Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN STYLE="font-weight:bold;">SLR Inundation Mapping</SPAN></P><P><SPAN><SPAN>The topographic data used for this analysis were derived from topographic light detection and ranging (LiDAR) data from NOAA. The SLR inundation mapping was completed on a 1-meter (3.28-feet) digital elevation model (DEM) derived from the bare-earth LiDAR data. </SPAN></SPAN></P><P><SPAN><SPAN>The inundation mapping effort leveraged existing and readily available model output from a large-scale MIKE21 San Francisco Bay hydrodynamic modeling effort completed as part of FEMA’s San Francisco Bay Area Coastal Study (DHI 2013). The model takes into account water level variations associated with astronomical tides, storm surge, and El Nino effects. The FEMA model output was used to determine the daily and extreme tide levels throughout the study area for input to the SLR inundation mapping.</SPAN></SPAN></P><P><SPAN><SPAN>The ten scenarios include 12, 24, 36, 48, 52, 66, 78, 84, 96, and 108 inches above current MHHW.</SPAN></SPAN></P><P><SPAN>Inundation maps were developed using the NOAA Coastal Services Center methods (Marcy et al. 2011). The initial step in creating the inundation maps was to create the inundated water surface DEM. Daily and extreme high tide elevations derived from the FEMA MIKE 21 model output points were used to define the water surface elevations for the existing and future conditions MHHW and 100-yr SWEL. The water surface elevations were then extended inland to project the water surface over the inundated topography. Depth of flooding raster files were created by subtracting the land-surface DEM from the water surface DEM. The resultant DEM provides both the inland extent and the depth of inundation in feet. The final step used in creating the depth and extent of flood maps relies on an assessment of hydraulic connectivity. The assessment of hydraulic connectivity removes areas from the inundation zone if they are protected by levees or other topographic features that are not overtopped.</SPAN></P></DIV></DIV></DIV>
Service Item Id: 4e58498997b94145bb1001c406779f5c
Copyright Text: AECOM 2017: (1) Justin Vandever (justin.vandever@aecom.com); (2) Mark Lightner (mark.lightner@aecom.com); (3) Mike Mak (michael.mak@aecom.com)
AECOM 300 Lakeside Drive, Suite 400, Oakland, CA 94612