Correction: Methods to monitor the defects of the drainage pipe network: a review

Methods to monitor the defects of the drainage pipe network: a review

Abstract In order to achieve the governance of urban water environment systems and ensure the normal operation of urban drainage systems, it is necessary to regularly inspect the drainage pipe network to detect and identify defects. Traditional methods of manually identifying defects in Close Circuit Television (CCTV) data and annotating them are labor-intensive and inefficient. To address this issue, a method for automatic identification of pipe network defects based on convolutional neural network (CNN) and transformer is proposed. The model is named RFCBAM-CGA-RTDETR and has been applied to detect 13 types of pipe network defects. Experimental results indicate an evaluation accuracy of 61.8%, demonstrating its effectiveness and reliability. This model outperforms RT-DETR and YOLOv8 models by 6.6% and 10%, respectively, providing a novel approach for drainage pipe network defect detection.

Quantitative simulation of urban waterlogging using computer models is an effective technical means for urban storm water management, especially for predicting and preventing waterlogging. In this study, a city in the northern Anhui Plain, China, was selected as the study site. The Storm Water Management Model was applied to simulate the dynamic changes in the pipeline overload, node overflow, and discharge port runoff characteristics from three perspectives: surface runoff, pipe network transmission, and flow control of low-impact development. The operation of the rainwater pipe network under different return periods and the real-time operation of the rainwater pipe network were simulated to seek solutions to urban waterlogging problems caused by flat terrain and slow drainage. The results revealed that surface runoff is the primary source of rainfall in the study area, with a runoff coefficient of 0.599. The drainage pipe network was optimized by expanding the diameter of the pipe from ≤1.5 mm to ≥2 mm. The water reduction rate was more than 50%, and overload did not occur after optimization. Therefore, sinking green space technology and optimization methods for expanding a pipe diameter can reduce urban waterlogging.

Numerical simulation study on the effect of underground drainage pipe network in typical urban flood

The rapid expansion of urban drainage pipe networks, driven by economic development, poses significant challenges for efficient monitoring and management. The complexity and scale of these networks make it difficult to effectively monitor and manage the discharge of urban domestic sewage, rainwater, and industrial effluents, leading to illegal discharges, leakage, environmental pollution, and economic losses. Efficient management relies on a rational layout of drainage pipe network monitoring points. However, existing research on optimal monitoring point layout is limited, primarily relying on manual analysis and fuzzy clustering methods, which are prone to human bias and ineffective monitoring data. To address these limitations, this study proposes a coupled model approach for the automatic optimization of monitoring point placement in drainage pipe networks. The proposed model integrates the information entropy index, Bayesian reasoning, the Monte Carlo method, and the stormwater management model (SWMM) to optimize monitoring point placement objectively and measurably. The information entropy algorithm is utilized to quantify the uncertainty and complexity of the drainage pipe network, facilitating the identification of optimal monitoring point locations. Bayesian reasoning is employed to update probabilities based on observed data, while the Monte Carlo method generates probabilistic distributions for uncertain parameters. The SWMM is utilized to simulate stormwater runoff and pollutant transport within the drainage pipe network. Results indicate that (1) the relative mean error of the parameter inversion simulation results of the pollution source tracking model is linearly fitted with the information entropy. The calculation shows that there is a good positive linear correlation between them, which verifies the feasibility of the information entropy algorithm in the field of monitoring node optimization; (2) the information entropy algorithm can be well applied to the optimal layout of a single monitoring node and multiple monitoring nodes, and it can correspond well to the inversion results of the tracking model parameters; (3) the constructed monitoring point optimization model can well realize the optimal layout of monitoring points of a drainage pipe network. Finally, the pollution source tracking model is used to verify the effectiveness of the optimal layout of monitoring points, and the whole process has less human participation and a high degree of automation. The automated monitoring point optimization layout model proposed in this study has been successfully applied in practical cases, significantly improving the efficiency of urban drainage network monitoring and reducing the degree of manual participation, which has important practical significance for improving the level of urban water environment management.

