North Carolina SWAT+ modeling | SWATGenX
Upper French Broad — USGS 03441440: documented SWAT+ USGS station watershed snapshot with Explorer-aligned maps.
SWATGenX documents a sample SWAT+ watershed model in North Carolina for Upper French Broad (USGS 03441440). The overview covers 107.2 km² with 11824 HRUs and 2397 channels, with deciduous forest prominent in the exported land-cover summary, using the same CONUS national data stack as every production build. Review DEM, land-cover, and structure summaries on this page, then open Watershed Explorer to model your own gage or HUC, or browse downloadable packages in the example models catalog.
Part of SWAT+ modeling by stateon SWATGenX: a sample example model for this state, built with the same CONUS national datasets as Watershed Explorer. Browse downloadable example models.
Why watershed modeling matters
Watershed models help connect landscape processes, managed systems, and channel routing to questions about water supply, water quality, and flood timing. SWAT+ represents those linkages over multi-year climate forcing using national soils, land cover, and hydrography. Study-specific calibration, local observations, and endpoint models remain the responsibility of each project team.
Case study basin: Upper French Broad
Below is a documented SWAT+ model-build snapshot for the Upper French Broad watershed—the same export class as Watershed Explorer. The metric strip, maps, charts, NHD flowline-length summary by feature class, and fact tables follow from that committed export.
The metric strip, fact tables, and optional DEM/CDL maps describe the exported SWAT+ workspace for Upper French Broad (HUC8 06010105). NHD-linked stream statistics and PRISM climate headers follow the same conventions as other SWATGenX state sample models across CONUS.
Counties in the basin overlay: Greenville, South Carolina, Henderson, North Carolina, Transylvania, North Carolina.
- Runoff timing and climate variability across multi-year forcing
- Channel routing and NHDPlus HR hydrography linkage
- Land cover and HRU discretization for management screening
- Reproducible SWAT+ package delivery via SWATGenX
Basin distributions (Upper French Broad · North Carolina)
CDL charts use the same basin-clipped raster summary as Explorer watershed reports. County population bars use US Census county-or-equivalent polygons only (not state, city, or township layers): one published headcount per county that intersects the basin, then summed for screening—not watershed-apportioned density.
CDL land cover (basin clip)
Population by county (overlay)
Land-cover mix (km², CDL clip)
Climate forcing (Upper French Broad · North Carolina)
Monthly climatology from basin PRISM precipitation and temperature plus NSRDB humidity, solar radiation, and wind files. The line is the mean daily value for each calendar month (averaged across all station files and years); the shaded band is the P05–P95 spread of those daily values (2000-01-01 – 2024-12-31). Source grid: 15 PRISM/NSRDB grid cells (4 km).
Precipitation
mm day⁻¹ (PRISM)Relative humidity
% (NSRDB)Solar radiation
MJ m⁻² day⁻¹ (NSRDB)Wind speed*
m s⁻¹ (NSRDB MERRA-2, ~2 m)Daily maximum temperature
°C max (PRISM)Daily minimum temperature
°C min (PRISM)* Wind speed. MERRA-2 at ~2 m above ground (not 10 m hub height). Daily arithmetic mean of 48 thirty-minute NSRDB steps; curves are monthly basin means with P5–P95 spread. NREL documents this for solar forcing, not wind-resource assessment.
Key facts
The first table lists basin id, climate window, CDL and population context, and the two published stream-length definitions (channel routing versus NHD-linked stream GIS). The strip above still carries headline structure counts (HRUs, channels, lakes).
| Metric | Value |
|---|---|
| WBD HU8 name | Upper French Broad |
| USGS site (HUC12 model folder) | 03441440 |
| WBD region (VPUID) | 0601 |
| Watershed area | 107.24 km² |
| SWAT+ stream GIS segments (NHDPlusID → NHDFlowline) | 2486 |
| Stream length — channel routing (rivs1, projected) | 506.32 km |
| NHD-linked stream length, GIS projected | 518.76 km |
| DEM resolution (m) | 29.98 |
| CDL cropland (basin clip) | 0.00 km² |
| CDL wetland (Woody + Herbaceous) | 0.12 km² |
| CDL developed | 6.25 km² |
| Population (by county, Explorer overlay) | 674,801 |
| Counties (gov. units) | 3 |
| Climate period (PRISM header) | 2000-01-01 – 2024-12-31 |
| Stats exported (UTC) | 2026-05-21 17:09 UTC |
| SWATGenX snapshot ID | 0601/huc12/03441440 |
| Snapshot label | Upper French Broad (North Carolina) — usgs_station — exported workspace |
| Model statistics generated (UTC) | 2026-05-21T17:09:22Z |
How to read this table: each row starts from Watershed/Shapes/SWAT_plus_streams.shp, where each segment carries NHDPlusID. Those IDs join to NHDFlowline in the USGS NHDPlus HR HU4 geodatabase (VPUID 0601). Lengths add in EPSG:5070 (planimetric km) and roll up by NHD FType / FCode. Row lengths sum to 518.76 km over 2,486 segments.
