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Velasco, Santa Cruz: 6,834 ha of forest-loss alerts in 90 days, confirmed by a sharp NDVI drop

Velasco, Santa Cruz (Bolivia) — tile 4/4 · seen · published

Between 28 June and 26 September 2026, satellite alert systems logged 579105 high-confidence deforestation alerts across tile 4/4 of Velasco, Santa Cruz, Bolivia, covering 6834.36 ha in 90 days. Of these, 207626 alerts (2449.96 ha) fall in the highest-confidence class. An independent optical check — Sentinel-2 median NDVI between 14 May and 26 September, with 100% valid pixels in both composites — shows greenness falling by -0.265, consistent with canopy being removed rather than a data artefact.

What this is not: the alerts cannot separate legal clearing, fire, storm damage, selective logging or plantation harvest from unauthorised clearing, and no cause is assigned here. The season sits under a strong El Niño (ONI 1.8), which can deepen drought stress and drive fire, both of which can mimic clearing in NDVI. Alert density here is 0.889× the surrounding 12 km ring (2608.435 vs 2935.032 alert ha per deg²), so this tile is slightly quieter than its neighbourhood, not an isolated outlier.

What would change our mind: high-resolution imagery showing burn scars or standing dead canopy, NDVI recovery next wet season, or concession and protected-area layers reframing the change.

Written by AI, then checked by a separate reviewer before publication. Every claim points at the evidence below.

Cloud-free satellite view around Velasco, Santa Cruz (Bolivia) — tile 4/4, with the finding area outlined
16.43°S 60.16°WNASA Blue Marble via GIBS · outline = finding area

What we saw

  • Area: 6,834 hectares — about 9,600 football fields
  • Nature’s work at stake: about $46M a year (a rough estimate of what this land does for people — clean water, carbon, food).
  • Global Forest Watch alerts — 579105 alerts (≥ high confidence), 6834.36 ha, 2026-06-28…2026-09-26. (Sep 26, 2026) See the source ↗
  • Global Forest Watch alerts — 579105 alerts (≥ high confidence), 6834.36 ha, 2026-06-29…2026-09-27. (Sep 27, 2026) See the source ↗
  • Sentinel-2 satellite images — Median-composite NDVI changed -0.265 (2026-05-14 → 2026-09-26); valid pixels 100% / 100%. Scenes: [object Object], [object Object], [object Object], [object Object], [object Object], [object Object] (Sep 26, 2026)

What it might not be

  • Alert type cannot distinguish fire, storm, logging or legal clearing from unauthorised clearing.
  • Alerts lag events by about 1–2 weeks, so a burst just before 26 September is undercounted.
  • Strong El Niño conditions (ONI 1.8) can depress NDVI through drought alone.
  • Alert density is 0.889× the 12 km regional ring — below, not above, local background.
  • Regrowth and plantation harvest cycles can look like loss in these data.
  • Dollar figures in context notes are order-of-magnitude benefit transfers, not market prices.
  • Coverage is 30°N–30°S only — zero alerts outside the tropics means 'not monitored', not 'no loss'.
  • Cannot distinguish legal clearing, fire, storm damage and selective logging from illegal clearing; attribution needs concession/protected-area layers (M3).
  • Alerts lag reality by ~1–2 weeks; a burst just before the sweep is undercounted.
  • Regrowth and plantation harvest cycles look like loss; the baseline ring only partly compensates.
  • Persistent cloud can delay optical confirmation for months (SAR-only RADD alerts stay 'candidate').

What would change our mind

Newer satellite images that show no change, a correction from the data source, or a reply with evidence from the ground. If that happens, the case is marked “Turned out wrong” — in public — and it stays on this site.

Why this was published

Two separate sources agreed — Global Forest Watch alerts, then Sentinel-2 satellite images — and a reviewer checked the evidence before it went up.

Right of reply

If a case names or affects you, you can reply. A reply channel that keeps both sides on record is being set up; until then, every case page carries its ledger id so a reply can be attached to it.