Experimental study of rainwater grate blocking and submergence of outfall on drainage network capacity

This article addresses the challenge of simulating rainstorm waterlogging in urban-scale areas where reliable drainage pipe network data are often lacking. Although methods have been developed to tackle this issue, there remains a gap in their effectiveness. We present a novel approach, the modified equivalent infiltration (MEI) method, by building upon the foundation of the Equivalent Infiltration (EI) method. This study focuses on the outer ring area of Shanghai, utilizing data from the “In-Fa” typhoon period for simulation and comparison. Our findings reveal that the MEI method, requiring the same data inputs as the EI method, surpasses its predecessor in both principle and simulation results. Additionally, the MEI method demonstrates robustness in handling rainstorm waterlogging scenarios.

Coastal cities often have advanced drainage systems connected to the sea, reducing the risk of flooding. In recent years, with climate change, global sea levels have been rising. In 2023, the sea level in the South China Sea rose by 52 mm compared to the long-term average. This study uses a coupled system of a two-dimensional hydrodynamic model and a one-dimensional drainage pipe network model to investigate the impact of rising sea levels on compound flooding in coastal cities under future climate change scenarios. The results indicate that rising sea levels increase the baseline water level of storm surges, significantly increasing the risk of flooding in cities.

China's urban drainage pipeline systems and pipeline inspection technologies have achieved significant progress in the past 40 years, whereas the existing drainage pipelines are facing damage, defects, and aging, and thus have received growing attention. To better understand the underlying reasons for the development of China's urban drainage pipeline systems, and improve the utilization efficiency of pipeline inspection technologies, this research comprehensively analyzed the development process of China's urban drainage pipeline systems in terms of the spatio-temporal characteristics of pipeline length, the types of sewer lines, existing problems and consequences. Moreover, the widely used pipeline inspection technologies were presented and compared, and appropriate inspection techniques were proposed for pipelines that are difficult to detect with the common techniques. Finally, specific suggestions and future developments were provided for the construction, defect inspection and condition assessment, and management and maintenance of urban drainage pipeline systems. This review will hopefully assist in the management and maintenance of China's urban drainage pipeline systems, and provide a valuable experience and practices for other developing countries.

Comprehensive Assessment Procedure for Metropolitan Drainage Pipe Network Considering Key Nodes

Research on intelligent control theory and strategy of gas drainage pipe network based on graph theory

Urban waterlogging control: A novel method to urban drainage pipes reconstruction, systematic and automated

Identification of high oxygen-consuming substances in stormwater drainage systems illicitly connected with sewage system

The highly intensive construction activities in the process of urbanization have led to the risk of soil loss, which is due to the disturbance of urbanization on the soil; this makes the soil more vulnerable to erosion by rain and other factors, thus causing soil loss to the urban drainage pipe network or the river channels around the city. This process is affected by both natural and human factors. Based on engineering experience and existing research, 13 influencing factors were identified and classified into four dimensions: Natural Conditions (NC), Construction Activities (CA), Conservation Measures (CM) and Management Measures (MM). Fifteen experts from Shanghai, Guangzhou and Zhengzhou, three main cities in China, were invited to assess the weight of each influencing factor through pairwise comparison. Based on the analytic hierarchy process, the soil erosion risk evaluation model of construction sites in megacities was established, and the weight of each influencing factor was determined. According to the weights, the weighted summation method can be used to calculate the comprehensive scores of these sites and the soil erosion risks of the construction sites can be ranked according to the comprehensive scores for multiple construction sites. The analysis of the model shows that MM is the most important factor, and improving the management level is the key measure to control the soil erosion of construction site in megacities. In addition, in the four dimensions, the results of the weight of each influencing factor in the NC dimension are quite different; this is due to the different cities where the experts are from, indicating that the natural conditions of the location will affect empirical judgment. By inviting many experts to evaluate, the deviation in judgment results, caused by differences in natural conditions, can be reduced.