| NHD class (label) | Length (km) | Share | Segments |
|---|---|---|---|
| Stream / riverFType 460 · FCode 46000 | 491.16 | 94.7% | 2,218 |
| Artificial path (NHD)FType 558 · FCode 55800 | 27.55 | 5.3% | 267 |
| ConnectorFType 334 · FCode 33400 | 0.05 | 0% | 1 |
The county total matches the bar chart: county-or-equivalent units only (cities and townships excluded), one Census headcount per county intersecting the basin. Screening context only—not basin density or a regulatory design population.
SWATGenX documented snapshot (usgs_station) for North Carolina: model id 0601/huc12/03441440. Values come from the exported SWAT+ workspace plus Explorer-style overlays where present; they support screening and documentation, not regulatory determinations.
What SWATGenX generates
SWATGenX assembles national inputs, runs the QSWAT+ / SWAT+ Editor workflow, and exports a reviewable SWAT+ workspace (TxtInOut + GIS + SQLite). Open the package in SWAT+ Editor for scenarios; add calibration and validation with local data where your study requires it.
Related on SWATGenX
National datasets (labels)
This sample build uses the same CONUS resolutions as every SWATGenX package—NHDPlus HR at 1:24k, 30 m terrain (from 10 m 3DEP), 250 m NLCD/CDL (from 30 m), 250 m gSSURGO (from 10 m), ~4 km PRISM, and daily NSRDB at PRISM stations (from ~2 km, 30-minute data). See SWAT+ by state for the full stack. Methodology & provenance.
Citations for on-page facts
- Hydrologic catalog: USGS WBD — USGS station 03441440 (HUC12-located SWAT+ model)
- Hydrography: USGS NHDPlus HR — SWAT+ ``SWAT_plus_streams.shp`` ``NHDPlusID`` joined to HU4 ``NHDFlowline`` (FType/FCode); lengths summed in EPSG:5070 for the distribution table.
- Land cover (CDL): USDA NASS Cropland Data Layer (clipped to basin)
- Climate forcing: PRISM Climate Group (OSU), daily met files referenced in weather-sta.cli
- Regional population context: USGS governmental units overlay — county totals (sum within county, then across counties; avoids double-count from overlapping polygons).
SWAT+ in North Carolina — common questions
- How do I run SWAT+ in North Carolina? Use SWATGenX to screen basins in North Carolina on the Watershed Explorer map, then queue a SWAT+ model build for a USGS gage, catalog HUC12, or HUC8. The platform assembles national datasets into a SWAT+ Editor package without manual QSWAT+ desktop prep for each basin. The sample model on this page is Upper French Broad (USGS 03441440).
- What is the difference between SWAT and SWAT+ in North Carolina? SWAT (legacy) and SWAT+ (current process-based watershed model) both support long-term hydrology and water-quality studies in North Carolina. SWATGenX targets SWAT+ and delivers reproducible, high-resolution projects on NHDPlus HR hydrography.
- Can SWATGenX build SWAT+ models for North Carolina watersheds? Yes. SWATGenX covers CONUS, including North Carolina, with the same national data stack (WBD, NHDPlus HR, PRISM, NLCD, gSSURGO). Each state page documents a sample basin snapshot from a real SWATGenX build; open the live map at https://www.swatgenx.com/watershed-workspace to model your own watershed.
- Is SWAT+ modeling in North Carolina free on SWATGenX? Signed-in users can explore North Carolina on the map and use tiered quotas for reports and model builds. See https://www.swatgenx.com/pricing for Basic vs Pro limits; Pro adds optional cloud calibration where enabled.
Open Upper French Broad in Watershed Explorer
Preview uses the USGS WBD boundary with NHDPlus HR context, zoomed to basin extent on a Streets-style basemap. Follow the card into the live workspace (HUC8 06010105).
