Research/Terra/ 819657
Task evidence / population-density-share

What percentage of Chile's population lives in areas with population density over 1000 people per square km?

PassComputational taskUnpublished draft
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The question

819657
What percentage of Chile's population lives in areas with population density over 1000 people per square km?
Exact submitted task and declared adaptations
What percentage of Chile's population lives in areas with population density over 1000 people per square km?

Task conventions: Use the frozen WorldPop 2020 UN-adjusted population-count raster, band 1, not current data. Its values are people PER CELL, not people/km². Define density as each original valid cell count divided by that geographic cell’s full WGS84 ellipsoidal area in km² (meridian/parallel cell edges). Do not use a constant 1 km² approximation or resample counts. Strict density >1000 qualifies; sum the original counts in qualifying cells and divide by the sum of original counts over all valid cells, then multiply by 100. The denominator is the supplied raster’s valid country coverage, not an invented census total. Genuine zeros remain zero; NoData is unknown, not zero. Return a full-grid selected-population raster: original population for qualifying cells, zero for other valid cells, and the original missing-data mask. Also retain the density raster with the same grid and mask.



Compute the percentage and publish the two inspectable rasters. A map is optional. End with one fenced JSON object: {count: qualifying cell count, unknown_count: original masked/nonfinite cell count, coverage_note, selection:{collectionId,itemId,assetKey} for selected-population counts, density:{collectionId,itemId,assetKey}, metrics:{selected_people: number, total_people: number, percentage: number}}. Report original year and the valid-raster coverage limitation. Do not round the machine-readable metrics to whole people or whole percentages.

Delivery format: provide the answer object with all fields specified above as final_response on assess_result, alongside the inspected final artifact_refs. This replaces the JSON-code-block formatting requirement above. Blue attaches your explicit selection to the accepted final answer. Finish with a concise ordinary-language answer agreeing with that selected result; do not duplicate the JSON in chat.

Supplied immutable inputs:
[
  {
    "name": "Chile population count, WorldPop 2020",
    "edition": "2020 UN-adjusted population counts aggregated to 1 km cells",
    "units": {
      "band1": "people per cell"
    },
    "collectionId": "blue-generated--[resource id withheld]",
    "itemId": "[resource id withheld]",
    "assetKey": "data"
  }
]

Outcome & verification

Independent artifact and delivery checks passed.

Duration
14m 36s
Recorded Blue tool calls
37
Total tokens
2,103,268
Model cost
Not recorded
Application revision
d50497ea9084f29c91b05406688f87035df98d8a
Release
terra-geobenchx-v1

Recorded final answer

Using the supplied WorldPop 2020 Chile raster, 67.99322101098751% of the valid-raster population lives in cells with density over 1000 people/km². That is 12,997,726.24017334 people out of 19,116,209.00864947 across 4,931 qualifying cells; the published density and selected-population rasters are attached, and 22,670,617 masked cells were unknown and excluded. ### Limitations - Coverage follows the raster's valid-cell mask only; masked or nonfinite cells remain unknown and are excluded from numerator and denominator. - Coverage follows the supplied raster's valid-cell mask only; 22,670,617 masked cells are unknown and excluded from both numerator and denominator. - This is a share of the supplied WorldPop 2020 valid-raster population, not an external Chile census total. - Coverage is limited to the raster's valid-cell mask rather than an external census total. - Density is derived only for valid source cells; masked cells remain unknown. - The published rasters remain limited to the source raster's valid-cell coverage.

Independent checks

These checks are separate from the agent's own assessment. A successful job or an assertion of success is not enough to pass.

