Abstract
 Variability in Time of Concentration with Finite Increment Computations Track: Water Resources Author(s): Darren Baird, Matt Breen The Soil Conservation Service's time of concentration calculation methodology is one of the most universally used methods when computing the time of concentration for a hydrologic basin. The approach is to break up the path of a drop of water into three distinct flow types: (1) sheet flow for the first 300 feet of flow length, (2) shallow concentrated flow from the point at which sheet flow ends, (3) stream flow from the point the flow enters a well-defined channel. By using the raster calculation functions available within ArcView Spatial Analyst, the effects of finite increment calculations on the results of the SCS equations are examined. This paper presents the potentially large variability in time of concentration calculations introduced by performing the calculations as the cumulative of finite increment calculations. Darren Baird Esri 8620 Westwood Center Drive Vienna , VA 22182 US Phone: 703-506-9515 E-mail: dbaird@Esri.com Matt Breen AMEC Earth & Environmental 14428 Albemarle Point Place Suite 150 Chantilly , VA 22150 US Phone: 703-488-3787 E-mail: matt.breen@amec.com |
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