Bloomington Leader

The Indiana Geological and Water Survey at Indiana University is conducting research to assess landslide risks across the state. The project is supported by high-resolution imagery and digital elevation data from the Indiana Geographic Information Office.

Lead researcher Victoria Leffel and her team are working on creating a landslide inventory in central and southern Indiana. The study uses light detection and ranging (lidar) technology, which has been used in states with more severe topography such as Washington, Oregon, and Kentucky. Lidar data helps researchers create three-dimensional models to better identify potential landslide sites.

A significant advancement for Indiana came with the release of statewide lidar imagery in 2020. This new dataset allows researchers to see potential landslide movement over time, offering insights into areas susceptible to these hazards. Since joining the survey in 2022, Leffel has been developing the first statewide landslide risk maps using this lidar data.

Leffel's research findings have been published in the open-access Indiana Journal of Earth Sciences in 2024, with further publications expected over the next two years. Her studies conclude that bedrock geology and lack of glacial cover are linked to landslide occurrences, particularly where shale bedrock and variable topography exist.

In February 2024, Leffel investigated an incident at Clifty Falls State Park where a limestone chunk fell near a trail. Her report led to the closure of a tunnel due to weathering concerns of underlying shale. Further fieldwork identified numerous landslides on public forest land in southern Indiana.

Leffel's current project focuses on mapping landslide hazards within a specific area of southeast-central Indiana, funded by a $45,439 grant from the U.S. Geological Survey. The project aims to produce landslide maps for state parks in those counties by fall.

Additionally, a proposed grant seeks funding for a comprehensive landslide inventory covering parts of 13 counties in south-central Indiana. This would incorporate lidar data along with historical records related to transportation infrastructure dating back decades.

“While the proposed and future project boundaries are subject to change,” Leffel said, “our current goal is to eventually map landslide risk for all areas of the state south of the Wisconsin Glacial Boundary.”

“Landslides in Indiana go beyond simple erosion; they involve the movement of soil and rock on a large scale,” she explained, noting that while most are slow-moving compared to those often highlighted in news stories, they still pose maintenance challenges.