Spatial Data: Land Cover Type from MRLC NLCD
Data Category: Land Cover Type
Data Description: The National Land Cover Database (NLCD) is a compilation of land cover data collected and maintained by the Multi-Resolution Land Characteristics (MRLC).
Data Link: http://www.mrlc.gov/index.php
Data Use Policy: http://www.usgs.gov/laws/policies_notices.html
Use With R: When using NLCD data with R, the information can be downloaded from the MRLC website (link above).
Note that this data set can be memory intensive for an average computer. Due to the size of the data file (i.e., the entire U.S.A.) it may take a considerable amount of time to retrieve and plot. Once rasterized, it is possible to decrease the resolution of the data (depending on your scale of interest) to reduce the size of the file, as demonstrated in the following example, before plotting the data. Decreasing the resolution may not be desirable in many situations so keep in mind the scale and region size of interest.
Useful packages for working with this data in R include “raster” in order to rasterize the data.
In this example, I have downloaded the entire continental U.S. and presented it at a resolution of 100 m.
Install and load relevant packages
Rasterize the data (package “raster”)
Change the resolution of the data to decrease file size using aggregate()
Plot the NLCD data