfall: 0.6 3-h Maximum Rainfall: 114mm 6-h Maximum Rainfall: 147mm
Page 22 CASE 3: URBAN WATERLOGGING RISK WARNING (Megacity, Guangzhou)
Observed submerging depth at Jinan University: 100cm Predicted depth: 126cm
Observed Depth of Tianhe Road: 70cm Observed Depth at Predicted Depth: 86cm Gangding: 60cm Predicted Depth: The Accuracy of urban waterlogging warning 76cm for depth ≥20CM reached 76%. Page 23 s l e v 8. Dissemination of Risk-based Warning Information e l l
l Department of Transportation; Ministry of Finance ;Ministry of d a
Civil Affairs; Ministry of Land and Resources; Earthquake n t 1 a a n
Administration; Ministry of Water Resources ; Ministry of d w d e o e 【Cross-sector】 Health; China Meteorological Administration; Ministry of i l h 2 d
- Central Sharing information c p Foreign Affairs…
p a p 【 Government with DMAs and o e a
r other policy makers T 25 Ministries n o i t a 3 Dissemination m r
o 短信
f 31 Provinces
】 SMS n I Website User Emergency information Email Interface 电话 distribution system Landline 电视 TV SMS 传真 343 Cities Management Platform dissemination Fax Commun SMS platform Collection Proce- cation n ssing io Display Feedbaactk b in 大喇叭 eem Loud- Wss Sharing Monitoring di 广sp播eaker Broadcast ck … … Assessment ba Feedback ed report Fe …… Website platform 2015 Counties Evalution feedback system
PageN 24ational Emergency Dissemination System 9. Mechanism of Disasters Prevention and Mitigation
Ø Meteorology Law of the People's Republic of China
Ø Regulation on the Defence against Meteorological Disasters
Ø Planning on the Defence against Meteorological Disasters
Ø Emergency Plan on National Meteorological Disasters
Ø Opinions of the General Office of the State Council on Strengthening Meteorological Disaster Monitoring, and Warning and Information Distribution
Ø …
Page 25 25 Prevention of meteorological disasters chain in China
Forecasting Forecast Emergency monitoring Risk transfer and warning impacts Response
•Elements Weather event •Assessment •Emergency •Insurance •Disasters Risk warning plan compensation •Zoning •Action •Post-disaster reconstruction
页 面 Page 26 26 Warning Disaster- governance induced threshold Database of exposure & vulnerability Accurate and precise of weather Under the framework of “Government Leadership, forecast Cross-sector Coordination, Public Participation” , effective warning information will promote the further development of the disaster risk assessment and early warning system.
Strengthening the Improving the early Strengthening R&D, Strengthening understanding of warning system, technical training cross-sector disaster risk streamlining and expert team coordination and assessment and business processes development and exchanges to early warning and establishing the promoting maximize the Service IBW/RBW system application in benefits of the early grassroots services warning system
Page 27 The national flood risk survey and the determination of the disaster thresholds in China should be completed as soon as possible. The accuracy and precision of the weather forecast needs to be further improved. To enhance the risk-based warning system and to improve the service level . This will better serve and safeguard people's welfare and the sustainable development of the national economy.
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