Cristiana Di Cristo

University of Naples Federico II | UNINA · Department of Civil, Architectural and Environmental Engineering

Urban drainage network (UDN) monitoring is an important task whose planning can be related to various purposes, as for example contaminant detection and epidemiological studies. This paper proposes two different strategies for the identification of a monitoring system for UDNs. The optimal solution, in terms of location and number of sensors, is fi...

The mechanical reliability of Water Distribution Networks (WDNs) is a relevant technical and scientific issue. During planned maintenance or unplanned interruptions, the affected area must be isolated by valves shutdown. This operation involves the alteration of the network structure, i.e., the domain of the hydraulic system, and for this reason th...

Urban drainage networks (UDNs) represent important infrastructures to protect and maintain community health and safety. For these reasons, technicians and researcher are focusing more and more on topics related to vulnerability, resilience and monitoring for controlling illicit intrusions, contaminant and pathogenic spread. In the last years the co...

Mud flows represent one of the major causes of natural hazards in mountain regions. Similarly to debris flows, they consist of a hyper-concentrated mixture of water and sediments flowing down a slope and may cause serious damages to people and structures. The present paper investigates the force produced by a dam-break wave of mud impacting against...

We measured the surface tension of linear alkylbenzene (LAB) HYBLENE 113 mixed with Diphenyloxazole (PPO) as well as of pure LAB HYBLENE 113 as part of material studies for the liquid-scintillator based surround background tagger (SBT) in the proposed SHiP experiment. The measurement was performed using the iron wire method and the surface tension...

We measured the surface tension of linear alkylbenzene (LAB) HYBLENE 113 mixed with Diphenyloxazole (PPO) as well as of pure LAB HYBLENE 113 as part of material studies for the liquid-scintillator based surround background tagger (SBT) in the proposed SHiP experiment. The measurement was performed using the iron wire method and the surface tension...

Simplified versions of the Shallow Water Equations, known as Kinematic and Diffusive models, are commonly applied to the analysis of debris- and mud- flow dynamics. For this reason, the study of their applicability conditions represents an important concern. The present work investigates on the applicability conditions of the Diffusive Wave Model (...

The evaluation of the impact force on structures due to a flood wave is of utmost importance for estimating physical damage and designing adequate countermeasures. The present study investigates, using 2D shallow-water approximation, the morphodynamics and forces caused by a dam-break wave against a rigid obstacle in the presence of an erodible bed...

Water distribution networks are expected to fulfill the water demand by all consumers and at all times, even during critical scenarios, such as pipe failures. In this work, a methodology is proposed to maximize the quality of service during pipe failures by operating valves. The selection of the valves to operate is done by solving an optimization...

A methodological framework for the estimation of the expected value of hourly peak water demand factor and its dependence on the spatial aggregation level is presented. The proposed methodology is based on the analysis of volumetric water meter measurements with a 1-h time aggregation, preferred by water companies for monitoring purposes. Using a p...

The 2D shallow water equations are often solved through finite volume (FV) methods in the presence of irregular topography or in non-rectangular channels. The ability of FV schemes to preserve uniform flow conditions under these circumstances is herein analysed as a preliminary condition for more involved applications. The widely used standard Hart...

Water distribution networks (WDNs) need to guarantee that water is delivered with adequate quality. This paper compares the performance of 12 multiobjective procedures to limit water quality deterioration in a WDN through the optimal operation of valves. The first objective (ObF1) is to minimize the water age, chosen as a surrogate parameter of qua...

This paper compares the performance of 12 multiobjective procedures to limit water quality deterioration in a WDN through the optimal operation of valves. The first objective is to minimize the water age, chosen as a surrogate parameter of quality deterioration, and the second objective is to minimize the number of valve closures. The optimization...

In the last decade, the growth of the micro-industry in urban areas has produced an increase in the frequency of xenobiotic polluting discharges in drainage systems. Wastewater treatment plants are usually characterized by low removal efficiencies in respect of such pollutants, which may have an acute or cumulative impact on environmental and publi...

The Kinematic Wave Model (KWM), representing a simplification of the Full Wave Model (FWM) under the shallow-water approximation, is still used for predicting flood propagation requiring a reduced computational effort and for being more easily coupled with high-resolution topographic data. It is as suitable approach also for predicting debris and m...

The Kinematic Wave Model (KWM), representing a simplification of the Full Wave Model (FWM) under the shallow-water approximation, is often used in the one-dimensional formulation for describing the dynamics of debris/mud flood. The present work investigates the applicability conditions of the KWM to analyze mud floods, characterized by a rheologica...

