Papers by Giovanni de Marinis
Water Hammer in Branched Systemsbehaviour of Viscoelastic Pipes
sbe.hw.ac.uk
Fluid-structure interaction is an important topic for modeling water hammer pressure surges in pi... more Fluid-structure interaction is an important topic for modeling water hammer pressure surges in piping systems. This becomes more complex in branched pipes. In fact in this case it is not possible to describe water hammer effects without an accurate estimate of the ...
River flow rate prediction in the Des Moines watershed (Iowa, USA): a machine learning approach
Stochastic Environmental Research and Risk Assessment
Prediction of flow rate in rivers is essential for the planning and management of water resources... more Prediction of flow rate in rivers is essential for the planning and management of water resources. This study shows that, based on a Machine Learning approach, accurate models for streamflow prediction can be developed. The Des Moines watershed, which includes both Des Moines River and Raccoon River, was chosen as a case study. Only the daily river discharge was considered for the modeling of 10 stations located on different tributaries of the two rivers. Four machine learning algorithms were applied for the streamflow prediction: Random Subspace, M5P, Random Forest and Bagging. The performance of applied algorithms was assessed using statistical performance indicators and graphical representations. Three stations were selected for the training and testing of the different Machine Learning models. Then, the best model was validated on the other seven stations. Prediction accuracy was also assessed as the forecast horizon increased. Overall, M5P algorithms led to the best predictions, with R2 equal to 0.970 and 0.960 for the stations of East Fork Des Moines River at Dakota City and Des Moines River near Tracy, respectively. Accurate predictions were obtained also on the Raccoon River, with R2 equal to 0.938 and 0.887 for the stations of North Raccoon River near Jefferson and Raccoon River at Van Meter, respectively.
Un Criterio Per La Riabilitazione DI Reti DI Distribuzione Idrica
Estimation of Reliability thresholds for the rehabilitation of hydraulic networks
Incidenza della politica gestionale sull’efficienza dei sistemi idrici
Impiego delle variabili complesse per i moti irrotazionali di fluidi perfetti
Sovrappressioni idrodinamiche su contenitori deformabili in zona sismica
La Modellazione Della Richiesta Idrica Per Utenze Residenziali Aggregate Mediante L’Op Model
Pozzetti di salto in correnti veloci – Primi risultati sperimentali
Multiobjective Optimal Rehabilitation of Hydraulic Networks based on the Cost of Reliability
Water Distribution Systems Analysis Symposium 2006, 2008
Abstract The problem of Water Distribution System (WDS) rehabilitation is formulated here as a mu... more Abstract The problem of Water Distribution System (WDS) rehabilitation is formulated here as a multiobjective optimisation problem under uncertain demands. The objectives are to minimise the total rehabilitation cost and to maximise the hydraulic reliability of the WDS. In this context, reliability is defined as a probability of simultaneously satisfying the minimum pressure head constraints at all nodes in the network. The total rehabilitation cost takes into account, not just the structural costs, but also the revenue lost due to the volume of water ...
Discussion of “Hydraulic Characteristics of a Drop Square Manhole with a Downstream Control Gate” by Rita F. Carvalho and Jorge Leandro
Journal of Irrigation and Drainage Engineering, 2013
Vo (m=s) 0.97 1.06 1.12 1.17 1.21 1.28 1.32 1.38 1.4 1.41 1.47 1.48 1.52 1.53 I (-) 0.52 0.56 0.5... more Vo (m=s) 0.97 1.06 1.12 1.17 1.21 1.28 1.32 1.38 1.4 1.41 1.47 1.48 1.52 1.53 I (-) 0.52 0.56 0.58 0.60 0.62 0.65 0.67 0.69 0.70 0.70 0.73 0.73 0.75 0.75
Flow-improving elements in circular drop manholes
Journal of Hydraulic Research, 2014
ABSTRACT
Economic level of reliability for the rehabilitation of hydraulic networks
Civil Engineering and Environmental Systems, 2006
The problem of water distribution system rehabilitation is formulated here as a multiobjective op... more The problem of water distribution system rehabilitation is formulated here as a multiobjective optimisation problem under uncertainty. The two objectives are to minimise the structural rehabilitation cost and to maximise the hydraulic reliability of the system. In this context, reliability is defined as a probability of simultaneously satisfying minimum pressure head constraints at all nodes in the network. An economic analysis has been performed, taking into account not only the structural costs but also lost revenue owing to the volume of ...
La sicurezza dei sistemi idrici rispetto al rischio di contaminazioni intenzionali: il contributo del progetto DISWIP
Sustainability, 2022
Precipitation forecasting is essential for the assessment of several hydrological processes. This... more Precipitation forecasting is essential for the assessment of several hydrological processes. This study shows that based on a machine learning approach, reliable models for precipitation prediction can be developed. The tropical monsoon-climate northern region of Bangladesh, including the Rangpur and Sylhet division, was chosen as the case study. Two machine learning algorithms were used: M5P and support vector regression. Moreover, a novel hybrid model based on the two algorithms was developed. The performance of prediction models was assessed by means of evaluation metrics and graphical representations. A sensitivity analysis was also carried out to assess the prediction accuracy as the number of exogenous inputs reduces and lag times increases. Overall, the hybrid model M5P-SVR led to the best predictions among used models in this study, with R2 values up to 0.87 and 0.92 for the stations of Rangpur and Sylhet, respectively.
Atmosphere, 2021
The extreme values of high tides are generally caused by a combination of astronomical and meteor... more The extreme values of high tides are generally caused by a combination of astronomical and meteorological causes, as well as by the conformation of the sea basin. One place where the extreme values of the tide have a considerable practical interest is the city of Venice. The MOSE (MOdulo Sperimentale Elettromeccanico) system was created to protect Venice from flooding caused by the highest tides. Proper operation of the protection system requires an adequate forecast model of the highest tides, which is able to provide reliable forecasts even some days in advance. Nonlinear Autoregressive Exogenous (NARX) neural networks are particularly effective in predicting time series of hydrological quantities. In this work, the effectiveness of two distinct NARX-based models was demonstrated in predicting the extreme values of high tides in Venice. The first model requires as input values the astronomical tide, barometric pressure, wind speed, and direction, as well as previously observed sea...
Journal of Marine Science and Engineering, 2021
One of the main sources of microplastics inside surface waters is represented by combined sewer o... more One of the main sources of microplastics inside surface waters is represented by combined sewer overflows (CSOs), involving severe risks for the environment. The entry of microplastics into water bodies also depends on the characteristics of sewer diversion structures used as flow control devices. In this work, an experimental investigation was carried out to evaluate the outflow of microplastic particles, consisting of different types of nylon fibers, from a side weir located on a channel with a rectangular section. A specific methodology was developed for the fiber sampling and outflow assessment after the tests were performed. For the tested configurations, an increase in fibers discharged up to 196.15% was measured as the water flow rate increased by 62.75%, combined with an increase in the side weir length up to 40% and a decrease in the crest height up to 20%. The size and weight of the different fibers showed a low impact due to their low inertia, and their motion was governe...
Un modello per la riabilitazione delle reti di distribuzione idrica
Un laboratorio di campo per il monitoraggio di una rete idrica: Richieste di portate – primi risultati
Modelli di mescolamento nei serbatoi idrici
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Papers by Giovanni de Marinis