The New Inland Flood Model and Updated Typhoon Model for Japan Marc Marcella, Ph.D. Yang “Gabby” Gao, Ph.D. Ruilong Li, Ph.D. CONFIDENTIAL ©2017 AIR WORLDWIDE 1 Agenda - Modeling Flood Hazard for Japan - Modeling Flood Vulnerability for Japan - Updates to the AIR Typhoon Model for Japan CONFIDENTIAL ©2017 AIR WORLDWIDE 2 Modeling Precipitation in Touchstone JapanTyphoon Typhoon Related Model Perils Non Tropical Typhoon Typhoon Tropical Cyclone Cyclone Wind Surge Precip. Flood Precip. Flood JapanWater Inland Related Flood Perils Model - SOLUTIONS in Touchstone®: • Two models in Touchstone - AIR Typhoon Model for Japan: wind, surge, tropical cyclone precipitation flood - AIR Inland Flood Model for Japan: non tropical cyclone precipitation flood CONFIDENTIAL ©2017 AIR WORLDWIDE 3 Modeling Flood Hazard for Japan CONFIDENTIAL ©2017 AIR WORLDWIDE 4 Flood Model Components GEOPROCESSING PRECIPITATION HYDROLOGY HYDRAULICS VULNERABILITY CONFIDENTIAL ©2017 AIR WORLDWIDE 5 Flooding in Japan Flood peril is a significant risk for Japan • 50% of population and 75% of assets located in a floodplain • Major evacuations, loss of life, and billions in damage Aso, Kyushu - 2012 Koshigaya, Honshu - 2015 Non Tropical Cyclone Tropical Cyclone Rainfall 40% 60% CONFIDENTIAL ©2017 AIR WORLDWIDE 6 Geoprocessing GEOPROCESSING HYDROLOGY HYDRAULICS CONFIDENTIAL ©2017 AIR WORLDWIDE 7 17,425 ~1,100 river dams & Reservoirs segments ~1,000 103,000 km streamflow total stream gauge stations length 2 20,263 338,000 km catchments modeled CONFIDENTIAL ©2017 AIR WORLDWIDE 8 Geoprocessing Data Layers Digital Terrain Model Model Boundary: (DTM): Country Border Provided by MLIT Unit Catchments: River Network: From DTM & River Derived from DTM Networks Catchment Properties: Land Use: JAXA, MODIS, Cross Sections: AIR , Impervious Surface: MLIT & DTM River Network NOAA & Soil: MLIT Dams & Reservoirs: Flood Defenses: MLIT, iCold, GRAND & DTM & River Network SRTM CONFIDENTIAL ©2017 AIR WORLDWIDE 9 Japan Digital Terrain Model Availability ➢ 5m DTM covers 60% of Japan ➢ Most major cities and rivers included ➢ 10m DTM used to supplement remaining area 10m5m DTMDTM CONFIDENTIAL ©2017 AIR WORLDWIDE 10 Precipitation Generation PRECIPITATION HYDROLOGY HYDRAULICS CONFIDENTIAL ©2017 AIR WORLDWIDE 11 Overview of Steps for Simulating Precipitation 1. Numerical modeling of historical TC events and non TC rainfall 2. Stochastic simulations of precipitation learning from numerically modeled precipitation 3. Blending of non TC and TC precipitation. 1. 2. 3. CONFIDENTIAL ©2017 AIR WORLDWIDE 12 Step 1: Numerical Modeling Coarse-Resolution Fine-Resolution Global Model Regional Model downscaling General Circulation Model, Numerical Weather Prediction Reanalysis Data Model Regional Domain Selection for Numerical Weather Prediction (fine resolution) CONFIDENTIAL ©2017 AIR WORLDWIDE 13 Step 2: Stochastic Simulation of Non TC Precipitation Numerical Weather Prediction Model Stochastic Simulation Output Statistically robust perturbation of precipitation patterns CONFIDENTIAL ©2017 AIR WORLDWIDE 14 Step 2: Stochastic Simulation of TC Precipitation Group models in bundles representing different stages during a typical TC life cycle: 1. Central pressure 2. Storm evolution time (genesis, dissipation, etc.) At simulation stage, draw samples from distinct models according to stochastic tracks: 1. Central pressure value 2. Time within storm cycle of stochastically simulated Japan catalog track CONFIDENTIAL ©2017 AIR WORLDWIDE 15 Step 3: Blending Non TC and TC Precipitation Tropical cyclone simulations are blended into the non tropical cyclone rainfall simulation BLENDED CONFIDENTIAL ©2017 AIR WORLDWIDE 16 Hydrology Model PRECIPITATION HYDROLOGY HYDRAULICS CONFIDENTIAL ©2017 AIR WORLDWIDE 17 Hydrologic Model: Transforming Precipitation to Flow Precipitation Runoff and Flow Generation Probability Distributed Model (PDM) Snow Model Flow Time Muskingum-Cunge Channel Routing Flow Time CONFIDENTIAL ©2017 AIR WORLDWIDE 18 Hydrologic Modeling Stages Develop All Model Components River (Snow model, runoff, River Flow Network & reservoir, diversions, etc.) Topography New Bayesian Aproach Compile Input Hydrological Model Data Calibration Others.. Met Data Calibrated Parameters Simulate Simulate 35 Year 10K Historical Stochastic Dynamically Stochastic Downscaled Events Events Validate Validate Historical Stochastic Events/ Catalog Catalog CONFIDENTIAL ©2017 AIR WORLDWIDE 19 Reservoirs, Dams, and Diversions Metropolitan Area Outer Underground Discharge Kurobe Dam, Honshu Channel, Greater Tokyo Tokuyama Dam, Ibigawa • Reservoirs/dams significantly attenuate the flows downstream • The operation rules (reservoir rule curves) determine the desired reservoir stage at any given time CONFIDENTIAL ©2017 AIR WORLDWIDE 