West Virginia Statewide Flood/Landslide Risk Assessment
West Virginia Statewide Flood/Landslide Risk Assessment Maneesh Sharma, Kurt Donaldson, Eric Hopkins GISP, CFM WV GIS Technical Center West Virginia University u.edu;eric.Hopkins@mail.wvu.edu
Hazard Mitigation Grant Project A Statewide Approach to Risk Studies Multi-Hazard Risk Assessments Flood Risk #1 WV Hazard Landslide Risk #2 WV Hazard Reference Data Development Professional Services Flood Risk 4% Data 31% Vendor Contracts 27% Inventory of Building-Level Flood-Risk Structures Statewide Budget Breakdown Data Gap Services 17% Landslide Risk 21%
Hazard Mitigation Grant Multi-Agency Coordination Federal Agencies State Agencies 55 Counties 11 Regional Planning & Development Councils Universities Regional Councils Local Counties 232 municipalities Private Companies 3
Statewide Flood Risk Assessment (TEIF – Total Exposure in Floodplain) Devastating June 2016 Flood
Statewide Flood Risk Assessment Floodplain regulatory, advisory, and risk assessment products available to the State and published on the WV Flood Tool Community-level profiles generated that answer the questions what is at risk? what is the degree of risk? what has been mitigated? The statewide vulnerability study quantifies the hazard risk Flood-prone communities can identify potential mitigation projects consistent with a community’s capabilities and goals
Statewide Hazard Assessment 213 55 268 18 286 8 294 incorporated areas unincorporated areas NFIP Communities no SFHA communities WV Communities split communities Statistical Geographies 294 Statistical Geographies form 286 Communities which form 55 Counties which form 11 PDC Regions which form 1 Statewide Flood Risk Assessment 94% of WV Communities have Special Flood Hazard Areas (SFHA) 268 FloodProne Communities SPLIT COMMUNITY PDF Map Alderson Huntington Montgomery Nitro Paden City Smithers Wheeling Weirton COUNTY 1 Greenbrier Cabell Fayette Kanawha Tyler Fayette Marshall Brooke COUNTY 2 Monroe Wayne Kanawha Putnam Wetzel Kanawha Ohio Hancock
WV Building-Level Flood Risk Assessment Building-Level Flood Risk Assessments support: BLRA Cycle and Methodology Hazard Mitigation Plans Floodplain Management Community Assisted Visits Community Rating System 1 BUILDING INVENTORY Primary Building Identification & Hazus Attributes Essential Facilities & Community Assets Benefits More detailed and accurate assessments Automated scripts generate outputs quickly Cost savings through efficiencies Helps multiple stakeholders Comprehensive Building Risk Spatial Database Methodology Consistent methodology statewide Semi-automated workflows Continuous cycle to improve and update assessments 4 COMMUNITY ENGAGEMENT Risk Assessment Data Verification Building-Level Risk Assessment (BLRA) Cycle 2 FLOOD LOSS MODELS Open Hazus FAST Flood Depths Mitigation Actions Identified Building Damage Estimates 3 Tabular Output BLDG. LEVEL RISK ASSESSMENT (BLRA) DATABASE Published to WV Flood Tool Building Level & Community Level Outputs Map Output
Risk Assessment Layers on Flood Tool Dam Landslide Flood Zone https://www.mapwv.gov/flood/map/?wkid 102100&x -8771562&y 4715438&l 7&v 2 ,1690a,35y,44.59t/data !3m1!1e3 Potential Flood, Dam Failure and Landslide Vulnerabilities on WV Flood Tool’s RiskMAP View Hardy County, West Virginia
WV Statewide Risk Assessment Building Level Risk Assessment
High Risk Advisory Zones More info on High-Risk Advisory Zones Preliminary NFHL Advisory A Updated AE Preliminary NFHL Advisory A Updated AE
Floodplain Building Inventory Refer to Overview and Other Resources about WV Flood Tool Enhanced inventory of more than 98,000 building in high-risk floodplains completed by WVU in 2021 and published to WV Flood Tool Vulnerability Risk Assessment https://www.mapwv.gov/flood/map/?wkid 102100&x -8985707&y 4589317&l 3&v 2
Future Map Condition High-Risk Effective & Advisory 1%-Annual-Chance (100-Yr) Floodplains Residential Structure “remains same” in SFHA Residential Structure “mapped out” of SFHA Commercial Structure “mapped in” of SFHA WV Flood Tool Map Link Future Map Conditions for structures are inventoried for counties with mapped High-Risk Advisory Floodplains
