rapid damage assessment methodology for catastrophic souris river flooding minot, north dakota
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Rapid Damage Assessment Methodology for Catastrophic Souris River Flooding Minot, North Dakota. Analyzing the Extent of Flooding Impacts Using Site Specific Analysis and User Generated Depth Grids. Jesse Rozelle FEMA Region VIII Risk Analyst/Regional GIS Coordinator - PowerPoint PPT PresentationTRANSCRIPT
Rapid Damage Assessment Methodology for Catastrophic Souris River Flooding
Minot, North Dakota
Jesse RozelleFEMA Region VIII
Risk Analyst/Regional GIS CoordinatorHIFLD Working Group Meeting
Silver Springs, MD.
Analyzing the Extent of Flooding Impacts Using Site Specific Analysis and User Generated Depth Grids
Souris (Mouse) River Geographical Context
• Headwaters in Southeastern Saskatchewan, Canada. Water controlled by the Alameda Rafferty Dam project.
• Water flows southeast into North Dakota, water controlled by the Lake Darling Dam.
• Approximately 20 miles southeast of Lake Darling is the city of Minot, North Dakota (2010 pop.- 40,888)
• Water flows southeast for roughly another 20 miles and then flows in a northeast direction into southwestern Manitoba, Canada
• 700km (435mi) in length and drains an area of 61,100km2 (23,600mi2).
2011 Flood Event Overview
• Historic snowpack within Souris River Basin and surrounding drainages.
• Rapid spring snowmelt• Heavily saturated soils• Reservoirs at full capacity• Multiple severe rainfall events
Physical influence behind Souris (Mouse) River flooding:
Souris (Mouse) River:
• Dam Controlled Seasonal Average Flow
• ~200 to 2,000cfs• 100yr floodplain = 5,000cfs
• 2011 Flooding Event• Peak Flow Recorded June 26th
• ~ 24,000cfs
Lake Darling Anticipated Inflow/Outflow
2011 Flood Event Overview
Minot Flood Information Timeline
-1wk -1day 0 +2days 1week 2weeks +3 weeks
Pre-e
vent
inun
datio
n mod
eling
Flood
Cre
st 1,5
61.8’
Sun
day J
une 2
6th
USGS Su
rvey
-Fall
Bac
k Lev
ee P
rotec
tion
Pictom
etry O
bliqu
e Imag
ery A
cquis
ition
Pictom
etry p
rodu
cts av
ailab
le
Flooding/Mandatory Evacuations June 22nd to July 10th
Imag
eCat
Damag
e Ass
essm
ents
Comple
ted
Reside
nts R
eturn
USGS RTK
-GPS S
urve
y-Dail
y Upd
ates
Contin
ued S
uppo
rt fo
r IA an
d PA In
spec
tions
Task 1: USGS HWM MA• Utilized RTK GPS to provide daily measurements
of water surface +/- 0.1’ accuracy• Ground-truthed pre event lidar-based inundation
modeling rather than creating IDW-depth grid from scratch
• Small expert USGS field team deployed from MT and WI working with ND office
• $26,000 total MA costs or $6 per damaged structure to provide accurate water depths at each structure relative to ground surface
Task 2: Oblique Imagery• Contracted through USGS Rolla Mission Assignment• High res (6 inch-5 way) product with pre-event
available• Ability to measure depth of water relative to finished
floor• Shared with community through a public website
(minot.skygone.net)• Not available for response but excellent to ongoing
inspection validation • $35,000 or $8.50 per impacted structure
Task 3: Imagery Exploitation• Contract with ImageCat• Engaged Catastrophe Assessment Network
(CAN) analysts in academia and outside U.S. • Completed in 3 days over July 4th weekend• Joined assessments with parcel and IA data• Completed detailed assessment of large loss
structures (schools, significant facilities)• $35,000 or $17 per impacted structure assessed
Rapid Turnaround Damage Assessment
• Coordination with USGS to collect perishable data (high water mark collection).
• Pictometry Oblique Arial Imagery• New Light/ImageCAT Damage Assesment
Rapid turnaround Damage Assessment needed
Damage Assessment Accomplished using the following:
Near Real Time Results:
• Number of structures impacted by flood event• Approximate depth of water at each impacted structure• HAZUS site specific derived financial impacts• Established an SOP(Standard Operating Procedure) for rapid
turnaround Damage Assessments.
• Digital Globe Satellite Imagery• Houston Engineering• FEMA Region VIII Risk
Analysis Team
Rapid Turnaround Damage Assessment
• Preliminary inundation maps were produced for anticipated peak flows and sent into the field
• USGS captured locations (using Real Time Kinematic (RTK) GPS techniques) of the temporary levees and high water marks used to calibrate inundation depth model.
USGS High Water Mark Collection
Rapid Turnaround Damage Assessment
• Captures 5 angles of oblique imagery, including orthophotos• Assisted in obtaining structure attributes required for HAZUS financial loss
estimation
Pictometry Oblique Arial Imagery
Rapid Turnaround Damage Assessment
• Assisted in flood exposure development• Determined occupancy types
of structures in flooded area• Residential basement
identification as well as number of stories
• Flood depth protocols• Identified priority areas for
response• Rapid online product
development to support widespread interpretation
ImageCat New Light Technologies
Rapid Turnaround Damage Assessment
Rapid Turnaround Damage Assessment
Interagency Coordination/Collaboration• USGS: Perishable Data Collection (High water marks)• City of Minot: Pre-event Data
• LiDAR• Pictometry• Parcel Data
• Pictometry: Oblique Aerial Imagery• New Light / ImageCAT: Damage Assessment Data• Digital Globe satellite imagery• Houston engineering: Depth Grid development• NOAA: Stream Gauge Monitoring
Pre Event Data Collection• Most critical component to Rapid Turnaround Damage Assessment• Coordination with community• Coordination with private sector• Coordination with Federal, State, Local, and Tribal partners• Rapid evaluation of population and building exposure to flood event• Publically published maps gave displaced citizens a opportunity to
understand the flooding situation