# Civil Engineering - Water Resources Engineering - Discussion

### Discussion :: Water Resources Engineering - Section 1 (Q.No.33)

33.

From the Survey of India map, the distance of the critical point is 20 km and difference in elevation is 193 m. The over land flow time, is

 [A]. 2 hours [B]. 3 hours [C]. 2 hours and 30 minutes [D]. 3 hours and 30 minutes [E]. 4 hours.

Explanation:

No answer description available for this question.

 Murali Krishna said: (Jun 8, 2014) Why it is 4 hours is it standard or any calculation is there?

 Gopal Dev Sharma said: (Jul 4, 2014) I guess, over land time duration: = ( 0.885 *L^3 / h )^0.385. = ( 0.885 *20^3 / 193 ) ^ 0.385. = ( 36.68 ) ^ 0.385. = 4.002 ~ 4 hours. Note : I'm not sure If It Is correct ... Let me know if it is.

 Srinu said: (Oct 14, 2016) @Gopal. Is this formula correct& how did you get this? Are you sure?

 Mughal Saltanat said: (Dec 4, 2016) T = (0.885 L^3/H)^0.385

 Subhadeep Mandal said: (May 24, 2017) This mathematical approach is based on Kirpich Equation (1940). Tc (in minute) =[ 0.01947*(L^0.77) * ((h/L)^-0.385)], h = 193 m, L = 20000 m, Tc = 238.29 min ~ 3.97 hr ( ~ 4 hr.).

 Akhilesh Yadav said: (Jun 9, 2017) Kirpich Time Of Concentration. Watershed Hydrology Equations Formula:- Time of concentration (tc)=.0078{(L^.77)/(S^.385)}. Where- S=193/20000=.00965. Travel length (L)= 20000meter = 65616.797900262 foot, Slope (S)= 0.00965. Time of concentration (tc)=.0078{(20000^.77)/(.00965^.385)}, Time of concentration (tc)= 238.31597891773minute, Time of concentration (tc)=3.97193298197hour.

 Vjay said: (Aug 21, 2020) I am not getting this, please anyone explain this in detail.