Worked Example 8.3
Design a Crump weir to be installed to measure the flow from a small
catchment. The cross-section of the river where the structure is to be built
is shown in Fig. 8.21, and existing current meter gaugings of the river flow
are tabulated below.
Staff gauge reading, h(m) Measured discharge, Q (m^3 s^1 )
0.12 0.75
0.15 1.10
0.19 1.21
0.26 1.80
0.32 2.30
0.42 4.36
1.04 15.40
The staff gauge reading is 0.00 when the flow depth in channel is
0.37 m (z). Additional data are as follows:
- The dry weather flow range is 0.5–1.0 m^3 s^1.
- The 20-year return flood is 25 m^3 s^1 and the 100-year return flood is
60 m^3 s^1.
- The river channel upstream of the proposed site lies in a flood plain
(used for cattle grazing).
354 RIVER ENGINEERING
Fig. 8.21 River cross-section
