Improvement of pre- and post-processing environments of the dynamic two-dimensional reservoir model CE-QUAL-W2 based on GIS

2003 ◽  
Vol 48 (10) ◽  
pp. 79-88 ◽  
Author(s):  
S.-R. Ha ◽  
G.-J. Bae ◽  
D.-H. Park ◽  
J.H. Cho
Keyword(s):  
Water Quality ◽  
Information System ◽  
Water Body ◽  
Model Simulation ◽  
Depth Map ◽  
Water Volume ◽  
Data Set ◽  
Environmental Information System ◽  
Water Quality Models ◽  
Optimal Set

An Environmental Information System (EIS) coupled with a Geographic Information System (GIS) and water quality models is developed to improve the pre- and post-data processing function of CE-QUAL-W2. Since the accuracy of the geometric data in terms of a diverse water body has a great effect on the water quality variables such as the velocity, kinetic reactions, the horizontal and vertical momentum, to prepare the bathymetry information has been considered a difficult issue for modellers who intend to use the model. For identifying Cross Section and Profile Information (CSPI), which precisely contains hydraulic features and geographical configuration of a waterway, the automated CSPI extraction program has been developed using Avenue Language of the PC Arc/view package. The program consists of three major steps: (1) getting the digital depth map of a waterway using GIS techniques; (2) creating a CSPI data set of segments in each branch using the program for CE-QUAL-W2 bathymetry input; (3) selecting the optimal set of bathymetry input by which the calculated water volume meets the observed volume of the water body. Through those approaches, it is clear that the model simulation results in terms of water quality as well as reservoir hydraulics rely upon the accuracy of bathymetry information.

GIS-based Surface Water Monitoring System and Modelling for Conservative and Reactive Pollutants, Applied on the Upper Basin of Olt River

2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Alexandru M�sz�ros ◽  
Szabolcs L�nyi ◽  
Szilard M�t� ◽  
Nicolae Vasiliu ◽  
Daniela Vasiliu
Keyword(s):  
Experimental Data ◽  
Water Quality ◽  
Information System ◽  
Surface Water ◽  
Quality Parameters ◽  
Oxygen Balance ◽  
Data Set ◽  
Proposed Model ◽  
Environmental Information System ◽  
Pollutant Propagation

This paper presents the problem of pollutant propagation monitoring and modeling on the upper zone of a river. The first model of the pollutant propagation is based on the averaging mass balance, without computing chemical and biochemical transformations. The second model was developed using the Streeter Phelps oxygen balance, including the kinetic terms of re-aeration and oxygen consuming. Experimental data set was obtained on the upper zone of the Olt River; using this data set, the proposed model was calibrated. The development of the model is like a part of a GIS-based environmental information system. Calculated results are depicted by diagrams and thematic maps of the upper Basin of Olt River, representing the water-quality parameters.

scholarly journals Linking Numerical Water Quality Models in an Environmental Information System for Integrated Environmental Assessments

2013 ◽  
Vol 04 (07) ◽  
pp. 126-137 ◽  
Author(s):  
Franklin Torres-Bejarano ◽  
Hermilo Ramirez ◽  
Ralf Denzer ◽  
Steven Frysinger ◽  
Thorsten Hell ◽  
...  
Keyword(s):  
Water Quality ◽  
Information System ◽  
Environmental Information ◽  
Environmental Assessments ◽  
Quality Models ◽  
Environmental Information System ◽  
Water Quality Models

Techniques for Exploring and Presenting Data Applied to Lake Phosphorus Concentration

1980 ◽  
Vol 37 (2) ◽  
pp. 290-294 ◽  
Author(s):  
K. H. Reckhow
Keyword(s):  
Water Quality ◽  
Data Analysis ◽  
Information Transfer ◽  
Exploratory Data Analysis ◽  
Statistical Significance ◽  
Phosphorus Concentration ◽  
Data Set ◽  
Exploratory Data ◽  
Water Quality Models ◽  
Single Graph

Water quality sampling and data analysis are undertaken to acquire and convey information. Therefore, when data are presented, the form of this presentation should be such that information transfer is high. For example, a graph or table of average values is often an inadequate summary of batches of data. As an alternative, a technique is presented (that was developed for exploratory data analysis purposes) that can be used to display several sets of data on a single graph, indicating median, spread, skew, size of data set, and statistical significance of the median. This technique is useful in the study of phosphorus concentration variability in lakes. Additions to, and modifications of, this procedure are easily made and will often enhance the analysis of a particular problem. Some suggestions are made for useful modifications of the plots in the study and display of phosphorus lake data and models.Key words: limnology, exploratory data analysis, statistics, phosphorus, water quality, models, lakes

scholarly journals Auto-calibration of a one-dimensional hydrodynamicecological model (DYRESM 4.0-CAEDYM 3.1) using a Monte Carlo approach: simulations of hypoxic events in a polymictic lake

