Talk:Time of concentration

I have an hourly rainfall and streamflow data. I would like to get the time of concentration. How to do? please give any suggestion. TQ
 * I'm not sure you can determine time of concentration directly from hourly rainfall and streamflow data (particularly if the time of concentration is not one hour.) Time of concentration is frequently estimated with a nomograph.  You should be able to find an appropriate nomograph by an on-line search for "time of concentration nomograph".  The input variables required are typically an assumed roughness coefficient for the flow path and elevation change and channel distance from the most distant upstream point in the watershed to the point of interest. Thewellman (talk) 05:44, 27 October 2009 (UTC)