water quality modeling Articles
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Water Quality Modelling
Water quality modelling involves the prediction of water pollution using mathematical simulation techniques. A typical water quality model consists of a collection of formulations representing physical mechanisms that determine position and momentum of pollutants in a water body. Models are available for individual components of the hydrological system such as surface runoff; there also exist ...
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On the effect of scaling conceptual model complexity on stochastic response for water quality modeling
This paper extends previous work comparing the response of water quality models under uncertainty. A new model, the River Water Quality Model no. 1 (RWQM1), is compared to the previous work of two commonly used water quality models. Additionally, the effect of conceptual model scaling within a single modelling framework, as allowed by RWQM1, is explored under uncertainty. Model predictions are ...
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Water quality model parameter identification of an open channel in a long distance water transfer project based on finite difference, difference evolution and Monte Carlo
A new method is proposed based on the finite difference method (FDM), differential evolution algorithm and Markov Chain Monte Carlo (MCMC) simulation to identify water quality model parameters of an open channel in a long distance water transfer project. Firstly, this parameter identification problem is considered as a Bayesian estimation problem and the forward numerical model is solved by ...
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Applying Monte Carlo and classification tree sensitivity analysis to the Zayandehrood River
Water quality modeling is an important issue for both engineers and scientists. The QUAL2K model is a simulation tool that has been used widely for this purpose. Uncertainty and sensitivity analysis is a major step in water quality modeling. This article reports application of Monte Carlo analysis and classification tree sensitivity analysis in the modeling of the Zayandehrood River. First the ...
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Continuous simulation of suspended sediment through a stream section
This paper presents the development of a one–dimensional stream water quality model for the continuous simulation of suspended sediment transport and deposition processes along a particular stream section. The model integrates stream hydraulics and suspended sediment transport and deposition processes. The stream hydraulic model was developed using the Muskingum–Cunge method of channel routing. ...
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Parameter identification of river water quality models using a genetic algorithm
For solving the multi-parameter identification problem of a river water quality model, analytical methods for solving a river water quality model and traditional optimization algorithms are very difficult to implement. A new parameter identification model based on a genetic algorithm (GA) coupled with finite difference method (FDM) was constructed for the determination of hydraulic and water ...
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Input variable selection and calibration data selection for storm water quality regression models
Storm water quality models are useful tools in storm water management. Interest has been growing in analyzing existing data for developing models for urban storm water quality evaluations. It is important to select appropriate model inputs when many candidate explanatory variables are available. Model calibration and verification are essential steps in any storm water quality modeling. This ...
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Water Quality Models
' In order to determine the impacts of a particular discharge on ambient water quality, it is usually necessary to model the diffusion and dispersion of the discharge in the relevant water body. The approach applies both to new discharges and to upgrading of existing sources. This note provides guidance on models that may be applicable in the context of typical Bank projects.' Introduction ...
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IberWQ: new simulation tool for 2D water quality modelling in rivers and shallow estuaries
This paper presents a new freeware simulation tool (IberWQ) for 2D water quality modelling in rivers and non-stratified estuaries. The model computes the spatial and temporal evolution of several species and variables which are relevant for the evaluation of the environmental status of rivers and estuaries, including: Escherichia coli, dissolved oxygen, carbonaceous biochemical oxygen demand, ...
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Assessment of water quality modelling capabilities of EPANET multiple species and pressure-dependent extension models
The need for accurately predicting water quality through models has increasingly been crucial in meeting rigorous standards and customer expectations. There are several endeavours on developing robust water quality models for water distribution systems. In this paper, two variants of the EPANET 2 water quality model have been assessed to inform future research. The models are the multiple ...
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Impact of rainfall temporal resolution on urban water quality modelling performance and uncertainties
A key control on the response of an urban drainage model is how well the observed rainfall records represent the real rainfall variability. Particularly in urban catchments with fast response flow regimes, the selection of temporal resolution in rainfall data collection is critical. Furthermore, the impact of the rainfall variability on the model response is amplified for water quality ...
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Prediction of biochemical oxygen demand at the upstream catchment of a reservoir using adaptive neuro fuzzy inference system
The aim of this study is to examine the potential of adaptive neuro fuzzy inference system (ANFIS) to estimate biochemical oxygen demand (BOD). To illustrate the applicability of ANFIS method, the upstream catchment of Feitsui Reservoir in Taiwan is chosen as the case study area. The appropriate input variables used to develop the ANFIS models are determined based on the t-test. The results ...
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Neural network and genetic programming for modelling coastal algal blooms
In the recent past, machine learning (ML) techniques such as artificial neural networks (ANN) have been increasingly used to model algal bloom dynamics. In the present paper, along with ANN, we select genetic programming (GP) for modelling and prediction of algal blooms in Tolo Harbour, Hong Kong. The study of the weights of the trained ANN and also the GP-evolved equations shows that they ...
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Extension of the River Water Quality Model No. 1 with the fate of pesticides
The existing River Water Quality Model No. 1 (RWQM1) was extended with processes determining the fate of non-volatile pesticides in the water phase and sediments. The exchange of pesticides between the water column and the sediment is described by three transport processes: diffusion, sedimentation and resuspension. Burial of sediments is also included. The modified model was used to simulate the ...
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A study to estimate the fate and transport of bacteria in river water from birds nesting under a bridge
To investigate the effect of input parameters, such as the number of bridge-dwelling birds, decay rate of the bacteria, flow at the river, water temperature, and settling velocity, a parametric study was conducted using a water quality model developed with QUAL2Kw. The reach of the bacterial-impaired section from the direct droppings of bridge-nesting birds at the Guadalupe River near ...
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A hydrodynamic water quality model for propagation of pollutants in rivers
Numerical modelling can be a useful tool to assess a receiving water body's quality state. Indeed, the use of mathematical models in river water quality management has become a common practice to show the cause-effect relationship between emissions and water body quality and to design as well as assess the effectiveness of mitigation measures. In the present study, a hydrodynamic river water ...
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Effluent carbonaceous biochemical oxygen demand (CBOD) characterization for modern pulp and paper facilities
As receiving water quality models are being used to address dissolved oxygen issues requiring an increased degree of resolution, a more refined characterization of effluent CBOD can become an important aspect of the analysis. The selection and use of kinetic models to identify effluent specific parameters can have a significant impact on this characterization. This study modeled effluents from ...
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Applicability of MIKE 21 to assess temporal and spatial variation in water quality of an estuary under the impact of effluent from an industrial estate
This study aims at analysing the impact of wastewater load of industrial units in Haldia on the water quality of the Hoogly estuary using numerical modelling techniques. Modelling was never attempted in this region because it was generally felt that simulating such a complex system would not be easy with limited data availability but MIKE 21, a hydrodynamic and water quality model, was used to ...
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Predictive water quality modelling and resilience flow conditioning to manage discolouration risk in operational trunk mains
This paper presents predictive discolouration modelling and subsequent field trial validation for a cast iron trunk main network. This enabled a UK water company to propose an ‘operational flow conditioning’ maintenance plan that reduces discolouration risk, improves network resilience and asset condition and yet does not require the trunk main to be decommissioned for invasive ...
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A grey-encoded hybrid accelerating genetic algorithm for parameter optimisation of environmental models
A new method, grey-encoded hybrid accelerating genetic algorithm, is presented for the parameter optimisation of environmental models. With the shrinking of searching range, the method gradually directs to optimal result with the excellent individuals obtained by grey genetic algorithm embedding Nelder-Mead simplex searching operator. The convergence theorem is given for guaranteeing the global ...
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