Geospatial applications to landslide riskscape development: a modeling approach to quantify landslide riskscapes in the Colorado Front Range, USA

Abstract

\n Riskscapes are interdisciplinary concepts that integrate multiple facets of physical, environmental, and social components in a spatial and temporal context. While the notion of risk is well documented for landslides, riskscapes are a novel approach in the natural hazard and spatial assessment studies. This term, ‘riskscape’, is described in terms of parameters required and quantification methodological approaches. Geographic Information Systems (GIS) or geospatial methods are an appropriate tool to define the development of these riskscape quantification methods. A weighted sum overlay model for a riskscape is developed with three weighted approaches using GIS to measure the strength of spatial relationships across a regional landscape in Colorado, focused on landslide susceptibility modeling in the riskscape context. Binary riskscapes resulted in a limited understanding of the impact of features related to landslide riskscapes, but both ranked and human-factor weighted riskscape models provided more details to inform policy and plan for response to landslide events. Clustering measures using spatial-autocorrelation tools revealed that riskscape outputs are clustered and can further be used to identify areas of increased risk due to landslides in emerging population-growth areas. In conclusion, ranked and human-factor riskscape models are developed and can support decision-making and prioritization for response deployment based on landslide susceptibility criteria to focus resources on areas of interaction between landslide risk and social factors.