Construction Plan for Safety Monitoring and Management System of Large and Medium sized Water Gates

Background Introduction
At present, China has built 100321 water gates with a flow rate of 5m ³/s or above, including 923 large water gates and 6697 medium-sized water gates; According to the types of water gates, there are 8193 flood diversion gates, 17808 discharge (retreat) gates, 4955 tide blocking gates, 13796 diversion gates, and 55569 control gates, which have enormous economic and social benefits in flood control and disaster reduction, optimization of water resource allocation, and improvement of ecological environment.

However, due to the limitations of economic, social, and technological conditions during the construction period, water gates in China generally have problems such as low standards, poor quality, and incomplete supporting facilities. Influenced by the idea of "rebuilding light management", most water gates lack effective management and maintenance after completion. After long-term operation, there are currently many safety hazards and prominent risks to safe operation.

Safety monitoring is an important means to timely grasp the operational status of water gate projects, analyze abnormal situations, and ensure the safety of project operation. In order to comprehensively grasp the safety monitoring work of large and medium-sized water gates nationwide, the Operations Management Department of the Ministry of Water Resources issued a letter on April 29, 2022, titled "Investigation on the Safety Monitoring of Large and Medium sized Water Gates Nationwide" (Yunguan Han [2022] No. 3), requiring provincial water administrative departments and basin management agencies to supervise and guide their large and medium-sized water gate management units to carefully fill out the safety monitoring survey form for large and medium-sized water gates according to the actual situation. On November 12, 2024, a notice was issued by the Operations Management Department of the Ministry of Water Resources on the preparation of implementation plans for safety monitoring of important embankments and large and medium-sized water gates during the 15th Five Year Plan period (Yunguan Han [2024] No. 22), requiring provincial water administrative departments and basin management agencies to prepare safety monitoring implementation plans for large and medium-sized water gates during the 15th Five Year Plan period.

Regarding the current situation and existing problems of safety monitoring for large and medium-sized water gates in China, many water gate safety monitoring systems lack advanced technology and mainly rely on manual observation, with low automation levels, and urgently need to be upgraded and renovated.

System Introduction
The water gate safety monitoring and management system combines the "Water Gate Operation Management Measures", "Guiding Opinions on Promoting Standardized Management of Water Conservancy Projects", and "Technical Specifications for Water Gate Safety Monitoring" to standardize the design and construction of safety monitoring systems, management and protection of safety monitoring facilities, and the compilation and analysis of safety monitoring and monitoring data.

In recent years, safety monitoring technology has continued to advance, and monitoring facilities such as distributed, non-contact, automated, and networked have gradually matured. Technological means such as big data, the Internet of Things, robots, satellite remote sensing, and intelligence can achieve all-weather and large-scale monitoring in complex environments. The water gate safety monitoring and management system will actively utilize new technologies and means to comprehensively improve the modernization level of water gate operation and management, promote high-quality development of water conservancy, and ensure national water security.

The safety monitoring, analysis and early warning system includes automated information monitoring system, intelligent inspection system, monitoring data analysis and early warning system, etc.

System topology diagram

perception layer

The perception layer includes all water situation information, engineering information, on-site videos, etc. inside the water gate, using all-round perception technology: water level gauge, flow meter GNSS、 Automated video monitoring equipment and other sensor technologies enable precise perception and real-time collection of relevant information such as engineering conditions, water conditions, and environmental observations across the entire region. By collecting real-time information, provide analysis and decision-making basis for the water gate safety monitoring and management system.

Transport layer

The transport layer includes the local area network where the users of each level of the system are located and the wide area network that interconnects the local area networks of each level. It is a platform for transmitting various business information and a carrier of system data, providing a reliable and secure transmission channel for collecting information, video images, and other types of information.

The monitoring management center can remotely monitor the on-site monitoring equipment. The on-site equipment communicates with the computer of the higher-level management department through flexible networking methods such as 5G/4G networks and wired networks to achieve remote monitoring.

Front end wireless RTUs, multifunctional data acquisition devices, etc. are based on mobile communication networks, Ethernet communication networks, etc., and together with data center interface equipment, provide encrypted hydrological and water resources protocol data transmission channels to form a user specific data network.

management

The data management layer is the hub for system information aggregation and distribution, as well as the core area for data storage and management. The data management content includes self built databases for water gate monitoring, video surveillance, automated business management, data analysis, etc. based on spatial data frameworks.

application layer

The application layer is the core of the system's implementation of "platform intelligence, flat management, and pre service". This layer comprehensively manages and analyzes water gate monitoring data, and provides standard service interfaces to provide functionality and service sharing for the rapid construction of business application systems.

