# raleigh_northcarolina_usa_epsg6542

A GRASS project covering central Raleigh, Wake County, North Carolina, USA.

It bundles elevation, land cover, satellite imagery, hydrography, soils, geology,
transportation and administrative boundaries for a single 24 x 13.5 km area, all in one
projected CRS, for teaching and for testing GRASS tools.

## Contents

```
elevation                 landsat8_2025_B1 … landsat8_2025_B7        (raster)
landuse                                                              (raster)
census_blocks  geology  hospitals  lakes  municipal_boundary         (vector)
roads  schools  soils  streams  watersheds  zipcodes                 (vector)
```

Everything lives in the `PERMANENT` mapset; an empty `mapset_1` is provided as a working
mapset.

## Coordinate reference system

| | |
|---|---|
| CRS | EPSG:6542 — NAD83(2011) / North Carolina |
| Projection | Lambert Conformal Conic (2SP), SPCS83 North Carolina zone |
| Units | meters |
| Datum | NAD83(2011) / GRS 1980 |

## Computational region

Set in `PERMANENT` as the default region:

| | |
|---|---|
| north / south | 228500 / 215000 |
| west / east | 629000 / 653000 |
| resolution | 10 m |
| rows x cols | 1350 x 2400 (3,240,000 cells) |
| extent | 24.0 km (E–W) x 13.5 km (N–S) |
| approx. lon/lat | -78.7857 to -78.5198 E, 35.6872 to 35.8096 N |

## Raster maps

| Map | Res. | Type | Rows x cols | Data range | Description |
|---|---|---|---|---|---|
| `elevation` | 10 m | FCELL | 1350 x 2400 | 21.50 – 158.84 m | USGS 3DEP 1/3 arc-second elevation, 2025-05-07 release (tile `n36w079`), imported with the `r.in.usgs` addon and reprojected with bilinear resampling |
| `landuse` | 30 m | CELL | 450 x 800 | 11 – 95 | Annual NLCD land cover 2024 (CONUS, `Annual_NLCD_LndCov_2024_CU_C1V1`), reprojected with `r.proj` (nearest neighbor); NLCD category labels and `nlcd` color table applied |
| `landsat8_2025_B1` … `B7` | 30 m | — | — | surface reflectance DN | Landsat 8 Collection 2 Level-2, single scene, seven bands |

### Landsat scene

Selected from the `landsat-c2-l2` STAC collection on the Microsoft Planetary Computer over
the region for 2025-03-01 to 2025-07-01 with `eo:cloud_cover < 10`, taking the least
cloudy item:

| | |
|---|---|
| Scene | `LC08_L2SP_015035_20250321_02_T1` |
| Platform / instruments | Landsat 8, OLI + TIRS |
| Acquired | 2025-03-21 15:46:55 UTC (stored as a GRASS timestamp on every band) |
| Cloud cover | 0.02 % (0.02 % over land) |
| WRS-2 path / row | 015 / 035 |
| Collection / category | 02 / T1, `L2SP` corrected |
| Source CRS | EPSG:32618 (reprojected on import) |

Each band carries a semantic label, so the maps work directly with the `i.*` imagery tools:

| Map | STAC asset | Landsat band | Semantic label |
|---|---|---|---|
| `landsat8_2025_B1` | `coastal` | B1 coastal/aerosol | `L8_1` |
| `landsat8_2025_B2` | `blue` | B2 blue | `L8_2` |
| `landsat8_2025_B3` | `green` | B3 green | `L8_3` |
| `landsat8_2025_B4` | `red` | B4 red | `L8_4` |
| `landsat8_2025_B5` | `nir08` | B5 near infrared | `L8_5` |
| `landsat8_2025_B6` | `swir16` | B6 shortwave infrared 1 | `L8_6` |
| `landsat8_2025_B7` | `swir22` | B7 shortwave infrared 2 | `L8_7` |

## Vector maps

| Map | Type | Features | Records | Description |
|---|---|---|---|---|
| `roads` | lines | 28,262 | 28,262 (15 cols) | Drivable OpenStreetMap road network, downloaded with OSMnx. `highway` is collapsed to a single value per edge by road-class rank (motorway → crossing); OSMnx `u`, `v`, `key` columns dropped. Attributes include `name`, `oneway`, `length`, `lanes`, `maxspeed`, `bridge`, `tunnel`. |
| `schools` | points | 61 | 61 (33 cols) | Public schools, with `elem` / `middle` / `high` / `pre_k` / `early_coll` level flags, grade range, enrollment-related fields |
| `hospitals` | points | 4 | 4 (39 cols) | Hospitals and related licensed facilities, with `hltype`, bed counts, address |
| `census_blocks` | areas | 3,754 | 3,716 (18 cols) | 2025 TIGER/Line census blocks, Wake County (state 37, county 183), with `POP20`, `HOUSING20`, `ALAND20`, `AWATER20` |
| `municipal_boundary` | areas | 204 | 1 | City of Raleigh place polygon, 2025 TIGER/Line places |
| `zipcodes` | areas | 18 | 15 (16 cols) | ZIP Code Tabulation Areas, 2010 vintage |
| `geology` | areas | 203 | 165 (15 cols) | Macrostrat "small" scale geologic map units, clipped to the North Carolina state boundary; `name`, `age`, `lith`, `best_age_top`/`best_age_bottom`; vector colors set from the `color` attribute |
| `soils` | areas | 2,977 | 2,873 (21 cols) | SSURGO soil map units, imported with the `r.in.ssurgo` addon and clipped to the region; `mukey`, `compname`, `hydgrp`, `drainagecl`, `slope_r`, `ksat_*`, texture fractions, `awc_r`, `om_r`, `ph1to1h2o_r`, `cec7_r` |
| `watersheds` | areas | 11 | 11 | HUC12 subwatersheds from the USGS Watershed Boundary Dataset (e.g. Lower Crabtree Creek, Lake Wheeler-Swift Creek), with `huc12`, `name`, `areaacres`, `tohuc` |
| `lakes` | areas | 685 | 667 (5 cols) | Lakes, ponds and reservoirs (`HYDRO_TYPE` in `LAKE/POND`, `RESERVOIR`) |
| `streams` | lines | 14,693 | 14,685 (7 cols) | Streams and rivers (hydrolines), with `NAME` where known |