Because of climate change, flood-prone areas are more and more frequently exposed to potential casualties and damage. The capability of the flow to carry relevant quantities of sediments during these critical events adds to the further complexity of the resulting scenarios. The interaction between the flow and the obstacles in flood-inundated areas...

Water quality deterioration in water distribution networks can be associated with high water residence time in the network. To this end, some previous studies have proposed optimization procedures for valve management. However, these studies generally come up with operational configurations assuming deterministic user demand patterns that may never...

The study of the interaction of mud-flows with obstacles is important to define inundation zones in urban areas and to design the possible structural countermeasures. The paper numerically investigates the impact of a mud-flow on rigid obstacles to evaluate the force acting on them using two different depth-integrated theoretical models, Single-Pha...

Climate change is exposing more and more frequently flood prone areas to potential casualties and damages. The capability of the flow to carry relevant quantities of sediments interacts with the presence of obstacles in flood-inundated areas and contributes to the increase the related hazard, constituting a relevant concern in the framework of risk...

Negli ultimi decenni, la crescita del settore micro-industriale ha prodotto, tra le altre cose, un aumento degli scarichi di reflui di origine produttiva nelle fognature urbane. Mentre un evento di contaminazione dell’acqua potabile determina un immediato allarme per la salute pubblica, gli scarichi anomali in fognatura hanno un impatto meno rileva...

Chlorination is an effective and cheap disinfectant for preventing waterborne diseases-causing microorganisms, but its compounds tend to react with the natural organic matter (NOM), forming potentially harmful and unwanted disinfection by-products (DBPs) such as trihalomethanes (THMs), haloacetic acids (HAAs), and others. The present paper proposes...

In the last decades, the growth of mini- and micro-industry in urban areas has produced an increase in the frequency of xenobiotic polluting discharges in drainage systems. Such pollutants are usually characterized by low removal efficiencies in urban wastewater treatment plants and they may have an acute or cumulative impact on environment. In ord...

The paper investigates the applicability of Kinematic and Diffusive Wave models for mud-flows with a power-law shear-thinning rheology. In analogy with a well-known approach for turbulent clear-water flows, the study compares the steady flow depth profiles predicted by approximated models with those of the Full Dynamic Wave one. For all the models...

Dikes and levees are encountered very often along rivers. They are crucial as defence structures for flow channelization, protecting population and properties from floods as well as against lateral riverbed migration. However, the combination of their aging and increased exposition to extreme hydrological events may cause these structures to breach...

Trihalomethanes (TTHMs) are water disinfection by-products whose consumption via drinking water may eventually be harmful for human health, as they could have carcinogenic effects, also for the exposure to them via non-ingestion routes [1]. In the present work the possibility to reduce the vulnerability of the population exposed to TTHMs by the opt...

Wastewater quality monitoring is receiving growing interest with the necessity of developing new strategies for controlling accidental and intentional illicit intrusions. In designing a monitoring network, a crucial aspect is represented by the sensors' location. In this study, a methodology for the optimal placement of wastewater monitoring sensor...

A depth-averaged model with a power-law rheology, usually adopted for debris flow of fine sediment-water mixtures, is studied analytically, considering the complete (Full Dynamic Model) and the simplified momentum equations, known as Kinematic, Diffusion, and Quasi-steady Models. Applying the Laplace transform to the linearized equations, the analy...

The impact of a dam-break wave on an erodible embankment with a steep slope is studied in the paper using both experimental and numerical approaches. The laboratory experiments have been specifically designed and performed for a range of the storage water levels and the embankment elevations and slopes. The simulations were carried out using a rece...

Efficient management of a sewer system includes the control of the conveyed wastewater quality to adequately operate treatment plants and protect the receiving water bodies. Moreover, these systems are vulnerable to either accidental spills or intentional unauthorized discharges. To properly manage them, a limited number of sensors could be placed...

The paper investigates the influence of the inlet boundary condition on the spatial evolution of natural rollwaves in a power-law fluid flowing in steep slope channels. The analysis is carried out numerically, by solving the von Kármán depth-integrated mass and momentum conservation equations, in the long-wave approximation. A second-order accurate...

A very important aspect in sewer systems management is represented by the detection of illicit intrusions, which recently supported the development of online sensors for wastewater quality monitoring. The present paper proposes a new methodology for characterizing an illicit intrusion in a sanitary or combined sewer system, using on-line pollutant...

This paper investigates the spatial evolution of a disturbance in an open-channel flow of a power-law fluid at non-uniform accelerated and decelerated initial profiles, up to the occurrence of roll-waves in mild and steep slope channels. Both theoretical and numerical analyses are applied to the depth-averaged continuity and momentum conservation e...

