Compute the discharge of a river from the data given in table below. The current meter coefficients are; a = 0.04 and b = 0.76.

 

Compute the discharge of a river from the data given in table below. The current meter coefficients are; a = 0.04 and b = 0.76.

 

Distance from bank (ft)	Depth (ft)	Meter Depth (ft)	Revolutions	Time (sec)
2	1	0.6	10	30
4	1.5	0.9	22	30
6	4	0.8	35	30
		3.2	28	30
8	3	0.6	45	30
		2.4	28	30
10	2	1.2	33	30
12	1	0.6	22	30

 

Solution#2

As we have

  V = a + bN_s

Average width

W =(2+4-2/2)2 /2×2

(W = 2.25 ft

 

For rest of segments

W1 = (2÷2 + 2÷2)

(W1 = 2 ft

 

For depth less than 2ft, velocity is measured at 60% of depth, hence it is the average velocity. For depth more than 2ft, velocity is measured at 20% and 80% of depth,

 

Distance from bank (ft)	Average width	Depth (ft)	Revolutions	Time (sec)	Ns Rev/sec	Velocity a=bN	Area	discharge
2	2.25	1	10	30	0.33333	0.29333	2.25	0.645326
4	2	1.5	22	30	0.73333	0.59735	3	1.79193
6	2	4	35	30	1.16666	0.926616	8	7.413328
	2		28	30	0.93333	0.74933	0	0
8	2	3	45	30	1.526	1.182	6	7.08
	2		28	30	0.93333	0.74933	0	0
10	2	2	33	30	1.112	0.876	4	3.504
12	2.25	1	22	30	0.73333	0.59733	2.25	1.34399

                                                                                                                                         TOTAL= 21.778544