Overview
Last updated
Last updated
© 2024 PredictHQ Ltd
Geographic information for an event describes where the event is located and the geographic area impacted. This page introduces geographic information available in events:
geo.geography
Geo data in GeoJSON format for the area impacted by the event.
place_hierarchies and scope
Place where the event is located.
Events also have the formatted_address field for venue entities with the street address of an event where it is present.
The location field was previously ued for geographic information but is now deprecated.
Point events' locations are represented by latitude, longitude coordinates. An example is this MLB game located at 37.77859,-122.38926.
Area events impact a geographic area such as a region, or an entire country. For example, Christmas Day in the United Kingdom, is a country-wide public holiday.
Area events can be represented by a polygon. The example image shows this flood warning for several rivers in Mississippi, USA.
Our APIs offer spatial search parameters to discover all events that impact your locations of interest.
The geo field in the Events API response contains the longitude and latitude for point events. Below is an example of the location information for point events in the geo field. For a point type geometry object the coordinates are in the order longitude, latitude (as this follows the geojson standard). See the example below:
In the geo.geometry field we follow the GeoJSON standard which orders coordinates as longitude followed by latitude (i.e., [longitude, latitude]).
For a point event, its location coordinates are where the event occurs. This may be the location of a venue. For example, a San Francisco Giants MLB game at Oracle Park has a latitude and longitude of -122.38926979999997, 37.7785951, which corresponds to the address of Oracle Park, 24 Willie Mays Plaza.
For an area event that does not have a polygon, its coordinates will be the center of the area where the event occurs.
Area events cover either a Geonames Place, for example Thanksgiving Day, or a specific geographic area bounded by a geometry (polygon). The next section details geometries and polygons, additional geometric data available in the geo field for area events. See GeoJSON for more information.
The location field was previously used for latitude and longitude information. The location field's value contains coordinates in GeoJSON order: [longitude, latitude]. Note the geo field is preferred over the location field as the location field will be deprecated in future.
The geo field also contains address information (as of June 2024). The address subfield within the geo field can contain the following information:
country_code (required) - 2 letter country code
formatted_address (optional) - a fully formatted address which can include street address, locality, postcode, region and country
postcode (optional)
locality (optional) - indicates the city or town the event occurs in
region (optional) - the region or state at which the event takes place
For attended events when they are linked to a venue entity then the address information will correspond to the address of the venue.
Events that cover a larger area (for example non-attended events like holidays) tend to have less address information. For example, a country-wide holiday may only have the country code field in the address field.
See below for an example of the address subfield within the geo field:
The geo field contains geometry information about an event's location in GeoJSON format. Point events will have a Point-type geometry, with the coordinates of the event's location (same as the location field). Area events may have Polygon or MultiPolygon-type geometries representing the specific area impacted by the event.
Where an area event has a Point-type geometry, it means the event applies to the Geonames Place of the event.
The example event snippet is a flood warning in Missouri. The GeoJSON data in the geo.geometry field can be plotted using tools that accept GeoJSON such as geojson.io. All our events with a Polygon or MultiPolygon will display the geometry's shape when viewed in Control Center or our Public Event page. A plot of the flood warning event's geometry is shown below.
Below is an example of an event with a MultiPolygon geometry; you can see it has two polygons for one event.
We provide examples and code snippets to plot polygons in a Jupyter notebook in our Severe-Weather Events Data Exploration notebook.
Our raw polygon sources can have extremely detailed geometries which result in large GeoJSON filesizes. Polygons of this nature aren't practical to use for individual events either in the PredictHQ API or a customer's data lake. The complexity of such polygons often result from capturing geographic features that aren't relevant for practical use cases in determining the impact of an event (for example small bodies of water, or small unpopulated islands off a coast).
For this reason, we may pre-process polygons to simplify them to reduce the number of points. This results in smoothing out the shape while retaining the key boundaries of the geographic area of impact.
In the example images, the first polygon is part of a raw polygon before simplification; the second is after simplification. The original GeoJSON data contained about 18000 coordinate points (the JSON data for this alone is around 700kb) to accurately outline individual offshore land masses.
