This issue mention the existing GIS data issue, the data issue from upstream site is faulty, so this issue is to list them out and highlight correction strategy.
Incorrect BBox data
Some wards data from the origin source have corrupted BBox value
E.g:
Correction strategy: Programmatically calculate BBox from the temporary database Postgis with ST_Envelop function
✅ Patch already applied.
Corrupt GIS Data for An Giang
GIS data of An Giang Province level (code=91) have corrupted GIS response. The Geometry of this province is POLYGON, which is incorrect and suppose to be MULTIPOLYGON like the rest.
This make the GIS map not properly render when zoom in closely.
Correction strategy: Replace the GIS Geometry data with the previous healthy data of the sapnhap bando site snapshot before their site UI change. Snapshot date 11 March 2026
An Giang GIS snapshot file: https://github.com/thanglequoc/vietnamese-provinces-database/blob/master/dataset-generation-scripts/resources/gis/geojson_11Mar2026/32_tinh_an_giang/province.geojson
✅ Patch already applied.
The GIS province level is missing the islands
The GIS province level of Khanh Hoa (code=56) and Da Nang (code=48) don't include the Spratly and Paracel islands,
this is the data error from the upstream sapnhap bando site
Screenshot taken at 12 July 2026
Correction strategy: Manually patch the GIS of these provinces by including the additional polygon of Spratly and Paracel islands, with the Postgis ST_Union function
✅ Patch already applied in #174
This issue mention the existing GIS data issue, the data issue from upstream site is faulty, so this issue is to list them out and highlight correction strategy.
Incorrect BBox data
Some wards data from the origin source have corrupted BBox value
E.g:
Correction strategy: Programmatically calculate BBox from the temporary database Postgis with ST_Envelop function
✅ Patch already applied.
Corrupt GIS Data for An Giang
GIS data of An Giang Province level (code=91) have corrupted GIS response. The Geometry of this province is POLYGON, which is incorrect and suppose to be MULTIPOLYGON like the rest.
This make the GIS map not properly render when zoom in closely.
Correction strategy: Replace the GIS Geometry data with the previous healthy data of the sapnhap bando site snapshot before their site UI change. Snapshot date 11 March 2026
An Giang GIS snapshot file: https://github.com/thanglequoc/vietnamese-provinces-database/blob/master/dataset-generation-scripts/resources/gis/geojson_11Mar2026/32_tinh_an_giang/province.geojson
✅ Patch already applied.
The GIS province level is missing the islands
The GIS province level of Khanh Hoa (code=56) and Da Nang (code=48) don't include the Spratly and Paracel islands,
this is the data error from the upstream sapnhap bando site
Screenshot taken at 12 July 2026
Correction strategy: Manually patch the GIS of these provinces by including the additional polygon of Spratly and Paracel islands, with the Postgis
ST_Unionfunction✅ Patch already applied in #174