intro to raft · intro to raft rapid assessment of flooding tool ryan cahill hydraulic engineer...
TRANSCRIPT
US Army Corps of EngineersBUILDING STRONG®
Intro to RAFTRapid Assessment of Flooding Tool
Ryan CahillHydraulic Engineer
Oregon Silver Jackets Coordinator
U.S. Army Corps of Engineers-Portland District
September 10, 2015
BUILDING STRONG®
PORTLAND DISTRICT2
Outline
Motivation behind RAFT RAFT structure Applications of RAFT Development status
BUILDING STRONG®
PORTLAND DISTRICT3
When Flood Conditions arrive…
What resources are available to characterize the flood?
How useful are these resources/what is missing?
BUILDING STRONG®
PORTLAND DISTRICT4
Existing Tools
waterwatch.usgs.gov Shows recent peak
flows as percentile of historic flows for the same day
Advantages► Quick overview of
current conditions Drawbacks
► Percentile of current day
USGS WaterWatch
BUILDING STRONG®
PORTLAND DISTRICT5
Existing Tools
http://www.nwrfc.noaa.gov/rfc/ Shows 10-day river forecast Advantages
► Flood demarcations for context► Some “Impacts”
Drawbacks► Only a subset of gage locations► No “what-if” functionality► Little sense of damage caused
NOAA River Forecast Center
BUILDING STRONG®
PORTLAND DISTRICT6
Flood Frequency Curves
Show how rare an event is Return Period vs. Annual Exceedance
Probability
50% 20% 10% 4% 2% 1% 0.2%
2 yr 5 yr 10 yr 25 yr 50 yr 100 yr 500 yr
1000
10000
100000
Return Period
Dis
char
ge (c
fs)
Annual Exceedance Probability
Flood Frequency Curve
BUILDING STRONG®
PORTLAND DISTRICT7
More info would be nice…
How rare really is this event? What levees are in danger?
BUILDING STRONG®
PORTLAND DISTRICT8
Colorado 2013 Flood Headlines
Discover Magazine: Colorado Deluge could be classified as a 1000-year event
Time: The science behind Colorado’s Thousand Year Flood
University of Copenhagen: 25-50 year flood CU: 100-year flood in many drainages NWS warning: MAJOR FLOODING/FLASH FLOODING
EVENT UNDERWAY AT THIS TIME WITH BIBLICALRAINFALL AMOUNTS REPORTED IN MANY AREAS IN/NEAR THE FOOTHILLS
BUILDING STRONG®
PORTLAND DISTRICT9
Introducing… RAFT
Real-time tool Consolidates data from many agencies Output
► Informative (e.g. flood frequency)► Practical (e.g. levee freeboard)
Assists in disaster declaration
Rapid Assessment of Flooding Tool
BUILDING STRONG®
PORTLAND DISTRICT10
RAFT StructureFlowchart
Real-time Inputs RAFT Analysis Outputs
RAFT Database
RAFT
BUILDING STRONG®
PORTLAND DISTRICT11
RAFT Structure
Geospatial data (shapefile and kml)► Gages color coded by frequency► Levees color coded by freeboard► HUCs color coded by frequency
Outputs
Real-time Inputs RAFT Analysis Outputs
RAFT Database
BUILDING STRONG®
PORTLAND DISTRICT12
What is a HUC?
HUC: Hydrologic Unit CodeHUC-6 (Basin) HUC-8 (Sub-basin)
BUILDING STRONG®
PORTLAND DISTRICT13
RAFT Gage KML Output
BUILDING STRONG®
PORTLAND DISTRICT14
RAFT Structure
Automated retrieval► Flood forecasts from RFC► Observed data from USGS (or others)► Historic events
Ability to manually modify data to run “what-if” scenarios
Real-time Inputs
Real-time Inputs RAFT Analysis Outputs
RAFT Database
BUILDING STRONG®
PORTLAND DISTRICT15
RAFT Structure
Gage/Levee information Flood frequency curves Impacts Historic Peaks
RAFT Database
Real-time Inputs RAFT Analysis Outputs
RAFT Database
BUILDING STRONG®
PORTLAND DISTRICT16
RAFT: Frequency CurvesWhich frequency curve is best?
