The Department of Agriculture publishes a National Resource Inventory. The report is focused mainly around agricultural issues, but it does contain some information about land use/land cover (LULC). The report divides the country into agricultural regions. The Corn Belt includes Missouri, Iowa, Illinois, Indiana, and Ohio. The graph at right shows the changes in the number of acres devoted to 9 types of LULC in the Corn Belt from 1982 to 2007.
Cropland and Pastureland showed persistent losses over the period. – 9.9 million acres, all totaled. Part of the reason is that land was put into the Conservation Reserve Program, which was implemented in 1985. However, land was withdrawn from the program after 1992, and the net gain over the whole period was 3.9 million acres. Developed Land increased by 3.7 million acres, with the gains being remarkably consistent. Forest Land gained 2.1 million acres, although the number of acres actually decreased in the most recent period. Federal Land, Water Areas, Other Rural Land, and Rangeland were mostly unchanged.
I have found two datasets that I could use to construct maps of Missouri that show LULC at different time periods. The maps are at right. The first is from 1991, the second from 2005. One must be careful in comparing these maps, as some of the colors do not appear to have rendered the same way between the two maps. For instance, I would be cautious comparing the amount of yellow, which represents forest land. However, it appears that the dark blue, which represents urbanized land, has rendered comparably. Notice that the large and mid-sized urban areas – St. Louis, Kansas City, Springfield, Columbia, Joplin, and St. Joseph – have all sprawled. But in addition, on the 2005 map notice the many small urbanized areas throughout the state. We usually think of urban sprawl as affecting our major metropolitan areas, but something very similar is happening in small towns and cities in otherwise rural areas.
Overall, between 1982 and 1992, Missouri developed an average of 20,900 acres of land per year. Between 1992 and 1997, Missouri developed an average of 44,800 per year, more than double the amount.
I was able to find maps of the St. Louis Metropolitan Region for the years 2009 and 2013. This is only a 4-year timespan, but they provide detail to some of the trends we have been discussing.They are shown at right.
Because developed land is coded into many colors, the maps may be hard to follow. However, one can notice at least three things. First, the area of yellow land around St. Louis is a bit darker in 2013 and it has expanded. Yellow represents single family housing.
Second, the area of brown land has shrunk substantially in 2013, especially in Jefferson and Franklin Counties, but also somewhat in St. Charles County. Brown land represents vacant or undeveloped land. Some of the land that was brown in 2009 is light green in 2013. Light green represents agricultural land, and this land might be land on which crops were not grown in 2009, but which has been returned to production by 2013. But some of the brown land in 2009 is yellow in 2013, and this represents vacant land that has become residential land.
Third, I noted in my previous post that land in its natural state provides certain environmental services, and when it is developed, it loses its ability to provide them. Large contiguous tracts are better at providing these services, fragmented tracks less good. In looking at the 2013 map, the undeveloped and recreational categories probably best represent land that can provide these services. They are very fragmented!
For summary statistics of land types in the Corn Belt: 1982-2007: Table 25. Total Surface Area, by Land Cover/Use, by Farm Production Region and Year, in Thousands of Acres, with Margins of Error, 2007 National Resources Inventory, Natural Resources Conservation Service, U.S. Dept. of Agriculture, http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/technical/nra/nri.
For the datasets used to create the maps of LULC in Missouri in 1991 & 2005: Missouri Land Cover, Missouri Spatial Data Information Service, http://www.msdis.missouri.edu/data/lulc/index.html.
For the number of acres of land that were developed 1982-1992 and 1992-1997: Blodgett, Clayton, Missouri Statewide Landcover Mapping, http://www.cerc.usgs.gov/morap/FileDownload.aspx?WebPath=http%3a%2f%2fwww.cerc.usgs.gov%2fmorap%2fAssets%2fUploadedFiles%2fProjects%2flulc%2flandcover.pdf.
For the maps of LULC in the St. Louis Metro Region: Existing Land Use 2009, East-West Gateway Council of Governments, http://www.ewgateway.org/pdffiles/maplibrary/ExistingLandUse-0109.pdf.
Existing Land Use 2013, East-West Gateway Council of Governments, http://www.ewgateway.org/pdffiles/maplibrary/existinglanduse-0113.pdf.