Hydraulic Structures: Fourth Edition

8.4.5 Sediment transport The sediment concentration in rivers varies enormously with time and between continents, countries, and ...

the range of field conditions in which they are to be used (Novak, 1957; Hubbellet al., 1981). 8.4.6 Water quality The quality o ...

sediment-laden streams, as deposition may take place upstream of the weir, thus changing the approach conditions of the flow. Fl ...

Table 8.1 Types of weirType Shape K n Remarks Sharp-crested weir Rectangular (Fig. 8.6(a)) 2/3 Cd C (2v g) 1/2 b 3/2 b effective ...

Inreservoir flood routingonly the storage effects are considered, as the influence of impulsive motion of the inflow on the mome ...

channel geometry. For further details see for example Price (1985) and Raudkivi (1979). The hydrologic method (kinematic soluti ...

with c 0  , c 1  , c 2  (c 0 c 1 c 2 1). In the original Muskingum method Kandx(which are assumed to be constant for a gi ...

and the processes involved. The return period of this discharge may range from 1 to 100 years and in very special cases (large s ...

environmental constraints. In the upstream reaches the main problem is the short-term and seasonal variation of flow, high veloc ...

force of the stream. The change of slope may require narrowing (for increasing slope) or widening of the river which, if left to ...

Fig. 8.10 Increase of sediment run-off due to channel contraction Fig. 8.11 High, mean and low water training Fig. 8.12 River ju ...

8.7.2 Groynes, dykes, vanes, and sills Groynesare small jetties, solid or permeable, constructed of timber, sheet piling, vegeta ...

some groynes with short longitudinal dykes to protect the head against erosion and aid sediment deposition between the groynes; ...

RIVER IMPROVEMENT 349 their location are best determined by model studies or experiments in situ. Deflectors rely in their actio ...

350 RIVER ENGINEERING Fig. 8.16 River training with groynes and training wall Fig. 8.17 Use of deflectors for bank protection 8. ...

are withstood without damage and geotextiles placed between the soil and riprap are cheaper and give greater control during cons ...

Fig. 8.18 Bank protection with fascines and brush rollers filled with stones Fig. 8.19 Bank protection with gabions; dimensions ...

Worked Example 8.1 A wide open channel has a depth of flow 1.7 m and mean velocity 2.5 m s^1. Taking (^) s2650 kg m^3 , find th ...

Worked Example 8.3 Design a Crump weir to be installed to measure the flow from a small catchment. The cross-section of the rive ...

Solution Figure 8.22 shows the details of a Crump weir profile. Figure 8.23 shows a typical layout of the design flow chart base ...