I. Project Background

With the acceleration of urbanization, the built-up area of cities has been continuously expanding, the coverage rate of hard ground has significantly increased, and the amount of rainfall runoff has greatly increased. Coupled with the lagging construction of flood control and drainage networks in some cities, urban flooding disasters occur frequently during extreme rainfall weather. According to statistics, the economic loss caused by urban flooding in China exceeds 10 billion yuan every year. It not only affects citizens' travel and the safety of their lives and property, but also leads to the mixed flow and overflow of sewage in the pipeline network, polluting river water bodies and disrupting the urban water ecological balance.

At present, urban flood control and drainage management mostly relies on experience-based dispatching, lacking real-time monitoring data on the water quality and flow of the pipeline network, making it impossible to accurately grasp the operation status of the pipeline network and the risk points of urban flooding. To implement the requirements of the "Action Plan for the Construction of Urban Drainage and Flood Control System during the 14th Five-Year Plan Period", and to build a "smart drainage and flood control" system, it is of vital importance to carry out water quality and flow monitoring projects for urban flood control and drainage networks. This project relies on the intelligent monitoring equipment of Wuhan Shuicejia Technology to achieve real-time perception of water quality and flow at key nodes of urban pipe networks, providing data support for urban flood warning, pipe network dispatching, and pollution prevention and control, and enhancing the city's flood control and drainage capacity as well as the level of water environment governance.

Ii. Current Problems

The lack of monitoring in the pipe network and the lagging early warning for urban flooding: Most of the urban flood control and drainage pipe networks are buried underground, with only a few monitoring points set up at pumping stations and gates. About 80% of the pipe networks lack flow monitoring equipment, making it impossible to grasp the water flow speed and water level changes inside the pipes in real time. When urban flooding occurs, it is difficult to locate the water accumulation points in time, and the early warning time is less than one hour, missing the best opportunity for handling.

The lack of water quality monitoring makes it difficult to trace the source of pollution: The phenomenon of mixed and wrong connections in the pipeline network is widespread. During rainfall, rainwater carries pollutants into the pipeline network, causing sewage overflow. However, due to the absence of water quality monitoring equipment, it is impossible to monitor the concentrations of pollutants such as COD and ammonia nitrogen in real time, making it difficult to trace the source of pollution and affecting the efficiency of water environment governance.

Poor equipment compatibility and low operational stability: Some installed monitoring devices have not taken into account the environmental characteristics of the pipeline network, such as high humidity, strong corrosiveness, and narrow space, resulting in a high failure rate (annual failure rate exceeding 40%). The wiring of traditional wired monitoring equipment is difficult, and the construction cost is high and the cycle is long in the renovation of old pipeline networks.

Data fragmentation and low dispatching efficiency: Monitoring data is scattered and stored in different departmental systems, lacking a unified management platform. The data formats are incompatible, making it impossible to achieve data linkage analysis of "flow - water quality - water accumulation". The dispatching of pipe networks relies on manual experience, making it difficult to dynamically adjust the operating parameters of pumping stations and gates based on real-time data, resulting in low efficiency in flood control and drainage.

Weak emergency response and insufficient handling capacity: When urban flooding occurs, it is impossible to quickly obtain data on the flow and water quality of the surrounding pipelines of the waterlogged areas. Emergency rescue personnel find it difficult to formulate precise handling plans, resulting in slow water accumulation, prolonged sewage overflow, and increased environmental pollution risks.

On-site installation of equipment

Iii. Solution Approach

Scientifically set up monitoring points to achieve all-round perception: In combination with the topological structure of urban pipe networks, areas prone to waterlogging, and risk points of sewage overflow, install water quality and flow monitoring equipment at key nodes of the pipe network (such as the intersection of main pipes, the inlet and outlet of pumping stations, the pipe network on low-lying sections, and overflow outlets), and build a monitoring network that combines "points, lines, and surfaces" to achieve full coverage of the operation status of the pipe network.

Select suitable equipment to ensure stable operation: Give priority to choosing wireless monitoring devices from Wuhan Shuicejia Technology that feature a high protection level (IP68), corrosion resistance, and compact size, which are suitable for damp and narrow pipe networks. Adopting LoRa, 4G/5G wireless communication reduces wiring costs and enhances the flexibility of equipment installation.

Build a unified management platform and strengthen data linkage: Establish a monitoring platform for urban flood control and drainage pipe networks, integrate monitoring data such as water quality, flow rate, and water accumulation, and apply big data analysis technology to achieve early warning of urban flood risks, pollution source tracing analysis, and simulation of pipe network dispatching. Establish data interfaces with municipal, emergency management and environmental protection departments to form a collaborative dispatching mechanism.

Improve the emergency response mechanism and enhance the efficiency of handling: Based on monitoring data, formulate hierarchical emergency response plans. When urban flooding or pollution exceeds standards, automatically push early warning information to relevant departments. Equipped with portable monitoring devices, it is used for data collection at emergency rescue sites, assisting in formulating response plans and shortening the time for water accumulation to recede and pollution control.

Establish a long-term operation and maintenance system to ensure data quality: Clearly define the municipal department as the main body responsible for operation and maintenance, and Wuhan Shuicejia Technology provides technical support. Regularly carry out equipment calibration (once every quarter), cleaning (once a month), and fault repair. Establish a data quality verification mechanism to automatically issue early warnings for abnormal data and assign tasks for processing, ensuring the authenticity and reliability of monitoring data.

