Hurricanes - Coastal Flooding from Hurricane Katrina

In this lab we were to assess the damage from storm surge caused by Hurricane Katrina to  three counties in Mississippi.  The three counties Hancock, Harrison and Jackson Counties are all on the Gulf Coast with wetlands and barrier islands that normally protect the coast from too much damage.  We are told that the wetlands and coastal woodlands are important not only for habitat but also for the economy due to the fishing and paper industries.

Looking at the maps, we can see that many of the populated areas are along the Gulf coast and rivers.  The storm surge inundated the coastal communities, wetlands, coastal forests and inland. 

This map shows the elevation and hydrography of the three counties and the surrounding area.

This map shows the flooded areas with a graph of percentage of type of lands flooded.

This map shows the infrastructure and health facilities at risk from storm surge.

This Map is an addition showing the table with acres of coverage per type of land.

Using these maps as reference, I would suggest that the first priority would be to repair damage to Highway 90 that runs through all three counties along the coast.  Along this highway are the majority of hospitals and populated areas.  This highway will be essential to bringing more aid in and allowing access to vital health facilities and communities. Restoring the wetland and forested areas to bring the economy back to a viable and sustainable working area will need to be a priority after these first essential areas are repaired.

Process Summary

Deliverable 1:

1)      Examined the directory structure

2)      Documented the map for “Coast1”

3)      Set the environments

4)      The instructions said to Expand General Settings.  There was no “General Settings” that I saw, so I chose “workspace” and it seemed to be the same thing.

5)      Used the Mask function to limit the analysis to the three counties.

6)      Set the features for the Elevation feature class.

7)      Added the layers islands, water and river layers, setting the symbology.

8)      Created a map showing elevation, hydrology and populated areas.

9)      Exported as Coast1_cmb.jpg 

Deliverable 2 and 3:

   Documented the map for “Coast2” and set the environments

1)      Used the Spatial Analyst feature and the Math toolset to calculate the storm surge in meters and to isolate the area flooded by the storm surge.

2)      Used the Reclass tool to “reclassify” the land values.

3)      Saved the output raster as “reclandcover”

4)      Isolated the flooded land cover using the Times tool and saved the raster as “floodedlc”.

5)      Relabled the reclassified flooded land cover by adding new field to attribute table.

6)      Saved as a new layer.

7)      Added the counties, places and island layers and labled and symbolized.

8)      Calculated the percent in the attribute table and created graph of flooded land by land-cover type.

9)      Added the graph to the map. Saved and exported the map of flooded land and graph to Coast2_cmb.jpg

Deliverable 4 and 5:

   Documented the map for “Coast3” and set the environments

1)      Added counties and usa_streets layers. 

2)      Changed the symbology

3)      Added railroads, hospital and churches layers and symbolized

4)      Added flooded_land layer and made 50% transparent instead of 25% because I thought it worked better to show the other information more clearly.

5)      Calculated the acreage by clearing map and adding counties and floodedlc layers. 

6)      In the floodedlc attribute table added two float fields “acres” and “sqmiles”

7)      I tried to add this table to the Coast3 map but I couldn’t get the sizes to work right.

8)   Saved and exported the map of infrastructure impacts to Coast3_cmb.jpg