2017 ◽  
Author(s):  
Liancong Luo ◽  
David Hamilton ◽  
Jia Lan ◽  
Chris McBride ◽  
Dennis Trolle
Keyword(s):  
Water Quality ◽  
Monte Carlo ◽  
Pearson Correlation ◽  
State Variables ◽  
Data Set ◽  
Quality Models ◽  
One Dimensional ◽  
R Value ◽  
Water Quality Models ◽  
Polymictic Lake

Abstract. Automated calibration of complex deterministic water quality models with a large number of biogeochemical parameters can reduce time-consuming iterative simulations involving empirical judgements of model fit. We undertook auto-calibration of the one-dimensional hydrodynamic-ecological lake model DYRESM-CAEDYM, using a Monte Carlo Sampling (MCS) method, in order to test the applicability of this procedure for shallow, polymictic Lake Rotorua (New Zealand). The calibration procedure involved independently minimising the root-mean-square-error (RMSE), maximizing the Pearson correlation coefficient (r) and Nash-Sutcliffe efficient coefficient (Nr) for comparisons of model state variables against measured data. An assigned number of parameter permutations was used for 10,000 simulation iterations. The optimal temperature calibration produced a RMSE of 0.54 °C, Nr-value of 0.99 and r-value of 0.98 through the whole water column based on comparisons with 540 observed water temperatures collected between 13 July 2007–13 January 2009. The modeled bottom dissolved oxygen concentration (20.5 m below surface) was compared with 467 available observations. The calculated RMSE of the simulations compared with the measurements was 1.78 mg L−1, the Nr-value was 0.75 and the r-value was 0.87. The autocalibrated model was further tested for an independent data set by simulating bottom-water hypoxia events for the period 15 January 2009 to 8 June 2011 (875 days). This verification produced an accurate simulation of five hypoxic events corresponding to DO < 2 mg L−1 during summer of 2009–2011. The RMSE was 2.07 mg L−1, Nr-value 0.62 and r-value of 0.81, based on the available data set of 738 days. The auto-calibration software of DYRESM-CAEDYM developed here is substantially less time-consuming and more efficient in parameter optimisation than traditional manual calibration which has been the standard tool practiced for similar complex water quality models.

Application of Geostatistics Model Based on Geographic Information System in Urban Heat Environment

2011 ◽  
Vol 58-60 ◽  
pp. 2303-2307 ◽  
Author(s):  
Guo Dong Li ◽  
Jun Hua Zhang ◽  
Zi Sheng Zhao ◽  
Li Ping Zhao
Keyword(s):  
Information System ◽  
Geographic Information System ◽  
Spatial Data ◽  
Thermal Field ◽  
Model Simulation ◽  
Geographic Information ◽  
Observation Data ◽  
Analysis Model ◽  
Data Set ◽  
Simulation Accuracy

Geographic Information System (GIS) database is built by ArcGIS software based on observation data in Lanzhou city. GIS data set was analyzed, including testing data distribution, the trend analysis of spatial data, data outlier analysis. According to the analysis results, the appropriate spatial analysis model is chosen to simulate and predict thermal field. Cross validation method is used to verify simulation accuracy and validity of model. Simulation map of urban thermal in is output by optimal model and parameters eventually. Results show that urban thermal field presents regular distribution in summer. The spatial distribution characteristics of thermal field have directly relations with land use type, urban energy consumption, population density, building volume rate, and thermodynamic properties of underlying surface.

Test of the efficiency of three storm water quality models with a rich set of data

2005 ◽  
Vol 51 (2) ◽  
pp. 171-177 ◽  
Author(s):  
M. Ahyerre ◽  
F.O. Henry ◽  
F. Gogien ◽  
M. Chabanel ◽  
M. Zug ◽  
...  
Keyword(s):  
Water Quality ◽  
Global Scale ◽  
Storm Water ◽  
Rain Event ◽  
Quality Model ◽  
Data Set ◽  
Quality Models ◽  
Order Of Magnitude ◽  
Rain Events ◽  
Water Quality Models

