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Question 4 [25 marks) a. A basin in Hulu Langat has been developed into a 1.0 acre park (C-0.3) and 2.0 acres of residential use (C-0.9). Determine the weighted surface runoff of the area. (PLO3: CLO 4: C3) (5 marks) A new development of residential area will be developing in Kuala Lumpur. Total area of the development is 4.0 ha which consist of 30% green garden, and 70% covered development. Assume the value for green garden and covered development=0.43, and 0.9 respectively. The overland flow from the longest path is 1.5 km with manning's coefficient for the land surface, n=0.012 and slope of overland surface is 2%. The estimated channel flow is 12 minutes to the outlet drain. Refer Appendix Q4. (i) Calculate the design flow, Qe using Rational Method for 20 years ARI (ii) Verify the size of the rectangular drain with maximum velocity is 2.2m/s, maximum depth without protective cover is 0.6 mx 1.2 m width to cater the peak flow from the new development area. (PLO3: CLO 4: C5) (20 marks)

Answer 1

AI 1acre CIO.3 A22 2 acra 22 0-9 weiged sursau run ofp - AICITA22 Al A2 1XO 3 2x0 9 13 C O.7 Ans TOtal area 4 ha etere 30% 4O30 12 ha UTreen 07axden C 8or arean uTarden = o-43 cOvered developameut 0 o-7 2.8ha అకిం 1-2x0-43 +2-8x0.9 4 Weiatad surtou rumfF 759 Az 12 AO.co12m2 !-2t exo.6 2-Ym O.Cm Re A P .2m 2 O 12 0 3 2.4 2213. 2 So nco.012 S205 0.02 SiVen 2/3 03)x (o 02) 2 012 5 29 ms 316 8 m/minuct 5-29X 60

o Time ragaird ungh of Longest Path veloity 1-5X 1000 m 316.8 m minut Time 4.485 minut So, TOtal time 16.135 minul 12 +Y 735 So, Design discharge = L*C* PcA 36 Pp Sursau runOfF A = Arka (in ha ber rainfau intensity om/h 5 te 2omin. thun 75 em Ao+ to hr be f. 75 2.805 hr 10f16-735 2.805 LRO159x 2202 36 O.2365 m/sec cheek Sor Size PP AVmax epP 2 0235 mls 2 2 mls Apo 0B Areg O107 m2 O72m7 A providnd Areg Hance ok