renata della morte - Academia.edu (original) (raw)

Papers by renata della morte

Research paper thumbnail of Evaluating upward trends in groundwater nitrate concentrations: an example in an alluvial plain of the Campania region (Southern Italy)

Environmental Earth Sciences, 2020

Research paper thumbnail of On integral and differential porosity models for urban flooding simulation

Advances in Water Resources, 2019

Abstract A novel differential porosity model for urban flooding, namely the Binary Single Porosit... more Abstract A novel differential porosity model for urban flooding, namely the Binary Single Porosity model (BSP), is proposed in the present paper. The BSP model, which is derived from the Single Porosity (SP) model by constraining the porosity to attain only the values zero inside the buildings and one in the voids among the buildings, is local and independent on the existence of a Representative Elementary Volume (REV). The BSP model satisfies the Galilean invariance, while the corresponding wave speeds are identical to those of the Shallow water Equations model, and its integral formulation coincides with the original integral model by Sanders et al. (2008). The structure of the BSP model implies that the solution of the SP Riemann problem is the numerical building block for the construction of the corresponding Finite Volume schemes. This observation prompts a further study of the SP model and its solutions, demonstrating that the exact SP Riemann problem solution has the potential to take into account the transient energy losses due to wave reflections through the urban fabric in BSP models. Nonetheless, a further comparison with the two-dimensional SWE results demonstrates that additional stationary energy dissipations must be accurately taken into account through porosity reductions in the case of supercritical flow. The numerical experiments show that available approximate SP Riemann solvers may cause a systematic underestimation of the energy dissipation through the urban fabric and an overestimation of the flood celerity. The improvement of SP Riemann solvers could limit the resort to additional drag and momentum dissipation terms that are frequently added in numerical models. Finally, the investigation of the differential porosity models where different definitions are used for storage and conveyance porosity shows that these models suffer from a fundamental lack of physical congruence, implying that they cannot be used for the analysis of flood wave propagation through the urban fabric.

Research paper thumbnail of Multiple Solutions for the Riemann Problem in the Porous Shallow Water Equations

EPiC Series in Engineering

The Porous Shallow water Equations are widely used in the context of urban flooding simulation. I... more The Porous Shallow water Equations are widely used in the context of urban flooding simulation. In these equations, the solid obstacles are implicitly taken into account by averaging the classic Shallow water Equations on a control volume containing the fluid phase and the obstacles. Numerical models for the approximate solution of these equations are usually based on the approximate calculation of the Riemann fluxes at the interface between cells. In the present paper, it is presented the exact solution of the one-dimensional Riemann problem over the dry bed, and it is shown that the solution always exists, but there are initial conditions for which it is not unique. The non-uniqueness of the Riemann problem solution opens interesting questions about which is the physically congruent wave configuration in the case of solution multiplicity.

Research paper thumbnail of Cost-Based Design and Selection of Point Absorber Devices for the Mediterranean Sea

Research paper thumbnail of Flood propagation modeling with the Local Inertia Approximation: Theoretical and numerical analysis of its physical limitations

Advances in Water Resources, 2019

Research paper thumbnail of The solution of the Riemann problem in rectangular channels with constrictions and obstructions

Advances in Water Resources, 2019

Research paper thumbnail of The solution of the dam-break problem in the Porous Shallow water Equations

Advances in Water Resources, 2018

Research paper thumbnail of Nitrate trends in groundwater of the Campania region (southern Italy)

Environmental science and pollution research international, Jan 14, 2017

The Environmental Protection Agency of the Campania region in Italy (ARPAC) manages a groundwater... more The Environmental Protection Agency of the Campania region in Italy (ARPAC) manages a groundwater quality monitoring network. For almost all the polluted waters, the key parameter driving the classification is the concentration of nitrate; hence, the Campania region, in coherence with the EU regulations, outlined the vulnerable areas and undertook remediation policies. The best groundwater quality is recorded for carbonate aquifers of the Apennine chain; on the contrary, the Tyrrhenian coastal plains are affected by severe contamination, with a locally very contaminated groundwater of the shallow and also the deeper aquifers. The study is especially focused on a large coastal plain of Campania region, where nitrate concentration sometimes exceeds 200 mg/L. The study, based on almost 200 sampling points for the whole region during the period 2003-2015 (approx two samples per year), verified the effectiveness of the groundwater monitoring network, the present distribution of nitrate i...