Construction Implementation Plan
According to relevant technical standards and document requirements, gradually establish and improve facilities such as environmental quantity, deformation, seepage, stress-strain and temperature, special monitoring, and automation systems for existing large and medium-sized water gates; Strengthen the risk warning of gate opening and closing, promote the application of advanced technologies such as satellite remote sensing, GNSS (Beidou), unmanned aerial vehicles, etc., comprehensively consider daily and emergency monitoring needs, strengthen cross validation and linkage analysis of various monitoring data, improve the dynamic sensing level of all elements and all-weather three-dimensional coordination of water gates, build an integrated monitoring and perception network of "sky ground water engineering", and comprehensively enhance the safety monitoring and perception capabilities of water gates; Support the improvement of the water gate model library and knowledge base in the digital twin water conservancy platform, support the construction of digital twin water gates, and achieve the "four pre projects" of water conservancy business.

Environmental monitoring:
It mainly includes monitoring of water level before and after the gate, monitoring of flow through the gate, monitoring of rainfall, meteorological monitoring, etc.

Monitoring the environmental parameters of water gates is a key link in the safety management of water gates. By setting up observation points for precipitation and meteorological elements around the sluice site, and setting up water level and flow measurement points upstream and downstream of the sluice, suitable sensors are selected based on the on-site environment to obtain real-time meteorological information, water level data, and water flow conditions, providing important support for the scientific scheduling and safe operation of the sluice.

1.1 Water level monitoring

Use radar water level gauge. Real time understanding of water level changes, timely hydrological forecasting and scheduling management.

Radar water level gauge is a fully automatic water level gauge based on millimeter wave radar technology, which uses the ranging function of high-frequency pulse or frequency modulated continuous wave (FMCW) radar to achieve water level measurement. When it works, the water level probe emits high-frequency pulses or continuous waves downwards. When the pulses or continuous waves encounter the water surface, they will be reflected and then received by the probe. There is a time difference between the emission and reception of electromagnetic waves. Using this small time difference and the transmission speed of the wave (light speed C), the distance H2 from the probe to the target (water surface) can be calculated. Then, the water level h can be obtained by subtracting the distance H2 from the range H1.

1.2 Monitoring of Overpass Flow

Radar flowmeter can be used. Radar flowmeter is a fully automatic flowmeter based on millimeter wave radar technology. The radar flowmeter first uses the ranging function of frequency modulated continuous wave (FMCW) radar to measure water level. When it works, the water level probe emits a high-frequency continuous wave downwards. The continuous wave will be reflected when it encounters the water surface and then received by the probe. The frequency of the received echo is the same as that of the emitted frequency, both of which follow the triangular wave pattern, except for a time difference. By using this small time difference and the transmission speed of the wave (light speed C), the distance D from the probe to the target (water surface) can be calculated, and then the water level can be obtained by subtracting the distance D from the measurement range.

At the same time, the radar velocity probe generates electromagnetic waves towards the water surface. When the electromagnetic waves encounter the moving water surface, they scatter and form echoes. Due to the frequency deviation of the received echoes relative to the transmission frequency, the water surface velocity can be obtained from the Doppler frequency equation.

The radar flowmeter host then uses the built-in "water level - cross-sectional area algorithm" and "relationship algorithm between surface velocity and laminar velocity" to obtain the cross-sectional area and discharge flow rate. By calculating the relationship between water level and cross-sectional area, as well as surface velocity and laminar velocity, the cross-sectional area and flow rate can be determined.

1.3 Rainfall Monitoring

Adopting a tipping bucket rain gauge. When the rain gauge is in operation, the rainwater collected at the water inlet is filtered through the upper funnel and injected into the metering tipping bucket. The tipping bucket is a mechanical bistable structure, and when one compartment receives water, the other compartment is in a waiting state. When the received rainwater volume reaches the predetermined value, due to gravity, it flips over and is in a waiting state, while the other chamber is in the working state of receiving rainwater. When its water intake reaches the predetermined value, it flips over on its own and is in a waiting state. There is a permanent magnet installed on the side wall of the tipping bucket, which sweeps past the dry reed switch when the tipping bucket flips, causing the dry reed switch to switch on and off alternately. The dry reed switch sends an on-off signal (pulse signal) every time the tipping bucket flips over.

