NOAA AHPS Flood Inundation Mapping

“America’s NOAA National Weather Service: Protecting Lives, Livelihoods, and A Way of Life”“America’s NOAA National Weather Service: Protecting Lives, Livelihoods, and A Way of Life” 1

NOAA AHPS Flood Inundation MappingNOAA AHPS Flood Inundation Mapping

Victor HomNational Inundation Mapping

Services Leader

National Weather Service Office of Climate, Water, and Weather Services

Hydrologic Services DivisionSilver Spring, MD

Southeast Regional Flood Mapping Meeting Southeast Regional Flood Mapping Meeting October 29, 2009October 29, 2009


• Enhancing the Communication of Flood RiskEnhancing the Communication of Flood Risk

• Current AHPS Flood Mapping Projects Current AHPS Flood Mapping Projects

• The MappingThe Mapping Web InterfaceWeb Interface

• Flood Inundation Mapping ChallengesFlood Inundation Mapping Challenges

NOAA NWS AHPS Flood Mapping NOAA NWS AHPS Flood Mapping

Presentation Outline


On average, over the past 20 years in the U.S., flooding has claimed On average, over the past 20 years in the U.S., flooding has claimed

over 90 lives and caused damages in excess of $7 billion annually.over 90 lives and caused damages in excess of $7 billion annually.

• Flooding is responsible for more fatalities than any other severe Flooding is responsible for more fatalities than any other severe

weather related phenomenon.weather related phenomenon.

• More than half of all flood-related deaths result from motorists More than half of all flood-related deaths result from motorists

being swept away in their vehicles.being swept away in their vehicles.

Socioeconomic ImpactsSocioeconomic Impacts


• For over 30 years, the NWS has utilized a 3-tier, impact based, flood severity scale with the categories minor, moderate, and major flooding

• For each NWS river forecast location, flood stage and the stage associated with each of the NWS flood severity categories are established in cooperation with local

public officials

NCC049-107-070200- /O.NEW.KMHX.FL.W.0001.010407T1300Z-000000T0000Z/ /KINN7.1.ER.010407T1300Z.010412T0100Z.000000T0000Z.NO/ 200 PM EDT FRI APR 6 2001

THE NATIONAL WEATHER SERVICE IN NEWPORT HAS ISSUED A • FLOOD WARNING FOR NEUSE RIVER AT KINSTON • FROM SATURDAY MORNING UNTIL FURTHER NOTICE• AT 9 AM EDT FRIDAY THE STAGE WAS... 13.5 FEET• MINOR FLOODING IS FORECAST * FLOOD STAGE IS...14.0 FEET • FORECAST...FLOOD STAGE WILL BE REACHED AT 900 AM SATURDAY. MAXIMUM STAGE WILL BE 15.0 FEET AT 900 PM EDT WEDNESDAY. THE RIVER MAY REMAIN ABOVE FLOOD STAGE FOR SEVERAL WEEKS. THE EXACT FLOOD DURATION IS DIFFICULT TO PREDICT DUE TO THE VERY SLOW RISE AND FALL TIMES FOR THIS RIVER. • AT 14 FEET...WATER WILL BEGIN TO OVERFLOW INTO LOWLANDS ADJACENT TO THE NEUSE RIVER. $$

http://www.weather.gov/ahps/

Enhancing the Communication of Flood RiskEnhancing the Communication of Flood Risk


•• The Inland Flood Forecasting and The Inland Flood Forecasting and Warning System Act of 2002, Pub. Law Warning System Act of 2002, Pub. Law No. 107-253No. 107-253

Championed by Representative Bob Championed by Representative Bob Etheridge (2Etheridge (2ndnd District NC) District NC)

Authorized NOAA to conduct activities to Authorized NOAA to conduct activities to improve inland flood forecasting, develop a improve inland flood forecasting, develop a new flood warning index, train and educate new flood warning index, train and educate officials regarding improved forecasting officials regarding improved forecasting techniques and the inland flood warning techniques and the inland flood warning indexindex



• Since 2002, NWS has conducted extensive Since 2002, NWS has conducted extensive outreach to determine whether our current flood outreach to determine whether our current flood severity index satisfies user needsseverity index satisfies user needs

