HR: 14:55h
AN: B13D-06    [Abstracts]
TI: The Geographic Variability of Contemporary United States Land Cover Change
AU: * Loveland, T R
EM: loveland@usgs.gov
AF: U.S. Geological Survey, EROS Data Center 47914 252nd Street, Sioux Falls, SD 57198 United States
AB: The U.S. Geological Survey, in cooperation with NASA and the U.S. Environmental Protection Agency, is conducing a study to document the rates, causes, and consequences of 1973 to 2000 land cover change for the eighty-four ecoregions of the conterminous United States. Estimates of change are based on the interpretation of five dates of Landsat MSS and TM data (nominally 1973, 1980, 1986, 1992, and 2000). Results from an analysis of the first twenty-five ecoregions indicate that the rates, causes, and consequences of change are relative consistent within ecoregions but there are significant differences in the rates of change and types of dominant land use and land cover conversions occurring between ecoregions. For example, high rates of cyclic change are found in ecoregions dominated by resource-based economies while lower but unidirectional change is more common in more urbanized ecoregions. The specific character of change in each ecoregion is shaped by the resource potential of each ecoregion and the historical settlement patterns. Land uses changes that determine changes in cover in a given ecoregion are typically based on the highest economic use enabled by the physical environment (i.e., climate, soils, geology, landforms, etc.) and the comparative advantages associate with resource, location, and history. The differences in rates of change combined with the prevailing land use practices and enduring environmental character of different regions have a significant impact on issues such as carbon dynamics. An assessment of the ecoregion carbon dynamics also shows significant differences in flux rates over time. Overall, the results of this study show that the fabric of change across the conterminous United States highly variable in time and space and understanding the geographic dimensions of change. This suggests that ecoregions offer a framework for projecting rates, types, and the subsequent consequences of change.
DE: 1600 GLOBAL CHANGE (New category)
DE: 1615 Biogeochemical processes (4805)
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting