Dams play a crucial role in providing water, energy, and flood control to communities across the world. However, the safety and stability of these structures are essential to ensure their continued operation and to prevent potential disasters. This is where dam monitoring and control come into play. In this blog, we will discuss the importance of dam monitoring and control, the key factors that are monitored, and the major instrumentation and control systems used in dams. Whether you are an engineer, a student, or just interested in dams and their operation, this blog will provide you with a comprehensive overview of the topic.
In dam monitoring, various factors are monitored to ensure the safety and stability of the dam. Some of the key factors that are typically supervised include:
- Reservoir water level and storage: The water level in the reservoir and the storage capacity are important indicators of the dam's performance and the potential for overtopping or other issues.
- Seepage and infiltration: The monitoring of seepage and infiltration helps to detect any changes in the water balance in the dam and to identify potential issues with the dam's integrity.
- Deformation and displacement: The monitoring of deformation and displacement of the dam and its foundations is important for detecting any changes in the stability of the dam, such as settling, cracking, or slipping.
- Stress and strain: The monitoring of stress and strain in the dam and its foundations helps to detect any changes in the structural integrity of the dam, such as overloading or excessive stress.
- Weather and seismic activity: The monitoring of weather conditions, such as rainfall, snowmelt, and earthquakes, helps to identify any potential threats to the dam and its stability.
- SCADA systems: SCADA (Supervisory Control and Data Acquisition) systems are used to collect, process, and display data from the various sensors and control systems in the dam, and to provide real-time monitoring and control of the dam's operation.
- These are some of the key factors that are monitored in dam monitoring, but the specific factors that are monitored can vary depending on the size, type, and location of the dam, as well as its specific design and operational requirements.
Monitoring of Reservoir Water Level and Storage in Dams
The reservoir water level and storage of a dam are monitored using a combination of physical and instrument-based methods. Some of the common methods include:
1. Direct Measurement: The water level in the reservoir can be directly measured using a staff gauge or other physical measurement device. This method provides a direct and accurate reading of the water level, but it is limited in its ability to continuously monitor the water level over time.
| Automatic Water Level Recorder: EWLR-101 |
2. Remote Sensing: Remote sensing methods, such as radar and laser-based systems, can be used to measure the water level from a distance. This method is useful for continuous monitoring of the water level and for monitoring of large reservoirs.
3. Pressure Transducers: Pressure transducers can be installed in the dam or in the reservoir to measure the water level and pressure. This method provides a continuous and accurate reading.
| Load Cell for Dams: ELC-30S |
Monitoring of Seepage and Infiltration in Dams
Seepage and infiltration in a dam are monitored to ensure the safety and stability of the dam and to prevent water loss or damage to the dam's structure. The monitoring of seepage and infiltration can be done using various methods, including:
1. Piezometers: Piezometers are installed in the dam to monitor pore pressure or seepage of water through the cross-section of the dam. This method provides continuous and accurate reading. It requires the installation of sensors in the dam body at different elevations. Also in the dam foundation drilling holes.
| Piezometers for Dams: EPP 30V, EPP 40V, EPU 20V (uplift) |
2. Groundwater Wells: Groundwater wells can be installed around the dam to monitor the groundwater level and flow. This method provides information about the water balance in the area and can help to identify changes in the seepage and infiltration over time.
3. Seepage Meters: Seepage meters are devices that are installed in the dam to measure the seepage flow through the dam or its foundation. This method provides direct and continuous measurements of the seepage, it requires the installation of sensors in the downstream side of the dam.
| Seepage System for Dams: ESM 12S |
Monitoring of Deformation and Displacement in Dams
Deformation and displacement in a dam are monitored to ensure its safety and stability and to detect any changes in the dam's structure over time. The monitoring of deformation and displacement can be done using various methods, including:
1. Surveys: Surveys can be performed using conventional survey equipment, such as total stations and level instruments, to measure the elevation and position of points on the dam. This method provides direct measurements of the deformation and displacement, but it is limited in its ability to continuously monitor the dam.
2. Extensometers: Extensometers are devices that are installed in the dam or its foundation to measure the deformation and displacement. This method provides continuous and direct measurements of the deformation and displacement, it requires the installation of sensors in the dam foundation with the top assembly in a cross or transverse gallery.
| Extensometer for Dams: EDS-70V |
3. Inclinometers: Inclinometers are devices that are installed in the dam or its foundation to monitor the lateral movement of the foundation of the dam. This method provides continuous and direct measurements of the deformation and displacement, it requires the installation of sensors across the dam body; from the base of the dam to the top.
| Inclinometer for Dams: EAN-52, EAN-56 |
4. Crack Meters: Crack meters are devices that are installed in the dam or its foundation to measure the opening and closing of cracks in the dam. This method provides direct measurements of the deformation and displacement.
5. Strain Gauges: Strain gauges are devices that are installed in the dam or its foundation to measure the strain in the dam. This method provides direct and continuous measurements of the strain, it requires the installation of sensors in the concrete face of the dam.
| Strain gauges for Dams: EDS-11V |
6. Remote Sensing: Remote sensing methods, such as satellite imagery and InSAR, can be used to monitor the deformation and displacement of the dam and its surroundings. This method provides comprehensive and continuous monitoring of the deformation and displacement, but it can be limited by environmental conditions and the availability of data.
These are some of the methods that are used to monitor deformation and displacement in a dam, but the specific methods used can vary depending on the size, type, and location of the dam, as well as its specific design and operational requirements.
Monitoring of Weather and Seismic Activity in Dams
Weather and seismic activity in a dam are monitored to ensure its safety and stability and to detect any changes in the dam's environment that may affect its performance. The monitoring of weather and seismic activity can be done using various methods, including:
1. Weather Stations: Weather stations can be installed near the dam to measure the local weather conditions, including temperature, precipitation, wind speed, and humidity. This method provides direct and continuous measurements of the weather conditions.
2. Seismographs: Seismographs can be installed near the dam to measure the seismic activity in the area. This method provides direct and continuous measurements of the seismic activity.
| Seismometers for Dams: ESDA-120S | | Accelerographs for Dams: EADA-350F |
3. Remote Sensing: Remote sensing methods, such as satellite imagery, can be used to monitor the weather conditions and meteorological patterns in the area around the dam. This method provides comprehensive and continuous monitoring of the weather conditions, but it can be limited by environmental conditions and the availability of data.
Read more: Instrumentation & Structural Monitoring of Dams
Early Warning Systems
Early warning systems can be installed near the dam to detect and alert to any potential seismic activity or weather events that may affect the dam. This method provides timely warnings of potential hazards, but it may not provide direct measurements of the seismic activity or weather conditions.
These are some of the methods that are used to monitor weather and seismic activity in a dam, but the specific methods used can vary depending on the size, type, and location of the dam, as well as its specific design and operational requirements.
Conclusion
To summarize, the monitoring and control of a dam is critical to ensure its safety, stability, and performance. Various factors are monitored in a dam, including water level and storage, seepage, and infiltration, deformation and displacement, and weather and seismic activity. The monitoring of these factors can be done using various instrumentation and control systems, including level sensors, flow meters, pressure sensors, deformation sensors, seismic sensors, weather sensors, and SCADA systems. The specific systems and methods used for monitoring and controlling a dam can vary depending on the size, type, and location of the dam, as well as its specific design and operational requirements.