Partnered with Claes Fornell International (CFI) Group Partnered with Claes Fornell International (CFI) Group to survey users of NOAA’s hydrologic information via to survey users of NOAA’s hydrologic information via the American Customer Satisfaction Index (ACSI)the American Customer Satisfaction Index (ACSI)

Conducted user forums with State and Local Officials Conducted user forums with State and Local Officials in North Carolinain North Carolina

Partnered with David Ford Consulting Engineers, Inc Partnered with David Ford Consulting Engineers, Inc to conduct a national survey of emergency managersto conduct a national survey of emergency managers

Conducted additional local and regional user Conducted additional local and regional user outreachoutreach




Partners and Users are telling us that they…. are familiar with NWS flood severity

categories find them useful do not want changes to the existing flood

severity indices need the communication of flood risk to be

enhanced by use of inundation graphics (maps)



"The problem for our emergency responders during flooding is that we rush over our floodplain maps but they are basically a 100 year storm event that rarely informs the expected flooding from a particular storm event."

Floodplain Manager Baltimore Area


• Provide enhanced water availability and flood warning information by leveraging NOAA’s infrastructure and expertise

• Modernize services through infusion of new science and technology

- Flash-flood to seasonal freshwater forecasts

- Quantification of forecast certainty

- More accurate and timely forecasts and warnings

- Partnered flood inundation mapping

- Visually-oriented products

• Provide consistent access to standardized graphics via web interface

Advanced Hydrologic Prediction Service (AHPS)Advanced Hydrologic Prediction Service (AHPS)


In the Southeastern U.S.

North Carolina Flood Mapping Program

In the Southern U.S.

Gulf Coast States (Katrina Supplemental)

Lower Colorado River Authority

San Antonio River Authority

In the Northeastern U.S.

Susquehanna River Basin (Upper/Lower)

Delaware River Basin Commission

In the Midwestern U.S.

Indiana DHS, Indiana University Purdue University POLIS Center

State of Kansas, University of Kansas

City of Findlay Ohio, Killbuck Township of Ohio

NOAA AHPS Flood Mapping PartnershipsNOAA AHPS Flood Mapping Partnerships

Blanchard River at Blanchard River at Findlay, OHFindlay, OH

10 new Flood Map

10 new Flood Map

Libraries added in

Libraries added in

September 2009

September 2009

~50 new Flood Map ~50 new Flood Map Libraries since Oct Libraries since Oct

20072007


• From NC Partnership Established Flood Mapping Techniques in cooperation with USGS North Carolina

Water Science Center, NCFMP Office

Added Flood Categories and Depths to the AHPS Flood Mapping Interface

AHPS Flood Mapping Partnership BenefitsAHPS Flood Mapping Partnership Benefits

• From Gulf Coast Partnerships Refined Quality Assurance, Instituted

Quality Checks, Field Review Procedures

• From Midwest Partnerships

Improved Spatial Analysis for Display of Inundation and Generation of Depth Grids

• From Northeastern Partnerships

Enhanced Guidelines, Statement of Work Templates, and Procedural Development


• Additional cost to complete one inundation map library as part of a Additional cost to complete one inundation map library as part of a detailed FEMA FIS: detailed FEMA FIS: 5 – 10 K5 – 10 K

• Cost doubles and time increases if inundation map library is created Cost doubles and time increases if inundation map library is created after the FIS is completed: after the FIS is completed: 10 – 20 K10 – 20 K

• Developing inundation libraries in conjunction with the detailed FIS Developing inundation libraries in conjunction with the detailed FIS yields significant user benefit for small incremental cost.yields significant user benefit for small incremental cost.

• AHPS Web Implementation: AHPS Web Implementation: ~7 K~7 K

Efficiency goes upEfficiency goes upCosts go downCosts go down

Partnering to Reduce Costs and Improve EfficiencyPartnering to Reduce Costs and Improve Efficiency


Target Goals

• Information to make risk based decisions

• Easy product access

• Visually oriented products

• Link to other AHPS Products

• Flood severity categories: minorminor, moderatemoderate, and majormajor flooding

