A directly connected portion (to the outlet) of an Adelaide catchment (total Area = A ha) was subjected to an industrial development. Travel time before the development was t_c minutes (to travel from the furthest point, P to the catchment outlet, O). After the development, travel time for the developed area is approximately t_c1 minutes and that is for the undeveloped area still equals to t_c. The runoff coefficients at 10-year ARI, C₁₀ for the undeveloped (pervious) and developed (impervious) areas are C₁ and C₂ respectively. Based on the data provided below, select the set of parameters for the analyses from the data. The IFD data (mm/hr) and Frequency conversion factors are given in Tables 4 and 5 respectively.?

(a) Based on the data selected, indicate developed and undeveloped areas on a typical catchment. Also indicate furthest point, P and the catchment outlet, O.

(b) Using Rational method of peak flow estimation, compute the percentage increase of the T-year (ARI = T years) design flood peak due to the development. All the calculations need to be presented logically and clearly.

Total Area (At)	tc (min)	tc1 (min)	C1 at 10-year ARI (previous)	C2at 10-year ARI (impervious)	ARI (T years)	Developed area (% of At) = 30Total Area (At)
4	30	15	0.25	0.8	70	40

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Table 4 Frequency conversion factor F₁ (for questions 52 ARI (T-years) FT Duration (min) 5 1 0.8 10 15 20 25 30 35 40 45 2 0.85 5 0.95 1 2 42.9 57.95 32.18 43.34 26.5 35.62 22.83 30.65 20.22 27.11 24.43 22.32 18.24 16.69 15.42 14.37 10 Table 5 IDF data (mm/hr) for Adelaide region (for questions 52 ARI = T (Years) 5 10 20 50 81.43 97.96 121.04 156.02 60.46 72.42 89.15 114.39 49.45 59.06 72.52 92.77 42.38 50.51 61.89 78.89 37.37 44.45 54.39 69.27 33.59 39.9 48.75 61.99 30.62 36.33 44.33 56.29 28.22 33.33 40.76 51.69 26.23 31.04 37.81 47.89 20.61 19.19 1 20 40 60 1.05 1.13 1.17 80 100 1.2 1.19 100 186.54 136.34 110.32 93.78 82.13 73.42 66.6 61.11 56.57 Table 4 Frequency conversion factor F₁ (for questions 52 ARI (T-years) FT Duration (min) 5 1 0.8 10 15 20 25 30 35 40 45 2 0.85 5 0.95 1 2 42.9 57.95 32.18 43.34 26.5 35.62 22.83 30.65 20.22 27.11 24.43 22.32 18.24 16.69 15.42 14.37 10 Table 5 IDF data (mm/hr) for Adelaide region (for questions 52 ARI = T (Years) 5 10 20 50 81.43 97.96 121.04 156.02 60.46 72.42 89.15 114.39 49.45 59.06 72.52 92.77 42.38 50.51 61.89 78.89 37.37 44.45 54.39 69.27 33.59 39.9 48.75 61.99 30.62 36.33 44.33 56.29 28.22 33.33 40.76 51.69 26.23 31.04 37.81 47.89 20.61 19.19 1 20 40 60 1.05 1.13 1.17 80 100 1.2 1.19 100 186.54 136.34 110.32 93.78 82.13 73.42 66.6 61.11 56.57

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aThe following data are provided Area of the catchment A 100 ha Area of the developed portion A1 10 ... View the full answer