scholarly journals Application of MODFLOW with Boundary Conditions Analyses Based on Limited Available Observations: A Case Study of Birjand Plain in East Iran

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1904 ◽  
Author(s):  
Aghlmand ◽  
Abbasi
Keyword(s):  
Boundary Conditions ◽  
Groundwater Resources ◽  
Model Performance ◽  
Absolute Error ◽  
Real Field ◽  
Model Parameters ◽  
Water Demands ◽  
Modeling Software ◽  
Sustainable Planning

Increasing water demands, especially in arid and semi-arid regions, continuously exacerbate groundwater resources as the only reliable water resources in these regions. Groundwater numerical modeling can be considered as an effective tool for sustainable management of limited available groundwater. This study aims to model the Birjand aquifer using GMS: MODFLOW groundwater flow modeling software to monitor the groundwater status in the Birjand region. Due to the lack of the reliable required data to run the model, the obtained data from the Regional Water Company of South Khorasan (RWCSK) are controlled using some published reports. To get practical results, the aquifer boundary conditions are improved in the established conceptual method by applying real/field conditions. To calibrate the model parameters, including the hydraulic conductivity, a semi-transient approach is applied by using the observed data of seven years. For model performance evaluation, mean error (ME), mean absolute error (MAE), and root mean square error (RMSE) are calculated. The results of the model are in good agreement with the observed data and therefore, the model can be used for studying the water level changes in the aquifer. In addition, the results can assist water authorities for more accurate and sustainable planning and management of groundwater resources in the Birjand region.

scholarly journals Calibration and Validation of SWAT Model for Low Lying Watersheds: A Case Study on the Kliene Nete Watershed, Belgium

1970 ◽  
Vol 6 ◽  
pp. 47-51 ◽  
Author(s):  
Narayan K. Shrestha ◽  
P C Shakti ◽  
Pabitra Gurung
Keyword(s):  
Assessment Tool ◽  
Swat Model ◽  
Model Performance ◽  
Time Frame ◽  
Model Parameters ◽  
Domain Modeling ◽  
Calibration And Validation ◽  
Modeling Software ◽  
Interesting Task

Use of easily accessible; public domain modeling software called Soil and Water Assessment Tool (SWAT) and its testing in watersheds has become essential to check developers' claims of its applicability. The SWAT model performance on Kliene Nete Watershed (Belgium) is examined. Given the watershed’s characteristic of a low lying; shallow ground water table, the test becomes an interesting task to perform. This paper presents calibration and validation of the watershed covering area of 581km2 . Flow separation is carried on using Water Engineering Time Series Processing tool (WETSPRO) and shows that around 60% of the total fow is contributed by base fow. Altogether seven SWAT model parameters have been calibrated with heuristic approach for the time frame of 1994-1998. Validation of these calibrated parameters in another independent time frame (1999-2002) is carried out. The parameter CH_k2 (Channel Effective Hydraulic Conductivity) is found to be the most sensitive. Nash Sutcliff Efficiency (NSE) values for the calibration and validation periods are found to be 74 and 67 percent-age, respectively. These ‘goodness-of-ft’ statistics, supported by graphical representations, show that the SWAT model can simulate such watershed with reasonable accuracy.Key words: SWAT; WETSPRO; Kliene Nete Watershed (Belgium); NSEDOI: 10.3126/hn.v6i0.4194Hydro Nepal Journal of Water, Energy and EnvironmentVol. 6, January 2010Page: 47-51Uploaded Date: 24 January, 2011

Probabilistic Analysis by Applying Uncertainty Worflows: A Case Study of the Teak Field, East Coast Trinidad

2014 ◽  
Author(s):  
C.J.. J. Segnini ◽  
M.. Rashwan ◽  
M.J.. J. Hernandez ◽  
J. A. Rojas ◽  
M.A.. A. Infante
Keyword(s):  
Reservoir Simulation ◽  
Probabilistic Analysis ◽  
East Coast ◽  
Dynamic Properties ◽  
Large Population ◽  
Model Performance ◽  
Current Standard ◽  
Modeling Software ◽  
Uncertainty Analyses