Statewide Building Inventory Building Estimates 84,351 structures in SFHA 13,996 structures in “High-Risk” Advisory (Orange Zones) 354 Essential Facilities in High-Risk Flood Zones (K-12 Schools, 911 Centers, Police/Fire Stations Depts., Hospitals, Nursing Homes) Buildings Pre-FIRM/Post-FIRM 38 Essential Facilities in Regulatory Floodway 503 Essential Facilities total in both high and moderate risk floodplains 67% are Pre-FIRM (majority) 26% are Post-FIRM 7% are unknown Based on Building Year of assessment data All ESSENTIAL FACILITIES SHOULD BE FIELD VERIFIED Community Kanawha County* Logan County* Mingo County* Boone County* Wheeling** Lincoln County* McDowell County* Raleigh County* Mercer County* Wyoming County* Wayne County* Putnam County* Cabell County* Charleston Wood County* Fayette County* Randolph County* Greenbrier County* Marion County* Huntington** Buildings in SFHA 8,890 5,247 3,393 3,313 2,836 2,563 2,408 2,252 2,233 2,226 2,221 1,902 1,887 1,872 1,562 1,528 1,268 1,182 1,162 1,148 Top 20 Communities Building Counts by Flood Zone
Building Risk by Region Regions 10 and 11 high density Region 3 Highest % and Density Regions 1, 2, and 3 comprise 56% of flood-risk buildings PDF Map
Building Risk Reports Incorporate information from Risk Assessment Reports into local hazard mitigation planning All Regions: Building Types & Exposure All Regions: Essential Facilities Report All Regions: Community Assets Report
State Risk Assessment DATA FIELD VERIFICATION of MITIGATED PROPERTIES COMMUNITY ENGAGMENT IDENTIFY MITIGATED ACTIONS FOR HAZARD MITIGATION PLANS What mitigation actions can be identified
Field Verification Field Verification of the structure located at 781 Avon Bend Road in Charles Town along the Shenandoah River in the Regulatory Floodway reveals that this Post-FIRM (2011) structure is built on a piles foundation. The Foundation Type/First Floor Height will be changed in the Building Inventory and the OpenHazus Flood Assessment Structure Tool (FAST) utility executed again for this structure. Field Verification is important to improve the accuracy of certain properties! The estimated Base Flood Water Depth for this structure is 10 feet. 781 Avon Bend Road, Charles Town, WV 25414 Building ID 19-06-009H-0019-0000 781 WV Flood Tool Link: https://mapwv.gov/flood/map/?wkid 102100&x 8664165&y 4753090&l 13&v 1 Field Verified from Shenandoah River
Mitigated Properties - Verification Buckhannon, WV Elevation Certificate of Elevated Structure (Bldg. Diagrams 5-8) Verify MITIGATED STRUCTURE Verify BUYOUT PROPERTY Parcel https://mapwv.gov/flood/map/?wkid 102100&x -8929946&y 4721378&l 10&v 2
Areas of Mitigation (AoMI) Interest In progress PDF Map
Areas of Mitigation Interests / Repetitive Loss Areas Repetitive Loss Areas Substantial Damage Estimates High-Water Marks Buyout Properties https://www.mapwv.gov/flood/map/?wkid 102100&x -8669471&y 4802931&l 9&v 2
Local Community Engagement COMMUNITY ENGAGMENT & VERIFICATION Floodplain Building Risk Inventory Essential Facilities & Community Assets Risk Assessment Mitigated Structures Buyout Properties Areas of Mitigation Interest Other Mitigation Activities Risk Assessment Data for Community Engagement, Verification, and Identifiable Mitigation Actions incorporated into Local Hazard Plans Identifiable Mitigation Actions Local Hazard Mitigation Plan Primary Objective: Incorporating Mitigation Actions in Local Hazard Mitigation Planning
Community Rating System 8.5x11 PDF Graphic 11x17 PDF Graphic
Access Risk Assessment Info Use the Risk Information Index to access Data and Products Building Level Risk Assessment (BLRA) Products GIS Files Tables (Excel) o Community Level (CL) o Building (or Feature) Level (BL) with links to online maps Table Extracts Top Lists Maps o Interactive Web Maps o Graphics and Maps Reports (Word Docs) 3D Flood Visualizations Most of the risk assessment data can be viewed on the RiskMAP View of the WV Flood Tool
Statewide Hazard Assessment Landslide Risk Assessment
Landslide Risk Assessment Goals Develop landslide inventory Create valid landslide models for specific WV regions Generate county-level resolution landslide maps Create an interactive web map application for displaying landslide models and variables Use the new landslide models and information to update the State Hazard Mitigation Plan Did you know? Landslides are the #2 Hazard in West Virginia 2015 Yeager Airport Slide
Landslide Study Limitations Limitations 1. This study is suitable for overview planning-level and general emergency services planning 2. The risk analysis for roads should be used in conjunction with site-specific risk analysis performed by WV Department of Transportation 3. This study has NOT been done for, and may not be suitable for legal, design, engineering, or site-preparation purposes. 4. This study can NOT substitute for site-specific investigations by qualified practitioners. Landslide risk is complex and continually changing. Although other existing studies may provide more precise and comprehensive information, detailed original site investigations are normally an essential best practice for public safety, sustainability, and financial viability.