In this way, the number of flips of the tipping bucket is counted by scanning the dry reed switch with magnetic steel and sending out pulse signals. Each recorded pulse signal represents precipitation at a depth of 0.5 or 0.2 millimeters, achieving the purpose of precipitation telemetry.

1.4 Meteorological Monitoring

Adopting an integrated louver box and wind speed and direction sensor. Monitoring the temperature and other meteorological information of the gate and its surrounding environment has a warning effect on situations such as gate freezing and equipment failure.

The device can be widely used for environmental detection, integrating noise collection, PM2.5 and PM10, temperature and humidity, atmospheric pressure, and lighting. It is installed in a louver box and adopts the standard MODBUS-RTU communication protocol with RS485 signal output. The communication distance can reach up to 2000 meters (measured). This transmitter is widely used in various situations that require measurement of environmental temperature and humidity, noise, air quality, atmospheric pressure, lighting, etc. It is safe, reliable, aesthetically pleasing, easy to install, and durable.

The wind direction transmitter is compact and lightweight in appearance, easy to carry and assemble, and can effectively obtain wind direction and speed information. The housing is made of polycarbonate composite material, which has good anti-corrosion and erosion resistance characteristics, ensuring that the transmitter will not deform during long-term use. At the same time, it is matched with an internal smooth bearing system to ensure accurate information collection.

Deformation monitoring:
Deformation monitoring adopts a combination of manual and GNSS automated observation methods.

Artificial displacement observation is achieved by constructing deformation monitoring points and using monitoring equipment such as theodolites and total stations to monitor the deformation of the dam.

The GNSS system mainly includes the Global Positioning System (GPS) of the United States and the GLONASS satellite navigation system of Russia

(GLONASS)、 China's Beidou Satellite Navigation System (BDS) and the European Union's Galileo Satellite Navigation System (GALILEO), among others. GNSS technology has the advantages of real-time, continuity, global, automation, and all-weather. It has been successfully applied in monitoring the deformation of highways, bridges, super high-rise buildings, railways, water gates, and water conservancy slopes. It has also played an important role in monitoring and early warning of ground subsidence, expansive soil slopes, landslides, geological disasters, and other hazards.

By continuously observing GNSS monitoring stations, the position information of each monitoring point at different times can be obtained; Then, high-precision computing technology is used to process the position information using software, removing various environmental impact error factors, and comparing them with the initial results to obtain displacement information of each monitoring point at different times; Finally, the monitoring results will be displayed on the system monitoring platform for on-site personnel to have real-time understanding of the structural condition.

Seepage monitoring:
Mainly including uplift pressure monitoring, gate pier seepage monitoring, bypass seepage monitoring, etc.

The permeability of the bedrock in water gate engineering will change due to the presence of structural cracks, and the resulting uplift pressure will increase the sliding force of the gate foundation, increasing the probability of damage to the gate foundation. Therefore, monitoring the uplift pressure and analyzing the changes in seepage characteristics are very important.

At the same time, gates with high water head and gates with good soil permeability on both sides will produce lateral seepage. Lateral seepage exerts lateral horizontal water pressure on the bank wall and wing wall, affecting their stability; There may be seepage damage at the outlet of seepage, as well as at the junction between the fill and the shore wall or wing wall. Therefore, lateral seepage is also a key focus of water gate seepage monitoring.

The seepage situation of the water gate structure can be monitored by installing pressure measuring pipes at appropriate positions such as piers and slope protection, and placing pressure gauges, uplift pressure gauges, etc. When the monitoring value exceeds the set threshold, the system automatically alarms to ensure the stability of the water gate structure, timely detect potential safety hazards, and provide solid guarantees for the safe operation of the water gate.

Stress and strain monitoring:
By installing vibrating wire surface strain gauges on the surface of hydraulic structures or other structures, the strain on the surface of the structure can be measured, and the temperature at the installation points can be synchronously measured.

The vibrating wire surface strain gauge has a small elastic modulus, good tracking performance with the measured structure, and will not interfere with the original stress field during measurement. It has an inclusive design, all stainless steel structure, simple installation, reliable use, and can be recycled and reused.           

When the tested structure undergoes deformation, it will drive the surface strain gauge to deform, and the deformation will be transmitted to the vibrating wire through the front and rear end seats to transform into changes in the vibrating wire stress, thereby changing the vibration frequency of the vibrating wire. The electromagnetic coil excites the vibrating string and measures its vibration frequency. The frequency signal is transmitted to the reading device through the cable to measure the strain of the structure. Synchronously measure the temperature values of the buried points.

