Estimating the extent of near‐surface permafrost using remote sensing, Mackenzie Delta, Northwest Territories
Bibliographic record
Abstract
Abstract The extent of near‐surface permafrost, or perennially frozen ground within 3 m of the surface, was estimated for the Mackenzie River delta by determining its association with riparian vegetation communities in the field, and by subsequently mapping these vegetation communities using SPOT‐5 data and the supervised maximum‐likelihood classification technique. Near‐surface permafrost was absent beneath willow–horsetail (Salix‐Equisetum) vegetation communities on point bars and alluvial islands throughout the delta and beneath horsetail (Equisetum) communities in the southern and central delta. Near‐surface permafrost was found beneath all other vegetation communities and land surface types. Multispectral SPOT‐5 data were classified with overall accuracies greater than 80 per cent. Using the remotely sensed vegetation community data, near‐surface permafrost was estimated to occur beneath 93 per cent, 95 per cent and 96 per cent of the land surface within the investigation areas of the southern, central and northern delta, respectively. In contrast to the most recent Permafrost Map of Canada, these results indicate that the Mackenzie Delta is part of the continuous permafrost zone. Copyright © 2009 Her Majesty the Queen in right of Canada. Published by John Wiley & Sons, Ltd.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".