Fayette County in south-central Illinois is mostly agricultural in the 2025 land-cover data, but the county is not a uniform field landscape. Agriculture accounts for 66.97% of the mapped area, while forest reaches 20.40%. Developed land makes up 7.57%, wetlands 3.38%, and water 1.59%. The four maps on this page separate those broad classes from forest-and-farmland patterns, impervious surfaces, and mapped class differences between 1985 and 2025.
Each WebP map can be viewed in the article, and the four original JPG maps are available together in one ZIP download. Start with the general land-cover map for a countywide overview. The forest and farmland version makes wooded belts easier to follow, the impervious map isolates roads and built-up centers, and the change map is useful when the question is how the 1985 and 2025 classifications differ rather than what the county looks like today.
Table of Contents
A broad farm landscape is broken up by substantial forest and a distinct southwest water area
Yellow agricultural cover fills much of the center, southeast, and northwest on the general map. That broad farm pattern explains the 66.97% countywide share, yet large green forest patches repeatedly interrupt it. Wooded cover is especially noticeable across the north and east, where it forms branching bands and larger blocks instead of isolated dots. The southwest corner adds another strong contrast because water and wetlands occupy a visibly larger area there than in most of the county.
The summary figures help keep the color patterns in perspective. Forest is the second-largest class at 20.40%, so its presence is not a minor edge feature even though agriculture remains dominant. Developed land is much smaller at 7.57% and appears mainly in compact centers and narrow corridors. Wetlands and water together account for less than 5% of the total area, but their clustering makes them locally prominent, particularly around the larger southwest water feature and along several internal drainage-like bands.
Land cover should not be confused with zoning, parcel ownership, or legal land use. Annual NLCD classifies the physical surface seen in the source imagery, such as crops, forest, water, wetland, or developed cover. A cell shown as agriculture does not identify a particular crop or farm boundary. Likewise, developed land does not tell whether a place is residential, commercial, industrial, or legally available for construction. The maps are best used for county-scale pattern comparison rather than parcel decisions.
The southwest corner shows why the water and wetland classes matter despite their small percentages
The most visually distinctive non-farm area lies near the southwest edge. Blue water occupies a broad block there, with teal wetland and green forest around parts of the same area. Smaller wetland and water features also appear farther inside the county. Because these classes are clustered rather than evenly distributed, their local importance is greater than a countywide percentage alone might suggest. A reader interested in watershed or habitat context should therefore look at location as well as the 1.59% water and 3.38% wetland totals.
Fayette County’s official website describes the Kaskaskia River State Fish and Wildlife Area as one of the county’s natural attractions and identifies Vandalia as the county seat. That local information provides useful background for reading a county where agricultural land exists alongside significant water-related and wooded environments. The land-cover maps, however, do not draw the legal boundary of a wildlife area or label every river, lake, or protected tract. Those boundaries require the appropriate agency map rather than an NLCD classification layer.
Forest reaches 20.40%, with the strongest wooded pattern in the north and east
Removing most developed detail makes the forest-and-farmland map especially useful in Fayette County. Green forest blocks and bands become easier to trace through the northern and eastern portions, while broad yellow cropland remains dominant across the middle and much of the south and southeast. In some areas the forest follows narrow branching shapes; elsewhere it forms wider patches. The result is a farm landscape with a much stronger wooded component than a simple agriculture percentage might imply.
Built surfaces are concentrated in several centers and along thin transportation corridors
The impervious-surface map changes the visual emphasis completely. Most of Fayette County becomes very light because the average impervious share is only 1.83%. Darker colors appear in a few compact built-up centers, while many pale linear features extend across agricultural areas. These lines are consistent with the mapped hard-surface network, including roads and other paved routes. The strongest cluster lies in the west-central part of the county, with smaller concentrations elsewhere.
Impervious surface means pavement, rooftops, parking areas, and similar surfaces that do not readily absorb water. Only 0.60% of the county is mapped at 50% or greater imperviousness, which explains why the darkest colors occupy small areas. The developed-land class is larger at 7.57% because a developed cell can contain trees, lawns, soil, and other permeable surfaces along with buildings or pavement. The two measurements should therefore be read together rather than treated as interchangeable.
