Land Cover Trends

Land Cover Trends is a research project focused on understanding the rates, trends, causes, and consequences of contemporary U.S. land use and land cover change. The research is supported by the Geographic Analysis and Monitoring Program of the U.S. Geological Survey (USGS) and is a collaborative effort with the U.S. Environmental Protection Agency (EPA) and the National Aeronautics and Space Administration (NASA).

Land use and land cover change is a pervasive environmental change that modifies land cover characteristics and affects a broad range of socio-economic, biologic, and hydrologic systems. Understanding the impacts and feedbacks of land use and land cover change on environmental systems requires an understanding of the rates, patterns, and drivers of past, present, and future land use change.

The objectives of the project are to:

1. document the types, rates, and temporal variability of land cover change on a region-by-region basis over the past 30 years for the conterminous U.S.,
2. document the regional driving forces and consequences of land cover change, and
3. synthesize individual ecoregion investigations into a national assessment of land cover change.

The rates of land use and land cover change are estimated using a stratified random sampling of 10-km by 10-km blocks allocated within an ecoregion-based spatial framework. The Land Cover Trends project uses the EPA defined Level III ecoregions as the spatial framework for national assessment and reporting. Ecoregions are designed to serve as a spatial framework for environmental resource management and denote areas that contain a geographically distinct assemblage of environmental conditions, natural communities, and plant species.

We use historical Landsat Multispectral Scanner (MSS), Thematic Mapper (TM), and Enhanced Thematic Mapper Plus (ETM+) satellite images, along with historical aerial photographs, to interpret land cover change for each sample block on five separate dates (nominally 1973, 1980, 1986, 1992, and 2000). We then use the sample block land cover data to analyze the spatial, temporal, and sectoral dimensions of change. We identify and document the forces driving land cover change using field observation, socio-economic data analysis, and an analysis of published reports. You can find a full discussion of the project methodology in Loveland et al. (2002).

The research team includes staff from the: USGS Center for Earth Resources Observation and Science (EROS) Rocky Mountain Geographic Science Center Eastern Geographic Science Center Mid-Continent Geographic Science Center Western Geographic Science Center

Other partners include researchers at: South Dakota State University University of Southern Mississippi State University of New York College of Environmental Science and Forestry