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IDMC

The Internal Displacement Monitoring Centre (IDMC) maintains the Global Internal Displacement Database (GIDD), which provides comprehensive information on global internal displacement events from 2008 onwards.

Collection: idmc-events

A STAC collection holding IDMC disaster-related displacement events.

Data

Disasters Dataset

The GIDD Disasters Dataset provides event information through the /gidd/disasters/ API endpoint.

Nevertheless, the items in this dataset are not consolidated into a single event. Instead, they are individual records of displacement events. We will focus on the event information provided in the GIDD disaggregated data.

GIDD disaggregated data

The GIDD Disaggregated Data provides quality-controlled, annually validated data on internal displacement due to conflicts and disasters, disaggregated by caseload. This dataset is disaggregated by caseload, location and event.

Endpoint URL: <https://helix-tools-api.idmcdb.org/external-api/gidd/disaggregations/disaggregation-geojson/?client_id=>

The returned data is a geojson feature collection. Each feature represents a displacement item that includes the following properties:

  • ID: IDMC figure unique identifier
  • ISO3: ISO 3166-1 alpha-3 country code
  • Country: Country or territory name
  • Geographical region: IDMC's geographical region classification
  • Figure cause: Trigger of displacement (e.g., Conflict, Disaster)
  • Year: Reporting year
  • Figure category: Type of displacement metric (Internal Displacements or Total Number of IDPs)
  • Figure unit: Unit of measurement (Person, Household)
  • Reported figures: Values reported by original source
  • Household size: Average number of individuals per household
  • Total figures: Total number of displaced people
  • Hazard category: Primary hazard classification (e.g., Geophysical, Weather related)
  • Hazard sub category: Secondary hazard classification
  • Hazard type: Specific hazard type
  • Hazard sub type: Detailed hazard classification
  • Start date: Displacement start date
  • Start date accuracy: Accuracy of start date
  • End date: Displacement end date
  • End date accuracy: Accuracy of end date
  • Stock date: Date of IDP metric collection (for stock figures)
  • Stock date accuracy: Accuracy of stock date
  • Stock reporting date: IDMC reporting year for total IDPs
  • Publishers: Organizations distributing the data
  • Sources: Primary data providers
  • Sources type: Category of data source
  • Event ID: Unique identifier for events
  • Event name: Coded event name including location and date
  • Event cause: Trigger of the event
  • Event main trigger: Primary hazard or conflict type
  • Event start date: Event start date
  • Event end date: Event end date
  • Event start date accuracy: Accuracy of event start date
  • Event end date accuracy: Accuracy of event end date
  • Is housing destruction: Indicates if displacement includes housing destruction
  • Violence type: Category of violence (for conflict events)
  • Event codes: External reference codes (e.g., GLIDE numbers)
  • Locations name: Names of affected locations
  • Locations coordinates: Geographic coordinates of locations
  • Locations accuracy: Precision level of reported locations
  • Locations type: Type of displacement location (Origin/Destination)
  • Displacement occurred: Indicates if preventive evacuations were reported

Event Items

The IDMC event items are derived from the GIDD disaggregated data.

Important

A GIDD geojson is a collection of displacement items. Multiple items can be associated with a single event. The event item is created by consolidating these items into a single event.

The following table shows how IDMC event fields map to STAC Item fields:

STAC field IDMC field Required Notes
id idmc-event- Yes Use format idmc-event-{id}
geometry feature geometry aggregation Yes Aggregation in multi points or multipolygon of all the items referencing the event
collection idmc-events Yes
title {Event name} Yes
datetime {Event start date} Yes Convert to datetime with UTC timezone
start_datetime {Event start date} Yes Convert to datetime with UTC timezone
end_datetime {Event end date} Yes Convert to datetime with UTC timezone
monty:country_codes[0] country_iso3 Yes Direct mapping to array
monty:hazard_codes {Hazard Category} and Yes Map using the hazard type mapping
monty:hazard_codes Yes Always 1 (IDMC doesn't track episodes)
monty:corr_id id Yes Generated following the event pairing procedure

Displacement items geometry aggregagtion for event geometry

The geometry of the event is derived from the geometry of the displacement items. The geometry of the event is an aggregation of the geometries of all the displacement items associated with the event. The aggregation is done based on the following rules:

  1. If all the geometries are points, the event geometry is a MultiPoint geometry.
  2. If all the geometries are polygons, the event geometry is a MultiPolygon geometry.
  3. If the geometries are a mix of points and polygons, the event geometry is a MultiPolygon geometry with the points converted to polygons.

Hazard Type Mapping

IDMC uses the same hazard classification as EM-DAT CRED and must follow the general rule for hazard codes generation.

