Search results for "Water model"
showing 8 items of 18 documents
Effects of karst processes on surface water and groundwater hydrology at Skaistkalne Vicinity, Latvia
2012
The Skaistkalne area in Latvia is one of the places where karst processes in gypsum strata occurs. The Iecava and Memele rivers border the area with extensive surface karst features such as sinkholes and karst lakes. Earlier investigations suggested a hydraulic connection between the Iecava and Memele rivers exists via the karst conduits due to the water level (WL) difference in the rivers. A set of methods was performed to study the possible connection: dye tracer was applied in the Iecava river and its occurrence was visually observed at the karst lakes and Memele river; the current velocity was measured and discharge of rivers calculated at several profiles; surface water and groundwater…
Urban runoff modelling uncertainty: Comparison among Bayesian and pseudo-Bayesian methods
2009
Urban stormwater quality modelling plays a central role in evaluation of the quality of the receiving water body. However, the complexity of the physical processes that must be simulated and the limited amount of data available for calibration may lead to high uncertainty in the model results. This study was conducted to assess modelling uncertainty associated with catchment surface pollution evaluation. Eight models were compared based on the results of a case study in which there was limited data available for calibration. Uncertainty analysis was then conducted using three different methods: the Bayesian Monte Carlo method, the GLUE pseudo-Bayesian method and the GLUE method revised by m…
Solute-induced Water Structure: Computer Simulation on a Model System
1988
Abstract Two series of Monte Carlo simulations have been carried out on a system consisting of 125 water molecules, one of which is kept fixed to simulate a water molecule whose mobility is restricted by a solute. The results are checked against similar simulations without restrictions, used as a control, and they show how the blocked molecule helps increase both the structural order and the connectivity of the hydrogen bond network. Cooperativity originating from proton polarizability of H-bonds and/or from many-body terms of interaction potentials cannot be involved since we use a rigid water model and ab initio pair potentials. The present findings are interpreted as indicative of a moti…
The GSA-GLUE approach for uncertainty assessment of an integrated MBR model
2012
In the recent literature, the uncertainty of wastewater treatment plant (WWTP) modelling has had relevant interest both for designers and operators. Indeed, the frequent data lacking and the need to improve process knowledge, in case of innovative technologies, make the use of mathematical models more uncertain. Therefore, the need to make model uncertainty more explicit is warmly recommended. However, only few applications of uncertainty analysis in the wastewater field have been carried out. In this work, the combination of the global sensitivity analysis (GSA) and the Generalized Likelihood Uncertainty Estimation (GLUE) is applied for the uncertainty assessment of a WWTP model, in order …
A shallow water SPH model with PML boundaries
2015
Abstract We focus on the study and implementation of Smoothed Particle Hydrodynamics (SPH) numerical code to deal with non-reflecting boundary conditions, starting from the Perfect Matched Layer (PML) approach. Basically, the method exploits the concept of a physical damping which acts on a fictitious layer added to the edges of computational domain. In this paper, we develop the study of time dependent shallow waves propagating on a finite 2D-XY plane domain and their behavior in the presence of circular and, more generic, rectangular boundary absorbing layers. In particular, an analysis of variation of the layer׳s thickness versus the absorbing efficiency is conducted. In our model, the m…
Uncertainty assessment of a model for biological nitrogen and phosphorus removal: Application to a large wastewater treatment plant
2012
Abstract In the last few years, the use of mathematical models in WasteWater Treatment Plant (WWTP) processes has become a common way to predict WWTP behaviour. However, mathematical models generally demand advanced input for their implementation that must be evaluated by an extensive data-gathering campaign, which cannot always be carried out. This fact, together with the intrinsic complexity of the model structure, leads to model results that may be very uncertain. Quantification of the uncertainty is imperative. However, despite the importance of uncertainty quantification, only few studies have been carried out in the wastewater treatment field, and those studies only included a few of …
Simple absorbing layer conditions for shallow wave simulations with Smoothed Particle Hydrodynamics
2013
Abstract We study and implement a simple method, based on the Perfectly Matched Layer approach, to treat non reflecting boundary conditions with the Smoothed Particles Hydrodynamics numerical algorithm. The method is based on the concept of physical damping operating on a fictitious layer added to the computational domain. The method works for both 1D and 2D cases, but here we illustrate it in the case of 1D and 2D time dependent shallow waves propagating in a finite domain.
New Trends in Urban Drainage Modelling
2019
This book addresses the latest research advances, innovations, and applications in the field of urban drainage and water management as presented by leading researchers, scientists and practitioners from around the world at the 11th International Conference on Urban Drainage Modelling (UDM), held in Palermo, Italy from 23 to 26 September, 2018. The conference was promoted and organized by the University of Palermo, Italy and the International Working Group on Data and Models, with the support of four of the world’s leading organizations in the water sector: the International Water Association (IWA), International Association for Hydro-Environment Engineering and Research (IAHR), Environmenta…