The Lugeon Test: Methodology, Interpretation, and Applications in Geotechnical Engineering

Canal automation involves a combination of technical, managerial, and organizational upgrades to improve water use efficiency and distribution in irrigation systems. It replaces or reduces human decision-making and effort in regulating water systems.

The equipment used in canal automation typically includes:

• Control Systems

  • SCADA (Supervisory Control and Data Acquisition) software functions as a supervisory control interface and provides a data interface for automatic control. SCADA systems are centralized control systems that retrieve information from remote sites, process it for display, store data, and send control signals or new targets. Many commercial SCADA packages are available, such as iFix by GE Fanuc, Rubicon SCADAConnect, CITECT, ClearSCADA, Emerson Open Enterprise, ABB SCADA, and IGSS. They enable operators to monitor flows, water levels, gate positions, and component status, and remotely open or close control gates and other field devices like pumps.
  • Remote Terminal Units (RTUs) or Programmable Logic Controllers (PLCs) are electronic devices that accept analog or digital inputs, make logical decisions based on these inputs, and send control signals to external devices. In canal automation, they often reside at control gates and contain the algorithms for communicating with sensors and actuators. RTUs typically offer greater CPU processing power, programming flexibility, and broader communication support than PLCs, making them widely used in open canal automation for remote sites requiring local processing power. Examples include Automata "Mini" RTUs.
  • Microcontrollers like Arduino and Raspberry Pi can be used as controllers for constructing control systems in water irrigation canals. Arduino is an open-source framework based on an ATmega328 microcontroller board, known for its low cost, ease of use, quick prototyping, and energy efficiency, though it has limited memory and processing power. Raspberry Pi is also pivotal in managing and operating canal systems.
  • Accompanying Software Programs (e.g., SACMan) developed by entities like the U.S. Water Conservation Laboratory (USWCL), implement local control, central feedback control, and feedforward control functionality, and generate management information for the supervisory interface.
  • Irrigation Network Management System (INMIS) software can manage the entire canal network by automating office processes and providing single-click information about canal details, end-users, and beneficiaries. It integrates with SCADA for canal water regulation and revenue generation.

• Gates and Actuators

  • Canal gates are fundamental components that manipulate and regulate water movement in rivers, streams, and reservoirs, storing surplus water and ensuring safe passage around, over, or through a dam. Types include:
    • High pressure vertical lift gates.
    • Sluice gates.
    • Radial (or tainter) gates.
    • Floodgates (also called stop gates).
    • Movable weirs (e.g., Armtec overshot, Obermeyer, Rubicon FlumeGates, or Langemann gates). Rubicon FlumeGates are specifically mentioned as being almost always automated.
    • Hydraulic gates like AMIL, AVIS, AVIO, or MIXTE, which are designed for water level control without electricity, operating on balanced couples with floats and weights.
    • Flap gates, also working on balanced couples with counterweights.
  • Gate actuators are devices that physically move gates, converting control output into mechanical operation. Electric gate actuators are commonly used, with quality, reliability, and complexity varying among available types. They typically include a motor (DC, single, or 3-phase AC), gearbox, limit switches, over-torque protection, and a hand wheel for power failure.

• Sensors

  • Water level sensors are crucial. Primary technologies include:
    • Submerged pressure transducers.
    • Downward-looking, above-the-water ultrasonic sensors.
    • Bubblers with above-water transducers.
    • Floats with cables and linear potentiometers.
    • Downward-looking, above-the-water radar sensors.
  • Flow rate sensors.
  • Gate position sensors measure the mechanical position of a gate and provide a signal. Encoders are used for measuring rotation on shafts, such as for radial gates. Redundant sensors are highly recommended in automated structures.
  • Soil moisture sensors assess irrigation requirements and quantify moisture levels in the soil.
  • Rain sensors detect precipitation and can automatically deactivate irrigation systems to conserve water.
  • Other sensors measure water velocity, pressure, pump status (on/off), pump speed, and temperature.

• Communication Systems

  • Radios are a popular communication medium for SCADA operations in canal networks, especially in remote, sparsely populated areas due to their cost-effectiveness and reliability. This includes spread spectrum radios.
  • Wireless Ethernet radios provide high-speed operation, transmitting real-time images or video, and making information available to local networks in standard IP configurations.
  • Serial RS-232 interface using the Modbus protocol is also used for communication between SCADA and field hardware.
  • Optical fiber cable and VSAT (Very Small Aperture Terminal) are other communication mediums.
  • MQTT protocol is used for data transmission from Raspberry Pi to monitoring systems.
  • Hybrid wireless data communication networks combine various elements like a main SCADA center, data concentrator stations, and slave stations, essential for extensive canal networks.

• Power Supply

  • Solar-powered systems are commonly used for automated gates and other field components due to their minimal power requirements and suitability for remote locations.
  • Uninterruptible Power Supplies (UPS) and emergency backup generators are advisable for base unit equipment, especially in remote locations prone to power outages.
  • Gates can also be powered by DC or AC current.

• Other Components / Tools

  • Hydraulic simulation software like Sobek (by Delft Hydraulics) and MIKE11 (from Danish Hydraulics Institute) are used for evaluating canal automation methods, determining canal pool properties, and validating control methodologies. They can also serve as training tools.
  • CCTV cameras can be integrated into solar-powered automated gates for monitoring.
  • Information kiosks for farmers, used for disseminating irrigation schedules, weather forecasts, commodity prices, and other government information.
  • Computer systems for viewing soil dryness data and managing irrigation.

Overall, the equipment ranges from large physical structures like gates to sophisticated electronic and software systems for monitoring, control, and data management, often integrated to work seamlessly.