Terrain and land cover. Part of what the twin can answer. Every figure below is the value the route serves, with its source; the raw response is at /api/twin/brain/terrain.
Not validated
Basis: computed from raster (NOT-VALIDATED): exact arithmetic over sha256-pinned stored tiles (pixel-centre ownership, histogram percentiles, approximate pixel areas); no validation gate.
One row per COD-AB v03 upazila polygon; a pixel belongs to the upazila whose polygon contains the pixel centre; every figure is exact arithmetic over the sha256-pinned stored pixels.
pixel-weighted over the 507 upazila rows; per-upazila percentiles are not aggregated into a national percentile
| Class | Share of pixels | Approximate area |
|---|---|---|
| Tree cover | Share of pixels: 36.45% | Approximate area: 53,301.26 km² |
| Upazila | District | Mean elevation |
|---|---|---|
| Monpura | District: Bhola | Mean elevation: 1.23 m |
| Tazumuddin | District: Bhola |
| Dataset | Tiles stored | Valid raster pixels | Pixels inside the polygons | Pixels outside them | Tile-manifest sha256 |
|---|---|---|---|---|---|
| Copernicus-dem-glo30-bd | Tiles stored: 31 | Valid raster pixels: 401,760,000 |
| Source | Published by | What it is | Caveat |
|---|---|---|---|
| Copernicus DEM GLO-30 tiles, stored copy | Published by: Copernicus DEM (ESA/Copernicus); stored at copernicus-dem-glo30-bd | What it is: 30 m elevation pixels, EPSG:4326, float32, nodata None; 31 tiles covering all 507 upazila polygons | Caveat: The stored tiles carry no version tag or licence file, so source_version says so. Percentiles come from a fixed histogram (0.5 m bins below 32 m, 4 m bins to 1280 m); the below-5 m and below-10 m shares are exact pixel counts. Coastal polygons include sea and river pixels, and a GLO-30 water surface reads near 0 m, so 'below 5 m' is a share of raster pixels inside the polygon, not of land. |
source_version carries 'not stated in the stored files' rather than a version guessed from the name.| Share of pixels: 0.01% |
| Approximate area: 7.92 km² |
| Grassland | Share of pixels: 1.52% | Approximate area: 2,225.54 km² |
| Cropland | Share of pixels: 46.21% | Approximate area: 67,242.78 km² |
| Built-up | Share of pixels: 1.53% | Approximate area: 2,234.16 km² |
| Bare/sparse vegetation | Share of pixels: 0.64% | Approximate area: 928.16 km² |
| Permanent water bodies | Share of pixels: 9.31% | Approximate area: 13,669.11 km² |
| Herbaceous wetland | Share of pixels: 1.39% | Approximate area: 2,013.6 km² |
| Mangroves | Share of pixels: 2.94% | Approximate area: 4,339.75 km² |
| Daulatkhan | District: Bhola | Mean elevation: 1.68 m |
| Ashashuni | District: Satkhira | Mean elevation: 1.69 m |
| Paikgachha | District: Khulna | Mean elevation: 2.02 m |
| Upazila | District | Share below 5 m |
|---|---|---|
| Austagram | District: Kishoreganj | Share below 5 m: 94.46% |
| Ashashuni | District: Satkhira | Share below 5 m: 92.97% |
| Mithamain | District: Kishoreganj | Share below 5 m: 92.74% |
| Monpura | District: Bhola | Share below 5 m: 92.7% |
| Khaliajuri | District: Netrakona | Share below 5 m: 91.78% |
| Upazila | Built-up share |
|---|---|
| Dhaka South City Corporation | Built-up share: 61.52% |
| Narayanganj City Corporation | Built-up share: 54.51% |
| Khulna City Corporation | Built-up share: 49.95% |
| Dhaka North City Corporation | Built-up share: 49.45% |
| Sylhet City Corporation | Built-up share: 48.54% |
Not held: District.
| Upazila | Cropland share |
|---|---|
| Lakhai | Cropland share: 86.54% |
| Niamatpur | Cropland share: 82.81% |
| Mithamain | Cropland share: 82.44% |
| Itna | Cropland share: 81.69% |
| Nasirnagar | Cropland share: 81.54% |
Not held: District.
| Pixels outside them: 234,162,154 |
| Tile-manifest sha256: 18cad22bdc81355709eebbaa0117ed5840429d2dba0acd1540966bc62b3a5565 |
| Esa-worldcover-bd | Tiles stored: 6 | Valid raster pixels: 5,061,964,954 | Pixels inside the polygons: 1,862,199,364 | Pixels outside them: 3,199,765,590 | Tile-manifest sha256: 058d3b77437df89ac54694b74f221d8a4b5123e7d71ae51e13ff56c618854b58 |
| ESA WorldCover v200 (epoch 2021) tiles, stored copy | Published by: ESA WorldCover project 2021 (algorithm_version tag V2.0.0); stored at esa-worldcover-bd | What it is: 10 m class pixels, EPSG:4326, uint8, nodata 0; 6 tiles covering all 507 upazila polygons; class labels and the CC-BY 4.0 licence are read from the tiles' own metadata tags | Caveat: Class shares are pixel-count shares of the upazila's valid pixels (a row sums to 100 by construction); per-class areas use the latitude-corrected pixel size at the upazila centroid and are approximate. The epoch is 2021, one snapshot, not a time series. |
| OCHA COD-AB v03 admin3 (upazila) polygons, the layer bulkbd used | Published by: OCHA Common Operational Datasets; stored at bgd_admin3 | What it is: 507 polygons keyed by adm3_pcode; a pixel belongs to the upazila whose polygon contains the pixel centre (all_touched=False, polygons verified non-overlapping) | Caveat: Twin place links are the D1 crosswalk bbs_geocode adm3 rows: 468 of the 507 upazilas carry a portal_id; the other 39 serve null portal_id, never a guess. |