Advanced Hydrologic Prediction Services
NWS Inundation Mapping
Eastern Region Flash Flood Workshop
June 4, 2010
Presentation by Laurie Hogan
NOAA/NWS Eastern Region Headquarters
Page 1
Floods are a big deal!!
Q: Is flooding really that big of a deal?
Flooding causes more damage in the United States than
any other severe weather related event, an average of
$5 billion a year. Flooding can occur in any of the 50
states or U.S. territories at anytime of the year.
http://www.weather.gov/floodsafety/floodsafe.shtml
Recent Record Floods
from the Headlines
Nashville, TN
Cranston, West Warwick, RI
Page 2
Advanced Hydrologic Prediction Services
NWS Inundation Mapping
• Features of NWS Inundation Maps
• Use of NWS Maps for Risk-Based
Decisions
Page 3
NWS Inundation Mapping
Features
• Partnered effort, utilizing FEMA approved
hydraulic models
• Visually oriented products
–
Flood emergency operation/planning, available to public
• Easy product access linked to existing AHPS info
• Flood depth estimates
• KML and shape files (GIS formats) to integrated
with user-specific data.
Inundation Mapping on AHPS
Inundation Mapping on AHPS
Water Depth Estimates
Inundation Mapping on AHPS
Shape files imported into ESRI ArcMap software
Record flood stage and 3 ft above record flood stage
Imported into Google Earth
Thoughts borrowed
from FEMA‘S RiskMAP
Identify Risk
Things to identify:
• Inundation areas for
continuum of flooding
• Depth of flood waters
• Historic flood crests
• What does a more
extreme flood look like for
this city/community?
Assess Risk
With the inundation areas,
you can assess:
• What neighborhoods will
be impacted?
– How/when will they be
evacuated?
• Are critical facilities or
evacuation routes in
jeopardy?
– Can preventative efforts be
successful?
Communicate Risk
Pictures are powerful!
• Depiction of historic
floods with a current
context (existing roads,
schools, etc)
• Are family flood
preparedness plans
needed?
Mitigate Risk
Decisions/Investments:
• Protective measures and
evacuation during floods
• Improvements to
infrastructure, public and
personal
• Zoning changes, new
regulations
Review of AHPS
Inundation Maps
http://water.weather.gov/ahps/inundation.php
• Continuum of flooding, action
stage to record levels
• Both NAVD88 and stage
inundation selections
• Web interface and GIS formats
• Available 24x7
Nashville Flood
Rhode Island Flood
•10 inches < 48 hours
• River crested 5 feet
above previous record
laurie.hogan@noaa.gov
Telephone: 631-244-0114