Last Updated: 1/23/2025
Contact: Bhuwan Ghimire (bhuwan.ghimire@usu.edu)

This resource contains data on land cover, used in the MS Thesis:
Ghimire, B. (2025). "Investigating Changes in Hydroclimate, Land Cover, and Evapotranspiration across The Great Salt Lake Basin and its Major Subbasins," Civil and Environmental Engineering, Utah State University.

Overview
It contains the maps, data and Python scripts used to estimate changes between land cover classes within the subbasins of the Great Salt Lake Basin. Annual land cover raster maps from Land Change Monitoring, 
Assessment, and Projection (LCMAP) (https://eros.usgs.gov/lcmap/apps/data-downloads) were used for the analysis. These data were used to analyze changes between land cover classes within the Great Salt Lake
 basins and later help to investigate the impact of land cover change on the water balance in the basin.

General description of data sources:
	- Raster maps retrieved from LCMAP, a collection produced by the USGS.
	- Maps are available from 1985 to 2021, annually.
	- Has 8 Primary land cover classes; Cropland, Developed, Tree, Grass, Water, Wetland, Barren and Snow
	- Grid Size of 30 m x 30 m

To ensure consistency with other studies in the MS thesis, the land cover change analysis was conducted for the calendar years 2003 to 2021, aligning with the water years 2004 to 2021. Therefore, the data and
 maps are for the calendar years 2003 to 2021.

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Folder Structure
#1. LandCover_Area
This folder contain excel files that summarizes area of 7 primary land cover classes (except snow, since area of Snow ~= 0) over the Bear, Weber, Jordan and GSL basin as a whole. It also provides the results for 
the Mann Kendal Trend test using the area of land cover class over the period of time. The files Bear.xlsx, Weber.xlsx, Jordan.xlsx, and GSL.xlsx contains area (in square km) of land cover class, 
while Bear_MKTrend.csv, Weber_MKTrend.csv, Jordan_MKTrend.csv, and GSL_MKTrend.csv hold the results of the Mann-Kendall Trend test for each basin.

Note: The header in these files represents the land cover class.

#2. LandCoverMaps
It contains the land cover map of the Great Salt lake basin, clipped from the extent of the CONUS map, using the basin's boundary. The analysis also used maps clipped from these for individual subbasins within
 the Great Salt lake basin, using subbasin boundaries. Note: Due to storage limits in the HydroShare, land cover maps for subbasins are not stored here.

#3. LandCoverTransformation
This folder contain files with data on changes in area between land cover classes (land cover transformation) from 2003 to 2021, showing which classes changed to which and the corresponding areas. 
These data were used to plot the Sankey diagram.
	## Description of the file
	Headers : Source -> Land cover class at the year 2003
		  Target -> Land cover class at the year 2021
		  Class  -> Which class changed to which (E.g. Cropland- Tree represents transformation the area that was Cropland in year 2003 was transformed into Tree by the Year 2021.)
		  Area   -> Area in square Kms that was transformed.

#4 PythonCodes
This folder contains python scripts used to visualize timeseries of area of land cover class and Sankey diagram that represents the land cover transformation in the basin.