WebThe equation to the curve was of the type: q = C. A n where q represents the peak flow per unit area . A represents the catchment area . ... where Q is peak discharge in cumec . P is runoff coefficient which depends on the characteristics of the catchment area. It is a ratio of runoff: rainfall. (P values are given later). WebRainfall intensity (i) in Equation 2.1 8.1 is the average or constant rain intensity (inches per hour) lasting a duration equal or longer than the time of concentration ( Tc) of the drainage area (Cleveland, 2011) . ... The rational method assumes that the peak runoff rate occurs when the entire area is contributing flow. Therefore, th e time ...
Assessing Hydrological Effects of Bioretention Cells for Urban ...
WebThe time of concentration can be calculated by the kinematic-wave equation. The drainage channel is to be sized for the peak runoff resulting from a 10-year rainfall event, and the 10-year IDF curve is given by i = (t + 8.96) 0.78 150 where i is the average rainfall intensity in cm / h and t is the duration in minutes. The minimum time of ... WebDec 11, 2009 · The storm duration and design return period can be used with an IDF (intensity-duration-frequency) graph or equation to determine the design storm rainfall intensity. ... to be used in the Rational Method … iphoto events
RUNOFF CALCULATIONS
WebPeak rate of runoff - (Measured in Cubic Meter per Second) - Peak rate of runoff is the maximum rate of discharge during the period of runoff caused by a storm. Runoff … WebThese design equations (Steel Equation), data and calculator will determine Rainfall Intensity and Peak Storm Water Runoff Rate for proper design of drainage requirements. Using the STEEL equation ( i = a/ (d + b) NOTE: … Weba. Peak Rate of Runoff by Rational Model: . An important method for determining the peak runoff rate is the rational formula. It is an empirically developed model, characterized by consideration of the entire drainage area as a single unit and estimation of flow at the most downstream point with the following assumptions- oranges cut in half