The present work investigates the effect of the flow profile induced by an inlet condition on the roll-wave evolution in turbulent clear-water flows. The study employs theoretical and numerical analyses. Firstly, the influence of the inlet condition on the spatial evolution of a single perturbation in a hypercritical flow is examined through the ex...

Fast geomorphic transients may involve complex scenarios of sediment transport, occurring near the bottom as bed load (i.e., saltating, sliding, and rolling) or as suspended load in the upper portion of the flow. The two sediment transport modalities may even coexist or alternate each other during the same event, especially when the shear stress va...

Simplified wave models -such as kinematic, diffusion and quasi-steady -are widely employed as a convenient replacement of the full dynamic one in the analysis of unsteady open-channel flows, and especially for flood routing. While their use may guarantee a significant reduction of the computational effort, it is mandatory to define the conditions i...

In the present paper the stability of gradually varying mud-flows in wide open channel is analyzed. The governing equations derive from a Saint–Venant-like approach with a Herschel & Bulkley model for the fluid rheology. In order to define the stability of a given initial accelerating or decelerating flow depth profile, the spatial evolution of a w...

Illicit intrusions in Sewer Systems (SSs), modifying the wastewater characteristics, may create problems to the treatment plant and/or to the final recipient water body. For this reason, the source identification (SI) problem is becoming an important issue also in SSs. For large real systems, the computational burden might make the SI methodologies...

A core problem associated with the water quality monitoring in the sewer system is the optimal placement of a limited number of monitoring sites. A methodology is provided for optimally design water quality monitoring stations in sewer networks. The methodology is based on information theory, formulated as a multi-objective optimization problem and...

The objective of present paper is to propose a criterion for performing a vulnerability analysis in a water distribution system, which involves the estimation of the consumers’ exposure to pathogenic risk and to elevated trihalomethanes concentration, deriving from the reaction of natural organic matter with sodium hypochlorite, widely used for the...

Disinfection of drinking water through chlorine is commonly used in many countries for reducing pathogenic infection problems, but it may pose a risk to human health due to the formation of some by-products, such as trihalomethanes (THMs). For an adequate management of the disinfection process, it is useful to have models capable of simulating THMs...

In the present paper the mathematical character of the two-phase depth-averaged morphodynamical model proposed by Di Cristo et. al (2014) is discussed. In particular, in this model the bed-load concentration is dynamically evaluated provided that an algebraic expression for bed-load thickness is assumed. To this aim, some adaptations of empirical c...

Dike erosion is a crucial issue in coastal and fluvial flood risk management. These defense structures appear vulnerable to extreme hydrological events, whose potential occurrence risk seems recently increased due to climate change. Their design and reinforcement is, however, a complex task and, although numerical models are very powerful nowadays,...

Waste water management plant protection is a major concern for water cycle management entities. The rapid identification and possible localization of anomalous or even malicious waste liquids immission may allow for undertaking pollution risk mitigation actions (e.g. using of ancillary basins) and reduce maintenance costs. Pervasive monitoring of t...

Granular flows have been the subject of several researches in the last years, not only in fluvial hydraulics and risk management but also in many other engineering applications, such as, for instance, material stockpiling and freights, food manufacturing and industrial processes.

The adoption of the Diffusive Wave (DW) instead of the Full Dynamic (FD) model in the analysis of mud flood routing within the shallow-water framework may provide a significant reduction of the computational effort, and the knowledge of the conditions in which this approximation may be employed is therefore important. In this paper, the applicabili...

The velocity field of a propeller jet induced by two different propellers has been investigated using the PIV technique in a still water basin with fixed bed. The main novelty is represented by the presence of a stern of an inland vessel model. The angles and distances of jet impact and maximum bed velocity have been evaluated from the measured ins...

The study of unsteady shallow-layer flows, as those occurring during floods, may be performed through either fully dynamic models or using simplified momentum equations (e.g. kinematic, diffusion and quasi-steady approximations). Among the latter, kinematic approximation may provide a significant reduction of the computational effort, which represe...

The velocity field of a propeller jet induced by two different propellers has been investigated using the PIV technique in a still water basin with fixed bed. The main novelty is represented by the presence of a stern of an inland vessel model. The angles and distances of jet impact and maximum bed velocity have been evaluated from the measured ins...

The Storm Water Management Model (SWMM) is considered one of the standard tools for modeling sewer systems, but it does not have the programmer's toolkit. In this work a toolkit library is presented, which has been built for running wastewater quality simulations from an outside environment. An example of the developed Toolkit use is furnished appl...