Answer Happy

Figure Q4 shows two catchments, A and B that are being facilitated by a drainage system which consist of two inlets and two pipes. Catchment A has an area of 1 ha and is 50% impervious; catchment B has an area of 2ha and is 10% impervious. The runoff coefficient, C; length of overland flow, L; average flow velocity, V; are given in Table Q4. Calculate the peak flow to be handled the both pipes based on 10 -years IDF equation, ln(i)=.a+bln(t)+c(ln(t))2+d(ln(t))3, where a,b,c, and d are 4.490,0.997,−0.328 and 0.021, respectively.
Figure Q4: Layout of a drainage system of a catchment. A 30-min unit hydrograph for a 2.25 km2 watershed is shown in Table Q4b. Verify that this unit hydrograph corresponds to a 1−cm rainfall excess. Using this unit hydrograph, estimate the direct runoff resulting from the 90−min rainfall shown in Table Q4c. Table Q4b: 30-min unit hydrograph Table Q4c: Hyetograph of a 90-min rainfall