Rangeland Condition Monitoring Assessment and Projection (RCMAP) Fractional Component Time-Series Across the Western U.S. 1985-2020

The RCMAP (Rangeland Condition Monitoring Assessment and Projection) dataset quantifies the percent cover of rangeland components across the western U.S. using Landsat imagery from 1985-2020. The RCMAP product suite consists of eight fractional components: annual herbaceous, bare ground, herbaceous, litter, non-sagebrush shrub, perennial herbaceous, sagebrush, shrub and rule-based error maps including the temporal trends of each component. Several enhancements were made to the RCMAP process relative to prior generations. We used an updated version of the 2016 base training data, with a more aggressive forest mask and reduced shrub and sagebrush cover bias in pinyon-juniper woodlands. We pooled training data in areas and times identified as having no spectral change relative to the base year across all years in the time-series and used a series of procedures to remove the most spatially and temporally common values. We also used composite Landsat Analysis Ready Data (ARD) in seven regions instead of using individual images by path and row. An automated method to identify change in spectral conditions between each year in the Landsat archive and the circa 2016 base map, resulted in a robust and sensitivity of subtle changes. Yearly fractional component cover outputs were inserted in the changed area while the base year values were maintained in the unchanged area. Processing efficiency has been increased through use of open-source software and High-Performance Computing (HPC) resources. The mapping area included seven regions which were subsequently mosaicked for all eight components. These data can be used to answer critical questions regarding the influence of climate change and the suitability of management practices. Component products can be downloaded from www.mrlc.gov.