Hazard Entity Rainfall in KnowWhereGraph
MAT 259, 2022
Zilong Liu

I am interested in the visualization of entities with temporal scopes (in fact almost every entity has a temporal scope) in knowledge graphs. Therefore, I choose KnowWhereGraph, a constantly growing knowledge graph with rich spatial and temporal information. Inspired by the 3D rain simulation, I realize that by controlling the velocity I can visualize entities with different scopes. Also, I can visualize the spatial information of a droplet (i.e., an entity in this visualization project) by showing this information in the splash caused by it falling onto the ground.

The data can be retrieved from this endpoint: https://stko-kwg.geog.ucsb.edu/graphdb/sparql. By using the SPARQL (which is similar to SQL but is tailor to information retrieval in knowledge graphs), I retrieved all earthquakes, wildfires and hurricanes along with their temporal and spatial information. The data repository is KWG-V3.
PREFIX kwg-ont: 
PREFIX sosa: 
PREFIX rdfs: 
PREFIX rdf: 
select ?hazard ?hazard_label ?hazard_type ?time ?time_label ?location ?location_label
    ?hazard kwg-ont:locatedIn ?location;
            sosa:isFeatureOfInterestOf/sosa:phenomenonTime | kwg-ont:hasTemporalScope ?time;
            rdfs:label ?hazard_label;
                rdf:type ?hazard_type.
    ?location rdfs:label ?location_label.
    ?time rdfs:label ?time_label.
    values ?hazard_type {kwg-ont:EarthquakeEvent kwg-ont:Hurricane kwg-ont:Wildfire}
} order by ?time_label

Visualization and Interaction
As the datetime increases, kwg-ont:Wildfire, kwg-ont:Hurricane and kwg-ont:EarthquakeEvent entities (depicted in different colors) keep falling from above. Their numbers accumlate as they appear. Different kinds of entities have different velocities. When they hit the ground, the caused splash show the location information of a droplet standing for an entity.

All work is developed within Processing