1. Dikes are to be installed on both channel banks of the 1.2 km long river section. The river width is 60 m, and 50% of the river width should be secured for flow passage. Determine the number of dikes can be installed in this section. Use the Winkel's formula and the angle from the front of the dike to the bottom of the next dike is 10 degrees.

a) A trapezoidal weedy excavated earth channel has a bottom slope of 1°, base width of 5 m and a side surface slope of 1:1, as shown in Figure 1. Given that n = 0.030, calculate the flow depth, y. 45° 45° - 5 m Figure 1

Civil

A very wide rectangular channel is designed to carry a discharge of 5 m³/s per metre width. The design is based on the Manning's equation with the roughness coefficient obtained from the grain size using Strickler's equation and results in a normal depth of 1.0 m. By mistake, however, the engineer used the grain diameter in mm in the Strickler's equation instead of in metre. What should be the correct normal depth?