• FEMA 1%, 0.2% Annual Chance Flood Maps

• Flood Depth Grids, Floodway

• KML and Shapefile Downloads

AHPS Flood Mapping InterfaceAHPS Flood Mapping Interface



www.weather.govwww.weather.gov


www.weather.gov/ahps/inundation.php



www.weather.gov/ahps/inundation.php



• 1% Annual Chance Flood

• 0.2% Annual Chance Flood

• Floodway


www.weather.gov/ahps/inundation/inundation_mapping_user_guide.pdf


AHPS Flood Mapping ChallengesAHPS Flood Mapping Challenges

• Data CollectionData Collection

• Hydrology & Hydraulics

• Inundation MappingInundation Mapping

• ProceduralProcedural

• Quality AssuranceQuality Assurance

http://www.weather.gov/os/water/


Data Collection ChallengesData Collection Challenges

• TopographicTopographic Need for Bare Earth – Correction for Lidar returns from trees, Need for Bare Earth – Correction for Lidar returns from trees,

cornfields, buildings, elevated structures, bridges, parklands.cornfields, buildings, elevated structures, bridges, parklands.

• HydrographicHydrographic Bathymetric Needs - Soundings, Cross-sections, Bathymetric Needs - Soundings, Cross-sections,

Acoustic Doppler Current Profiler, Acoustic Doppler Current Profiler, Graduated RodsGraduated Rods

Stream CenterlineStream Centerline

• Control StructuresControl Structures Top of levees, embankments, drainage controlTop of levees, embankments, drainage control

• Data Management IssuesData Management Issues Ground Control, Spatial Referencing, Datum, Ground Control, Spatial Referencing, Datum,

Projection, Vertical/Horizontal Accuracy, CostsProjection, Vertical/Horizontal Accuracy, Costs

http://www.csc.noaa.gov/crs/rs_apps/sensors/lidar.htm


• AHPS Flood Mapping Suitability AnalysisAHPS Flood Mapping Suitability Analysis USGS Gages, NWS Forecast LocationsUSGS Gages, NWS Forecast Locations

• Hydraulic Model TechniquesHydraulic Model Techniques• Adapting Existing Flood StudiesAdapting Existing Flood Studies

Flood Studies normally developed for higher flows Flood Studies normally developed for higher flows than NWS Flood Categoriesthan NWS Flood Categories

• Calibration and VerificationCalibration and Verification Hydrologic and Flood DataHydrologic and Flood Data

• FundingFunding

H&H Modeling ChallengesH&H Modeling Challenges

https://ocwws.weather.gov/intranet/floodmap/Outreach.shtml


• Hydro and Hydraulic connectionsHydro and Hydraulic connections

• Mapping Domain and Extents Mapping Domain and Extents

• Uncertainties near model boundariesUncertainties near model boundaries

• Flood Mapping OverlayFlood Mapping Overlay Orthophotos and Road NetworkOrthophotos and Road Network

Topology, Line thicknessTopology, Line thickness

• Tin to Raster Depth GridsTin to Raster Depth Grids

Inundation Mapping ChallengesInundation Mapping Challenges

http://pubs.usgs.gov/sir/2007/5032/http://pubs.usgs.gov/sir/2007/5032/


• NOAA NWS GuidelinesNOAA NWS Guidelines

• AHPS Flood MappingAHPS Flood Mapping

H&H/Spatial AnalysesH&H/Spatial Analyses

AHPS ImplementationAHPS Implementation

AHPS Map LibraryAHPS Map Library

• Project Tracking, Milestones, Oversight ChecksProject Tracking, Milestones, Oversight Checks

• Quality Assurance Measures Quality Assurance Measures

• NOAA NWS Statement of Work TemplatesNOAA NWS Statement of Work Templates

Procedural ChallengesProcedural Challenges

https://ocwws.weather.gov/intranet/floodmap/Docs.shtmlhttps://ocwws.weather.gov/intranet/floodmap/Docs.shtml


Quality Assurance• From start to finishFrom start to finish• Quality control checksQuality control checks

Maintenance• Land use changesLand use changes• Topographic changesTopographic changes• Mapping ReprocessingMapping Reprocessing• AHPS Web EvolutionAHPS Web Evolution

Quality Assurance and Maintenance ChallengesQuality Assurance and Maintenance Challenges

http://www.weather.gov/oh/ahps/http://www.weather.gov/oh/ahps/


National Weather ServiceNational Weather Service

… working with partners to improve the communication of flood risk

Documents

NOAA AHPS Flood Inundation Mapping