CE 4200 Chapter : Homework 7 Solution 2013 Fall
Document Summary
The ow consists of both overland ow and channel ow. Use the kinematic wave equation to estimate the time of concentration of overland ow, t1, where l = 30 m, ie = 50 mm/h, so. = 0. 01, and for an asphalt surface table 5. 17 gives n = 0. 011. The kinematic wave equation (equation 5. 94) gives t1 = 6. 99 (nl)0. 6 e s 0. 3 i0. 4 o. = 6. 99 (0. 011 30)0. 6 (50)0. 4(0. 01)0. 3 = 3 min. The ow area, a, in the drainage channel can be calculated using the manning equation. P 2/3 s 1/2 o where q = 0. 02 m3/s, n = 0. 013 (for concrete), and so = 0. 006. The area, a, and wetted perimeter, p , can be written in terms of the depth of ow, d, in the drainage channel as a = 0. 2d and p = 2d + 0. 20, therefore the manning equation can be put in the form.