20 Hydraulics Model PRECIPITATION Riverine flooding Flash flooding On-floodplain HYDROLOGY HYDRAULICS Off-floodplain FLUVIAL PLUVIAL Widespread Localized CONFIDENTIAL ©2017 AIR WORLDWIDE 21 Pluvial: New Off-Plain Flood Model Precipitation Intensity Urban Area Drainage 2D Pluvial Model Schematic CONFIDENTIAL ©2017 AIR WORLDWIDE 22 Pluvial Flood Model: Storm Drainage Capacity in Urbanized Areas Drainage sufficiency rate and design precipitation are used to estimate storm drainage capacity Drainage Sufficiency Rate (%) Precipitationhigh85 7 yr 2 hr (mm) Drainage Capacity (mm) low15 High High High Low Low Low CONFIDENTIAL ©2017 AIR WORLDWIDE 23 Fluvial: Explicit Two-Dimensional Modeling withstand after SOP failure before SOP Flood defense failures are dynamically simulated with one-sided failure possible failure point Wide floodplains modeled more effectively, with a more-robust approach and more-complex conditions CONFIDENTIAL ©2017 AIR WORLDWIDE 24 Summary of Advancements - Unified view of hazard, including tropical cyclone and non tropical cyclone rainfall - New, improved approach to hydrologic model calibration, as well as detailed reservoir representation - New physically based off-plain flood model explicitly simulates pluvial flooding - Explicit modeling of certain failure points, including one-sided flood defense failure CONFIDENTIAL ©2017 AIR WORLDWIDE 25 Modeling Flood Vulnerability for Japan CONFIDENTIAL ©2017 AIR WORLDWIDE 26 AIR’s Inland Flood Modeling Experience Inland Flood Model for Inland Flood Model for Germany Central Europe 2008 2011 2014 2015 2017 Inland Flood Model for Inland Flood Model for the Inland Flood & Typhoon Great Britain United States Models for Japan CONFIDENTIAL ©2017 AIR WORLDWIDE 27 Vulnerability Modeling Framework: Overview of Risk Features and Modeling Approach First Floor Ceiling Height Height Water Depth Basement Ground Elevation CONFIDENTIAL ©2017 AIR WORLDWIDE 28 Vulnerability Modeling Framework: Overview of Risk Features and Modeling Approach CONFIDENTIAL ©2017 AIR WORLDWIDE 29 Primary Risk Features Supported in Japan Conventional Occupancy, Construction, Height, and Coverage ➢ Composite Construction Class (Fire Codes) ➢ Low Rise: 1-, 2-, and 3-Story ➢ Unknown at Prefecture level CONFIDENTIAL ©2017 AIR WORLDWIDE 30 Special Properties Supported in Japan Inland Flood Modeling Marine, Inland Transit, Builder’s Risk, and Railway ~147,000 unique damage functions CONFIDENTIAL ©2017 AIR WORLDWIDE 31 Vulnerability: Component-Level Approach to Developing Damage Functions • Buildings are divided into 6 components, which total 100% of replacement value • Component-level damage functions (DFs) are then combined in proportion to their contribution to the overall replacement value CONFIDENTIAL ©2017 AIR WORLDWIDE 32 Vulnerability: Component-Level Approach to Developing Damage Functions Electrical Interior Foundation Mechanical Plumbing Structures U.S. Single-Family Home: Japan Single-Family Home: Wood Building Wood Building CONFIDENTIAL ©2017 AIR WORLDWIDE 33 Data Sources for Vulnerability Model Development ✓ Construction Research Institute Monthly Price Index ✓ Japan Survey and Inter-Risk Research Institute ✓ Japanese Architecture Disaster Prevention Association Ministry of Land, Infrastructure and Japanese & Global Publications Transport Water Management (MLIT) CONFIDENTIAL ©2017 AIR WORLDWIDE 34 Component-Based Damage Functions Evaluation Single-Family 3-Story Home: Steel Single-Family 3-Story Home: Wood Damage Function Damage Function Mean Damage Ratio Damage Mean Mean Damage Ratio Damage Mean Inundation Depth Inundation Depth CONFIDENTIAL ©2017 AIR WORLDWIDE 35 Benchmarking Loss Sources for Loss Validation • MLIT National Flood Database • Industry reports and research publications about major historical events losses CONFIDENTIAL ©2017 AIR WORLDWIDE 36 Regional Distribution of Total Flood Risk 5% 4% 21% 10% 31% 8% 4% 17% CONFIDENTIAL ©2017 AIR WORLDWIDE 37 Regional Distribution of Flood Risk for TC and Non TC Flood 5% Total 4% Total 2% TC 21% Total 3% Non TC 2% TC 12% TC 2% Non TC 9% Non TC 10% Total 31% Total 7% TC 25 % TC 3% Non TC 6% Non TC 8% Total 4% TC 17% Total 4% Non TC 4% Total 12 % TC 5% Non TC 3% TC 1% Non TC CONFIDENTIAL ©2017 AIR WORLDWIDE 38 Updates to the AIR Typhoon Model for Japan CONFIDENTIAL ©2017 AIR WORLDWIDE 39 Updates to the Typhoon Model for Japan Updated the IED and Introduced new IED enhanced building and and enhanced Introduce new IED, time element damage building damage new flood module, function (supported old function (supports and updated wind fire codes) new fire codes) and surge modules 2002 2007 2010 2012 2015 2017 Released the first Became part of the Introduced physically AIR Typhoon Northwest Pacific based storm surge Model for Japan Basinwide