SCSB# 395
Landuse and Landcover of the Southeastern United States
H.D. Scott and J.M. McKimmey
University of Arkansas
Chapter Contents Overview
An important aspect governing the movement of water and contaminants in soil is landuse and landcover. Characterization of the landuse of the conterminous United States was determined by the U.S. Geological Survey (USGS), EROS Data Center (EDC), and the Center for Advanced Land Management Information Technologies at the University of Nebraska in 1990. This spatial data set was considered a prototype at a 1-km resolution and developed for global environmental research. Generation of the data set was from the National Oceanic and Atmospheric Administration Advanced Very High Resolution Radiometer (AVHRR) satellite images with post-classification refinement based on other digital earth science data sets including topography, climate, soils, and ecoregions. The classes of landuse for the southern region are shown in Fig. 1. Several of the classes in the original work were combined for convenience using geographic information system techniques.

Fig. 1. Spatial distribution of landuse by class for the southern region.
 

The areal extent and percent of the total land area in the 14 states of the southern region of each landuse class are summarized in Table 1. In the region, the four largest general classes of landuse account for over 99% of the approximately 2.2 million km2 . The landuse class having the greatest areal extent was mixed vegetation. This class accounts for about 45.4% of the total land area in the southern region and includes interconnected areas of forest, cropland, range, and marsh. Forest is the next largest class and accounts for about 38.6% of the total land area in the region. The classes of range and cropland account for about 10.0 and 5.9% of the total land area in the region, respectively.

Similar landuse characteristics were found in the chosen MLRAs. Of the approximately 1.45 million km 2 in the chosen land area, 45.6, 37.3, 11.7, and 5.3% were in forest, mixed, range, and cropland, respectively. This shows that the percent of the land area in the chosen MLRAs had slightly greater area in forest than in the region. In the chosen MLRAs, the resolution land area in agriculture alone accounted for a little over 5% of the region.

The areal extent of each landuse category by MLRA is presented in Table 2 and illustrates the diversity of landuse across the southern region of the United States. The Central Great Plains in Texas and Oklahoma (MLRAs 42, 77, and 78) tend to have a large proportion of the land area in the range category and a small proportion in forest. The proportion of the land area in cropland is low in MLRA 42 but is higher in MLRAs 77 and 78. In the East and Central Farming and Forest region (MLRAs 116A, 121, 123, 125, and 128) forest is the dominant landuse with some combination of forest and cropland. In the Mississippi Delta region (MLRAs 131 and 134), cropland and forest dominate the landscape. In the South Atlantic Gulf region (MLRAs 133A, 133B, 135, 136, and 137), forest is the dominant landuse category with smaller proportions of mixed cropland, pasture, and forest. In the Atlantic and Gulf Coast regions, forest, mixed forest, and cropland dominate the landscape.



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Electronic document prepared by:
D.L. Nofziger, Oklahoma State University
Email address: david.nofziger@okstate.edu