Crack and structural joint monitoring:
Under the combined effects of internal and external temperature differences, concrete shrinkage, external constraints, and uneven settlement of the foundation, cracks may occur in the concrete of the gate pier, which greatly affects the durability of the structure and often becomes a cause of structural damage.

By installing crack gauges on the cracks, the existing cracks on the gate pier can be monitored, and the changing patterns of the cracks can be analyzed to ensure the stability and integrity of the water gate structure and ensure its safe operation.

When the measured structure undergoes displacement, it will drive the measuring rod of the surface joint meter to expand and contract, and transmit it to the vibrating wire through the universal joint to transform it into a change in vibrating wire stress, thereby changing the vibration frequency of the vibrating wire. The electromagnetic coil excites the vibrating string and measures its vibration frequency. The frequency signal is transmitted to the reading device through the cable, which can measure the displacement of the measured structure and simultaneously measure the temperature value of the buried point.

Gate and hoist status monitoring:
Mainly includes gate opening, voltage and current monitoring of the hoist, etc

Gate opening monitoring:

By monitoring the opening of the gate in real-time, abnormal situations and safety hazards such as jamming and deformation during gate operation can be detected in a timely manner, and corresponding maintenance measures can be taken to ensure the safe operation of the gate.

In extreme weather or water level changes, gate opening monitoring can help engineers quickly adjust the gate opening to adapt to environmental changes and reduce equipment damage or safety accidents caused by improper operation. ‌

At the same time, it can reduce the frequency of manual inspections, lower labor costs, and through data analysis, potential problems can be identified in advance, reducing downtime and improving overall work efficiency.

By installing appropriate gate sensors to monitor the opening of the gate in real-time, the sensors convert the gate opening information into electrical signals and transmit them to the control center for processing and analysis.

Monitoring of voltage and current of the switchgear:

Monitoring the voltage and current changes of the gate motor can determine the working and operating status of the motor.

Voltage is the foundation for the normal operation of equipment, and high or low voltage can affect the operation of the equipment. High voltage may cause equipment to burn out, while low voltage may result in slow operation, low efficiency, or even inability to start the equipment. By monitoring the voltage, voltage fluctuations or abnormalities can be detected in a timely manner, and corresponding measures can be taken to avoid equipment damage caused by voltage problems and extend the service life of the equipment.

Current is an important parameter that reflects the load situation of equipment. By monitoring the current, it is possible to determine whether the equipment is operating under normal load, avoiding problems such as overheating and damage caused by excessive or unbalanced load. Excessive current or three-phase imbalance may indicate internal faults in the equipment, such as bearing oil shortage, rotor sweeping, etc. Timely monitoring of the current can help prevent these faults and reduce equipment downtime.

Through the intelligent monitoring system, the voltage and current of the gate opening and closing machine can be monitored in real time to ensure that the equipment operates within the normal working range. When abnormal voltage or current is detected, the system will automatically sound an alarm and notify management personnel through computers, mobile apps, and other means to ensure timely resolution of issues.

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Video AI monitoring:
The video surveillance system can monitor key areas of the gate station in real time, such as access channels, operation rooms, etc., to ensure the safety of personnel and equipment. Through high-definition cameras and intelligent recognition technology, the system can automatically identify abnormal behavior, issue warning signals in a timely manner, and prevent potential safety hazards.

The video surveillance system can monitor the gate station 24/7 and in all directions, reducing the need for manual patrols and lowering labor costs. Management personnel can monitor on-site dynamics in real-time through the monitoring center, promptly identify and address issues, and improve management efficiency.

The images and video data recorded by the video surveillance system can serve as important basis to help management personnel analyze the operation of the gate station, optimize scheduling plans, and improve resource utilization efficiency. The system can also automatically generate various work reports, providing comprehensive data support for the management department.

Meanwhile, video surveillance systems have a deterrent effect and can effectively reduce the occurrence of criminal activities such as theft and robbery. By recording the real-time dynamics of the scene through a video system, it provides a basis for the investigation of the case and is used for evidence collection after work.

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Automated drone patrol:
The unmanned aerial vehicle autonomous inspection system can include end perception devices such as unmanned aerial vehicles, dual light pan tilt cameras, remote speakers, and large automatic machine nests, as well as network infrastructure such as high-precision centimeter level positioning services.

