Peak Cumulative (LOS)
-2.9 cm
Vertical Est. (37.8°)
-3.6 cm
3-Ref Sensitivity
[-2.9, -1.3] cm LOS
Rate (cm / 100 days)
-2.4 cm/100d
Annualized est.: -8.7 cm/yr
Latest Pair & Cumulative Summary
- Latest Consecutive Pair Step: +0.39 cm LOS (2026-10-07 to 2026-10-19 at p01: 38.876N 117.341E; cumulative at point: -2.87 cm)
- Affected Population (GHSL GHS-POP E2025, 108d eq., ≥ 0.66 cm 2σ): 127,600 residents (< -2 cm), 3,676 residents across 7.85 km² (< -5 cm).
Top 3 Most-Subsiding Areas
| Rank | 1 km Block Center (Lat, Lon) | Cumulative LOS | Rate |
|---|---|---|---|
| #1 | 38.8761, 117.3408 | -2.87 cm | -2.39 cm/100d |
| #2 | 39.1764, 117.0773 | -2.68 cm | -2.24 cm/100d |
| #3 | 39.3260, 117.3068 | -2.68 cm | -2.23 cm/100d |
Top 5 At-Risk Infrastructure Segments
Infrastructure corridor ranking (OSM canal/road overlay) has not been computed for this regional subset yet.
GNSS Comparison & Calibration Status
Continuous GNSS time-series validation was not bundled for this regional subset.
Cumulative Displacement Map
What This Means
- Ground in Tianjin subsided up to -2.9 cm LOS (-2.4 cm/100d) between 2026-06-21 and 2026-10-19, consistent with active seasonal compaction.
- About 127,600 residents live on ground sinking faster than 2 cm per 108 days (and 3,676 residents across 7.85 km2 faster than 5 cm per 108 days, above the 0.66 cm 2-sigma noise floor).
- No local GNSS or canal-tilt overlay is bundled for this subset; field inspection and local piezometer records are needed to confirm infrastructure impacts.
Calibration & Quality Notice (PROVISIONAL): NISAR data are provisional. Calibration and validation are carried out by the NISAR project (NASA-JPL and ISRO), not by our team.
Sources: NASA-ISRO NISAR L2 GUNW (CRID P05023 via ASF DAAC); GHSL GHS-POP E2025 R2023A (JRC, CC BY 4.0); Nevada Geodetic Laboratory GNSS; OpenStreetMap (ODbL).
Sources: NASA-ISRO NISAR L2 GUNW (CRID P05023 via ASF DAAC); GHSL GHS-POP E2025 R2023A (JRC, CC BY 4.0); Nevada Geodetic Laboratory GNSS; OpenStreetMap (ODbL).