Transcript Tropical Storm Allison & its impact on Harris County Binbin Chen

Tropical Storm Allison
&
its impact on Harris County
Binbin Chen
Introduction
• Tropical Storm Allison formed 80 miles off the coast of
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Galveston, Texas on June 5, 2001
Over the next 5 days, Allison produced record-setting
rainfall, flooding and damage in Harris County and city of
Houston
Because of the magnitude of flooding, Harris County
Flood Control District and FEMA specially performed a
project “Tropical Storm Allison Recovery Project
(TSARP)”
Flooding after Allison
22 fatalities
95,000 damaged automobiles
73,000 damaged residences
Over $5 billion in property damage
Project Purpose
Perform an evaluation of the storm and its
consequences in Harris County
• Storm Track
• Precipitation
• Stream discharge
• Flooding area
Better understand water resource data and how to
integrate different source data using ArcGIS
Data Sources
• National Hurricane Center provides historical tropical ecyclone track
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GIS data at:
http://maps.csc.noaa.gov/hurricanes/viewer.html
National Climate Data Center provides NEXRAD Radar rainfall data
at: http://lwf.ncdc.noaa.gov/oa/radar/radarresources.html
NHD (Unit 1204) & NHDplus (Unit 12a) provide surface water data
of Harris County
USGS stream gages & real time data
Harris County Flood Control District Provides Harris County
watersheds data and flooding area data
City of Houston provides city land use data
Storm
History &Track
Storm Precipitation
• Rain gages
-150 rain gages operated by Harris County Office
of Emergency Management (HCOEM)
-3 rain gages operated by National Weather
Services (NWS)
• Radar data
-NWS collected rainfall radar data at WSR-88D
radar site covering the Houston area
Obtaining rainfall data
Visualize
Visualizedata
datainin
NEXRAD
NEXRADViewer
Viewer
Downloaded
rawradar
radardata
data
Download raw
Export
Exportradar
radardata
datainto
into
ESRI
ESRIraster
rasterdata
datausing
using
NEXRAD exporter
NEXRAD exporter
Storm Total Rainfall
*One Rain gage at Greens Bayou
recorded the highest rain as 38
inches.
Total Rainfall
from June 5 to June 7
14-hour Rainfall
Source: TSARP report
Stream discharge
Source: TSARP report
Flooding Area
Flooding land
in Houston
Flooded Major Roads
Conclusion
• Tropical Storm Allison was the most damaging
tropical storm in Harris County.
 Harris County received the heaviest rainfall from Tropical Storm Allison
 Streams in Harris County were greatly affected by Tropical Storm Allison, 17 out of

44 stations reached record peak flow on June 19,2001
A large amount of lands & roads in Harris County were flooded.
• ArcGIS has the powerful function to integrate
different source data, visualize and analyze data,
and depict a clear picture of the storm event,
which helps people understand flooding and
flood risk and better prepare for the next
“Allison”.
Questions?