Landslide Incident Inventory Key Takeaways 1. 159,247 landslide features inventoried I. II. III. 66,151 landslide initiation points mapped using high resolution (1- or 2-m) LiDAR. 46,330 landslide polygons digitized based on WV Geological and Economic Survey 1976 study. 41,307 landslide polygons digitized based on a USGS 19751985 study. 2. Most common landslide - Slides and slumps 3. Future work - Landslide mapping in areas where LiDAR coverage was incomplete; LiDAR for these areas delivered by FEMA in December 2021.
Landslide Incident Inventory # Agency Year Author or Source Agency 1 WVGES 1973 Landers and Smosna 2 WVGES 197680 Lessing et al. 3 USGS 197885 U.S. Geological Survey Bulletin 1981: Geomorphic studies Cheat and Potomac River of the storm and flood of November 3-5, 1985, in the basins; Wills Mountain upper Potomac and Cheat River basins in West Virginia Anticline; Eastern WV and Virginia Research study (1985) 3,571 Landslide incidences with Images Instruction & landslide inventory 46 WVU 198397 WVU 6 WVU 1996 Kite and Grubb 7 WVU 2008 Konsoer et al 8 NPS/WVGES 2014 Yates and Kite 9 NPS/WVGES 2015 Yates and Kite 12 WVU 41,307 41 LiDAR, GIS, and multivariate statistical analysis to assess landslide risk, Horseshoe Run watershed, West Virginia 149 Horseshoe Run Watershed, Surficial Geology Mapping Tucker County Unpublished Digital Surficial Geologic Map of Bluestone National Scenic River and Vicinity, West Virginia (NPS, Bluestone National Scenic GRD, GRI, BLUE, BLUS digital map) adapted from a West Surficial Geology Mapping River and Vicinity Virginia University and West Virginia Geological and Economic Survey Open File Map by Yates and Kite (2014) Digital Surficial Geologic Map of New River Gorge National River, West Virginia (NPS, GRD, GRI, NERI, NERS digital New River Gorge National map) adapted from a West Virginia University and West Surficial Geology Mapping River Virginia Geological and Economic Survey Open File Report map by Yates and Kite (and Gooding) (2015) Geospatial Transportation Road landslide inventory Information (GTI) Section WVGISTC Statewide 46,330 Update of 1976 Landslide Maps, Morgantown North and Morgantown, West Virginia Landslide inventory South Quadrangles 2017 State Hazard Mitigation Office FEMA Buyout Properties for Landslides 2022 10 Statewide (382 topo quads) Landslide mapping 5 WVDHSEM Landslide mapping Landslide Quad Maps: Open File Maps Jacobson et al 11 Final Report on Landslides of July 9, 1973 in Kanawha City Charleston, West Virginia Area of Charleston, West Virginia Total Incidence Data USGS (various) 1993 2016 Purpose Statewide (39 topo quads) Landslide mapping USGS WVDOT General Location WV Landslides and Slide-Prone Areas; funded by Appalachian Regional Commission 4 10 Title/Description Statewide Landslide Risk Assessment; Funded by FEMA and WV Division of Homeland Security and Emergency Management 12 212 Statewide Landslide inventory 1,406 Southern West Virginia Landslide mitigation 12 Statewide Landslide risk assessment 66,151 159,247 landslide features
Landslide Incident Inventory Landslide mapping from new LiDAR-derived DEM Identifying following types of landslides Slide Fall Flow Lateral Spread Multiple Failures Unknown Statewide DEM and MLRA Boundary
Landslide Incident Inventory Slide (includes rotational and translational movement)*: mass movements, where there is a distinct zone of weakness that separates the slide material from more stable underlying material Mineral County, WV *Description from ml Images from ml
Landslide Incident Inventory Debris Flow*: A form of rapid mass movement in which a combination of loose soil, rock, organic matter, air, and water mobilize as a slurry that flows downslope; they are often associated with steep gullies, and debris-flow deposits are usually indicated by the presence of debris fans at the mouths of gullies Pendleton County, WV *Description from ml Images from ml
Landslide Incident Inventory Lateral Spread*: When coherent material, either bedrock or soil, rests on materials that liquefy, the upper units may undergo fracturing and extension and may then subside, translate, rotate, disintegrate, or liquefy and flow; usually occur on very gentle slopes or flat terrain Greenbrier County, WV *Description from ml Images from ml
Landslide Incident Inventory Multiple Failures: This classification is used when multiple ( 4) failures, usually small debris flows, occur in a restricted area Pendleton County, WV *Description from ml Images from ml
