Climate Demo (Lao PDR)

Loads a published GeoZarr dataset over a time range and computes the per-pixel net change of its variable between the earliest and latest time step in that range (last − first), then publishes the result as a new GeoZarr dataset.

Use it to map increase/decrease between two time periods — e.g. population change between two census years, NDVI change between two dekads, or temperature change between two periods. Positive values are increases and negative values are decreases, so the result is best displayed with a diverging colormap centred on zero.

The result is a 2-D (y, x) raster: the time dimension is reduced away, leaving one change value per pixel. To get the change between exactly two years, pass a temporal_extent whose start and end fall on those two periods (any intermediate steps are ignored — only the first and last contribute).

If the output dataset does not already have a registered static data source, OCS auto-registers one in the instance plugin registry using source metadata plus derived defaults for display and naming.

Zarr output cannot be produced synchronously, so run this as a batch job (POST /jobs, then POST /jobs/{id}/results):

{
  "change": {
    "process_id": "temporal_change",
    "arguments": {
      "dataset_id": "worldpop_population_global2_100m",
      "output_dataset_id": "worldpop_population_change",
      "variable": "pop_change",
      "temporal_extent": ["2015-01-01", "2030-12-31"]
    },
    "result": true
  }
}