Abstract This paper presents a methodology for the probabilistic analysis of an infill or step-out opportunity using numerical simulation. Sensitivity and uncertainty analyses for all involved parameters were evaluated through different experimental design techniques. Subsequently, a proxy model was established to reproduce the numerical model performance. Finally, three appropriate solutions were selected from a large population of realizations corresponding to probabilistic percentiles (90%, 50%, and 10% certainty that the specified volume will be recovered). This proposed methodology helped the asset team to evaluate the well candidates more precisely, confidently, and in less time than the current standard methodology. More knowledge about the variables and their effects on overall outcomes was also gained, which helped the team make more-informed decisions. The workflow used the same numerical modeling software, incorporating and facilitating the changes of both static and dynamic properties simultaneously. A case study from Teak field, on the east coast of Trinidad, illustrates the applicability of the methodology and compares its results to those obtained using the standard workflow for the asset. The methodology is one of the latest developments in reservoir simulation, and it has not yet been incorporated into the operator's common practices and procedures for exploitation of the TSP fields.

scholarly journals An approach to identify time consistent model parameters: sub-period calibration

2013 ◽  
Vol 17 (1) ◽  
pp. 149-161 ◽  
Author(s):  
S. Gharari ◽  
M. Hrachowitz ◽  
F. Fenicia ◽  
H. H. G. Savenije
Keyword(s):  
Model Performance ◽  
Realistic Model ◽  
Parameter Estimates ◽  
Model Parameters ◽  
New Approach ◽  
Consistent Model ◽  
Set Up ◽  
Consistent Parameter

Abstract. Conceptual hydrological models rely on calibration for the identification of their parameters. As these models are typically designed to reflect real catchment processes, a key objective of an appropriate calibration strategy is the determination of parameter sets that reflect a "realistic" model behavior. Previous studies have shown that parameter estimates for different calibration periods can be significantly different. This questions model transposability in time, which is one of the key conditions for the set-up of a "realistic" model. This paper presents a new approach that selects parameter sets that provide a consistent model performance in time. The approach consists of testing model performance in different periods, and selecting parameter sets that are as close as possible to the optimum of each individual sub-period. While aiding model calibration, the approach is also useful as a diagnostic tool, illustrating tradeoffs in the identification of time-consistent parameter sets. The approach is applied to a case study in Luxembourg using the HyMod hydrological model as an example.

scholarly journals Assessing impacts of discrepancies in model parameters on autoignition model performance: A case study using butanol

2018 ◽  
Vol 190 ◽  
pp. 284-292 ◽  
Author(s):  
Sai Krishna Sirumalla ◽  
Morgan A. Mayer ◽  
Kyle E. Niemeyer ◽  
Richard H. West
Keyword(s):  
Model Performance ◽  
Model Parameters

Application of Visual MODFLOW to the Analysis of Boundary Conditions for a Phreatic Porous Aquifer Using Limited Available Information: A Case Study

2021 ◽  
Vol 44 ◽  
Author(s):  
Milena Stefany Lage Almeida ◽  
JOSÉ AUGUSTO COSTA GONÇALVES
Keyword(s):  
Boundary Conditions ◽  
Groundwater Flow ◽  
Root Mean Square ◽  
Flow Behavior ◽  
Groundwater Resources ◽  
Absolute Error ◽  
Mean Square ◽  
Visual Modflow ◽  
Porous Aquifer ◽  
The Mean

The increasing water demand, especially in developing regions, continuously puts pressure on groundwater resources both quantitatively and qualitatively. Hydrogeological modeling is a tool used in planning and management of groundwater resources. The factors that interfere in groundwater flow dynamics can be determined by developing a conceptual model and they can be validated via a numerical model. The objective of the manuscript is the hydrogeological groundwater flow modeling of the phreatic porous aquifer of the Ribeirão Candidópolis catchment in the Itabira municipality, State of Minas Gerais (Brazil). The software used in this study is GMS: MODFLOW, which enabled a steady state flow regime modeling by means of the Finite Difference Method (FDM) and the parameters calibration from a semi-transient approach. To assess the performance of the model, the Mean Error (ME), the Mean Absolute Error (MAE), and the Root Mean Square Error (RMSE) were calculated. The results proved to be compatible with the values observed in the field. After several adjustments of the boundary conditions, a Normalized Root Mean Square (NRMS) of 9.648% and a correlation coefficient of 0.993 were obtained. Despite the economic importance of the study area, studies made available on groundwater flow behavior are rare. The results obtained via modeling are in accordance with the data observed in the field and consequently our model can be used in the study of water level changes.