Expected count
4931
Reported count
4931
Computation verified
Yes
Answer fulfilled
Yes
Full grading and rubric record
{
  "expectedCount": 4931,
  "actualCount": 4931,
  "expectedMetrics": {
    "selected_people": 12997726.24017334,
    "total_people": 19116209.00864947,
    "percentage": 67.99322101098753
  },
  "actualMetrics": {
    "percentage": 67.99322101098751,
    "total_people": 19116209.00864947,
    "selected_people": 12997726.24017334
  },
  "computationCorrect": true,
  "answerFulfilled": true,
  "adjudication": null,
  "qualification": null,
  "reasons": []
}

Recorded investigation findings

The agent's reported hypotheses and assessments, retained as evidence of its process—not independent proof that the answer is correct. Failed calls retain their requested verdict, not an accepted assessment.

run_trial · completed

Does the original-grid density method preserve the source mask and produce the required strict-threshold selected-population raster and supporting totals on the supplied Chile WorldPop 2020 raster?

assess_trial · completed · assessment: sufficient

The tested full-extent computation used the supplied WorldPop 2020 Chile raster on its original EPSG:4326 grid (5166 by 4618 cells; 0.0083333333 degree resolution). The density output kept that grid and produced people/km2 values with the same valid-cell count as the source totals table: 1,185,971 valid cells and 22,670,617 missing cells. The selected-population raster also kept the same grid and missing-cell count, and map-algebra reported zero valid output pixels where any input was missing. The selected-population totals table confirms zeros remained valid values outside the strict threshold because the minimum is 0.0 while missing_count stayed 22,670,617. The qualifying 1/0 mask summed to 4,931.0, so 4,931 original valid cells exceeded 1000 people/km2. The selected-population sum, 12,997,726.24017334 people, is below the total valid-cell source sum, 19,116,209.00864947 people, so the threshold selection behaves as expected on the full requested extent.

assess_result · completed · assessment: sufficient

The published production outputs confirm the requested 2020 Chile calculation. The density raster and selected-population raster both use the original 5166 by 4618 EPSG:4326 grid at 0.0083333333 degree resolution, with 1,185,971 valid cells and 22,670,617 masked cells. The density raster is labeled in people/km2 and its inspected band describes counts divided by original ellipsoidal cell area. The selected-population raster is labeled in people, has minimum 0.0 on valid cells, and reports zero valid output pixels where an input was missing. The supporting production tables report total_people 19,116,209.00864947, selected_people 12,997,726.24017334, and 4,931 qualifying cells. That yields 67.99322101098751 percent of the supplied WorldPop 2020 valid-raster population in cells with density strictly greater than 1000 people per square kilometre.

Recorded workflow

  1. 01

    Chile density raster from WorldPop 2020 counts

    Recorded output · succeeded

  2. 02

    Chile selected population raster over 1000 people per square kilometre

    Recorded output · succeeded

  3. 03

    Chile total valid population summary

    Recorded output · succeeded

  4. 04

    Chile selected population summary

    Recorded output · succeeded

  5. 05

    Chile qualifying cell count summary

    Recorded output · succeeded

  6. 06

    Population density

    Recorded raster-count-density · succeeded

  7. 07

    Qualifying cell mask

    Recorded raster-map-algebra · succeeded

  8. 08

    Qualifying cell totals

    Recorded raster-statistics · succeeded

  9. 09

    Selected population counts

    Recorded raster-map-algebra · succeeded

  10. 10

    Selected population totals

    Recorded raster-statistics · succeeded

  11. 11

    Source population totals

    Recorded raster-statistics · succeeded

  12. 12

    Chile WorldPop 2020 counts

    Recorded source · succeeded

  13. 13

    Population density

    Recorded raster-count-density · succeeded

  14. 14

    Qualifying cell mask

    Recorded raster-map-algebra · succeeded

  15. 15

    Qualifying cell totals

    Recorded raster-statistics · succeeded

  16. 16

    Selected population counts

    Recorded raster-map-algebra · succeeded

  17. 17

    Selected population totals

    Recorded raster-statistics · succeeded

  18. 18

    Source population totals

    Recorded raster-statistics · succeeded

  19. 19

    Chile WorldPop 2020 counts

    Recorded output · succeeded

  20. 20

    Population density

    Recorded output · succeeded

  21. 21

    Selected population counts

    Recorded output · succeeded

  22. 22

    Source population totals

    Recorded output · succeeded

  23. 23

    Selected population totals

    Recorded output · succeeded

  24. 24

    Qualifying cell totals

    Recorded output · succeeded

  25. 25

    Chile WorldPop 2020 counts

    Recorded source · succeeded

Activity

Recorded actions

Recorded observable actions only, not private reasoning. Raw payloads, geometry, private links and credentials are omitted; full evidence is retained privately. Activity/workflow lists bounded at 500 entries.

