May 2011 Flooding

UPDATE: The files on the ftp site were updated on 5/7/2011 at 12:45.

Updates included full removal of <0.25 polys
Removed the file named recl_1. It was duplicative of other coverage. 

The State of Arkansas experienced extensive flooding in May of 2011. The AGIO acquired medium resolution imagery via the International Charter. The data was processed using the techniques below. Please refer to metadata associated with each file.

The files were generated as a visual representation of flooding that occurred in the Arkansas Delta in May 2011. The files should not be used for engineering or any other application that requires precise calculations.

  • Tiled files Downloaded from U.S. Geological Survey Hazards Data Distribution System (HDDS) 201104_Floods_Central_US under restricted International Charter Call 362.  Image Source SPOT – Agency DOD – Vendor Eagle Vision Information regarding the International Charter
  • Source imagery georectification was further refined by AGIO using Arkansas source basemap data.
  • Source image Band 1 was classified into 9 categories using ESRI Spatial Analyst extension. 
  • Resulting file reclassified Categories 2 and 3 to Category 1 representing water.  All other categories reclassified as No Data.
  • Files exported to vector forma
  • Image source Date column and values added.
  • Vector reprojected UTM Zone 15 North NAD83
  • Area column added and areas calculated.
  • Removed areas less than >0.25 ac., approx. 3×3 pixels.