Research paper thumbnail of Exact Solution of the Dam-Break Problem for Constrictions and Obstructions in Constant Width Rectangular Channels

Journal of Hydraulic Engineering, 2017

AbstractIn hydraulic engineering, it is common to find geometric transitions where a channel is n... more AbstractIn hydraulic engineering, it is common to find geometric transitions where a channel is not prismatic. Among these geometric transitions, constrictions and obstructions are channel reaches ...

Research paper thumbnail of One-dimensional Mathematical Modelling of Debris Flow Impact on Open-check Dams

Procedia Earth and Planetary Science, 2016

Research paper thumbnail of Optimal Location and Setting of PRVs in WDS for Leakage Minimization

Water Resources Management, 2016

Research paper thumbnail of Wind Height Distribution Influence on Offshore Wind Farm Feasibility Study

Research paper thumbnail of La riduzione delle perdite nelle reti di distribuzione idrica mediante il posizionamento e il settaggio ottimizzato di valvole

Nel presente lavoro viene proposta una metodologia per l’individuazione della posizione e del set... more Nel presente lavoro viene proposta una metodologia per l’individuazione della posizione e del settaggio ottimale di un preassegnato numero di valvole di riduzione della pressione da inserire all’interno di una rete di distribuzione idrica al fine di regolare l’andamento delle quote piezometriche. Pur rispettando i vincoli imposti sulle quote piezometriche, e tali da garantire il servizio all’utenza, la regolazione è effettuata in modo da ottenere una riduzione delle sollecitazioni a cui sono sottoposte le condotte e delle perdite di acqua nel sottosuolo che si realizzano nel corso della giornata. L’ubicazione ed il settaggio ottimale delle valvole vengono determinati mediante l’applicazione di un algoritmo genetico: la funzione obbiettivo utilizzata nella procedura di ottimizzazione è costituita dalla somma dei costi economici e sociali legati alle perdite idriche (qui identificati, a solo titolo esemplificativo, nel mancato beneficio per il gestore) e del costo di realizzazione e d...

Research paper thumbnail of Supercritical low-crested bilateral weirs: hydraulics and design procedure

Journal of Applied Water Engineering and Research, 2015

ABSTRACT Sideweirs are hydraulic structures commonly used in combined sewer systems for separatin... more ABSTRACT Sideweirs are hydraulic structures commonly used in combined sewer systems for separating excess storm water from urban sewage. In the case of low-crested sideweirs, the design is difficult because supercritical flows may establish along the overflow reach. This can lead to transcritical conditions not easily modelled in many cases. The present paper analyses the supercritical outflow process over a low-crested bilateral sideweir in a circular channel, based on both experimental and numerical investigations. Experiments were conducted to define the approach water depth and the free-surface profiles. The measurements were compared with the numerical values resulting from the application of energy and momentum conservation principles. The paper shows that the formulas used for estimating the end depth at free overfalls in circular channels can be applied to evaluate the approach water. The numerical investigation proves that the energy conservation approach allows for the computation of free-surface profiles with reasonable accuracy.

Research paper thumbnail of The analytic solution of the Shallow-Water Equations with partially open sluice-gates: The dam-break problem

Advances in Water Resources, 2015

Research paper thumbnail of One-dimensional Simulation of Debris-flow Inception and Propagation

Procedia Earth and Planetary Science, 2014

Research paper thumbnail of Boundary conditions in finite volume schemes for the solution of shallow-water equations: the non-submerged broad-crested weir

Journal of Hydroinformatics, 2014

The broad-crested weir can be regarded as a zone of rapid variation of the bottom elevation that ... more The broad-crested weir can be regarded as a zone of rapid variation of the bottom elevation that is short with respect to the characteristic length of the considered domain, and for this reason it can be conceptually modelled as a bed step. In this paper, the solution of the Riemann problem for the shallow-water equations over a bed step is exploited in order to simulate the behaviour of the broad-crested weirs, when these are present at the boundaries of the numerical domain. The issue of the multiplicity of solutions for this special Riemann problem is discussed, and rules are given in order to pick up the congruent solution among the alternatives. Finally, the proposed approach is implemented into a finite volume model for the approximate solution of one-dimensional shallow-water equations. Several numerical tests are carried out in order to demonstrate its possibilities and promising capabilities.

