Forty Years of Change
Land cover today · 2024 NLCD Annual
What the watershed looks like now.
The 2024 Annual NLCD maps every acre of Port Royal Sound across 15 land cover classes. Each class tells a distinct ecological story, from the lowest tidal flat to the most upland pine plantation.
2024 land cover · acres
- Woody Wetland
22.5% of watershed
215,858 - Forest
21.9% of watershed
210,163 - Open Water
20.1% of watershed
192,869 - Emergent Wetland
11.7% of watershed
112,295 - Developed
11.2% of watershed
107,889 - Developed, open space54,541
- Developed, low intensity36,879
- Developed, medium intensity14,354
- Developed, high intensity2,115
- Agriculture
6.5% of watershed
62,496 - Shrub / Herbaceous
5.6% of watershed
53,970 - Barren Land
0.5% of watershed
4,406
Wetlands dominate.
Woody wetland
215,858ac · 22.5%
Emergent wetland
112,295ac · 11.7%
Altogether, 328k acres of NLCD-mapped wetland comprise 34% of the watershed. Woody wetland covers bottomland forests and cypress swamps; emergent wetland captures tidal and freshwater marshes.
Forest is the second anchor.
Forest
210,163ac · 21.9% of watershed
Pine plantations and mixed pine-hardwood forests form much of the upland forest cover. Bottomland hardwoods are largely captured in NLCD's Woody Wetlands class above. Forest cover has shrunk by 31,951 acres since 1985.
Development has grown 72%.
All developed
107,889ac · 11.2%
Open space dev
54,541ac · largest subclass
From 62,784 acres in 1985 to 107,889 in 2024. Open-space development (low-intensity residential, golf, parkland) is the largest single subclass, reflecting the coastal resort and residential character of Beaufort County.
Annual NLCD · MRLC 1985–2024
Forty years of continuous change.
The Annual NLCD provides land cover for every year from 1985 to 2024, 40 consecutive snapshots of the watershed. Each class traces a distinct trajectory: development's steady climb, agriculture's long retreat, forest's compression, and the wetland classes holding remarkably stable.
Land cover trajectory 1985–2024 · annual acres
Use the buttons to show or hide groups. Hover for values.
Open Water includes estuarine and freshwater water bodies within the analysis extent.
Land cover transitions · 1985–2024
What changed into what.
Every colored ribbon is land that switched class between 1985 and 2024. The alluvial shows both the dominant conversion flows, forest to development and agriculture back to forest, and the smaller but ecologically significant reversals, including land that returned from development to forest cover.
Class-to-class flows · 1985→2024
Ribbons colored by 1985 source class. Stable land (same class in both years) shown faint. Hover for acres.
Only flows of 500 acres or more are drawn (21 flows). Width is proportional to acres transferred.
Key change flows (1985→2024)
- Forest → Shrub / Herbaceous32,642
- Forest → Developed32,032
- Shrub / Herbaceous → Forest18,357
- Agriculture → Forest18,113
- Agriculture → Shrub / Herbaceous13,492
- Woody Wetland → Emergent Wetland8,546
- Agriculture → Developed6,610
- Shrub / Herbaceous → Developed4,396
Reversion flows · land that came back
Development → Forest: 1,424 ac
Development → Shrub/Herb: 413 ac · Agriculture: 207 ac
Agriculture → Forest: 18,113 ac
Harvest & regrowth · annual pulse
Forest and scrub trade substantial two-way volume.
The most counterintuitive signal in the 40-year record: shrub and herbaceous cover has grown by 21k acres while 18k acres that were shrub in 1985 are forest again by 2024. This pattern is consistent with active timber harvest, clear-cutting followed by replanting that cycles through the landscape continuously.
Annual forest loss and regrowth signal · 1985–2024
When forest becomes shrub/herbaceous, the bar rises above zero. When shrub/herbaceous becomes forest, the bar falls below zero. The line tracks total forest acres on the right axis.
Shrub/herbaceous includes NLCD Shrub/Scrub (52) and Herbaceous (71). Barren Land is reported separately in the 2024 snapshot and is absent from this historical series. Annual transitions may count the same land more than once as it moves through repeated cycles.
The harvest cycle.
Clear-cut pine stands can read as shrub/herbaceous for a few years, then read as forest again as the canopy closes. The result is a background cycle that the single 1985→2024 comparison does not show.
Net position 1985–2024.
Forest net change
−31,951ac · 242k→210k
Shrub/herb net change
+21,001ac · 33k→54k
Across the annual maps, 160,167 acres changed from forest to shrub/herbaceous and 149,617 acres changed back. These are repeated year-to-year transitions, not unique acres. The 31,951-acre net forest decline reflects transitions among all land-cover groups, not only this pair.