### Extents

Not every layer is clipped to the computational region:

| Map | Extent |
|---|---|
| `elevation`, `landuse`, `soils` | exactly the region |
| `schools`, `hospitals` | points, all inside the region |
| `roads`, `lakes`, `streams` | region, ± an individual feature's own overhang |
| `census_blocks`, `zipcodes`, `watersheds` | whole features intersecting the region, so they overhang it (zipcodes reach ~616336–668108 E, 196572–234283 N) |
| `municipal_boundary` | the complete Raleigh city polygon, well north of the region (up to 246457 N) |
| `geology` | all of North Carolina |

## Sources

| Layer | Source | Service |
|---|---|---|
| `elevation` | USGS 3DEP | TNM Access API, via `r.in.usgs` |
| `landuse` | USGS / MRLC | `mrlc.gov` data bundles |
| `landsat8_2025_B*` | USGS | Microsoft Planetary Computer STAC API |
| `roads` | OpenStreetMap contributors | Overpass, via OSMnx |
| `schools`, `hospitals` | NC OneMap (2019), NC Dept. of Information Technology, Government Data Analytics Center, Center for Geographic Information and Analysis — <https://www.nconemap.gov> | `services.nconemap.gov`, via `v.in.ags` |
| `census_blocks`, `municipal_boundary`, `zipcodes` | US Census Bureau TIGER/Line | via pygris |
| `geology` | [Macrostrat](https://macrostrat.org) | `macrostrat.org/api/v2/carto/small` |
| `soils` | USDA NRCS [SSURGO](https://www.nrcs.usda.gov/resources/data-and-reports/soil-survey-geographic-database-ssurgo) | via `r.in.ssurgo` |
| `watersheds` | USGS Watershed Boundary Dataset | `hydro.nationalmap.gov`, via `v.in.ags` |
| `lakes`, `streams` | Wake County GIS | `services1.arcgis.com`, via `v.in.ags` |

## Licenses

There is no single license for the bundle — each layer keeps the terms of its originating
agency. Full text, including the ODbL conditions on `roads`, is in [LICENSE](LICENSE).

| Layer(s) | License / terms | Obligations |
|---|---|---|
| `elevation`, `landsat8_2025_B*`, `watersheds` | US Geological Survey, public domain — no restrictions on use or redistribution | None. USGS *requests* that its products be credited as the data source. |
| `landuse` | [CC0 1.0 Universal](https://creativecommons.org/publicdomain/zero/1.0/) — the NLCD ScienceBase record states the data "are in the public domain and do not have any use constraints" | None |
| `census_blocks`, `municipal_boundary`, `zipcodes` | US Census Bureau, not copyrighted (17 U.S.C. §105) | None, but *TIGER/Line®* is a registered trademark and may not be used in a product name |
| `soils` | USDA NRCS SSURGO, [public domain](https://www.usa.gov/publicdomain/label/1.0/) | USDA NRCS should be acknowledged as the data source in derived products |
| `roads` | **[ODbL 1.0](https://opendatacommons.org/licenses/odbl/)** — OpenStreetMap contributors | Attribution **and** share-alike — see [LICENSE](LICENSE) |
| `geology` | **[CC BY 4.0](https://creativecommons.org/licenses/by/4.0/)** — every Macrostrat API response carries `"license": "CC-BY 4.0"` | Credit Macrostrat, and cite the original map source behind each unit (the `source_id` attribute) |
| `schools`, `hospitals` | NC OneMap: "Geospatial data, web services and applications provided directly from this NC OneMap geoportal are free to use by anyone without restriction." No warranty, express or implied. | None |
| `lakes`, `streams` | Wake County GIS: "Wake County GIS does not restrict the use of our data. You are welcome to use and/or redistribute the data." Access constraints: none. | None; Wake County asks that users be referred to its site for current data |

## Acknowledgment

This material is based upon work supported by the National Science Foundation under Grant
No. [2303651](https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2303651), *POSE: Phase II:
Growing GRASS OSE for Worldwide Access to Multidisciplinary Geospatial Analytics*.

Any opinions, findings, and conclusions or recommendations expressed in this material are
those of the author(s) and do not necessarily reflect the views of the National Science
Foundation.
