At the end of 2020, we teased a map showing a new Terrain Ruggedness Index that we promised would be coming to the AGS lineup in 2021. We are excited to share with you the sneak peek of the index that will be released this spring.

Adapted from academic work, the Terrain Ruggedness Index is based on the most detailed USGS digital elevation model. The ruggedness index measures the overall terrain variability within an area and is based on the calculation slopes between all adjacent points on a detailed grid. In addition to the terrain ruggedness index, we can report for any geographic area the percentage of the area by slope class (e.g. 8-9%), maximums and minimums, and of course, elevation.

To show the index, we looked at the Los Angeles metropolitan area. The first map below shows the terrain of the area. While there are many areas that are relatively flat, the Los Angeles area is surrounded by hills and mountains, which for many people, adds to the overall beauty of the area and makes it a desirable place to live. Where else can you surf in the morning, and ski in the afternoon? When we add a layer of population, as seen in the second map, it becomes more interesting. Outside of a few farming areas in Ventura county and the San Gabriel Valley, there are very few places left that can be developed for residential housing.

Terrain Ruggedness Index: Los Angeles Metropolitan Area


Terrain Ruggedness Index with Population: Los Angeles Metropolitan Area

We anticipate the Terrain Ruggedness Index to be useful for site selection, insurance underwriting, and more. Be on the lookout for this new addition to our data this spring.