Merge pull request #3 from glemieux/readme-update

Update README with more information about the data provenance

README.md

@@ -4,11 +4,19 @@ A python tool for processing LUH2 data for use with FATES landuse run modes
 
 ## Purpose
 
-This tool takes the raw [Land Use Harmonization](https://luh.umd.edu/), or LUH2, data files as
-input and prepares them for use with FATES.  The tool concatenates the various raw data sets into
-a single file and provides the ability to regrid the source data resolution to a target
-resolution that the user designates.  The output data is then usable by FATES, mediated through
-a host land model (currently either CTSM or E3SM).
+This tool creates the necessary land use datasets to be used as inputs for running FATES with land use cover and change.  The tool has two major options, i.e. python subcommands, to provide the data set of interest:
+
+- land use timeseries data
+- land use association to plant functional type (land use x pft) static mapping data
+
+The tools provides these data sets as netcdf files by concatenating the various raw input data sets into a single file.  The tool provides the ability to regrid the source data resolution to a target
+resolution that the user designates for either output option.  The output data is then usable by FATES, mediated through a host land model (currently either CTSM or E3SM).
+
+takes the raw  data files as
+
+## Input data sources
+
+The tool requires input data from two primary sources: the [Land Use Harmonization](https://luh.umd.edu/), or LUH2, historical data sets and the [THESIS Tools Datasetes](https://doi.org/10.5065/29s7-7b41).  A static mapping file from the LUH2 data is required for both output options.  The historical LUH2 transient, state, and management data is used as input for the FATES land use timeseries data output option, whereas the THEMIS tools forest, pasture, "other" and current surface data sets are necessary for the land use x pft static map output option.  These data sets can be downloaded directly from their respective sources and are not provided as part of this package.
 
 ## Installation