Henry County, Illinois is overwhelmingly agricultural in the 2025 land-cover summary, yet the map contains several distinct patterns within that farm-dominant landscape. Agriculture accounts for 85.28% of the county, followed by developed land at 8.26%, forest at 5.07%, wetlands at 0.77%, and water at 0.38%. The northwest has the most noticeable combination of forest, wetland, and water patches, while additional wooded areas appear through the middle and southeast. Built cover is divided among several centers rather than forming one continuous urban area.
This page compares four map views: general 2025 land cover, forest and farmland, impervious surface and developed land, and the 1985–2025 class-difference layer. WebP versions can be viewed on the page, and the four original JPG maps are available together in one ZIP download. The maps describe what covers the ground surface; they should not be read as zoning, ownership, parcel boundaries, or permission to develop a site.
Table of Contents
Agriculture covers 85.28% and forms a nearly continuous countywide background
The 2025 land-cover map is dominated by the yellow agricultural class. Large farm blocks extend across the north, center, east, and south, creating a grid-like background over most of Henry County. Narrow developed lines cross those fields, and small green forest patches interrupt the agricultural pattern in several places. Seen from a countywide view, agriculture is the defining cover, while other classes appear mainly as clustered pockets, corridors, and edge features.
The agricultural majority does not erase local differences. The northwest edge contains a denser mix of forest, wetland, water, and developed cover than most of the interior. Farther east, a few elongated green patches follow narrow landscape features through otherwise broad fields. In the southeast, another sizable group of wooded patches sits near one of the county’s larger developed concentrations. These areas help explain how a county with more than 85% agriculture can still contain visible natural-cover clusters.
Wetlands and water together make up a small share of the total, but their locations are still useful for understanding the map. Teal wetland pixels and blue water are most noticeable in the northwest and along a few narrow interior features. Because these are land-cover classes, their mapped edges should not be treated as legal wetland boundaries or precise waterlines. They show generalized surface classification at the scale of the source raster.
Developed land is split among several centers connected by thin road corridors
Developed cover accounts for 8.26% of Henry County, but its geography is more important than the single percentage. A large built cluster appears in the northwest, another in the north-central part of the county, and separate concentrations occur farther east and southeast. Smaller developed nodes are scattered through the southern half. Between these places, the map quickly returns to agricultural cover, showing that the developed class is concentrated rather than continuous.
Thin red lines extend from several of the larger clusters and cross the yellow agricultural grid. These linear features correspond to the developed surfaces associated with roads and nearby built cover at the mapped resolution. One of the clearest east-west connections runs through the middle of the county, linking multiple developed nodes. A separate southeast cluster stands out because it occupies a relatively large area compared with the surrounding fields.
The developed class should not be interpreted as pavement or buildings alone. Annual NLCD developed categories may include lawns, trees, bare soil, and other permeable surfaces within built settings. That is why developed cover and impervious cover are related but not identical measurements. The land-cover map also does not identify zoning or ownership, so a developed pixel says nothing about a parcel’s legal use or future development status.
The forest-and-farmland map isolates the main wooded pockets inside the farm grid
The forest-and-farmland map strips away much of the developed detail and makes the contrast between agriculture and forest easier to follow. Yellow cropland dominates almost every direction. Green forest, at 5.07%, is concentrated most visibly in the northwest, with additional patches in the west-central, east-central, and southeast portions of the county. Several smaller wooded strips thread between field blocks rather than forming large continuous forests.
The northwest is the most complex part of this view because forest, wetlands, water, and non-agricultural surfaces appear close together. In the east-central part of the county, elongated green pieces run through otherwise uninterrupted cropland. The southeast contains another broad collection of wooded pixels around a larger developed area. These patterns show why the 5.07% forest share should be interpreted spatially rather than as an evenly spread countywide layer.
Grassland is listed at 0.12%, while shrubland is effectively 0.00% in the summary. Neither class is large enough to define Henry County’s overall pattern. Wetlands at 0.77% and water at 0.38% are also small in total area, but they have more visible local importance in the northwest and along a few narrow corridors. Keeping small classes in proportion prevents the map from being turned into a story that the supplied data do not support.
Mean impervious cover is 2.22%, with higher values concentrated in the same built nodes
Impervious surface measures the share of mapped ground covered by hard surfaces such as roads, parking areas, and rooftops. Henry County has a mean impervious value of 2.22%, and 1.12% of the county falls in the 50% or greater impervious category. Those values are much lower than the 8.26% developed-land share because developed land can contain permeable surfaces along with pavement and buildings.
The darkest impervious colors cluster in the northwest, north-central, east-central, and southeast developed areas. Thin orange and red lines trace the connecting road network across the agricultural interior. Several smaller southern nodes also stand out against a mostly pale background. That pale background is important: it shows how little hard surface occupies the broad farm areas compared with the more concentrated developed centers.
