SETRIC, a Mathematical Model for Sediment Transport in Irrigation Canals - Sediment Transport in Irrigation Canals: A New Approach - page 171

- Final water flow (actual, normal and critical depth and modified bottom
level);
- Initial sediment concentration along the canal (actual and equilibrium);
- Final sediment concentration along the canal (actual and equilibrium);
- Initial and final bed levels along the canal;
- Local and accumulated deposition in the canal at the end of the
simulation.
6.2 DOWNSTREAM CONTROLLED IRRIGATION SYSTEMS
6.2.1 Background
Only a few sediment transport models for open channels can be applied to
irrigation canals. There are some commonly used models for steady and
unsteady state flow simulations in irrigation canals such as RootCanal
(Utah State University, 2006), SIC (Baume et al., 2005) and CanalMan
(Merkley, 1997), but only the SIC model, out of these three models, is
capable of modelling the sediment transport in irrigation canals.
Flow and sediment transport simulations in demand-based systems
consider automatic flow controllers as an integral part of the models.
Generally most mathematical models do not have an automatic flow
control module and the application of these models for automatically
controlled irrigation systems becomes difficult. Additionally, these sim-
ulations need fully dynamic models which can solve the Saint-Venant
equations, which takes a lot of time during simulations.
These factors together make simulation complicated and too diffi-
cult for designers and canal managers, particularly in canal automation.
A simple model which would be able to simulate flow and sediment
transport in supply and demand-based irrigation canals with fixed and
automatic flow operations would help designers and canal managers.
Therefore SETRIC has been further developed to cope with these problems
of flow and sediment transport simulations in demand-based irrigation
canals. The concept of this model was developed by Méndez (1998) with
the focus on sediment transport modelling in irrigation canals. Later,
Paudel (2002; 2010) developed and tested the model for supply-based
irrigation canals. Munir (2011) improved SETRIC with the incorporation
of a module for downstream controlled systems.
6.2.2 Downstream control considerations
The approach of the hydraulic aspects of the downstream controlled irriga-
tion systems is somehow different from the upstream controlled systems.
The hydraulic models developed for upstream control need some modifi-
cations to be applied for downstream control systems. In upstream control