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Deforestation & PeatMar 4, 20267 min read

Peat depth thresholds are not the policy you think they are

Field measurements, satellite proxies, and self-reporting in the Sarawak peatlands diverge more than most buyers realise.

AZ

Ahmad Zulkifli

Senior Geospatial Analyst, Geometrack

Field study · Sarawak
Three sources of truth, three different answers.

Most NDPE policies draw the line at 'no development on peat'. Some specify a depth — typically 50cm — below which an area is considered peat and off-limits. Sounds simple. It isn't.

Three measurements, three answers

We ran field cores at 42 sample points across a single concession in Sarawak. We then compared the results to two satellite-derived peat depth products and to the supplier's own self-reported peat map. The three sources agreed on classification at fewer than half of the sample points.

42

Field cores taken

47%

Agreement across all three sources

11

Sites classified as 'mineral soil' by supplier but >50cm peat in field

6

Sites flagged as peat by satellite but mineral in field

Why this matters

A concession that looks NDPE-compliant on a desk review can fail comprehensively in the field. The reverse is also true — areas flagged as peat by remote sensing sometimes aren't, and good supplier development depends on knowing the difference rather than reflexively suspending operations.

"Peat depth is a measurement, not an opinion. Three different measurement methods give you three different answers — pick yours deliberately."

Our working rule

  • Satellite products are screening tools, not classification tools. Use them to prioritise field work, not to make sourcing decisions.
  • Self-reported maps from the operator are starting points, never end points.
  • Field cores remain the standard for any decision with financial or reputational consequences.

The hard part isn't the science. It's deciding which of three honest answers you'll let your policy stand on.

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