This mapping enables standardized hazard categorization while preserving IDMC's original classification in the source properties.

Impact Items

Displacement Items (GIDD Disaggregated Data)

The following table shows how IDMC displacement item fields map to STAC Item fields:

STAC field IDMC field Required Notes
id idmc-gidd-impact--displaced Yes Use format idmc-impact-{ID}-displaced
geometry [feature geometry] Yes Direct mapping from feature geometry
collection idmc-gidd-impacts Yes
title '{Figure category} of {Figure unit} for {Event name} ' Yes
datetime {Start date} Yes Convert to datetime with UTC timezone
start_datetime {Start date} Yes Convert to datetime with UTC timezone
end_datetime {End date} Yes Convert to datetime with UTC timezone
keywords [{Locations name}, {Figure category}, {Figure unit}, {Country}, {Geographical region}, {Figure cause}]
monty:country_codes[0] {ISO3} Yes Direct mapping to array
monty:hazard_codes {Hazard Category} and Yes Map using the hazard type mapping
monty:impact_detail See Displacement Impact details Yes
Displacement Impact details

The following table shows how IDMC displacement impact fields map to impact_detail STAC Item fields:

STAC field IDMC field Required Notes
category people Yes Always "people" for IDMC impacts
type displaced_internal Yes Always "displaced_internal" for IDMC impacts
value {Total figures} Yes Direct mapping
unit count Yes Always people count (household figures are converted)
estimate_type primary Yes Always "primary" for IDMC impacts
Impact Item Generation Rules
  1. Each displacement item in the GIDD dataset becomes a separate impact item
  2. Geometry is taken directly from the displacement item's feature geometry
  3. Dates are converted to UTC timezone
  4. Event ID reference uses the format idmc-gidd-event-{id}

Internal Displacement Updates (IDU) Items

The Internal Displacement Updates (IDU) provide near real-time information about displacement events. Key characteristics include:

Impact Item Field Mapping

The following table shows how IDU fields map to STAC Item fields for impact items:

STAC field IDU field Required Notes
id idmc-idu-impact--displaced Yes Use format idmc-idu-impact-{id}-displaced
geometry {latitude}, Yes Convert point coordinates to GeoJSON Point geometry
collection idmc-idu-impacts Yes
title {displacement_type} displacement for Yes
datetime {displacement_date} Yes Convert to datetime with UTC timezone
start_datetime {displacement_start_date} Yes Convert to datetime with UTC timezone
end_datetime {displacement_end_date} Yes Convert to datetime with UTC timezone
keywords [{locations_name}, {displacement_type}, {role}, {sources}] No
monty:country_codes[0] {iso3} Yes Direct mapping to array
monty:hazard_codes {category}, Yes Map using the hazard type mapping
monty:impact_detail See IDU Impact details Yes
IDU Impact details

The following table shows how IDU fields map to impact_detail STAC Item fields:

STAC field IDU field Required Notes
category people Yes Always "people" for IDU impacts
type displaced_internal Yes Always "displaced_internal" for IDU impacts
value {figure} Yes Direct mapping
unit count Yes Always people count
estimate_type {role} Yes Maps "Recommended figure" to "primary", "Triangulation" to "secondary"
IDU Impact Item Generation Rules
  1. Each IDU record becomes a separate impact item
  2. Point geometry is created from latitude/longitude coordinates
  3. Dates are converted to UTC timezone
  4. Event ID reference uses the format idmc-idu-event-{event_id}
  5. Role field determines estimate_type in impact_detail
Hazard Classification

Maps to standard hazard codes:

  • Wildfire → WF (GLIDE) / nat-cli-wil-for (EM-DAT) / EN0013 (UNDRR-ISC)
  • Flood → FL (GLIDE) / nat-hyd-flo-flo (EM-DAT) / MH0007 (UNDRR-ISC)
  • Mass Movement → LS (GLIDE) / nat-hyd-mmw-lan (EM-DAT) / GH0007 (UNDRR-ISC)
  • Sinkhole → OT (GLIDE) / nat-geo-mmd-sub (EM-DAT) / GH0026 (UNDRR-ISC)
Impact Classification
  • Type: displaced_internal (internal displacements)
  • Category: people (total displaced population)
  • Two main categories:
  • Preventive evacuations (marked in displacement_occurred field)
  • Forced displacement due to damage/destruction
Data Quality Notes
  • Provides near real-time updates compared to annually validated GIDD data
  • Includes source URLs for verification
  • Distinguishes between recommended figures and triangulation
  • Specifies accuracy of location information
  • Indicates if displacement was preventive or post-disaster