للمهندسين المدنيين (مدني+موارد مائية)

SD= Sqrt(Σ(pi-px)2 / (N-1)
SD: Standard Deviation
PTr=px+KSD
PTr: Estimated max 24 hr rainfall for specified period Tr
K=[ -(√6) /π] * [0.557 + (ln(ln (Tr / (Tr-1))]
P Tr3 = 62.21 + (0.27) 29.67 = 70.22 mm
P Tr5 = 62.21 + (0.73) 29.67 = 83.87 mm
P Tr10 = 62.21 + (1.32) 29.67 = 101.37 mm
P Tr25 = 62.21 + (2.06) 29.67 = 123.33 mm
P Tr50 = 62.21 + (2.61) 29.67 = 139.64 mm
P Tr100 = 62.21 + (3.15) 29.67 = 155.67 mm
Tc=0.01947L 0.77 S -0.385
Tc: Time of concentration (hr)
L: Length of the stream (m)
S: Slope
Q=(P-0.2S) 2 /(P+0.8S)
Q: Monthly Runoff (mm)
P: Monthly Rainfall (mm)
S: Detention
S= (25400/CN)-254
CN: Runoff Curve Number (from table)
Q Peak =0.0208 AQ/T p
Q Peak : m 3 /s
A: Area in Hectares
Q: is in (cm) from equation (P-0.2S) 2 /(P+0.8S)
Tp=0.6Tc+ √Tc
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