  1. Progress update

    I’ll inspect the supplied raster first, then test the density calculation on its original grid so the final result uses the exact valid-cell coverage and mask.

  2. get_analysis

    Recorded tool call · completed

  3. get_collection

    Recorded tool call · completed

  4. Progress update

    I found the source raster. Next I’m checking which raster processors can keep the original grid and mask while deriving exact per-cell density and the selected-count output.

  5. update_analysis_brief

    Recorded tool call · completed

  6. list_processors

    Recorded tool call · completed

  7. inspect_artifact

    Recorded tool call · failed

  8. describe_processors

    Recorded tool call · completed

  9. get_tool_help

    Recorded tool call · completed

  10. get_tool_help

    Recorded tool call · completed

  11. Progress update

    Before I run the test, I’m checking output shapes so I can publish only the two requested rasters and keep the summary tables as supporting evidence for the percentage.

  12. describe_processors

    Recorded tool call · completed

  13. run_trial

    Recorded tool call · completed

  14. get_trial_report

    Recorded tool call · completed

  15. Progress update

    The trial finished successfully at full Chile extent. I’m reading the combined report now to confirm the grid, mask, and output structure before I save the production workflow and select the final rasters.

  16. Progress update

    The full-area test supports the method: same grid and mask, strict threshold, and complete valid-cell totals. I’m recording that judgment and turning the tested computation into the final workflow so the two rasters can be selected as final outputs.

  17. assess_trial

    Recorded tool call · completed

  18. get_tool_help

    Recorded tool call · completed

  19. get_tool_help

    Recorded tool call · completed

  20. get_tool_help

    Recorded tool call · completed

  21. get_tool_help

    Recorded tool call · completed

  22. get_tool_help

    Recorded tool call · completed

  23. get_tool_help

    Recorded tool call · completed

  24. update_analysis_brief

    Recorded tool call · completed

  25. Progress update

    I’ve turned the tested full-area method into a saved workflow draft with the two final rasters and supporting totals. Next I’ll inspect the validated outputs from that exact workflow run and record the final answer object.

  26. propose_workflow

    Recorded tool call · failed

  27. Progress update

    Blue flagged one wiring choice as ambiguous, so I’m correcting that exact requirement binding and resaving the same tested workflow rather than changing the method.

  28. propose_workflow

    Recorded tool call · completed

  29. Progress update

    The saved draft exposed a fixable contract mistake: my fixed parameter paths were one level too deep. I’m correcting those paths on the same tested workflow so the final raster outputs are no longer withheld.

  30. propose_workflow

    Recorded tool call · completed

  31. execute_workflow

    Recorded tool call · completed

  32. Progress update

    The workflow is now validated and matches the successful full-extent trial. I’m starting its execution so I can inspect the final deliverables and bind the answer to the published raster artifacts.

  33. inspect_workflow_results

    Recorded tool call · completed

  34. get_tool_help

    Recorded tool call · completed

  35. Progress update

    I have the published output identities. I’m doing bounded inspections on the final rasters and summary tables now so the final answer is tied to the production outputs, not only the earlier trial.

  36. Progress update

    I’ve already verified the run created the right five outputs. Now I’m pulling the exact values from the two final rasters and the three supporting tables needed for the percentage.

  37. inspect_artifact

    Recorded tool call · completed

  38. inspect_artifact

    Recorded tool call · completed

  39. inspect_artifact

    Recorded tool call · completed

  40. inspect_artifact

    Recorded tool call · completed

  41. inspect_artifact

    Recorded tool call · completed

  42. Progress update

    The bounded inspections finished in the background. I’m fetching their completed receipts now and then I’ll record the final result against the production outputs.

  43. inspect_artifact

    Recorded tool call · completed

  44. inspect_artifact

    Recorded tool call · completed

  45. inspect_artifact

    Recorded tool call · completed

  46. inspect_artifact

    Recorded tool call · completed

  47. inspect_artifact

    Recorded tool call · completed

  48. get_tool_help

    Recorded tool call · completed

  49. assess_result

    Recorded tool call · completed

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