SETRIC, a Mathematical Model for Sediment Transport in Irrigation Canals - Sediment Transport in Irrigation Canals: A New Approach - page 176

depending on the selected option. The program encompasses the

following tables:
- Hydraulic results: results related to the water flow: the initial and final
water flow, including critical, normal and actual water depth, discharge
and de Chézy coefficient;
- Concentrations: table for the initial and final sediment transport results
with the water depth, equilibrium concentration and actual concentra-
tion, initial bed level and modified bed level and deposition volume per
length step for the entire canal.

The program includes the following figures for the main canal and
separately for the laterals:
- Initial water flow;
- Final water flow;
- Initial sediment concentration;
- Final sediment concentration;
- Initial and final bed level;
- Accumulated sediment deposition.

6.3 CONCLUSIONS

The mathematical model will predict the water flow and sediment trans-
port together with the variation in bottom level of the canal and is based
on an uncoupled solution of the water flow and sediment transport equa-
tions. The model can be used for simulating the sediment entrainment
in an irrigation network under changing flow conditions and sediment
characteristics during the whole irrigation season and over one or more
years. The model can be used for evaluating the effects of the interrela-
tion between irrigation practice (operation and maintenance) and sediment
deposition. The direct effect of irrigation practices on the sediment depo-
sition or erosion of earlier deposited sediment may include changes in
discharge, changes in sediment load, flow control structures, controlled
entrainment, operation and maintenance activities, diverted sediment
load to the farmlands, etc. Sediment deposition in the canal reaches
may affect the following hydraulic aspects, such as water level varia-
tion (overtopping of canals), water distribution at outlets and flow control
structures.
The theoretical background and assumptions made in the model has
been comprehensively analysed by Paudel (2010) for upstream con-
trolled systems and confirmed by Munir (2011) for downstream controlled
irrigation systems. The main conclusions can be summarized as follows:
- comparison of SETRIC results with other existing flow and sedi-
ment transport models, namely DUFLOW (IHE, 1998; Clemmens
et al., 1993) for the hydraulic computations and with the SOBEK