Finding Potential Sites for Small-Scale Hydro Power in Uganda: a ...

A = ( b ⋅ h)2(4.3)Where A equals the cross-sectional area and b is the width of the stream and h is thedepth of the stream.Figure 4.12 Charting the cross-sectional area of a stream.Source: Fraenkel et al., 1991To estimate the flow velocity, a series of floats, e.g. convenient pieces of wood, weretimed over a measured length of stream. The results were averaged and a flow velocitywas obtained. The velocity must then be reduced by a correction factor, which estimatesthe mean velocity as opposed to the surface velocity. Approximate correction factors toconvert surface velocity to mean velocity are according to Fraenkel et al. (1991):Concrete channel, rectangular, smooth 0.852Large slow clear stream (>10 m ) 0.75Small slow clear stream (