Field observations are carried out to assess the discharge of a river. Measurements are taken in a 2000 m straight reach. Slope is approximately 1 in 4000. Bed slope is determinably to a possible accuracy of 0.4 cm; wetted perimeter is determinable within 4% of possible error; and sectional area within 6% of possible error. Using Chezy’s equation, the assessed discharge will be accurate to within

Field observations are carried out to assess the discharge of a river.

1.	Field observations are carried out to assess the discharge of a river. Measurements are taken in a 2000 m straight reach. Slope is approximately 1 in 4000. Bed slope is determinably to a possible accuracy of 0.4 cm; wetted perimeter is determinable within 4% of possible error; and sectional area within 6% of possible error. Using Chezy’s equation, the assessed discharge will be accurate to within
A.	9.6%
B.	10.8%
C.	11.4%
D.	12.7%
Answer» D. 12.7%