Landslide Incident Inventory Fall*: Abrupt movements of masses of geologic materials, such as rocks and boulders, that become detached from steep slopes or cliffs Undetermined: Some failure is present, but it is not possible to determine the type of movement Pendleton County, WV *Description from ml Images from ml
Landslide Incident Inventory WV GIS TC Landslide Mapping 2018-April 2022 WV GIS TC Mapping on LiDAR-Based DEMs 66,151 Failures ( 10 m wide) Most from 1 m DEMs 882 Debris Flows 313 Lateral Spreads 64,800 Other Failures 97 % “Slides” (or Slumps) Few Rock Falls Identified Mapped Landslides Verified on best available DEMs 1,082 WVGES (1976-80) Monongalia Co. Slides
Landslide Method Development Key Takeaways 1. Landslide susceptibility modeling I. Performed using machine learning I. II. Random forest method most efficient Performed for various MLRA’s to minimize heterogeneity in physiographic conditions that may influence landslide susceptibility 2. Main Landslide contributing factor- Slope, soil type, and geology I. Steeper slopes, unconsolidated soils, and less resistant rock units like shale and siltstone will increase landslide susceptibility. 3. Anthropogenic disturbance contributes heavily to landslide risk 4. Future work - Rerun models after new LiDAR-based landslide mapping is complete.
Landslide Method Development The West Virginia University Study Team includes Dr. Steve Kite (Geomorphologist), Dr. James Thompson (Soil Scientist), Dr. Aaron Maxwell (Geologist/Modeler), and Dr. Maneesh Sharma (Geologist/GIS)
Landslide Method Development West Virginia Physiography & NRCS MLRAs Existing Physiographic Maps Inadequate for WV Landslide Project MLRA Boundaries Better Provinces & Subdivisions Appalachian Plateaus Kanawha Section Logan Plateau Allegheny Mountains Valley & Ridge Ridge & Valley Great Valley Blue Ridge Red Landslide-Prone Kanawha Section Logan Plateau
Landslide Method Development Thing you want to predict Things you know that might help you predict the new thing Machine learning algorithm Trained Model New things to predict Predictions Machine Learning Learning from Examples
Landslide Risk Assessment Results Key Takeaways 1. 2. 3. 4. Risk assessment performed at sub-county scale 53% area in high/medium susceptibility 11% roads in high/medium risk* Structures- majority located in high medium landslide susceptibility area are Residential I. II. Kanawha and Monongalia counties rank 1st or 2nd Harrison and Ohio counties rank 1st and 2nd for Commercial asset values 5. Essential Facilities – 14 located in high/medium susceptibility area 6. Relative risk to humans and related infrastructure is highest in Region 6, which ranks either 1st or 2nd in all five road and structure risk analysis categories
Landslide Risk Assessment Results Landslide risk near Hinton, WV in Summers County WV Flood Tool WV Landslide Tool
Landslide Risk Assessment Results Structure/Parcel Risk Analysis 1. Risk assessment performed on parcel level data I. II. Primary structure point used within 1% annual chance floodplain Parcel with site address points used outside floodplain 2. Limitations I. Parcels containing no addressing points assigned a building value of zero ( 0). II. Building values for some structures are less than the values recorded I. Appraisal values may be in neighboring parcels instead of the parcel where the structure is located. This results in building values not being assigned to site address points. III. Some government and other property values do not get pulled in from the statewide assessment database, resulting in a lower value of at-risk structures. IV. This study is NOT intended for regulatory use and is NOT the final authoritative source of all landslide risk data in the community
Landslide Risk Assessment Results WV Flood Tool WV Landslide Tool Impacted Home Higher Risk Landslide Susceptibility Zone April 2020 Landslide Wood County Impacted home moved from foundation Landslide Susceptibility Spring 2020 Aerial Imagery
Landslide Risk Assessment Results Essential Facility Risk Analysis 1. Risk assessment performed on parcel level data I. Facilities included in this analysis include: police departments, fire departments, 911 centers, nursing homes, hospitals, and K-12 schools 2. Limitations I. This study is not intended for site-specific analysis or remediation measures and is only suitable for planning-level analysis II. Some government and other property values do not get pulled in from the statewide assessment database, resulting in a lower value of at-risk structures. III. This study is NOT intended for regulatory use and is NOT the final authoritative source of all landslide risk data in the community
