Presentation on theme: "Tropical Storm Allison & its impact on Harris County"— Presentation transcript:
1 Tropical Storm Allison & its impact on Harris County Binbin Chen
2 IntroductionTropical Storm Allison formed 80 miles off the coast of Galveston, Texas on June 5, 2001Over the next 5 days, Allison produced record-setting rainfall, flooding and damage in Harris County and city of HoustonBecause of the magnitude of flooding, Harris County Flood Control District and FEMA specially performed a project “Tropical Storm Allison Recovery Project (TSARP)”
3 Flooding after Allison 22 fatalities95,000 damaged automobiles73,000 damaged residencesOver $5 billion in property damage
4 Project PurposePerform an evaluation of the storm and its consequences in Harris CountyStorm TrackPrecipitationStream dischargeFlooding areaBetter understand water resource data and how to integrate different source data using ArcGIS
5 Data SourcesNational Hurricane Center provides historical tropical ecyclone track GIS data at:National Climate Data Center provides NEXRAD Radar rainfall data at:NHD (Unit 1204) & NHDplus (Unit 12a) provide surface water data of Harris CountyUSGS stream gages & real time dataHarris County Flood Control District Provides Harris County watersheds data and flooding area dataCity of Houston provides city land use data
6 Storm History &Trackwind speeds (in KTS, 1Windmph=1.15WindKTS)
7 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
8 Obtaining rainfall data Visualize data in NEXRAD ViewerVisualize data in NEXRAD ViewerDownloaded raw radar dataDownload raw radar dataExport radar data into ESRI raster data using NEXRAD exporterExport radar data into ESRI raster data using NEXRAD exporter
9 Storm Total Rainfall*One Rain gage at Greens Bayou recorded the highest rain as 38 inches.
26 ConclusionTropical Storm Allison was the most damaging tropical storm in Harris County.Harris County received the heaviest rainfall from Tropical Storm AllisonStreams in Harris County were greatly affected by Tropical Storm Allison, 17 out of 44 stations reached record peak flow on June 19,2001A 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”.