Japanese Equation - Xylem SonTek FlowTracker2 User Manual

There are few special cases to consider when applying the Mean-Section 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
iii). Correction factor (CF) is NOT applied in Mean-Section method to scale the
mean velocity at the edges from the adjacent station,
iv). The discharge on the edges can be determined by applying
the assumption that the velocity at the edges is zero.
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
component of
iv). Correction factor (CF) is NOT applied in Mean-Section method to scale the
mean velocity at the edges from the adjacent station,
v). The discharge on the edges can be determined by applying
the assumption that the velocity at the edges is zero.
5.1.2.3

Japanese Equation

The Japanese method is similar to both the Mean-Section and Mid-Section methods in
some respects with its own unique measuring technique. The most significant feature of
FlowTracker2 User's Manual (January 2019)
Figure 5:3 - Mean-Section Method
Equation 5:2,
73
SonTek – a Xylem brand
Equation 5:2,
73 with reference to the first
Equation 5:2 on
Equation 5:2 on