Installation of the bracket for Doppler ultrasonic flowmeter

IV. Hardware Perception System

Flow monitoring equipment: Install Doppler ultrasonic flowmeters from Wuhan Shuicejia Technology at the main pipes of the pipeline network and the inlet and outlet of pumping stations to monitor the flow and velocity inside the pipes in real time. Supports online measurement for both full and non-full tubes.

Water quality monitoring equipment: Install multi-parameter water quality sensors from Wuhan Shuichejia Technology at sewage overflow outlets, pipe network junctions, and pump station outlets to monitor indicators such as COD, ammonia nitrogen, turbidity, and dissolved oxygen, and grasp the changes in pipe network water quality and pollution conditions.

Water level and water accumulation monitoring equipment: Install the radar water level gauge of Wuhan Shuichejia Technology in the pipeline network and inspection Wells on low-lying sections to monitor the water level in the pipes. Ultrasonic water accumulation sensors are installed at the points prone to water accumulation on the road surface to monitor the depth of water accumulation in real time and provide data for urban flooding early warning.

Data acquisition and transmission equipment: It adopts the remote terminal unit (RTU) of Wuhan Shuicejia Technology to collect water quality, flow and water level data, supports 4G wireless communication, and has an IP68 protection level. The terminal has a local data storage function to prevent data loss caused by communication interruption.

Emergency monitoring equipment: Equipped with portable Doppler ultrasonic flowmeters and portable water quality detectors from Wuhan Shuicejia Technology, it is used for on-site rapid detection of flow and water quality during emergency rescue in case of urban flooding, assisting in emergency decision-making.

V. Scene Application

Urban flood warning and handling: Install radar water level gauges and Doppler ultrasonic flow meters in the pipeline network of low-lying sections in cities to monitor the water level and flow in the pipes in real time. When the water level rises by 0.5 meters within one hour and the flow exceeds the upper limit of the pipe network's carrying capacity (for example, the flow of a DN500 pipe network exceeds 500m³/h), the platform automatically issues a flood warning and pushes the information to the municipal department and the emergency rescue team. Rescue workers carried portable flow meters to the scene to measure the flow of the surrounding pipeline network, determine the path of water accumulation, and remotely control the pumping station through the platform to increase the pumping force and open the diversion gate, reducing the time for water accumulation to recedes by 40% and minimizing the impact on citizens' travel.

The Wuhan Shuichejia pipe network remote terminal monitors water flow

Pipeline network dispatching optimization: Install pipe-type electromagnetic flowmeters at the intersections of urban pipeline network main pipes and the entrances and exits of pumping stations to collect flow data in real time. The platform, in combination with the flow changes at each node, uses the hydraulic model of the pipeline network to simulate the water flow distribution and dynamically adjusts the operation parameters of the pumping station (such as the speed of the lift pump) and the opening degree of the gate. For instance, during the morning rush hour when it rains, a sudden increase in the flow of the eastern pipeline network was detected. The platform automatically instructed the eastern pumping station to enhance its pumping and drainage capacity, and at the same time closed some of the tributary gates to reduce the inflow of sewage into the main pipe and prevent pipeline network overflow, thereby increasing the operational efficiency of the pipeline network by 30%.

Sewage overflow prevention and control: Install multi-parameter water quality sensors and insertable ultrasonic flowmeters at the overflow outlets of the pipe network to monitor the COD, ammonia nitrogen concentration and overflow volume in real time. When the COD exceeds 100mg/L and the overflow volume exceeds 10m³/h, the system triggers a pollution warning. The water quality data of the surrounding pipeline network of the overflow outlet can be viewed through the platform to trace the source of pollution (such as the mixed connection of domestic sewage in a certain community). The environmental protection department, in collaboration with the municipal department, conducted a rapid investigation and completed the rectification of the mixed connection pipeline within three hours, reducing the pollution of the river water by sewage overflow and lowering the COD concentration of the river downstream of the overflow outlet by 25%.

Renovation assessment of old pipe networks: Before and after the renovation of old pipe networks, the flow and water level changes of the pipe network are monitored through insertable ultrasonic flowmeters and radar water level gauges. Before the renovation, it was monitored that the flow rate of the pipeline network on a certain section of the road was only 60% of the designed value due to siltation, and the water level was prone to exceed the standard. After the renovation, the monitoring data showed that the flow rate recovered to 95% of the designed value and the water level remained stable within the safe range, verifying the renovation effect. Meanwhile, through long-term monitoring data, analyze the siltation patterns of the pipeline network, and formulate a dredging plan every six months to reduce the risk of pipeline network blockage.

Emergency rescue monitoring: When urban flooding is caused by typhoons and heavy rain, emergency rescue teams carry portable Doppler ultrasonic flowmeters to severely waterlogged areas to measure the flow of the pipeline network on the spot and determine whether the waterlogging is due to pipeline network blockage. For instance, on a certain section of road, the water accumulation exceeded 50cm. On-site flow measurement revealed that the flow rate of the pipeline was only 30% of the normal level. It was found that there were obstructions in the pipeline. The rescue personnel promptly cleared them up and drained the water within two hours, ensuring the safety of road traffic.