Ingeniero Agricola

EXPORTING LAND DESKTOP DATA INTO HEC-RAS
Geometric data can be taken from Land Desktop and exported to a text file which can be loaded directly into the Hydrologic Engineering Center – RiverAnalysis System (HEC-RAS). You must have a terrain model set up that the program will use to extract data. From that, it will be sent to HEC-RAS. The terrain model can use data from detailed topographicsurveys, Digital Elevation Models (DEM), or manually digitized contours. 1. The first step is to define the locations of the sections that will be exported into HEC-RAS. Sections can be drawn usinglines or 2-D polylines with a maximum of three vertices (one change in direction). In this example, the section lines are drawn on top of a United States Geological Survey (USGS) raster image to helporient where the sections should go. The raster image lines up with a DEM file which will be used to obtain geometric information which will be exported to HEC-RAS. Keep in mind that HEC-RAS geometricinformation is entered from left to right when looking downstream. This is important when defining sections using polylines because the end on which you start your polyline will be the side that LandDesktop will use to begin the section. This means that if you draw your polyline from right to left instead of left to right, your section will import into HEC-RAS backward. This is less important withlines because Land Desktop will start the section on the end of the line nearest to where you select it, without regard to which direction the line was drawn. If you are working in an area where thechannel geometry does not make it possible to line up a section perpendicular to the stream channel, you can place one intermediate vertex in your section line such as with section 110 on the left.2. After you have drawn in the locations of the sections that you want to export, go to HEC2 Output, HEC2 Single, under the Hydrology drop-down menu. You may need to change to the Civil menu...