NWS Flood Forecast Mapping Application

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NWS Flood Forecast Mapping Application

• FLDVIEW
• NOAA/NWS/Office of Hydrologic Development
• Hydrology Laboratory
• Janice M. Sylvestre
• WMO/NOAAHydrologic Forecasting Course
• NWS Training CenterKansas City, MOOctober 27,
  2003

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Hydraulic Modeling Components
FLDWAV NWS Hydraulic Routing Model
Stand-Alone (RD Application) Operation
within NWSRFS FLDAT FLDWAV Analysis Tool
Generates input deck for FLDWAV Displays and
analyzes FLDWAV results FLDVIEW Flood Forecast
Mapping Application Displays the extent of
flooding FLDIMS Flood Internet Mapping Service
View flood maps in addition to other layers
over the Internet
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FLDVIEW Objectives

• Generate a flood forecast map based on NWS
  probabilistic river forecast
• Visually display flood forecast map and other
  geographical and structural layers

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FLDVIEW - Benefit
Flood forecast mapping improves the publics
understanding of river forecasts by representing
the extent of flooding along a river reach in a
non-technical way.
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Operational Priorities

• Stable - Runs under any condition
• Fast - Runs in a reasonable amount of time
  (minutes vs. hours)
• Accurate - Gives reasonable results
• Robust - Runs with limited data
• Easy to use - As many steps as possible are
  automated
• Independent Map application not dependent on
  any particular
  hydraulic model

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FLDVIEW Data Requirements
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Water Surface Profiles
Types of water surface profiles Deterministic
- Peak elevations along the channel reach -
Instantaneous elevations at a given time along
the channel reach Probabilistic - Elevations
along the channel having the same probability of
occurrence Source of profiles - NWS dynamic
routing models (DWOPER/FLDWAV) - Routing
methods in NWSRFS (e.g., Muskingum-Cunge) -
Simplified techniques (e.g., slope method,
backwater, etc.)
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Flood Map Generation

• Process DEM data
• Add channel bottom and man-made structures
• Generate ground grid
• Generate channel widths at water surface along
  the river
• Generate water surface grid
• Generate depth grid (water surface grid ground
  grid)
• Generate the flood map

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FLDVIEW Features

• Maps both drought and flood conditions
• Considers structures (dams, bridges,
  levees)
• Flood map may be generated
• with limited data
• Processes AutoCAD and
• USGS data automatically
• Multiple maps may be
• generated automatically
• Multiple rivers may be mapped

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FLDVIEW Applications
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FLDVIEW Applications
Susquehanna River System (MARFC) Lewistown,
PA lower West Branch, PA St. Johns
River Fredericton, New Brunswick Canada Tar
River NC (SERFC) St. Johns River FL (SERFC)
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FLDVIEW Current NWS Implementation
Water Surface Profile Ascii Text File
Geographic data Grid or Vector
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FLDVIEW Input Files
.xy file
.fcs file
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FLDVIEW Specifications

• System Hardware
• HP Unix workstation
• Windows 95/98/2000/Me/NT/XP
• System Software
• Arcview 3.1
• Spatial Analyst
• 3-D Analyst

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FLDVIEW Future Research

• Assess quality of results
• Accuracy compare against orthophotos of floods
• Sensitivity use different DEM sources
• Improve method to map water surface in
  floodplain
• Improve statistics for probabilistic water
  surface profile
• Investigate other methods for obtaining water
  surface profile

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NWS Flood Internet Mapping Service(Prototype)
FLDIMS
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FLDIMS Description

• MapGuide web application
• Displays FLDVIEW results without the need for
  the user to purchase expensive software
• Client-side driven

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FLDIMS Application
140.90.22.51
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FLDIMS Features

• Probabilistic flood forecast maps
• Deterministic peak flood forecast map
• Display other layers
• Historical flood maps
• Flood animation
• Identify information in flooded area

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FLDIMS Future Work

• Apply to another area to evaluate the
  adaptability of the template for use by the
  RFC in generating FLDIMS applications for
  different areas