Research paper thumbnail of A numerical model for the simulation of debris flow triggering, propagation and arrest

Research paper thumbnail of Enhancing the Efficiency of the Automatic Design of Rural Drainage Networks

Journal of Irrigation and Drainage Engineering, 2014

ABSTRACT The discharges flowing through rural drainage networks depend not only on the local clim... more ABSTRACT The discharges flowing through rural drainage networks depend not only on the local climatic and hydrologic characteristics, but also on the geometric characteristics of the channels constituting the network. For this reason, the evaluation of the design discharges should be accomplished during the search of the optimal network. This leads to time-consuming optimization procedures, and it is desirable to devise efficient numerical alternatives. Two novel models, EGA and EGA-f, are proposed in order to increase the numerical efficiency of Genetic Algorithms for the solution of the optimal rural drainage network problem. Both EGA and EGA-f procedures are based on the use of the nodal excavation depths at the channel ends as decision variables Moreover, the EGA-f procedure improves EGA by freezing temporarily the design discharges during the optimization process in the case that uniform flows through the channels can be assumed. The application of the two models is demonstrated by means of numerical experiments, confirming their superiority over existing Genetic Algorithms for the optimization of rural drainage networks.

Research paper thumbnail of A well-balanced spectral volume scheme with the wetting–drying property for the shallow-water equations

Journal of Hydroinformatics, 2012

The shallow-water equations are widely used to model surface water bodies, such as lakes, rivers ... more The shallow-water equations are widely used to model surface water bodies, such as lakes, rivers and the swash zone in coastal flows. Physically congruent solutions are characterized by non-negative water depth, and many numerical methods may fail to preserve this property at the discrete level when moving wet–dry transitions are present in the physical domain. In this paper, we present a spectral-volume method for the approximate solution of the one-dimensional shallow-water equations, which is third-order accurate in wet regions, far from discontinuities, and which is well balanced for water at rest states: the stability of the solution is ensured if reconstruction and limitation of variables preserves non-negativity of the depth and a suitable constraint for the time step length is satisfied. A number of numerical experiments are reported, showing the promising capabilities of the model to solve problems with non-trivial topographies and friction.

Research paper thumbnail of Evaluating upward trends in groundwater nitrate concentrations: an example in an alluvial plain of the Campania region (Southern Italy)

Environmental Earth Sciences, 2020

Research paper thumbnail of On integral and differential porosity models for urban flooding simulation

Advances in Water Resources, 2019

Abstract A novel differential porosity model for urban flooding, namely the Binary Single Porosit... more Abstract A novel differential porosity model for urban flooding, namely the Binary Single Porosity model (BSP), is proposed in the present paper. The BSP model, which is derived from the Single Porosity (SP) model by constraining the porosity to attain only the values zero inside the buildings and one in the voids among the buildings, is local and independent on the existence of a Representative Elementary Volume (REV). The BSP model satisfies the Galilean invariance, while the corresponding wave speeds are identical to those of the Shallow water Equations model, and its integral formulation coincides with the original integral model by Sanders et al. (2008). The structure of the BSP model implies that the solution of the SP Riemann problem is the numerical building block for the construction of the corresponding Finite Volume schemes. This observation prompts a further study of the SP model and its solutions, demonstrating that the exact SP Riemann problem solution has the potential to take into account the transient energy losses due to wave reflections through the urban fabric in BSP models. Nonetheless, a further comparison with the two-dimensional SWE results demonstrates that additional stationary energy dissipations must be accurately taken into account through porosity reductions in the case of supercritical flow. The numerical experiments show that available approximate SP Riemann solvers may cause a systematic underestimation of the energy dissipation through the urban fabric and an overestimation of the flood celerity. The improvement of SP Riemann solvers could limit the resort to additional drag and momentum dissipation terms that are frequently added in numerical models. Finally, the investigation of the differential porosity models where different definitions are used for storage and conveyance porosity shows that these models suffer from a fundamental lack of physical congruence, implying that they cannot be used for the analysis of flood wave propagation through the urban fabric.