Ledger id 01a0df80-ad0d-72d7-b068-6be6818c1e6f

Technical details rule, evidence ids, history, proof
Rule
forest_loss v1.0
Tier
T1
Tags
forest-hotspot, discovered, bol, bolivia, santa-cruz, velasco
Confirmed
Yes — independent sensor signal, 2026-09-26
Rule FP rate
40 % · 4 of 10 decided
Location
16.43°S 60.16°W
Observed
2026-09-26
Opened
2026-09-26 by automatic rule forest_loss v1.0
  1. candidate
  2. confirmed
  3. published
  4. resolved

Evidence3

alertgfw-integrated-alerts

579105 alerts (≥ high confidence), 6834.36 ha, 2026-06-28…2026-09-26.

alerts 579105ha 6834.36high_alerts 371479high_ha 4384.4highest_alerts 207626highest_ha 2449.96living_value_100y_npv2_usd 1978784531living_value_100y_usd 4591323000living_value_usd_yr 45913230
· forest_alerts v1.0 · gfw-integrated-bol-8-14-4-2026-06-28..2026-09-26
Source ↗
alertgfw-integrated-alerts

579105 alerts (≥ high confidence), 6834.36 ha, 2026-06-29…2026-09-27.

alerts 579105ha 6834.36high_alerts 371479high_ha 4384.4highest_alerts 207626highest_ha 2449.96living_value_100y_npv2_usd 1978784531living_value_100y_usd 4591323000living_value_usd_yr 45913230
· forest_alerts v1.0 · gfw-integrated-bol-8-14-4-2026-06-29..2026-09-27
Source ↗
scenesentinel-2-l2aConfirming signal

Median-composite NDVI changed -0.265 (2026-05-14 → 2026-09-26); valid pixels 100% / 100%. Scenes: [object Object], [object Object], [object Object], [object Object], [object Object], [object Object]

deltaNdvi -0.2653508479963954validPctA 100validPctB 100
· eo_compare v1.0 · s2-ndvi-median-bol-8-14-4-2026-05-14..2026-09-26

Context

0.89×
AOI vs its 12 km neighbourhood
AOI
2608.435
Ring
2935.032
Metric
alert ha per deg²
ENSO El Niño · ONI +1.8
  • Living value (benefit transfer, order of magnitude): 6834.36 ha of tropical forest ≈ $45,913,230/yr alive (band $13,484,192–$177,877,888, 2020 USD), ≈ $4,591,323,000 over 100 yr ($1,978,784,531 NPV @ 2 %). Source: Costanza R. et al. et al. — a floor for one kind of value, not a price.

Publication gates

  • Evidence — 2 pieces from gfw-integrated-alerts — met
  • Independent confirmation — a different sensor (sentinel-2-l2a), 2026-09-26 — met
  • Human approval — 1 of 1 needed at tier 1 — met
  • Narration — AI-drafted by claude-opus-5 — met
Published
2026-09-27 by AI model
Narrated By
AI model
Reviewed By
AI model
Policy
2026-09-26-autonomous
Note
autonomous publish: narrated by model:claude-opus-5, reviewed by model:claude-sonnet-5 (policy 2026-09-26-autonomous)

History6

  1. status changed → publishedAI model
  2. reviewed → confirmedAI model
  3. narrated → confirmedAI model
  4. evidence added → confirmedautomatic rule forest_loss v1.0
  5. confirmed → confirmedautomatic rule forest_loss v1.0
  6. created → candidateautomatic rule forest_loss v1.0

Verify

Checkpoint
earthdeck.dev/findings/v1 · 474 entries
Signed root
3d5c0e5366ef…1a817d
This case
6 signed events
Leaf
#452 of 474 — this case’s latest event
Leaf hash
934707941248…2d569c
Proof
8-hash audit path
  1. 2bf00fe23422dab8b3929c9c0cff0af4fbd8e26c7e54635749b2323f63acd3d8
  2. cd8d2c057192da86515fb25b4d29760eaaa061dcc3f2424a5e9826b3e7f3ca1a
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  5. d53da2d9a52c42afa1145e989e67defee70d1ab136a8450be836068243b2b4c4
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  8. 2334f041f7aa83a5ef6099e0c9511b6242e982238cdf9f30561e5bf0cb2526cc
Last event
4cdce7cfffe0…e4e9f1
Note
Checkpoint text
earthdeck.dev/findings/v1
474
PVwOU2bv7a9jengu9r9j3dQn4kFgYu/+tvWa/eQagX0=

— earthdeck TkCXv/cvio9EAdvkzlL+Yd2YP4DpbJfAKLucFWpg9Lx0fsSq96qdwI14h8khEO0RbAZGTNPZZvO7btaXxroLJftBzwc=

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