Gully plug near Khaksi
gp-8 · 20.8273, 79.6000 · PIN 441910
Contributing catchment 1.05 km² · soil HSG-D (clay 44%).
What it delivers · indicative
Primary benefit
Erosion & silt control
Catchment
1.05 km²
Recharge
Minor / local
A headwater gully plug has no modelled reservoir — its value is slowing erosive runoff and trapping silt in the ravine, which protects downstream tanks and check dams from siltation and seeds minor localized recharge. Not a water-storage structure.
Why this site
A first-order channel with steeper grade — a gully plug / gabion slows erosive flow and traps silt in the upper catchment.
Seasonal water extent · dual-sensor
Radar (S1, 48 passes) fills the monsoon gap that cloud hides from optical (S2, 37 scenes). Radar peak vs summer low: 1.7 → 0 ha, a 1.7 ha annual draw-down — the storage renovation recovers.
⚠ A gully plug’s pond is well under 0.5 ha — below the 10 m Sentinel pixel. This series reflects wetness in the surrounding ravine, not the structure itself; the real evidence here is terrain (flow accumulation, catchment, slope), not water extent.
Cross-witness & confidence — independent corroboration
Two sensors track together
Optical (S2) and radar (S1) rise and fall together with correlation r = 0.93 across 37 paired months. Absolute extents match 59% — they differ by sensor physics on a flowing nala, so the shared rhythm is the witness, not the magnitude.
Nala flow (new-build site)
No existing lake here — expected for a new structure. Sensors confirm a monsoon flow pulse in the nala; nearest mapped lake is 6,930 m away.
Land acquisition (submergence)
Submergence not computed for this structure type.
Low confidence — sensors disagree and no independent lake confirms this site. It must be ground-truthed before any commitment of funds.
Displacement witness — real building footprints
No structures in footprintIn the submergence footprint
0
buildings within the 120 m nominal radius.
Nearest structure
559 m
to the closest mapped building.
Within 500 m
0
buildings in the influence ring.
Overture Maps buildings 2026-05-20.0 (union of OSM / Google Open Buildings / Microsoft / Esri), Bhandara admin_code=506. A desktop displacement screen — precedes, not replaces, cadastral (7/12) verification.
Reconnaissance context & access — Ola + Google Places
Nearest habitation
Khaksi
2,085 m away · PIN 441910
Nearest landmark
Dongar MahaDev Korambhi (Khaksi)
Schools within 2 km
0
Health within 2 km
0
Google Places (New) searchNearby + Ola Maps Places nearbysearch · reconnaissance-grade. Independent witness to the buildings displacement layer — dense amenities near a site corroborate high displacement. Does not replace cadastral 7/12 records, geotechnical bores or a level survey.
Human pressure — land-cover change (2022 → 2026)
Stable land coverVegetation (NDVI) change
+0.049
15 ha lost · 24 ha gained over 1,872 ha land
Built-up (NDBI) change
7.7 ha
new built-up / bare (construction proxy)
Window
2022-11..2023-02 (8 scenes)
→ 2025-11..2026-02 (8 scenes)
Sentinel-2 L2A dry-season MEDIAN composites (2022-23 vs 2025-26), water-masked; NDVI+NDBI change screen — not cadastral or DEM cut/fill
DPR-grade desktop hydrology from Copernicus GLO-30 (30 m) + ISRIC SoilGrids + ESA WorldCover; water extent from Sentinel-2 L2A MNDWI (optical) and Sentinel-1 GRD VV radiometrically calibrated to σ⁰ (DN²/sigmaNought² from the product calibration LUT, GCP thin-plate-spline geocoded, open water at σ⁰ < −17 dB; thermal-noise floor not subtracted). A desktop assessment that precedes — not replaces — the statutory ground & geotechnical survey.