Increasing Transportation Planning Resiliency with Landslide Vulnerability Modeling

CLIENT: Southwestern Pennsylvania Commission (SPC)
LOCATION: Pittsburgh, Pennsylvania

This map displays five different levels of landslide susceptibility as well as historical landslides for Westmoreland county.

This map is from an indexed map series showing landslide susceptibility.

CHALLENGE

Increasing resiliency in transportation planning is a priority for the Southwestern Pennsylvania Commission (SPC), an agency responsible for planning the use of federal and state transportation funds for the Pittsburgh region. The southwest region has been hit by an overabundance of rain, resulting in more landslides, disrupting transportation networks. SPC needed to have a better idea of where to start work along the roadways and prevent these landslides.

SOLUTION

GeoDecisions developed a landslide susceptibility geographic information system (GIS) predictive analytics model for SPC based on a similar model released by the Minnesota Department of Transportation.

The model uses a variation of Coulomb’s law of friction to develop a mathematical equation that identifies how much rain could cause a landslide. By combining this information with the National Oceanic and Atmospheric Administration (NOAA) National Weather Service Precipitation Frequency Data, we can identify areas vulnerable to landslides. Running the model against historical landslide data, we can determine the possibility of future landslides.

The project involved finding available sources of data to plug into the equation’s variables and convert it to raster data – pixelating the data to become imagery that could be viewed on a map. Converting to raster data and analyzing the many maps and layers were facilitated easily using Esri®’s ArcGIS Pro, Esri’s professional desktop GIS software. The actual calculation, using the mathematical equation and the raster data, required the ArcGIS Map Algebra Raster Calculator included with the ArcGIS Spatial Analyst Tools. ESRI ArcGIS desktop was used to manipulate the digital elevation model (DEM), soil characteristics, and rain precipitation data.

Soil characteristics for the SPC region were obtained using the USDA ArcGIS Dataviewer plugin. Finally, we used ArcGIS to share model results.

KEY TECHNOLOGY

• Esri ArcGIS Desktop

• Esri Spatial Analyst Extension

• Esri ArcGIS Map Algebra Raster Calculator

• Python for ArcGIS

• EsriI ArcGIS Online

• USDA Soil Data Viewer 6.2

• USDA SSURGO Database

• NOAA Precipitation Frequency Data Server (PFDS) - ATLAS 14 Point Precipitation Frequency Estimages

KEY RESULTS

• Delivers an assessment and classification of transportation infrastructure assets’ vulnerability to landslide.

• Provides statistics on landslide impact on traffic volume, amount of truck, O&D traffic, and route detours.

• Determines optimal candidate mitigation project locations.