Correlation of Land Condition Trend Analysis (LCTA) Rangeland Cover Measures to Satellite-Imagery-Derived Vegetation Indices.

Abstract : Using field data from the U.S. Army's land inventory and monitoring program, a study was conducted to examine the utility in estimating the quantity of vegetation cover with satellite imagery across a large and complex rangeland. The U.S. Army's Yakima Training Center (YTC), WA, was studied for this investigation. The Land Condition Trend Analysis (LCTA) program at YTC has 202 permanent plots located in a randomly stratified manner across the installation. The principle measures taken along the transects were canopy cover and ground cover. These analyses used Landsat Thematic Mapper imagery collected in May and August of 1992. The satellite data coincided with the beginning and end of the field data collection period and were used to derive various vegetation indices (Vis), including the Ratio VI, the Transformed VI, the Soil Adjusted VI, and the Modified Soil Adjusted VI. Analysis of correlation of rangeland cover measures and satellite-imagery-derived VIs were performed. Correlation between the Vis derived from the May image and the cover measures were found to be stronger than those between the August image and cover measures.