scholarly journals IMPACTS OF CLIMATE CHANGES ON HYDROLOGIC BALANCE: A CASE STUDY OF VOCHA PLAIN, KORINTHIA

2017 ◽  
Vol 50 (2) ◽  
pp. 1068
Author(s):  
P. Venetsanou ◽  
C. Anagnostopoulou ◽  
K. Voudouris
Keyword(s):  
Climate Model ◽  
Coastal Region ◽  
Model Parameters ◽  
Southeastern Part ◽  
Water Demands ◽  
Precipitation Decrease ◽  
Reliable Model ◽  
The Future ◽  
Model Precipitation

The aim of this study is to evaluate climate model hydrological parameters in comparison to recorded hydrological data and estimate the impacts of climate change on water balance. For this purpose, a combination of climate model precipitation and temperature data and Thornthwaite method was applied for the period 1988-2000 and the future periods 2028-2040, 2058-2070 and 2088 2100. The application of this combination was carried out in a coastal region in Southeastern part of Korinthiakos Gulf (southern Greece). The area is suitable for this target, because it is characterized by urbanization, intensive agriculture and tourism development, with increasing water demands. The evaluation of climate model parameters in comparison to observed data shows that the RegCM3 model is a reliable model. According to the future projections and the Thornthwaite method, the real evapotranspiration is estimated to increase, as a result precipitation decrease and temperature increase.

scholarly journals GA-optimized model predicts dispersion coefficient in natural channels

2009 ◽  
Vol 40 (1) ◽  
pp. 65-78 ◽  
Author(s):  
Gokmen Tayfur
Keyword(s):  
Objective Function ◽  
Dispersion Coefficient ◽  
Mean Absolute Error ◽  
Nonlinear Models ◽  
Error Function ◽  
Model Performance ◽  
Absolute Error ◽  
Model Parameters ◽  
Longitudinal Dispersion Coefficient ◽  
Optimal Values

Models whose parameters were optimized by genetic algorithm (GA) were developed to predict the longitudinal dispersion coefficient in natural channels. Following the existing equations in the literature, ten different linear and nonlinear models were first constructed. The models relate the dispersion coefficient to flow and channel characteristics. The GA model was then employed to find the optimal values of the constructed model parameters by minimizing the mean absolute error function (objective function). The GA model utilized an 80% cross-over rate and 4% mutation rate. It started each computation with a population of 100 chromosomes in the gene pool. For each model, while minimizing the objective function, the values of the model parameters were constrained between [−10, +10] at each iteration. The optimal values of the model parameters were obtained using a calibration set of 54 out of 80 sets of measured data. The minimum error was obtained for the case where the model was a linear equation relating dispersion coefficient to flow discharge. The model performance was then satisfactorily tested against the remaining 26 measured validation datasets. It performed better than the existing equations. It yielded minimum errors of MAE = 21.4 m2/s (mean absolute error) and RMSE = 28.5 m2/s (root mean-squares error) and a maximum accuracy rate of 81%.

scholarly journals Erosion Potential Method (Gavrilović method) sensitivity analysis

2017 ◽  
Vol 12 (No. 1) ◽  
pp. 51-59 ◽  
Author(s):  
N. Dragičević ◽  
B. Karleuša ◽  
N. Ožanić
Keyword(s):  
Sensitivity Analysis ◽  
Model Performance ◽  
Potential Method ◽  
Future Research ◽  
Model Parameters ◽  
Model Concept ◽  
Individual Parameter ◽  
Sediment Production ◽  
Erosion Intensity

