A rectangular channel of width 12 ft has an upstream slope of 0.02 ft/ft and a downstream slope of 0.0005 ft/ft. Both reaches have lengths of 500 ft. The upstream reach has a Man- ning's roughness of 0.016 and the downstream reach has a roughness of 0.011. The design discharge is Q = 460 cfs, the low ow discharge is Q = 230 cfs, and the ood discharge is Q = 690 cfs. Problem 3a) Using the direct step method by hand with 1 step, determine the lo- cation of the hydraulic jump relative to the slope break for the design discharge. Classify the jump type and calculate the energy lost. Problem 3b) Design an Excel spreadsheet to calculate the location of the hydraulic jump relative to the slope break using a depth step size of 0.01 ft for the design discharge. All lengths and water depths must be accurate to 2 decimal places. Plot the water surface pro le relative to the slope break. Your spreadsheet will be uploaded to Moodle with the lename format of lastname rstname hw5 prob3.xls. Problem 4) In HEC-RAS, model this system as 1 reach with cross-sections every 2 ft. For all 3 discharges (labeled as: design, low, ood),
(a) Determine the water depths 10 ft from the upstream and down- stream boundaries.
(b) Determine the location of the hydraulic jumps (in ft from the slope break).
(c) Output the water surface pro le plots with all 3 discharges, including the water surface, energy grade line, and critical depth line. Hint: You only need to de ne 3 cross-sections (1 upstream one at the slope break, and 1 at the downstream location). You will be able to interpolate the intermediate cross-sections. To do this, go to Tools- XS Interpolation and choose Interpolation between 2 cross-sections. Use the required x and a linear interpolation. Also, you will need the 3 cross-sections you de ne to have the correct elevations for the designated channel slopes. It's easiest to start at the downstream reach and work upstream. Once you've created the rst cross-section, you can copy it upstream and then modify its evelation