A flight control platform can be designed within the system, consisting of modules such as airport overview, task planning, route planning, equipment management, alarm management, and system management. It is equipped with various artificial intelligence algorithms such as floating object recognition and fishing recognition, which can quickly identify water level changes and potential problems with the dam.

The unmanned aerial vehicle autonomous inspection system is a perfect supplement to the "air" monitoring and perception system of the "sky ground water engineering" integrated monitoring and perception system in water conservancy engineering. It realizes the control and automatic inspection of equipment such as machine nests and unmanned aerial vehicles under unmanned operation, and meets the fully automatic and uninterrupted inspection needs of hydraulic structures and landslides. When an emergency situation occurs, the system displays real-time footage from the drone through the guidance flight function, and obtains on-site information in a timely manner. The system can also collect inspection data and high-definition images of hydraulic structures and landslides from multiple times, angles, and directions, and form a database.

Platform Introduction
The basic version of the sluice safety monitoring and management system mainly includes functions such as basic information management, sluice operation management, sluice geographic analysis, sluice operation analysis, sluice safety management, sluice maintenance management, and image monitoring.

The system integrates automatic control image monitoring of gates, automatic collection, transmission, query, and decision-making of water information, realizing automatic control of gates, reducing the labor intensity of staff, and assisting management personnel in supervision and scheduling.

The intelligent water gate 3D visualization management platform is based on advanced digital twin technology. Through digital twin technology and advanced data processing algorithms, the platform can achieve comprehensive monitoring, maintenance, and management of water gates. Users can obtain real-time operation status and environmental data of the water gate through the platform, as well as perform remote control, which improves the flood prevention capability and response speed of the water gate facilities.

The digital twin sluice project refers to the use of advanced digital technology to digitize real-time environmental data such as the physical structure, water flow dynamics, and water quality of the sluice, and construct a virtual model corresponding to the real sluice. Using this virtual model, it is possible to simulate the operation of water gates, predict water flow, detect faults, and manage maintenance. The digital twin sluice project has the following characteristics:

1. Real time dynamic monitoring: Through sensors and monitoring devices, real-time data on the operation status, water level changes, water flow velocity, etc. of the water gate are obtained, and these data are digitized and updated in real-time into the virtual model.

2. Intelligent operation simulation: Through virtual models, various operating conditions of water gates can be simulated and predicted, and advanced simulation technology and algorithms can be used to provide intelligent decision support for the operation and management of water gates.

3. Fault detection and maintenance management: Through virtual models, it is possible to perform fault detection and maintenance management on water gates, detect and solve problems in advance, and ensure the normal operation of water gates.

4. Data sharing and collaborative work: Virtual models can achieve data sharing and collaborative work through cloud computing platforms, and multiple departments can jointly use virtual models for water gate management and operation.

5. Security management: Monitor the surrounding area of the water gate 24/7 through video surveillance cameras, and transmit the video stream to the backend for processing and storage. Users can view real-time video surveillance footage through the platform and take corresponding security measures immediately upon discovering abnormal situations.

The implementation of digital twin water gate projects can improve the operational efficiency and safety of water gates, reduce human errors and accidents, and provide new technical support for urban water resource management and flood control work. Implement online management of the entire lifecycle of water gates, strengthen risk analysis and warning for gate opening and closing, and ensure the safety of water gates.

systemic value
1. Improve the intelligence level of urban water resource management: The water gate safety monitoring and management system can achieve intelligent monitoring, operation simulation, and decision support of water gates, improve the intelligence level of urban water resource management, and provide safer and more reliable drinking water and water services for cities.

2. Enhance the capability and level of urban flood control work: The digital twin sluice project can achieve real-time dynamic monitoring and operation simulation of the sluice, improve the operational efficiency and safety of the sluice, enhance the capability and level of urban flood control work, and reduce the impact of floods on the city.

3. Promote innovation and development of urban water conservancy engineering technology: The digital twin sluice project needs to balance digital technology and water conservancy engineering technology, promote the integration and innovative development of the two, and provide new ideas and methods for urban water conservancy engineering technology.

In summary, the digital twin water gate project has important application prospects in urban water resource management and flood control work. It can improve the intelligence level of water resource management, enhance the ability and level of flood control work, promote innovation and development of water conservancy engineering technology, and improve the quality of urban water environment and ecological health. I hope that through continuous technological innovation and practical exploration, the digital twin sluice project can provide better technical support and solutions for urban water resource management and flood control work.