Geographic Information Analysis

Geographic Information Analysis

Tuesday 28th March 2007

Professor Sutton

Week 1 Assignment

Group: Team Mangrove

Team Members: Bill Jeffrey, Elthron Anderson, Jeni Peterson and Tom Gearing

Assignment:

Produce maps displaying wetlands (combined woody and herbaceous wetlands and herbaceous wetlands only) along the eastern sea coast that intersect a 100 km buffer from the coastline using 30 meter resolution National Land Cover Dataset (NLCD),which includes mapping for both herbaceous and woody wetlands.

Results:

The following steps were observed.

Step 1: The land cover layer from the NLCD data set wasreclassified to produce two categories; 1 representing wetlands and 0 representing not wetlands areas. Consequently, we combined the herbaceous wetlands and the woody wetlands into a single class.

Step 2: Another layer from the NLCD data set was created in which only the herbaceous wetlandsis reclassified as 1 while all the rest of the land cover classes are reclassified as 0.

Step 3: A shapefile for all fifty states of the continental United States (US) was obtained from the I:\Data Library at the University of Denver.

Step 4: The states were dissolved to produce an outline of the US and saved as a shapefile called USAoutline.

Step 5: The trace tool in the editor toolbar was used to outline the eastern coastline from Texas to New York and the resulting shapefile called USA_coast_In.

Step 6: A left hand buffer of 100 km from the coastline was applied to the USA_coastline shapefile.

Step 7: The buffer on the USAoutline shapefile was clipped to retain only the land areas since the jagged coastline often caused the buffer to be extend into the ocean as it attempted to apply a left hand side buffer of 100 km to areas where the available land area was insufficient for the buffer zone to overlay. It was called USA_coast100k_Clip.

Step 8: A field called “one” was added to the attribute table of the clipped buffer. The field calculator what used to assign a value of 1 to the “one” field. The feature to raster tool was applied to the polygon buffer to produce a raster buffer from the polygon buffer.

Step 9: Using the raster buffer as a mask, the wetlands that were within 100 km from the coast for both of the wetlands rasters (combined and herbaceous only)were extracted.The multiplicative tool in the raster calculator was then applied using these extracted wetlands (combined and herbaceous only) and the resulting outputs called coastwetlands and coast_herbs respectively.The raster outputs were created as temporary raster files. As a result, we right-clicked and “made Permanent" the outputs otherwise they would be erased when ArcMap is terminated.