\n The study compares an annual number of weir overflows calculated using a hydrodynamic model by continuous simulations and a probabilistic model. The weir outflow for a single precipitation event was successfully modelled using logistic regression. Performed numerical experiments showed that the calculated number of weir outflows with the hydrodynamic model falls within confidence intervals of the probabilistic model. This suggests that the model of the logistic regression can be used in practice. The probabilistic simulations revealed that a model with a probabilistic description of a number of annual precipitations and a model with an assumed average number of such events are not consistent. The proposed methodology can be applied for the design of outflow weirs and other storm devices.

Hydrodynamic and probabilistic modelling of storm overflow discharges

The paper presents an attempt to develop a probabilistic model for predicting an annual number of storm overflow discharges. Forecasting the occurrence of an overflow discharge event involved the application of the logistic regression, which does not require the development of complex hydrodynamic catchment models. The performed calculations showed that the logistic regression model can be successfully used to evaluate the performance of the emergency overflow weir. The resultant logit model eliminates the necessity to develop hydrodynamic models, to conduct continuous measurements of the flow intensity in the stormwater drainage system and to collect detailed information on the characteristics of the subcatchments within the analyzed catchment. The hydrodynamic model was used to simulate the annual number of discharges. The analysis of the results demonstrated that they are in the range of stochastic values, which indicates an application-related character of the method.

Probabilistic model for the annual number of storm overflow discharges in a stormwater drainage system

This paper presents the concepts of a probabilistic model for storm overflow discharges, in which arbitrary dynamics of the catchment urbanization were included in the assumed period covered by calculations. This model is composed of three components. The first constitutes the classification model for the forecast of storm overflow discharges, in which its operation was related to rainfall characteristics, catchment retention, as well as the degree of imperviousness. The second component is a synthetic precipitation generator, serving for the simulation of long-term observation series. The third component of the model includes the functions of dynamic changes in the methods of the catchment development. It allows for the simulation of changes in the extent of imperviousness of the catchment in the long-term perspective. This is an important advantage of the model, because it gives the possibility of forecasting (dynamic control) of catchment retention, accounting for the quantitative criteria and their potential changes in the long-term perspective in relation to the number of storm overflows. Analyses carried out in the research revealed that the empirical coefficients included in the logit model have a physical interpretation, which makes it possible to apply the obtained model to other catchments. The paper also shows the use of the prepared probabilistic model for rational catchment management, with respect to the forecasted number of storm overflow discharges in the long-term and short-term perspective. The model given in the work can be also applied to the design and monitoring of catchment retention in such a way that in the progressive climatic changes and urbanization of the catchment, the number of storm overflow discharges remains within the established range.

Urbanization and Management of the Catchment Retention in the Aspect of Operation of Storm Overflow: A Probabilistic Approach

Sewer systems are an essential part of sanitation infrastructure for protecting human and ecosystem health. Initially, they were used to solely convey stormwater, but over time municipal sewage was discharged to these conduits and transformed them into combined sewer systems (CSS). Due to climate change and rapid urbanization, these systems are no longer sufficient and overflow in wet weather conditions. Mechanistic and data‐driven models have been frequently used in research on combined sewer overflow (CSO) management integrating low‐impact development and gray‐green infrastructures. Recent advances in measurement, communication, and computation technologies have simplified data collection methods. As a result, technologies such as artificial intelligence (AI), geographic information system, and remote sensing can be integrated into CSO and stormwater management as a part of the smart city and digital twin concepts to build climate‐resilient infrastructures and services. Therefore, smart management of CSS is now both technically and economically feasible to tackle the challenges ahead. This review article explores CSO characteristics and associated impact on receiving waterbodies, evaluates suitable models for CSO management, and presents studies including above‐mentioned technologies in the context of smart CSO and stormwater management. Although integration of all these technologies has a big potential, further research is required to achieve AI‐controlled CSS for robust and agile CSO mitigation.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/wat2.1635

Smart management of combined sewer overflows: From an ancient technology to artificial intelligence

Using a case study on the Lambro River and the Stream Bevera, this paper compares the use of dynamic modelling with the “normative criteria” to evaluate the effects of Combined Sewer Overflows (CSOs). The normative criteria is the method currently used in Italy to design first flush water tanks to reduce the pollutant discharges. The dynamic modelling technique compares the natural river conditions and the conditions in the river when a CSO occurs. This study finds that the current law, which is based on an effluent standard approach, can significantly underestimate the size of the CSO storage tanks needed to prevent pollution. An alternative is to change the law to use a stream standard approach and to require the CSO tanks to be sized based on the volume and concentration of the pollutants at the CSO. By using a dynamic model of the river, it was found possible to provide a more accurate estimate of the size of the CSO storage tanks required to prevent pollution. Furthermore the paper finds that without...

Designing CSO storage tanks in Italy: A comparison between normative criteria and dynamic modelling methods

This paper is focused on ITS (Intelligent Transport Systems) for road transport, in particular, on the analysis and assessment of the effectiveness of one specific technology making highways and motorways more “perceptive” and “communicating”, i.e. “smart” using a fashion term, that is the dynamic weighing systems of vehicles, also recognised in literature as WIM (Weigh in motion). An application of the investigated technology has been developed at the Measurement Laboratory of the Politecnico di Torino (Italy) where a WIM based on fibre optical sensors has been arranged and tested. The aim has also been to evaluate its accuracy and the possibility of its practical use. The perspective goal is to make roads perceptive and alerting through ITS and the focus on optical fibre-based WIM, for pursuing smart road results, is interesting because fibre sensors are well suited to be employed in the monitoring of large infrastructures.

/pdf/theory-and-practice-of-weigh-in-motion-wim-based-on-fibre-3er18sio.pdf

Alessandro Gallina

Papers

Designing CSO storage tanks in Italy: A comparison between normative criteria and dynamic modelling methods

Theory and practice of Weigh in Motion (WIM) based on fibre Bragg gratings: lab tests for smart roads purposes