The objective of this article is to test the efficiency of three different Storm Water Quality Model (SWQM) on the same data set (34 rain events, SS measurements) sampled on a 42 ha watershed in the center of Paris. The models have been calibrated at the scale of the rain event. Considering the mass of pollution calculated per event, the results on the models are satisfactory but that they are in the same order of magnitude as the simple hydraulic approach associated to a constant concentration. In a second time, the mass of pollutant at the outlet of the catchment at the global scale of the 34 events has been calculated. This approach shows that the simple hydraulic calculations gives better results than SWQM. Finally, the pollutographs are analysed, showing that storm water quality models are interesting tools to represent the shape of the pollutographs, and the dynamics of the phenomenon which can be useful in some projects for managers.

scholarly journals Sensitivity Analysis of Input Data in Surface Water Quality Models

2019 ◽  
Vol 22 (2) ◽  
pp. 84-87 ◽  
Author(s):  
Martin Manina ◽  
Peter Halaj
Keyword(s):  
Water Quality ◽  
Input Data ◽  
Initial Conditions ◽  
Model Simulation ◽  
Roughness Coefficient ◽  
Strong Impact ◽  
Pollution Transport ◽  
Quality Models ◽  
Water Quality Models ◽  
The Impact

Abstract The article is focused on analysis of input data impact on outputs of water quality models. The authors examined the impact of roughness coefficient, both boundary and initial conditions setup on changes of outputs generated by HEC-RAS model. Simulation results have shown a various response rate of input data on simulated results. The strong impact shows roughness coefficient setup that through the value of longitudinal dispersion coefficient affects pollution transport process. Changes in boundary conditions have had less influence on outputs. Relatively strong impact shows the setup of initial state of pollution concentration along the reach mainly for the case of low gradient rivers.

scholarly journals Autocalibration of a one-dimensional hydrodynamic-ecological model (DYRESM 4.0-CAEDYM 3.1) using a Monte Carlo approach: simulations of hypoxic events in a polymictic lake

2018 ◽  
Vol 11 (3) ◽  
pp. 903-913 ◽  
Author(s):  
Liancong Luo ◽  
David Hamilton ◽  
Jia Lan ◽  
Chris McBride ◽  
Dennis Trolle
Keyword(s):  
Water Quality ◽  
Monte Carlo ◽  
Pearson Correlation ◽  
State Variables ◽  
Data Set ◽  
Quality Models ◽  
One Dimensional ◽  
R Value ◽  
Water Quality Models ◽  
Polymictic Lake

Abstract. Automated calibration of complex deterministic water quality models with a large number of biogeochemical parameters can reduce time-consuming iterative simulations involving empirical judgements of model fit. We undertook autocalibration of the one-dimensional hydrodynamic-ecological lake model DYRESM-CAEDYM, using a Monte Carlo sampling (MCS) method, in order to test the applicability of this procedure for shallow, polymictic Lake Rotorua (New Zealand). The calibration procedure involved independently minimizing the root-mean-square error (RMSE), maximizing the Pearson correlation coefficient (r) and Nash–Sutcliffe efficient coefficient (Nr) for comparisons of model state variables against measured data. An assigned number of parameter permutations was used for 10 000 simulation iterations. The “optimal” temperature calibration produced a RMSE of 0.54 ∘C, Nr value of 0.99, and r value of 0.98 through the whole water column based on comparisons with 540 observed water temperatures collected between 13 July 2007 and 13 January 2009. The modeled bottom dissolved oxygen concentration (20.5 m below surface) was compared with 467 available observations. The calculated RMSE of the simulations compared with the measurements was 1.78 mg L−1, the Nr value was 0.75, and the r value was 0.87. The autocalibrated model was further tested for an independent data set by simulating bottom-water hypoxia events from 15 January 2009 to 8 June 2011 (875 days). This verification produced an accurate simulation of five hypoxic events corresponding to DO < 2 mg L−1 during summer of 2009–2011. The RMSE was 2.07 mg L−1, Nr value 0.62, and r value of 0.81, based on the available data set of 738 days. The autocalibration software of DYRESM-CAEDYM developed here is substantially less time-consuming and more efficient in parameter optimization than traditional manual calibration which has been the standard tool practiced for similar complex water quality models.

Development of Environmental Information System for the Tarim River Basin

2010 ◽  
Vol 26 (3) ◽  
pp. 347-353
Author(s):  
Jian-kang SHI ◽  
An-ming BAO ◽  
Hai-long LIU ◽  
Xian-wei FENG ◽  
Wei-sheng WANG ◽  
...  
Keyword(s):  
Information System ◽  
River Basin ◽  
Environmental Information ◽  
Tarim River ◽  
Tarim River Basin ◽  
The Tarim River ◽  
Environmental Information System ◽  
The Tarim River Basin
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