HEC-RAS river stations 1

[chicopee]

The tributary to which I am assigning river station numbers is roughly 1.2 miles long. Yet when assigning river station (RS) numbers(.047,.099,.197,.214 miles)to its four cross sections, the tributary schematic drawn in the geometric data window shows the cross sections proportionally positioned across the entire length of the tributary when in fact they should be close to the junction. What's up with that? Does it mean that I should truncate the tributary to the .214 mile RS?

 

[RWF7437]

You can either "truncate" the reach to the 0.214 mile station or you could add a station at 1.200 miles. The 1.2 mi sta. need not be a "real" cross section but could be extrapolated from your surveyed stations. Remember that your flows are input at particular stations so, for example, you could input a flow of 0 cfs at mile 1.2 and your design flow at mile 0.214. Your calculations should be OK if you do this.

good luck

 

[francesca]

The geometry window is not drawn to scale, it's just a graphical depiction.

 

[chicopee]

In my case Francesca, I drew my river and its tributaries by inserting and redrawing over it, an ACAD drawing which is to scale. I did follow RWF7437 suggestion of putting a cross section at the 1.2 mile station and it worked. THX for your replies.