Xylem SonTek FlowTracker2, User Manual

Page: 76 / 308

SonTek – a Xylem brand
FlowTracker2 User’s Manual (January 2019)
75
The application of the Japanese equation within a measurement section that is greater
than 10m is graphically shown in
Figure 5:4 .
Figure 5:4 - Japanese Method >10m
There are few special cases to consider when applying the Japanese method in
calculating of total discharge.
a) Edges
i). Edge can be either the Left Bank or Right Bank,
ii). Edge calculations are handled exactly the same from stations in open water
with reference to the first component of Equation 5:3,
iii). Correction factor (CF) is NOT applied in Japanese method to scale the mean
velocity at the edges from the adjacent station,
b) Islands (multiple channels)
i). If a river is split into multiple channels, any internal island(s) must be
accounted for in the discharge calculation,
ii). The stations at each edge of the island(s) are treated as an Island Edge,
iii). Island edge calculations are handled the same as
75 with reference to the first
component of Equation 5:3,
iv). Correction factor (CF) is NOT applied in Japanese method to scale the mean
velocity at the edges from the adjacent station,
Determining Mean Station Velocity 5.1.3
The Mean Station Velocity or Mean Velocity in a Vertical determines how mean
velocity is determined at each station. The measurement techniques used involves
variations in the number of point velocity measurements taken at a range of