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Location and attributes for profile baseline and stream centerline features for the Flood Risk Project area. Updated on 20230710. |
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Location and attributes for profile baseline and stream centerline features for the Flood Risk Project area. Updated on 20230710. |
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5000 |
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<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The S_Profil_Basln layer is required for all types of riverine hydraulic analyses. Profile baselines are required to be shown on FIRM panels for all valid studies with profiles or otherwise established Base Flood Elevations. Profile baselines are also required in new riverine Zone A areas with model backup. At the discretion of the FEMA Project Officer water lines may be shown on vector maps to represent the bank or stream centerline location. When a profile baseline and water lines are available for the same stream reach, only the profile baseline shall be shown on the FIRM in order to eliminate overlaps. A profile baseline is also required when a Flood Risk Project is not being updated but the effective profile baseline still accurately represents conditions on the ground. This information is used in the following tables within the FIS Report: Flooding Sources Included in this FIS Report, Principal Flood Problems, Summary of Hydrologic and Hydraulic Analyses, Summary of Topographic Elevation Data Used in Mapping, the Stream-by-Stream Vertical Datum Conversion and Summary of Contracted Studies Included in this FIS Report. The spatial entities representing the profile baseline are lines. Profile baselines are to be stored in Polyline ZM feature classes, storing both profile station values (M-values) and 1-percent-annual- chance water-surface elevations (Z-values) at cross sections, structures and other modeled inflection points. For new models and effective models with valid profile baselines, vertices along the profile baseline are to be calibrated between cross sections and structures using linear referencing / dynamic segmentation tools in GIS. The first vertex of each profile baseline will be the downstream most point on the profile. </SPAN></P></DIV></DIV></DIV> |
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Profile Baselines |
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["DCR","VFRIS","Flooding","Floodplains","Virginia","VA","FEMA","NFIP","NFHL"] |
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en-US |
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150000000 |
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