Import shapefile polygone to define 2D flow area boundary

[Thea S.]

Hi!

I am trying to import a watershed polygon generated in ArcGis to be used as 2D flow area boundary for a rain-on-grid simulation to map overland surface flow paths.

I have work around the issues by importing the shapefile to RAS-mapper and draw the 2d boundary polygon around the shapefile.

Does anyone know a way to work around this?

I have tried to import the shapefile as a Land cover ( GIS tool/ Manning N Region Polygon (…)) and from there import the X and Y coordinates to the Storage area/ 2d Flow area outlines, but I am not able to copy/paste coordinates from one table to another.

[sjlynch]

Hi

I find the easiest and quickest way to create a 2D Flow Area is to create the polygon in ArcGIS, convert the polygon to a vertices point file using ET Geowizards, and calculate the coordinates at each point. Close ArcGIS and open up the point dbf file with Excel.

Next, open HecRas to the project and select Add 2D Flow Area. Draw a small square or any small shape and save it with the name you want to call your 2D Flow Area. Open the GIS Tools – “Storage Area/2D Flow Area outlines Table”. Copy and Paste the X, Y coordinates from the Excel File over the top of the coordinates in the open GIS Tools table. Click OK and when it closes, the altered 2D Flow Area will be drawn to match the ArcGIS polygon.

This works for me.

[PB]

You can also achieve this by importing the shapefile to RASMapper and copy pasting the feature into your 2D area perimeters layer in edit mode

[Author]

Posts