4. In a watershed, a rainstorm hyetograph was recorded at a time step of 15 minutes; it is found that the rainstorm occu
Posted: Sat May 21, 2022 2:52 pm
4. In a watershed, a rainstorm hyetograph was recorded at a time step of 15 minutes; it is found that the rainstorm occurred from time step 3 to step 5, and the related rainfall intensities in the units of mm/15 minute at three time steps are 15, 3, and 11, respectively. The p-index value of the watershed is 12 mm/hr. The following table gives the related flood hydrograph. The straight-line method is used to separate the baseflow. Derive and plot the 15-minute unit hydrograph through using the deconvolution method. Determine the watershed area and its time of concentration. (20 marks) Time step (15 minutes) 1 2 3 4 5 6 7 8 9 Discharge (m3/s) 2.32 2.26 10.44 29.06 14.36 121.14 8.00 4.54 4.42