{"id":795,"date":"2017-11-08T22:04:55","date_gmt":"2017-11-08T22:04:55","guid":{"rendered":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/?post_type=ht_kb&p=795"},"modified":"2017-11-08T22:17:10","modified_gmt":"2017-11-08T22:17:10","slug":"channel-reach-routing","status":"publish","type":"ht_kb","link":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/knowledge-base\/channel-reach-routing\/","title":{"rendered":"Channel Reach Routing"},"content":{"rendered":"

Hydrology Studio employs the Modified Att-Kin (Attenuation Kinematic) and the Muskingum-Cunge methodologies for channel reach routing.<\/p>\n

\"\"Both theories are based on a discharge-flow area relationship where:<\/p>\n

\"\"<\/p>\n

The equations and formulas used to compute x and m are further described in Technical Release 20 (TR-20). Hydrology Studio allows you to optionally directly enter these variables when using the Modified Att-Kin method.<\/p>\n

Modified Att-Kin<\/h2>\n

The Modified Att-Kin method’s procedures are as follows:<\/p>\n

\"\"<\/p>\n

Where:
\nOt + dt = outflow at time t+dt
\nOt = outflow at time t
\nIt = inflow at time t
\nC = routing coefficient<\/p>\n

The routing coefficient is computed as:<\/p>\n

\"\"<\/p>\n

Where:
\ndt = time interval in seconds or hours
\nK = L\/(mV)<\/p>\n

Where:
\nL = channel reach length (ft)
\nm = factor relating average velocity and wave velocity (celerity)
\nV = average velocity (ft\/s)<\/p>\n

Muskingum-Cunge<\/h2>\n

The Muskingum-Cunge routing procedure has been incorporated into the NRCS TR20 hydrologic model. It will typically give higher peak flows than the Modified Att-Kin method. Both methods are more appropriate for modeling long channels.<\/p>\n

Muskingum-Cunge computes outflows using four primary coefficients as shown in the following equation:<\/p>\n

\"\"<\/p>\n

Where:
\nO2 = Outflow discharge at time 2
\nO1 = Outflow discharge at time 1<\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

\"\" \u00a0 \"\"<\/p>\n

Where:
\ndt = time interval in seconds
\nK & X are constants determined from:<\/p>\n

\"\"<\/p>\n

Where:
\nL = length of the channel reach
\nm = factor relating average velocity and wave velocity (celerity)
\nV0 = average velocity<\/p>\n

\"\"<\/p>\n

Where:
\nQ = peak inflow
\nT0 = top width at Q
\nS0 = longitudinal slope<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

The Modified Att-Kin and Muskingum-Cunge methods are described.<\/p>\n","protected":false},"author":1,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"footnotes":""},"ht-kb-category":[37],"ht-kb-tag":[],"class_list":["post-795","ht_kb","type-ht_kb","status-publish","format-standard","hentry","ht_kb_category-runoff-hydrographs-and-processing"],"_links":{"self":[{"href":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/wp-json\/wp\/v2\/ht-kb\/795","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/wp-json\/wp\/v2\/ht-kb"}],"about":[{"href":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/wp-json\/wp\/v2\/types\/ht_kb"}],"author":[{"embeddable":true,"href":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/wp-json\/wp\/v2\/comments?post=795"}],"version-history":[{"count":6,"href":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/wp-json\/wp\/v2\/ht-kb\/795\/revisions"}],"predecessor-version":[{"id":800,"href":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/wp-json\/wp\/v2\/ht-kb\/795\/revisions\/800"}],"wp:attachment":[{"href":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/wp-json\/wp\/v2\/media?parent=795"}],"wp:term":[{"taxonomy":"ht_kb_category","embeddable":true,"href":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/wp-json\/wp\/v2\/ht-kb-category?post=795"},{"taxonomy":"ht_kb_tag","embeddable":true,"href":"https:\/\/learn.hydrologystudio.com\/hydrology-studio\/wp-json\/wp\/v2\/ht-kb-tag?post=795"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}