In recent decades, various methods for erosion intensity and sediment production assessment have been developed. The necessity for better model performance has led to the more frequent application of the method sensitivity and uncertainty assessments in order to decrease errors that arise from the model concept and its main assumptions. The analysis presented in this paper refers to the application of the Gavrilović method (Erosion Potential Method), an empirical and semi-quantitative method that can estimate the amount of sediment production and sediment transport as well as the erosion intensity and indicate the areas potentially threatened by erosion. The emphasis in this paper is given upon the method sensitivity analysis that has not previously been conducted for the Gavrilović method. The sensitivity analysis was conducted for fourteen different parameters included in the method, all in relation to different model outputs. Each parameter was perceived and discussed individually in relation to its effect upon the method outputs, and ranked into categories depending on their influence on one or more model outputs. The objective of the analysis was to explore the constraints of the Gavrilović method and the method response to changes deriving from the each individual parameter in an attempt to provide a better understanding of the method, the weight and the contribution of each parameter in the overall method. The parameters that could potentially be used in future research, for method modification and calibration in areas with different catchment characteristics (e.g. climate, geological, etc.) were identified. The most sensitive model parameters resulting from conducted sensitivity analysis for the Gavrilović method are also those considered to be significant in the scientific literature on erosion. The Gavrilović method sensitivity analysis has been done on a case study for the Dubracina catchment area, Croatia.

scholarly journals Moving beyond traditional model calibration or how to better identify realistic model parameters: sub-period calibration

2012 ◽  
Vol 9 (2) ◽  
pp. 1885-1918
Author(s):  
S. Gharari ◽  
M. Hrachowitz ◽  
F. Fenicia ◽  
H. H. G. Savenije
Keyword(s):  
Model Calibration ◽  
Model Performance ◽  
Realistic Model ◽  
Parameter Estimates ◽  
Model Parameters ◽  
New Approach ◽  
Consistent Model ◽  
Set Up

Abstract. Conceptual hydrological models often rely on calibration for the identification of their parameters. As these models are typically designed to reflect real catchment processes, a key objective of an appropriate calibration strategy is the determination of parameter sets that reflect a "realistic" model behavior. Previous studies have shown that parameter estimates for different calibration periods can be significantly different. This questions model transposability in time, which is one of the key conditions for the set-up of a "realistic" model. This paper presents a new approach that selects parameter sets that provide a consistent model performance in time. The approach consists of confronting model performance in different periods, and selecting parameter sets that are as close as possible to the optimum of each individual sub-period. While aiding model calibration, the approach is also useful as a diagnostic tool, illustrating tradeoffs in the identification of time consistent parameter sets. The approach is demonstrated in a case study where we illustrate the multi-objective calibration of the HyMod hydrological model to a Luxembourgish catchment.

THE ANALYSIS OF PROBLEM BASED LEARNING (PBL) IN MICRO TEACHING COURSE TO FIT THE REQUIREMENT OF EFFECTIVE PRE-SERVICE TEACHERS

2019 ◽  
Vol 7 (2) ◽  
pp. 119
Author(s):  
Linda Linda ◽  
Apandi
Keyword(s):  
Qualitative Method ◽  
Teaching Practice ◽  
Problem Based Learning ◽  
Real Field ◽  
English Department ◽  
Effective Teacher ◽  
Existing Problems ◽  
Apply Problem ◽  
Pre Service Teacher

One of phenomena that occur in the educational world is the issue of discrepancies that occur between theory the pre-service teacher learned in college with implementation when they should teach in thereal fields (schools). Problem Based Learning (PBL) becomes one of the efforts to bridge the existing problems. This research is conducted to find out the extend of Problem Based Learning (PBL) in Micro Teaching course since the course must be accomplished by students before carrying out practical activities in the real field in the school at teaching training program. The writer uses descriptive qualitative method. And in this research the writer uses case study as a research design to find out the purpose of the research. The participants of the the research are 8 students from a class of micro teaching course in English Department of Universitas Swadaya Gunung Jati. In this paper, The Students as the Pre Service Teacher(s) are coded PST(s). The writer uses observation as the instruments of the research. Theory of Miles and Huberman are used to collect data from observation. Regarding to the discussion above, the four aspects of competences of effective teacher are shown in the teaching practice done by the students of Micro teaching course that apply Problem Based Learning (PBL). The majority results of the observation explain that applying Problem Based Learning in Micro Teaching course develops pre-service teachers competence in their teaching in classroom. This research shows pre-service teachers can integrate their competences and create good performance in their teaching practice.

Sign in / Sign up

Export Citation Format

Share Document