Geographic information systems (GIS)
In the event of a fire on a university campus, quickly localizing the closest fire hydrants to the buildings that are on fire is essential information for firefighters to locate and secure the water sources. Identifying the neighbor buildings to those on fire is also necessary to evacuate the people in those buildings to safe places. For that purpose, I developed a Geographic Information System (GIS) tailored to the campus of the University of Southern California (USC). The user interacts with the system through a graphical user interface (GUI) that can show three types of elements on the map:
The user can select which features are shown on the map by clicking on the correponding check button(s). Then, the user can perform one of the following queries:
Whole Region: This is to display all the features of the active feature types in the whole map.
Range Query: When this radio button is checked, the user can draw a polygon in the map. After pushing the Submit Query button, only the features of the active feature types that are inside (or intersect with) the polygons are displayed. The user draws the polygon by clicking the left mouse button to select its vertices sequentially and then clicking the right mouse button to close the polygon. Red line segments on the screen connects the vertices as they are being selected. When the Range Query radio button is unchecked, the selected polygon disappears.
Find neighbor Buildings: When this radio button is checked, the buildings on fire are displayed as Red polygons and the neighbor buildings are shown in Yellow. The neighbor buildings are the buildings that are located within 100 pixels.
Find Closest Fire Hydrants: When this radio button is checked, the user could use click to specify the buildings that are on fire. The buildings are shown as red polygons and the closest hydrants are displayed as Green Squares. If there are multiple buildings on fire, two buildings on fire might have the same closest fire hydrant.
The system was based on a Java application that trigered SQL geospatial queries to an Oracle 11g database.
The video below shows the system in action: