Welcome to another MapReveal™ Software Community Post!
GIS is extremely useful in analyzing spatial relationships between features. In this post, I will show you how you can identify the nearest facilities from a set of origin points to their corresponding destinations in another reference layer.
Under Vector Processing tools, the Distance to Nearest Facility tool is available which can be used to identify nearest locations and the distance between the origin and the destination features. A key point to note here is that this tool considers the straight-line distance or 'as the crow flies' distance, and does not consider the actual road network. To generate road network-based shortest paths between every origin-destination pair, the Shortest Path tool is available, which I will cover in a separate post.
A common use case would be to identify the nearest fire station from every school in a city. For disaster-prone areas, it can help identify the closest relief shelter from every household location when disaster strikes.
In this example, I will cover a basic Network Management use case where my goal is to identify the nearest healthcare facility for every insured person in a city and the corresponding distance from their home locations. Let's take a look at the data. The first layer shows sample locations (represented by green dots) – we will consider these as Home locations of the Insured persons.
Next, we have a dataset representing the Healthcare facilities in the Insurer's Network.
Once the layers are added to the MapSession, I can use the Search Bar under Vector Processing Tools to find the 'Distance to Nearest Facility' tool.
Next, I can specify the following parameters and run the tool:
- Select Origin Layer: The vector layer containing the set of origin points ('Insured Persons' for this example)
- Select Destination (Facility) Layer: The vector layer containing the set of destination points (i.e., 'Healthcare Facilities')
- Destination Name Attribute: The attribute/field that contains the Name/Identifier from the Destination layer. This will be added in the Output file against the nearest feature.
- Units (Measurements): The unit for distance calculation between the origin and destination points. A user may choose between Meters / Kilometers / Feet / Miles.
- Generate Network Lines: Selecting this option will generate lines between each Origin-Destination pair. If left unchecked, the output created will be an extension of the Origin layer with additional attributes showing the Nearest destination name and the corresponding distance between them.
I can then save the tool output as 'Nearest Facility Lines'. Once processed, it will appear in the Layer Panel.
As you can see in the screenshot above, the orange-colored lines represent the lines from each feature in the Origin Layer (Insured Persons) to the nearest feature from the Destination layer (Healthcare Facilities).
Additional attributes – 'HubName' and 'HubDist' - have been added as well. In the next step, I want to apply a theme to this layer using the 'HubDist' attribute. To do this, I can expand the Styling Panel by clicking on the Layer and apply Graduated Styling and specify the relevant parameters. I have written a separate post on Creating Thematic Maps (Graduated Styling) on MapReveal™ Software that covers Graduated Styling in greater detail.
The following snapshot shows the final published map, and you can see how the lines get darker as the distance increases between the origin-destination pairs.
I hope you found this useful. As I mentioned above, I will write a separate post on creating road network-based shortest paths between 2 or more features. Do share your feedback/questions in the comments section.
------------------------------
Anurag Hazarika
Product Manager
Precisely | Trust in Data
------------------------------