ABSTRACT Urban drainage pipe network is the backbone of urban drainage, flood control and water pollution prevention, and is also an essential symbol to measure the level of urban modernization. A large number of underground drainage pipe networks in aged urban areas have been laid for a long time and have reached or practically reached the service age. The repair of drainage pipe networks has attracted extensive attention from all walks of life. Since the Ministry of ecological environment and the national development and Reform Commission jointly issued the action plan for the Yangtze River Protection and restoration in 2019, various provinces in the Yangtze River Basin, such as Anhui, Jiangxi and Hunan, have extensively carried out PPP projects for urban pipeline restoration, in order to improve the quality and efficiency of sewage treatment. Based on the management practice of urban pipe network restoration project in Wuhu City, Anhui Province, this paper analyzes the problems of lengthy construction period and repeated operation caused by the mismatch between the design schedule of the restoration scheme and the construction schedule of the pipe network restoration in the existing project management mode, and proposes a model of urban drainage pipe network restoration scheme selection based on the improved support vector machine. The validity and feasibility of the model are analyzed and verified by collecting the data in the project practice. The research results show that the model has a favorable effect on the selection of urban drainage pipeline restoration schemes, and its accuracy can reach 90%. The research results can provide method guidance and technical support for the rapid decision-making of urban drainage pipeline restoration projects.

In order to improve the regulation efficiency of the coal mine gas drainage pipe network, reduce the labor intensity of workers, and ensure the safe production of coal mines, a gas drainage pipe network regulation and control system is designed. The system adopts Siemens S7-1200 series PLC as the core control unit of the gas drainage pipe network. Through the explosion-proof treatment of the PLC control box, it meets the special requirements of PLC used in the coal mine environment. Through the design and selection of flow sensors and methane sensors it improves the flow and methane sampling accuracy of the gas drainage regulation system. By writing local control strategies and remote control strategies in PLC, the automatic regulation of the gas drainage pipeline network is realized.

Study on Measures of Construction Quality Management of Municipal Drainage Pipe Network Engineering

The development of building information modelling has facilitated the improvement of cost and time management in panelized construction. This research proposes an automated method to design and draft drainage systems in the BIM environment. The proposed method can improve design efficiency, eliminate design errors, and reduce material waste. In order to improve production efficiency at the panelized construction plant, the drainage pipe network is separated into smaller components at the geometric boundaries of the plumbing panel which is a floor or wall panel through which pipes pass. Meanwhile, a bill of materials for each plumbing panel is generated for the purpose of further cutting optimization. A prototyped BIM extension application, an add-on to Autodesk Revit, is developed as a proof of concept. A case study of residential drainage system design and optimization is presented to illustrate the feasibility of the proposed framework. As the key contribution of this research, the integration of the BIM model with the automated design system, rule-based pipe route planning approach, and optimal cutting stock algorithm achieves the automation in drainage system design in the context of panelized construction to improve design and production efficiency.

Urban rainwater pipe network is a direct way to resist urban waterlogging, and its safe and stable operation is the premise to ensure the normal operation of the city. However, in China and even around the world, the monitoring means for the operation of urban rainwater pipe network are very limited. For the occurrence and solution of urban waterlogging, it often mainly depends on the means of personnel inspection to monitor where the rainwater pipe network overflows, and then take measures. There is no effective monitoring method for the whole rainwater pipe network. Therefore, an accurate and efficient rainwater pipe network monitoring method is urgently needed. To solve the current problem of real-time monitoring of rainwater pipe network, the core problem is how to monitor the liquid level data of any pipe section of the whole rainwater pipe network in real time, so it is necessary to introduce hydrodynamic model. The traditional hydrodynamic model mainly simulates the hydraulic and hydrological, and does not simulate the rainwater pipe network, but makes a generalized estimation of the drainage of the rainwater pipe network. In addition, some hydrodynamic models for drainage pipe network are not established for the problem of rainwater pipe network monitoring. The ultrasonic liquid level gauge with real-time acquisition function is not introduced into the calculation simulation, and it does not have the ability of adaptive correction. Therefore, the traditional rainwater monitoring methods and hydrodynamic models can not fundamentally solve the problem of real-time monitoring of the whole rainwater pipe network. Using hydrodynamic model calculation, combined with rain gauge and liquid level gauge to monitor and modify model parameters, so as to intelligently monitor the whole rainwater pipe network, which can greatly improve the current monitoring level of urban rainwater pipe network and reduce the work cost of manual patrol monitoring.