Subject: flowstage curve function_water quality Posted: 2/2/2017 Viewed: 369 times
I am just learning the WEAP by going through tutorial version.
In water quality section of tutorial vesion, I couldn't get the same results in velocity even though I entered the exactly same data of flow stage width using wizard as indicated on page 154. Could you please explain why I couldn't get the same results of velocity as shown on page 155. Is there any more information on flowstage curve function (i.e., equation)?
You are correct, the values in the tutorial no longer work. We have been meaning to update this.
To explain why, formally we used rectangles to approximate the cross-section area of a river. So the "width" would be the width of the rectangle (the same at the top and the bottom). We have switched to using trapezoids, with a triangle at the very bottom. So the width of the trapezoid is (for the bottom), the width of the lower trapezoid (unless it is the bottom trapezoid, in which case it is a triangle pointing down), and the width at the top is the width you list.
In the meantime, to complete the Water Quality module, you'll need to enter a high flow for the third line of velocity data. It means your results won't exactly match the results in the Tutorial, but those need to be updated anyway to work with the current calculation methodology.