Impervious cover is useful for locating hard-surface concentration, but it cannot by itself establish drainage, runoff, or flood behavior. Terrain, soils, drainage infrastructure, rainfall, and nearby water conditions all affect how water moves. The map is therefore best used as a county-scale reference and as a way to identify areas that may deserve closer study, not as a stand-alone engineering or hazard assessment.
The 1985–2025 comparison shows 6.52% class difference, mostly in the “other” category
The land-cover change map highlights cells whose classifications differ between 1985 and 2025. Henry County has an overall class-difference value of 6.52%. The summary identifies 1.12% as classified to developed, 0.31% as forest loss, 0.37% as agricultural loss, and 4.69% as other class difference. Because the “other” category accounts for most of the total, the 6.52% figure should not be simplified into a single development or agricultural trend.
Purple “other” differences are scattered across the northwest, east-central, southeast, and smaller interior locations. Red developed differences are easier to see around existing built clusters and along portions of the road network. Orange forest-loss and yellow agricultural-loss cells appear as smaller pieces. Most of the county remains in the no-class-difference background, so the mapped differences are localized rather than spread evenly across the farm landscape.
A different class at the two endpoints may reflect real surface change, but classification differences can also be affected by imagery, methods, vegetation or moisture conditions, and mixed pixels. The map itself notes that classification variation may be included. For a specific site, the change layer should be treated as a screening tool; confirming what actually changed requires additional imagery, records, or field evidence.
Use each map for a separate question instead of combining all information into one view
The general land-cover map is the best starting point for describing Henry County as a whole. It shows the agricultural majority, the separate developed centers, and the main forest, wetland, and water pockets in one frame. The forest-and-farmland map is more effective when the goal is simply to show how scattered wooded cover sits within a very large agricultural grid.
The impervious map answers a narrower question about hard surfaces and road connections. Comparing it with the developed-land map also helps explain why 8.26% developed cover does not mean 8.26% pavement or rooftops. The 1985–2025 map serves a different purpose again: it marks classification differences between two dates rather than the present-day mix of land-cover classes.
For classroom use, presentations, or environmental reference, the four-map set works well when shown in sequence. Start with current cover, narrow the view to agriculture and forest, examine the built-surface pattern, and then finish with the change comparison. The downloadable JPG files keep those roles separate and can be used individually or placed side by side without forcing every type of information onto one map.
Thirty-meter raster cells generalize narrow roads, wetland edges, and small forest patches
Annual NLCD products are commonly represented with roughly 30-meter raster cells. A raster divides the landscape into a grid and assigns each cell a representative class or value. If one cell contains both a field and a road, or a forest edge and a wetland, the mapped result may simplify that mixed ground into a single class or impervious percentage.
This matters in Henry County because many roads are narrow compared with the surrounding fields, wooded patches can have irregular edges, and small wetland or water features may sit next to several other covers. The map is not a parcel survey. Forest colors do not identify ownership or protected land, wetland colors are not legal wetland boundaries, and developed classes do not define zoning.
The 2025 layer is also a snapshot of a particular classification year. Construction, crop rotation, vegetation changes, water levels, or other surface changes after that observation are not automatically included. The 1985–2025 comparison uses two endpoints and does not reconstruct every change in the years between them. These maps are most useful for county-scale comparison and for identifying places where newer or more detailed information may be needed.
Frequently Asked Questions
What is the largest 2025 land-cover class in Henry County?
Agriculture is the largest class at 85.28%. Developed land follows at 8.26%, forest at 5.07%, wetlands at 0.77%, and water at 0.38%. Agriculture is widespread, while natural-cover pockets are more noticeable in the northwest and several central and southeastern areas.
Why is developed land 8.26% while mean impervious cover is 2.22%?
Developed land-cover classes can include lawns, trees, soil, and other permeable surfaces as well as pavement and buildings. Impervious cover measures hard surfaces separately, so the countywide mean can be much lower than the developed-land share.
Does the 6.52% 1985–2025 class difference equal physical land-use conversion?
Not necessarily. It counts cells with different classifications at the two endpoints. Real surface change may be included, but imagery, classification methods, vegetation or moisture conditions, and mixed pixels can also affect the result. Other class difference accounts for 4.69%.
Map File Information
The download combines four original JPG maps for Henry County: 2025 land cover, forest and farmland, impervious/developed land, and the 1985–2025 land-cover class comparison.
- Included Versions: Land Cover Map, Forest & Farmland Map, Impervious/Developed Land Map, and 1985–2025 Land Cover Change Map
- File Type: One ZIP containing four JPG files
- Intended Use: agricultural and forest comparison, built-surface review, class-change reference, teaching, presentations, and county-scale environmental context
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 point for Annual NLCD land-cover and impervious-surface products.
- USGS Annual NLCD Land Cover Classification – official documentation for land-cover classes and interpretation of the raster product.
- U.S. Census Bureau TIGER/Line Shapefiles – official geographic boundary source used to identify Henry County.
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.
