Summary
Reach 17287000321 connects downstream to 17288100011 (AF region) with a 5.8 km boundary gap and a 142x facc jump (2,066 → 294,313 km²). Most anomalous facc discontinuity among the 27 UNC-inherited extreme boundary gap links investigated in #189.
Details
| Attribute |
Upstream (17287000321) |
Downstream (17288100011) |
| facc (km²) |
2,066 |
294,313 |
| width (m) |
154 |
78 |
| type |
1 (river) |
1 (river) |
| river_name |
NODATA |
NODATA |
| Pfafstetter-6 |
172870 |
172881 |
| boundary gap |
5.8 km |
|
The link crosses a Pfafstetter-6 basin boundary. The facc ratio (142x) is far beyond what's expected from tributary inflow in a 5.8 km gap. Width actually decreases downstream (154→78m), which contradicts the facc increase.
Context
Found during #189 investigation. QGIS verification confirms the reaches are on real, connected rivers — the topology link is likely correct. The facc discontinuity probably reflects a massive tributary (or the main stem itself) joining in the unmapped 5.8 km section, with the downstream reach being a narrow side channel rather than the main stem.
Action
- Identify what river/tributary joins between these two reaches
- Determine if the downstream reach is correctly on the main stem or a side channel
- Check if
main_side values are correct for both reaches
- May need centerline infill for v18
Summary
Reach
17287000321connects downstream to17288100011(AF region) with a 5.8 km boundary gap and a 142x facc jump (2,066 → 294,313 km²). Most anomalous facc discontinuity among the 27 UNC-inherited extreme boundary gap links investigated in #189.Details
The link crosses a Pfafstetter-6 basin boundary. The facc ratio (142x) is far beyond what's expected from tributary inflow in a 5.8 km gap. Width actually decreases downstream (154→78m), which contradicts the facc increase.
Context
Found during #189 investigation. QGIS verification confirms the reaches are on real, connected rivers — the topology link is likely correct. The facc discontinuity probably reflects a massive tributary (or the main stem itself) joining in the unmapped 5.8 km section, with the downstream reach being a narrow side channel rather than the main stem.
Action
main_sidevalues are correct for both reaches