A Script to Analyze Tree Canopy Change in Washington DC, 2006-2011, by American Community Survey (ACS) Block Group Boundaries

This script is used to analyze tree canopy and its change from 2006 to 2011 in Washington, D.C. with in American Community Survey (ACS) boundaries. The script will automatically read a small *.csv file (52kb) into memory and analyze in R. To download the file directly use the first link below. Rows correspond to block groups, data types using the R nomenclature shown in parentheses, the fields (columns) are:

[1] "OBJECTID" - created by ArcGIS, unique (integer)

[2] "AREAKEY" - the US Census Bureau FIPS code, the unique identifier for joining to other ACS/Census data (factor)

[3] "EHHMEDINC" - Median Household Income in $'s (integer)

[4] "Shape_Leng" - The length of the perimeter of the block group in meters (num)

[5] "Shape_Area" - The area of the block group polygon in square meters (num)

[6] "PctCanArea" - The percent of the block group that is covered by the sum of tree canopy datasets three categories 1) no change, 2) loss, and 3) gain. No change indicates that the tree canopy has not changed substantially from 2006 to 2011. Loss indicates that tree canopy was removed from 2006 to 2011. Gain indicates that new tree canopy was established between 2006 and 2011. The canopy data are described using the Letters from the SAL link provided below (num)

[7] "PctNo_Chan" - The proportion of "PctCanArea" that is from the no change class (num)

[8] "PctLoss" - The proportion of "PctCanArea" that is from the loss class (num)

[9] "PctGain"- The proportion of "PctCanArea" that is from the gain class (num)

[10] "IncomeQuan" - The median household income from "EHHMEDINC" categorized into quintiles (factor)