Digital Landcover Dataset for the Southwestern United States - Sonoran Desert eco-region

Multi-season satellite imagery (Landsat ETM+) from 1999-2001 were used in conjunction with digital elevation model (DEM) derived datasets (e.g. elevation, landform, aspect, etc.) to model natural and semi-natural vegetation. The minimum mapping unit for this dataset is approximately 1 acre. Landcover classes are drawn from NatureServe's Ecological System concept, with 109 of the 125 total classes mapped at the system level. For the majority of classes, a decision tree classifier was used to discriminate landcover types, while a minority of classes (e.g. urban classes, sand dunes, burn scars, etc.) were mapped using other techniques. Twenty mapping areas, each characterized by similar ecological and spectral characteristics, were modeled independently of one another. These mapping areas, which included a 4 km overlap, were subsequently mosaicked to create the regional dataset. An internal validation for modeled classes was performed on a withheld 20% of the sample data. Results of the validation will be presented in the project final report and are not available at this time. The entire modeling area encompasses 5 southwestern states (Arizona, Colorado, Nevada, New Mexico, and Utah).
Complete descriptions of each landcover class are available in the document titled:  "Landcover Descriptions for the Southwest Regional Gap Project" at http://earth.gis.usu.edu/swgap/swgap_legend_desc.pdf

Note: this file was clipped from the original dataset by Conservation Biology Institute, and only contains data for the area within the Sonoran Desert eco-region, a CEC Level III eco-region.