Research paper thumbnail of Multiple Solutions for the Riemann Problem in the Porous Shallow Water Equations

EPiC Series in Engineering

The Porous Shallow water Equations are widely used in the context of urban flooding simulation. I... more The Porous Shallow water Equations are widely used in the context of urban flooding simulation. In these equations, the solid obstacles are implicitly taken into account by averaging the classic Shallow water Equations on a control volume containing the fluid phase and the obstacles. Numerical models for the approximate solution of these equations are usually based on the approximate calculation of the Riemann fluxes at the interface between cells. In the present paper, it is presented the exact solution of the one-dimensional Riemann problem over the dry bed, and it is shown that the solution always exists, but there are initial conditions for which it is not unique. The non-uniqueness of the Riemann problem solution opens interesting questions about which is the physically congruent wave configuration in the case of solution multiplicity.

Research paper thumbnail of Cost-Based Design and Selection of Point Absorber Devices for the Mediterranean Sea

Research paper thumbnail of Flood propagation modeling with the Local Inertia Approximation: Theoretical and numerical analysis of its physical limitations

Advances in Water Resources, 2019

Research paper thumbnail of The solution of the Riemann problem in rectangular channels with constrictions and obstructions

Advances in Water Resources, 2019

Research paper thumbnail of The solution of the dam-break problem in the Porous Shallow water Equations

Advances in Water Resources, 2018

Research paper thumbnail of Nitrate trends in groundwater of the Campania region (southern Italy)

Environmental science and pollution research international, Jan 14, 2017

The Environmental Protection Agency of the Campania region in Italy (ARPAC) manages a groundwater... more The Environmental Protection Agency of the Campania region in Italy (ARPAC) manages a groundwater quality monitoring network. For almost all the polluted waters, the key parameter driving the classification is the concentration of nitrate; hence, the Campania region, in coherence with the EU regulations, outlined the vulnerable areas and undertook remediation policies. The best groundwater quality is recorded for carbonate aquifers of the Apennine chain; on the contrary, the Tyrrhenian coastal plains are affected by severe contamination, with a locally very contaminated groundwater of the shallow and also the deeper aquifers. The study is especially focused on a large coastal plain of Campania region, where nitrate concentration sometimes exceeds 200 mg/L. The study, based on almost 200 sampling points for the whole region during the period 2003-2015 (approx two samples per year), verified the effectiveness of the groundwater monitoring network, the present distribution of nitrate i...

Research paper thumbnail of Exact Solution of the Dam-Break Problem for Constrictions and Obstructions in Constant Width Rectangular Channels

Journal of Hydraulic Engineering, 2017

AbstractIn hydraulic engineering, it is common to find geometric transitions where a channel is n... more AbstractIn hydraulic engineering, it is common to find geometric transitions where a channel is not prismatic. Among these geometric transitions, constrictions and obstructions are channel reaches ...

Research paper thumbnail of One-dimensional Mathematical Modelling of Debris Flow Impact on Open-check Dams

Procedia Earth and Planetary Science, 2016

Research paper thumbnail of Optimal Location and Setting of PRVs in WDS for Leakage Minimization

Water Resources Management, 2016

Research paper thumbnail of Wind Height Distribution Influence on Offshore Wind Farm Feasibility Study

Research paper thumbnail of La riduzione delle perdite nelle reti di distribuzione idrica mediante il posizionamento e il settaggio ottimizzato di valvole

Nel presente lavoro viene proposta una metodologia per l’individuazione della posizione e del set... more Nel presente lavoro viene proposta una metodologia per l’individuazione della posizione e del settaggio ottimale di un preassegnato numero di valvole di riduzione della pressione da inserire all’interno di una rete di distribuzione idrica al fine di regolare l’andamento delle quote piezometriche. Pur rispettando i vincoli imposti sulle quote piezometriche, e tali da garantire il servizio all’utenza, la regolazione è effettuata in modo da ottenere una riduzione delle sollecitazioni a cui sono sottoposte le condotte e delle perdite di acqua nel sottosuolo che si realizzano nel corso della giornata. L’ubicazione ed il settaggio ottimale delle valvole vengono determinati mediante l’applicazione di un algoritmo genetico: la funzione obbiettivo utilizzata nella procedura di ottimizzazione è costituita dalla somma dei costi economici e sociali legati alle perdite idriche (qui identificati, a solo titolo esemplificativo, nel mancato beneficio per il gestore) e del costo di realizzazione e d...