Landslide Risk Assessment Results Essential facilities located in High/Medium Landslide Susceptibility Areas
Landslide Risk Assessment Results Iaeger Volunteer Fire Department. McDowell County WV Flood Tool WV Landslide Tool
Landslide Risk Assessment Results AMFM Nursing & Rehab Centers, Taylor County WV Flood Tool WV Landslide Tool
Landslide Susceptibility Prediction Susceptibility and Hazard Assessment Produced landslide susceptibility map by county Calculate at risk properties for each county/region
Landslide Incident Inventory www.mapWV.gov/Landslide Over 100,000 landslide incident point and polygon features have been inventoried into a digital geodatabase
Landslide Incident Inventory www.mapWV.gov/Landslide Over 100,000 landslide incident point and polygon features have been inventories into a digital geodatabase
Landslide Incident Inventory www.mapWV.gov/Landslide
Landslide Outreach Material StoryMaps West Virginia Landslides and Slide-Prone Areas, WVGES 1976 https://arcg.is/1KDnvq Causes of Landslides in Mountain State, West Virginia https://arcg.is/1SW0Sn
Landslide Outreach Material Brochures About identifying signs of slope instability and mitigation measures that may help reduce landslide risk at the community level About identifying signs of slope instability and mitigation measures that may help reduce landslide risk at the individual property level
Landslide Outreach Material Regional Reports Statewide Report
Landslide Risk Assessment QUESTIONS?
River, West Virginia (NPS, GRD, GRI, NERI, NERS digital map) adapted from a West Virginia University and West Virginia Geological and Economic Survey Open File Report map by Yates and Kite (and Gooding) (2015) New River Gorge National River Surficial Geology Mapping 212 10 WVDOT 2016 Geospatial Transportation Information (GTI) Section
Landslide Risk – the chance that any landslide hazard will cause harm to life or property. Landslide Warning System - a system that forecasts an increased likelihood of a landslide occurring. In general, landslides in the Sitka area ty
Kerala was known as the worst landslide in Kerala's history. The landslide occurred on November 9, 2001 due to heavy rains and around 40 people died in the incident. Kedarnath landslide in Uttarakhand: The landslide took place on June 16, 2013 and was the result of Uttarakhand floods.
Communicating Flood Risk, HAZUS Data and NFIP Information Eric Hopkins, Xiannian Chen and Kurt Donaldson West Virginia GIS Technical Center, West Virginia University 2014 West Virginia Floodplain Managers Annual Meeting Blackwater Falls State Park, West Virginia . MapWV.gov/flood - Mission . -Planning tool for public agencies & officials .
the statewide flood warning system. This will match 810,500 in federal and other funds for a total of 1,661,500 for O & M of the 319 rain gauges and 144 stream gauges necessary for an effective flood warning system in West Virginia. PUBLIC NOTIFICATION OF FLOOD WARNINGS For a flood warning to be effective it must be received and
Financial Management of Flood Risk isbn 978-92-64-25767-2 21 2016 03 1 P Financial Management of Flood Risk Contents Chapter 1. Introduction: The prevalence of flood risk Chapter 2. Flood risk in a changing climate Chapter 3. Insuring flood risk Chapter 4. Improving the insurability of flood risk C
1) The HEC-RAS provides the flood profile for the worst flood intensity. This profile will facilitate to adopt appropriate flood disaster mitigation measures. 2) The flood profiles for different flood intensities with different return periods can be plotted at any given cross section of river. Also, such flood
Landslide Risk and Hazard Assessment . To enhance land-use planning and protection efforts, the first step is to create a GIS-based Landslide Risk Assessment. The assessment identifies areas of higher landslide risk. At a minimum it uses geographic data related to slopes, geology, and the location and extent of historic landslides. TheFile Size: 1MB
Accounting and Reporting by Charities: Statement of Recommended Practice applicable to charities preparing their accounts in accordance with the Financial
