The effects of a changing climate on transportation corridor slopes are poorly understood, but several recent studies have suggested that landslide activity, especially rockfall, is likely to increase as a consequence of the increased occurrence of intense precipitation events. Effects from climate change such as extreme temperature fluctuations, freeze-thaw cycles, and increased rainfall quantity and intensity weaken geologic materials, exacerbating slope failures. In order to understand slope rockfall activity and its linkages to weather and climate, we acquired additional high-resolution lidar data and unmanned aircraft systems structure data from motion surveys of rock slopes in Alaska. Over several projects we have successively developed a rich data set spanning 5 years to quantitatively evaluate rockfall activity (the magnitude-frequency of rockfall events), which proved useful for examining correlations with historic weather patterns and future climate forecasts. As part of this research, we further developed the Rockfall Activity Index (RAI) and began to evaluate how the RAI can be linked to increasing temperature swings and freeze-thaw cycles. This quantitative approach for rockfall activity forecasting is an important step in providing tools to state departments of transportation to assess transportation corridor risks, sustainability, and resiliency, especially for Alaska in the face of a changing climate. This research is a first step in providing the analysis tools needed to meet a recent presidential directive and help improve our fundamental understanding of the potential impacts of climate change on the safety of and mobility within transportation networks in landslide-prone regions such as the Pacific Northwest in the U.S.Pacific Northwest Transportation Consortium
Alaska Department of Transportation & Public Facilitie