Research paper thumbnail of Supercritical low-crested bilateral weirs: hydraulics and design procedure

Journal of Applied Water Engineering and Research, 2015

ABSTRACT Sideweirs are hydraulic structures commonly used in combined sewer systems for separatin... more ABSTRACT Sideweirs are hydraulic structures commonly used in combined sewer systems for separating excess storm water from urban sewage. In the case of low-crested sideweirs, the design is difficult because supercritical flows may establish along the overflow reach. This can lead to transcritical conditions not easily modelled in many cases. The present paper analyses the supercritical outflow process over a low-crested bilateral sideweir in a circular channel, based on both experimental and numerical investigations. Experiments were conducted to define the approach water depth and the free-surface profiles. The measurements were compared with the numerical values resulting from the application of energy and momentum conservation principles. The paper shows that the formulas used for estimating the end depth at free overfalls in circular channels can be applied to evaluate the approach water. The numerical investigation proves that the energy conservation approach allows for the computation of free-surface profiles with reasonable accuracy.

Research paper thumbnail of The analytic solution of the Shallow-Water Equations with partially open sluice-gates: The dam-break problem

Advances in Water Resources, 2015

Research paper thumbnail of One-dimensional Simulation of Debris-flow Inception and Propagation

Procedia Earth and Planetary Science, 2014

Research paper thumbnail of Boundary conditions in finite volume schemes for the solution of shallow-water equations: the non-submerged broad-crested weir

Journal of Hydroinformatics, 2014

The broad-crested weir can be regarded as a zone of rapid variation of the bottom elevation that ... more The broad-crested weir can be regarded as a zone of rapid variation of the bottom elevation that is short with respect to the characteristic length of the considered domain, and for this reason it can be conceptually modelled as a bed step. In this paper, the solution of the Riemann problem for the shallow-water equations over a bed step is exploited in order to simulate the behaviour of the broad-crested weirs, when these are present at the boundaries of the numerical domain. The issue of the multiplicity of solutions for this special Riemann problem is discussed, and rules are given in order to pick up the congruent solution among the alternatives. Finally, the proposed approach is implemented into a finite volume model for the approximate solution of one-dimensional shallow-water equations. Several numerical tests are carried out in order to demonstrate its possibilities and promising capabilities.

Research paper thumbnail of A numerical model for the simulation of debris flow triggering, propagation and arrest

Research paper thumbnail of Enhancing the Efficiency of the Automatic Design of Rural Drainage Networks

Journal of Irrigation and Drainage Engineering, 2014

ABSTRACT The discharges flowing through rural drainage networks depend not only on the local clim... more ABSTRACT The discharges flowing through rural drainage networks depend not only on the local climatic and hydrologic characteristics, but also on the geometric characteristics of the channels constituting the network. For this reason, the evaluation of the design discharges should be accomplished during the search of the optimal network. This leads to time-consuming optimization procedures, and it is desirable to devise efficient numerical alternatives. Two novel models, EGA and EGA-f, are proposed in order to increase the numerical efficiency of Genetic Algorithms for the solution of the optimal rural drainage network problem. Both EGA and EGA-f procedures are based on the use of the nodal excavation depths at the channel ends as decision variables Moreover, the EGA-f procedure improves EGA by freezing temporarily the design discharges during the optimization process in the case that uniform flows through the channels can be assumed. The application of the two models is demonstrated by means of numerical experiments, confirming their superiority over existing Genetic Algorithms for the optimization of rural drainage networks.

Research paper thumbnail of A well-balanced spectral volume scheme with the wetting–drying property for the shallow-water equations

Journal of Hydroinformatics, 2012

The shallow-water equations are widely used to model surface water bodies, such as lakes, rivers ... more The shallow-water equations are widely used to model surface water bodies, such as lakes, rivers and the swash zone in coastal flows. Physically congruent solutions are characterized by non-negative water depth, and many numerical methods may fail to preserve this property at the discrete level when moving wet–dry transitions are present in the physical domain. In this paper, we present a spectral-volume method for the approximate solution of the one-dimensional shallow-water equations, which is third-order accurate in wet regions, far from discontinuities, and which is well balanced for water at rest states: the stability of the solution is ensured if reconstruction and limitation of variables preserves non-negativity of the depth and a suitable constraint for the time step length is satisfied. A number of numerical experiments are reported, showing the promising capabilities of the model to solve problems with non-trivial topographies and friction.