{"id":440,"date":"2017-11-03T15:50:26","date_gmt":"2017-11-03T15:50:26","guid":{"rendered":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/?post_type=ht_kb&p=440"},"modified":"2025-05-11T15:11:30","modified_gmt":"2025-05-11T15:11:30","slug":"routing-through-channels","status":"publish","type":"ht_kb","link":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/knowledge-base\/routing-through-channels\/","title":{"rendered":"Reach Routing Hydrographs Through Channels"},"content":{"rendered":"\n

Reach routing becomes necessary when your inflow hydrograph must travel through a substantially long and well-defined channel where the channel storage is expected to have a significant impact on attenuation of the hydrograph.<\/p>\n\n\n\n

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Image taken from Channel Studio<\/em><\/figcaption><\/figure>\n\n\n\n
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In many cases where the channel is small, less than 5 feet in width and\/or has a travel time less than the Time Interval used, it will not be necessary to perform a channel route.<\/p>\n<\/blockquote>\n\n\n\n

When the inflow hydrograph traverses the entire channel in a duration shorter than the Time Interval (typically one to two minutes), it is advisable to incorporate that section of the channel into the drainage subarea of the runoff hydrograph and the Tc calculations, while omitting the channel reach routing.<\/p>\n\n\n\n

To route a hydrograph, select the inflow hydrograph first by dragging a rectangle around it with your mouse or alternatively, click on the icon. Then click the [Reach] button on Ribbon Toolbar.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

A Reach icon will be added to your model.<\/p>\n\n\n\n

For example the following model shows Hydrograph 4 “Junct” was selected as the inflow to a channel Reach, Hydrograph 5 “Reach”.<\/p>\n\n\n\n

\"\"Next, click on the Reach icon to populate its input window.<\/p>\n\n\n\n

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Coefficients x, m are not required inputs<\/figcaption><\/figure>\n\n\n\n

Required Data<\/h2>\n\n\n\n

The following is a description of each of the required input items.<\/p>\n\n\n\n

Name Prefix
<\/span><\/b> You can include a prefix (\u201cPre\u201d, \u201cPost\u201d or nothing to your hydrograph Name field with a single mouse click. This saves precious keystrokes when doing a pre- and post-development study and you want to identify those hydrographs that are \u201cPre\u201d or \u201cPost\u201d development. The chosen prefix will be added to the front of the Name label on the Basin Model and throughout the software, for example, Tables, Charts, Reports, etc.<\/p>\n\n\n\n

Name<\/strong>
Enter any descriptive name for this hydrograph. It will appear on the printed reports as well as the Basin Model.<\/p>\n\n\n\n

Inflow Hydrograph<\/strong>
The inflow hydrograph has already been selected but can be edited at any time by re-selecting from the drop-down list.<\/p>\n\n\n\n

Keep in mind you can only select hydrographs that have numbers lower than your Reach Hydrograph number. As you progress downstream, hydrograph numbers must increase. The program automatically manages this numbering system to ensure the accurate construction of the routing schematic.<\/p>\n\n\n\n

Routing Method<\/strong>
Select your preferred calculation method from the drop-down list box. Your choices include Modified Att-Kin and Muskingum-Cunge. The Muskingum-Cunge method tends to give higher peak flow values than the Modified Att-Kin. See Computational Methods<\/a> for more information.<\/p>\n\n\n\n

Section Type<\/strong>
Select the type of section that best describes this channel section:<\/p>\n\n\n\n