Question

1. Determine the velocity of flow for the following:

1. a) using the Upland Method:

   • across a parking lot at a slope of 2%

   • across a short grass field at a slope of 4%

2. b) using Manning’s:

• down a small stream at 1%; the steam is trapezoidal-shaped, 0.7m deep with a bottom width of 1.0m and a top width of 3.0m. Determine the appropriate Manning’s n factor and justify your decision.

Answer 1

a)Velocity of flow by Upland method, V =4.9178*S^^0.5

Where, V= Velocity in m/s                  S= Slope of hydraulic grade line

Given Slope=2% across parking lot      So, Velocity of flow across parking lot V= 4.9178 * (0.02)^^0.5

V=4.9178 * 0.1414 = 0.6954 m/s

Flow of velocity across parking lot with slope 2% =0.6954 m/s

Given slope =4% across short grass field    SO, Velocity of flow across grass field V=4.9178 * (0.04)^0.5

V=4.9178 * 0.2 =0.98356 M/S

Flow of Velocity across Grass field with slope 4% =0.98356 m/s

b)Manning's equation .