HEC-RAS Model for flood-inundation maps for Cayuga Inlet, Sixmile Creek, Cascadilla Creek, and Fall Creek at Ithaca, New York
Dates
Publication Date
2018-12-19
Start Date
2015
End Date
2018
Citation
Nystrom, E.A., Lilienthal, A.G., and Coon, W.F., 2018, Geospatial dataset of flood-inundation maps for Cayuga Inlet, Sixmile Creek, Cascadilla Creek, and Fall Creek at Ithaca, New York: U.S. Geological Survey data release, https://doi.org/10.5066/P9V8ED23.
Summary
Flood profiles for the stream reaches were computed by combining a one-dimensional step-backwater model for the stream channels and a two-dimensional model for the overbank areas. The resulting hydraulic model was calibrated by using water-surface profiles from five observed storm events. The model was then used to compute 15 water-surface profiles for 5 flood frequencies (50- , 10- , 2- , 1- , and 0.2-percent annual exceedance probabilities, or 2- , 10- , 50- , 100- , and 500-year recurrence intervals) and 3 lake levels (representing average conditions, a 2-year-high condition, and a 100-year-high condition). The geographic information system flood-extent polygons, depth grids, and water surface elevation grids generated using this [...]
Summary
Flood profiles for the stream reaches were computed by combining a one-dimensional step-backwater model for the stream channels and a two-dimensional model for the overbank areas. The resulting hydraulic model was calibrated by using water-surface profiles from five observed storm events. The model was then used to compute 15 water-surface profiles for 5 flood frequencies (50- , 10- , 2- , 1- , and 0.2-percent annual exceedance probabilities, or 2- , 10- , 50- , 100- , and 500-year recurrence intervals) and 3 lake levels (representing average conditions, a 2-year-high condition, and a 100-year-high condition). The geographic information system flood-extent polygons, depth grids, and water surface elevation grids generated using this model are also available as part of this Data Release.
The availability of these maps will provide emergency management personnel and residents with information that is critical for flood-management planning, flood-response activities, and postflood recovery efforts.
