ANNEX -2
Hydrological Analysis
This procedure is used throughout the calculation of maximum flood discharge, [Q],
for all the projects:
Survey work was carried out to determine the maximum flood discharge, [Q], which
occurred in the past years. This was achieved by finding:
i. The maximum area of flow across the khor, [A], and its wetted perimeter,
[P], at a point about 1,200m upstream of the existing control structure.
ii. The longitudinal slope of the khor.
Using Manning Formula to find Q:
Where:
Q = A.[R].[S]
N
A: area of maximum flow
P: wetted perimeter
R: hydraulic radius [A/P]
S: khor slope
N: manning coefficient, [1/N = 33 for sandy soil]
22
PRACTICAL ANSWERS
TO POVERTY