The 1985–2025 map marks 8.81% as a different class, but most of that total is ‘other difference’
The change map compares classifications at two endpoints rather than showing a continuous history. Across Fayette County, 8.81% of the area is marked as having a different class in 1985 and 2025. The summary separates 0.91% classified to developed, 0.57% forest loss, and 0.91% agricultural loss. The largest component is other class difference at 6.19%, so the headline total cannot be interpreted as 8.81% urban growth or 8.81% vegetation loss.
Purple other-difference cells are scattered through the north, west, and southwest as well as smaller parts of the interior. Red developed-change cells appear near some existing built centers and corridors, but they occupy a limited share of the map. Forest-loss and agricultural-loss colors are also fragmented rather than forming one sweeping front. Around the southwest water and wetland area, several change colors occur close together, which is a reminder that class boundaries can shift between observation years.
A mapped class difference is evidence that the two classified cells do not match, not a complete explanation of why they differ. Real land-cover conversion may be part of the pattern, but image conditions, classification methods, mixed pixels, and changes at class boundaries can also contribute. If a particular field, forest patch, or wetland must be investigated, intermediate-year Annual NLCD layers, aerial imagery, and local records are more appropriate than relying on the two-endpoint map alone.
Choosing the right map first makes the set easier to use in class, planning, and comparison work
For a general county profile, the first map is usually enough to establish the main story: two-thirds agricultural cover, a substantial forest component, several developed centers, and a localized water-wetland concentration. A lesson focused on farm and forest relationships benefits from the simpler forest-and-farmland map because unnecessary developed detail is reduced. The impervious layer is more useful for discussions of built surfaces, while the change map belongs in a separate time-comparison question.
Thirty-meter raster cells are useful for county patterns, not exact parcel boundaries
Annual NLCD land-cover products use a raster grid, meaning the landscape is divided into cells and each cell receives a representative class. The standard land-cover grid is 30 meters. Narrow tree rows, small ponds, road edges, individual buildings, and mixed farm-and-forest boundaries can therefore be generalized. When several surface types occur within or near a cell, the displayed class may not reproduce every feature seen on the ground.
That limitation matters most where Fayette County’s forest strips weave through farmland or where wetland, water, and forest meet. A crisp color boundary on the map is not a surveyed property line or a legally established wetland boundary. Developed cover is not a zoning designation, and forest cover is not proof of ownership or conservation status. Parcel, zoning, regulatory, or protected-area decisions require the relevant local or state records.
Frequently Asked Questions
What is the largest land-cover class in Fayette County?
Agriculture is the largest 2025 class at 66.97%. Forest follows at 20.40%, developed land at 7.57%, wetlands at 3.38%, and water at 1.59%. The map shows broad farm areas interrupted by substantial wooded cover and a prominent southwest water-wetland area.
Why is developed land 7.57% while mean impervious cover is only 1.83%?
A developed land-cover cell can include lawns, trees, soil, and other permeable surfaces along with buildings or pavement. Impervious cover measures hard surfaces such as roads, rooftops, and parking areas more directly, so the two percentages describe different things.
Does the 8.81% change figure mean that 8.81% of the county was physically converted?
Not necessarily. The 8.81% figure is the area with different mapped classes in 1985 and 2025. Only 0.91% is listed as classified to developed, 0.57% as forest loss, and 0.91% as agricultural loss, while 6.19% is other class difference. Classification variation and mixed pixels can contribute to the result.
Map File Information
The ZIP contains four original JPG maps for Fayette County: 2025 land cover, forest and farmland, impervious/developed land, and the 1985–2025 land-cover class comparison.
- Included Versions: land cover, forest and farmland, impervious/developed land, and 1985–2025 land-cover change
- File Type: ZIP containing four JPG files
- Intended Use: printing, class presentations, farm/forest comparison, built-surface context, and county-to-county map comparison
Related Maps
- Adams County Illinois Land Cover Map
- Alexander County Illinois Land Cover Map
- Bond County Illinois Land Cover Map
Sources and references
- MRLC Annual NLCD Data – official access to Annual NLCD land-cover and related datasets.
- USGS Annual NLCD Land Cover Classification – definitions and background for the Annual NLCD land-cover classes.
- U.S. Census Bureau TIGER/Line Shapefiles – official geographic boundary data, including county boundaries.
- Fayette County, Illinois – About Us – official county background on Vandalia and local natural and agricultural context.
Green Map creates custom-edited map images using open geographic data sources such as geoBoundaries, Natural Earth, OpenStreetMap, and government open data.
These maps are edited visual materials, not raw data files, and are provided for education, documents, presentations, and graphic reference.