50% 20% 10% 4% 2% 1% 0.2%
2 yr 5 yr 10 yr 25 yr 50 yr 100 yr 500 yr
100000
1000000
Return Period
Dis
char
ge (c
fs)
Annual Exceedance Probability
Flood Frequency Curves
Superseded,USGS
Superseded,FEMA
Superseded,USACE
PRIMARY,USACE
BUILDING STRONG®
PORTLAND DISTRICT17
RAFT Structure
1. Gages► Event frequency► Impacts
2. Levees► Freeboard
3. HUCs► Event frequency
RAFT Analysis
Real-time Inputs RAFT Analysis Outputs
RAFT Database
BUILDING STRONG®
PORTLAND DISTRICT18
RAFT: Levee AnalysisHow to correlate gage stage to levees?
BUILDING STRONG®
PORTLAND DISTRICT19
RAFT: Levee AnalysisLevee Gage
2’
BUILDING STRONG®
PORTLAND DISTRICT20
RAFT Levee KML Output
BUILDING STRONG®
PORTLAND DISTRICT21
RAFT: HUC Analysis
Pick one “most representative” gage Gage not necessarily within HUC boundary Separate gage for observed and forecast
How to tie HUCs to gages?
BUILDING STRONG®
PORTLAND DISTRICT22
RAFT: HUC Analysis
BUILDING STRONG®
PORTLAND DISTRICT23
RAFT HUC Results
BUILDING STRONG®
PORTLAND DISTRICT24
Who can use RAFT?
FEMA USGS River Forecast Centers Emergency Managers
BUILDING STRONG®
PORTLAND DISTRICT25
RAFT output on the web
Oregon Emergency Management web-map Updates daily (more frequently during floods)
BUILDING STRONG®
PORTLAND DISTRICT26
Development Status
Oregon version released in late 2014 Preliminary data added for AK, WA, ID by FEMA Full expansion to Washington is ongoing
BUILDING STRONG®
PORTLAND DISTRICT27
Expanding to other states
1. Identify gages and compile information2. Gather frequency curve data, decide primary3. Gather levee data4. Import geospatial data (HUCs, levees)5. Import tabular data to RAFT
Items requiring programming/scripting background1. Retrieving data from the local RFC or other state
agency website
BUILDING STRONG®
PORTLAND DISTRICT28
Potential Enhancements
Link forecasted stage to bridge overtopping Expand to precipitation as well as streamflow Long-term streamflow volume forecasts
BUILDING STRONG®
PORTLAND DISTRICT30
Demonstration
Microsoft Excel/Access combo with VBA► Familiar format► Easy to modify► Any agency can use it (no IT issues)
BUILDING STRONG®
PORTLAND DISTRICT31
RAFT User Levels
Casual► View RAFT output maps only
Basic► Run the RAFT tool
Advanced► Add/Edit underlying data in RAFT
BUILDING STRONG®
PORTLAND DISTRICT32
RAFT Gage Dashboard
BUILDING STRONG®
PORTLAND DISTRICT33
RAFT Gage Output
BUILDING STRONG®
PORTLAND DISTRICT34
RAFT Gage KML Output
BUILDING STRONG®
PORTLAND DISTRICT35
RAFT Levee Dashboard
BUILDING STRONG®
PORTLAND DISTRICT36
RAFT Levee KML Output
BUILDING STRONG®
PORTLAND DISTRICT37
RAFT HUC Dashboard
BUILDING STRONG®
PORTLAND DISTRICT38
RAFT HUC Dashboard
BUILDING STRONG®
PORTLAND DISTRICT39
RAFT Gage Information
BUILDING STRONG®
PORTLAND DISTRICT40
RAFT: Frequency Curves
Unregulated sites1. Western OR: USGS (2005) report2. Eastern OR: OWRD (2006) report3. FEMA FIS (tidally influenced)4. OWRD Peak Estimation Program (with caveat)
Regulated sites1. USACE regulated frequency curves2. FEMA FIS
Principles for selecting “primary” curve