GEOGRAPHIC DATA SOURCES

Province and district boundaries: geoBoundaries gbOpen THA ADM1 / ADM2.
Sources: Royal Thai Survey Department, OCHA ROAP.
License: Creative Commons Attribution 3.0 IGO.
https://www.geoboundaries.org/api/current/gbOpen/THA/ADM1/
https://www.geoboundaries.org/api/current/gbOpen/THA/ADM2/
https://creativecommons.org/licenses/by/3.0/igo/

Subdistrict boundaries: mapthai, Royal Thai Survey Department / UNOCHA.
Source date stated by mapthai: 6 November 2019. Simplified polygons.
https://github.com/piyayut-ch/mapthai
https://github.com/piyayut-ch/mapthai/blob/master/data-raw/geojson/th_adm3.geojson
Changes: selected Phang Nga features, reduced precision, projected to local SVG view.
Geographic data is for visualization, not cadastral or navigation purposes.

mapthai repository license follows:

# MIT License

Copyright (c) 2021 Piyayut Chitchumnong

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.


3D TERRAIN
MapLibre GL JS 5.6.1, BSD 3-Clause. License: vendor/maplibre-LICENSE.txt
Mapzen Terrain Tiles accessed 2026-10-24 from https://registry.opendata.aws/terrain-tiles/
Terrain data courtesy of USGS SRTM and GMTED2010; global ETOPO1 courtesy of NOAA.
Full source-provider attribution: terrain/ATTRIBUTION.md
Terrarium RGB tiles at zoom levels 5-9. At zoom 9, sample spacing is approximately 300 metres in this region; smaller features are generalized.
Processing: elevations below sea level clamped to zero to keep the sea surface flat; positive land heights unchanged.
Display exaggeration: 1.8 times vertical height. Not surveying or navigation data.