This allows, for example, the user to toggle between the Google Map view and a terrain surface color relief view while digitizing the river centerline. The user can now turn ON and OFF the base map layer within the Map Data Layers panel while any digitizing command is active. For example, the user can select several layers at the same time by holding down the key to multi-select and then right-click and choose Remove from the displayed context menu. More than one layer at a time can be selected within the Map Data Layers panel in order to apply an operation to the selected layers. Multi-Select Layers in Map Data Layers Panel The modeler can examine the VxD (velocity x depth) factor, as this directly indicates greater flood hazard and hydraulic importance. This allows the modeler to have a better understanding of the true flow effects when attempting to determine the floodway in a complex flow situation. Similar to the 1D Floodplain Encroachment command within GeoHECRAS, the 2D Floodplain Encroachment command automates the placement and analysis of floodplain encroachments along the river reach when performing a 2D steady or unsteady flow computation. This command greatly speeds up defining ineffective flow areas at bridge and culvert roadway crossings.
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The button in the Bridge & Culvert Data dialog box causes the defined Ineffective Flow Areas to be adjusted so that their elevations match the roadway crossing high chord geometry. Automated Elevation Assignment for Roadway Ineffective Flow Areas