GOLDONGO is a terrain-screening tool. When the Indonesia network is scored, every stream segment will carry a rank for the physical conditions that let heavy minerals settle — so you can decide which streams are worth a visit before you leave the house.
A high score means a stream segment has the trap geometry to concentrate heavy minerals — not that there is gold upstream. Kalimantan and Sumatra rivers carry gold across huge, wet networks. Reaching the water is the hard part; reading it is what the map is for.
The score reads four shapes out of the elevation model. Each one is a place where the water slows and the heaviest grains drop first.
Where a steep reach flattens, the current loses the energy that carried heavy grains. Gold drops before anything else.
Water runs fastest on the outside of a bend and slowest on the inside. The bar on the inside is where the heavy fraction settles.
Where a tributary joins, the flow slows and spreads. The downstream side of the confluence keeps what both streams carried.
Where the valley narrows to rock, the bed is scoured to bedrock and every crack works as a riffle.
Each segment gets one score from those signals. Scores compare within a region — same elevation base, same rules — not across regions.
Planned: DEMNAS, the ~8 m national surface model from Badan Informasi Geospasial, with canopy correction where it matters.
The stream network is derived from the elevation model itself and cross-checked against OpenStreetMap waterways, HydroRIVERS and Sentinel-2 imagery, so the lines follow where water actually runs. Every source is open and credited in the footer.
Segments inside a protected area are forced to 0 and hatched red on the map. Official boundaries are incomplete in many countries — heritage sites rarely have a public service — so this gate can miss. Verify an area’s status yourself before you go.
In construction. Elevation data is the constraint under canopy; Kalimantan is the candidate once a clean surface model is ready.
GOLDONGO is a terrain-screening tool. A score is not a promise of gold, and it is not a licence: check land status and follow local rules before you dig.