Evaluation of Hydraulic Performance of Downstream‐controlled Maira‐phlc Irrigation Canals Under Crop‐based Irrigation Operations

Abstract

Demand-based irrigation systems are operated according to crop water requirements. As crop water requirements remain variable throughout the growing season, the discharges in the canal also vary to meet demands. The irrigation system under study is a demand-based semi-automatic irrigation system, where flows in the main canal are automatically controlled and secondary canals manually operated. The main canal headworks have been equipped with the SCADA system with proportional integral (PI) discharge controllers and the canal itself has been provided with self-regulating AVIS/AVIO downstream control gates for flow regulation in the canal. The secondary canals have manually operated sliding gates, which are opened or closed as per crop water requirements of the command area following a crop-based irrigations operation (CBIO) schedule under which they remain closed for one week after one or several weeks open, depending upon water needs. The flow in the main canal is then automatically adjusted according to the number of open or closed secondary offtakes. These operations result in fluctuating flows in the main canal and if not properly planned can cause serious implications for canal safety and its hydrodynamic performance. The PI discharge controllers regulate discharge releases to the canal in order to satisfy demands. The proper selection of PI coefficients ensures system safety and efficient water delivery. The operation of the secondary canals also plays a key role in defining the performance of the automatic operations. The planned opening and closure of a cluster of offtakes ensures safety of the self-regulating structures and stability of the flows in the main canal. In this paper various options have been tested using hydrodynamic modelling and we found some optimal values of PI coefficients and defined some rules for secondary canal operations to enhance the operational performance and sustainability of downstream-controlled irrigation canals. Copyright © 2011 John Wiley & Sons, Ltd. RÉSUMÉLes systèmes d'irrigation à la demande doivent être capables d'apporter l'eau au moment où la plante en a besoin. Comme les besoins en eau des cultures différent tout au long de la saison de croissance, le débit du canal doit varier pour s'adapter à la demande. Le système sous étude est équipé d'une régulation semi-automatique au sens où le canal principal est équipé d'un contrôle automatique et que les canaux secondaires sont actionnés manuellement. L'ouvrage de tête a été équipé de contrôleurs de débit proportionnels et intégraux (PI) de type SCADA et le contrôle aval est dédié à des vannes auto régulantes de type AVIS / AVIO. Les canaux secondaires sont équipés de modules à masque manoeuvrés selon le calendrier d'irrigation des cultures (CBIO) qui stipule que les modules doivent être fermés pendant une semaine après toute période d'irrigation, qui peut elle-même durer de une à plusieurs semaines après ajustée aux besoins en eau des cultures. Le flux dans le canal principal est alors automatiquement ajusté en...

Modeling and control in open-channel irrigation systems: A review

“…] ⊤ ∈ ℝ is considered as a desired level vector, and ̄ is the mean of because excessive gates and flows changes produce mechanical wear and water levels oscillations, to reduce excessive gates and flows changes is desired. The key performance indicators can be used as a measure of performance for controlled systems (e.g., Xu et al 2012;Munir et al 2012;Soler et al 2013a;Bonet et al 2017;Ke et al 2018;Zheng et al 2019), and as a design criteria in optimal controllers (e.g., Feliu-Batlle et al 2011;Ke et al 2018). A relation of the principal key performance indicators is presented in Table 3, where: i) the maximum absolute error (MAE) is the maximum normalized error between the desired and measured level; ii) the integral of the absolute error (IAE) accounts for the cumulative level error along a time period ( ); iii) the steady-state error (StE) is the maximum absolute level error during a time period when the steady state has been reached; iv) the integral square error (ISE) also accounts for the cumulative level error and weights large deviations; v) the absolute gate movement (IAW) relates to positions changes of the regulation structures; and vi) the integrated absolute discharge change (IAQ) accounts for flow variations.…”

“…Finite Differences Lemos et al 2009, Feng and Wang 2011, Shang et al 2011, Soler et al 2013a, Breckpot et al 2013, Soler et al 2013b, Bonet et al 2017, Cen et al 2017ID Ke et al 2018black-box Model Litrico et al 2007, Begovich et al 2007, Feliu-Batlle et al 2009a, Feliu-Batlle et al 2009b, Lozano et al 2010, Feliu-Batlle et al 2011, Munir et al 2012gray-Box Model Cantoni et al 2007, Domingues et al 2011, Herrera et al 2013, Bolea et al 2014b, Sadowska et al 2015a, (Horváth et al, 2015a)…”

The multi-point hydraulic control method for advanced controller design of the open canal irrigation systems

“…The number of offtakes located downstream of the main canal only accounts for 15%, which is recruited from field visits. Other cases are widespread (Georges 1994;Wahlin & Clemmens 2006;Munir et al 2012;Hong et al 2014;Shah et al 2016). Consequently, the conventional control method for a single point, like the distant downstream water level control, may be inappropriate for many real irrigation canals.…”