178 - Prediction of climate change-induced alterations in streamflow and bridge scour and exploration of mitigation strategies: an application in a central Pennsylvania watershed

Our study integrates the use of future climate projections derived from global climate models, the implementation of hydrologic and hydraulic modeling, and the execution of regional-level analyses specifically focused on bridge scour. We seek to understand climate change-induced damages to bridges due to scour and to offer relevant grey or nature-based solutions (NBSs). Our framework combines downscaled climate model outputs and geospatial information within the SWAT hydrologic model in order to simulate streamflow. The HEC-RAS hydraulic model is then used to estimate bridge pier scour depths, corresponding to the outputs of the hydrologic model. Probabilistic methods are also employed, to estimate bridge failure probabilities associated with scour depth estimates, considering also the climate change uncertainty. In this work, we: 1) analyze the climate change driven variations in basin hydrology and streamflow, and the collective impact on bridges in the Swatara Creek watershed in central Pennsylvania; 2) evaluate the performance of NBSs (e.g., stormwater basins up in the watershed, floodplain restoration), and other grey infrastructures (e.g., rip rap) as mitigation strategies to reduce flood induced scour risk for bridges; 3) perform Life Cycle Analysis (LCA) of the NBSs and grey infrastructures to inform optimal strategies considering both carbon and monetary costs. In this presentation, we will focus primarily on objectives 1 and 2. The outcomes of this study should inform the development and implementation of infrastructure protection strategies and policies, for sustainable floodplain management in the face of climate change risks.