NH51B-1890
New methods in hydrologic modeling and decision support for culvert flood risk under climate change

Friday, 18 December 2015
Poster Hall (Moscone South)
Ana Rosner1,2, Benjamin H Letcher1, Richard M Vogel3 and Paula Sturdevant Rees4, (1)USGS/Biological Resources Division, S.O. Conte Anadromous Fish Research Center, Turners Falls, MA, United States, (2)Cadmus Group, Inc., Waltham, MA, United States, (3)Tufts University, Department of Civil and Environmental Engineering, Medford, MA, United States, (4)Water Resources Research Center, University of Massachusetts Amherst, Amherst, MA, United States
Abstract:
Assessing culvert flood vulnerability under climate change poses an unusual combination of challenges. We seek a robust method of planning for an uncertain future, and therefore must consider a wide range of plausible future conditions. Culverts in our case study area, northwestern Massachusetts, USA, are predominantly found in small, ungaged basins. The need to predict flows both at numerous sites and under numerous plausible climate conditions requires a statistical model with low data and computational requirements.

We present a statistical streamflow model that is driven by precipitation and temperature, allowing us to predict flows without reliance on reference gages of observed flows. The hydrological analysis is used to determine each culvert's risk of failure under current conditions. We also explore the hydrological response to a range of plausible future climate conditions. These results are used to determine the tolerance of each culvert to future increases in precipitation. In a decision support context, current flood risk as well as tolerance to potential climate changes are used to provide a robust assessment and prioritization for culvert replacements.