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Bathymetric Map — Florianópolis (Ilha de Santa Catarina)

Vector bathymetric isobaths and coastline for the Greater Florianópolis region (Ilha de Santa Catarina, SC, Brazil). Free, open data derived from crowdsourced sonar readings, available in GeoJSON format.

Quick start

Download the GeoJSON files and open them in any GIS tool — QGIS, Google Earth, Leaflet, geopandas, R, ArcGIS, etc.

git clone https://github.com/paladini/mapa-batimetrico-florianopolis.git
cd mapa-batimetrico-florianopolis
ls data/vectorized/
# isobaths_z12.geojson  isobaths_z14.geojson  coastline_z12.geojson  coastline_z14.geojson  metadata.json

Or download individual files directly from the landing page or from GitHub Releases (for high-res data).

To browse the data interactively in your browser:

python3 serve.py
# Open http://localhost:8080/viewer.html

Available data

Isobaths (bathymetric contour lines)

File	Features	Resolution	Size	Download
isobaths_z12.geojson	4,284	~34 m/px (overview)	2.2 MB	repo
isobaths_z14.geojson	33,469	~8.5 m/px (medium detail)	19 MB	repo
isobaths_z16.geojson	145,237	~2.1 m/px (high detail)	80 MB	Release
isobaths_z18.geojson	1,272,324	~0.5 m/px (maximum detail)	524 MB	Release

Coastline (land/water boundary)

File	Features	Resolution	Size	Download
coastline_z12.geojson	459	~34 m/px (overview)	614 KB	repo
coastline_z14.geojson	7,053	~8.5 m/px (medium detail)	7.8 MB	repo
coastline_z16.geojson	32,459	~2.1 m/px (high detail)	28 MB	Release
coastline_z18.geojson	143,819	~0.5 m/px (maximum detail)	91 MB	Release

repo = included in the repository (download with git clone). Release = download from GitHub Releases (larger files).

Depth bands

Each isobath line separates two adjacent depth bands. There are 9 relative depth bands (band 0 = shallowest, band 8 = deepest).

Each GeoJSON feature has these properties:

• band_shallow — shallower side band index (0–7)
• band_deep — deeper side band index (1–8)
• depth_label — human-readable label (e.g., shallow, deep, very_deep)
• color — hex color for visualization

Note: Depths are relative, not absolute meters. The bands indicate where depth transitions occur, not exact depth values.

Coverage

Ilha de Santa Catarina (Florianópolis, SC, Brazil)
  North:  -27.35° (Ponta das Canas)
  South:  -27.85° (Naufragados)
  East:   -48.35° (oceanic coast)
  West:   -48.65° (inner Baía Sul)
  CRS:    EPSG:4326 (WGS84)

Usage examples

Python (geopandas)

import geopandas as gpd

gdf = gpd.read_file('data/vectorized/isobaths_z14.geojson')

# Filter deeper isobaths
deep = gdf[gdf.band_deep >= 6]
deep.plot(column='band_deep', cmap='Blues')

JavaScript (Leaflet)

fetch('data/vectorized/isobaths_z12.geojson')
  .then(r => r.json())
  .then(data => {
    L.geoJSON(data, {
      style: f => ({ color: f.properties.color, weight: 1 })
    }).addTo(map);
  });

QGIS

Open → Layer → Add Layer → Add Vector Layer → select any .geojson file.

R

library(sf)
isobaths <- st_read("data/vectorized/isobaths_z14.geojson")
plot(isobaths["band_deep"])

Website

The project has a bilingual landing page that explains the dataset, shows all available downloads, depth bands, coverage, compatibility with GIS tools, and code examples:

paladini.github.io/mapa-batimetrico-florianopolis

Downloading high-resolution data (z16 + z18)

The overview and medium-detail files (z12 + z14) are included directly in this repository. For high detail (~2.1 m/px) and maximum detail (~0.5 m/px), download from the GitHub Release:

Download z16 + z18 from Release v1.0.0

Release assets:

• isobaths_z16.geojson (145,237 features, 80 MB)
• isobaths_z18.geojson (1,272,324 features, 524 MB)
• coastline_z16.geojson (32,459 features, 28 MB)
• coastline_z18.geojson (143,819 features, 91 MB)

Structure

├── data/vectorized/            # Bathymetric data (z12 + z14 in repo)
│   ├── isobaths_z12.geojson    # Isobaths — overview
│   ├── isobaths_z14.geojson    # Isobaths — medium detail
│   ├── coastline_z12.geojson   # Coastline — overview
│   ├── coastline_z14.geojson   # Coastline — medium detail
│   └── metadata.json           # Dataset metadata
├── viewer.html                 # Interactive GeoJSON map viewer (Leaflet.js)
├── serve.py                    # Local HTTP server
├── index.html                  # Landing page (PT-BR)
├── index.en.html               # Landing page (EN)
├── README.md                   # English documentation
└── README.pt-BR.md             # Portuguese documentation

License

This dataset contains derived bathymetric data from crowdsourced sonar readings. The vector isobaths and coastline are geometric transformations and do not contain original source imagery.