Prediction of Log-Transmissivity

1995 ◽  
Vol 26 (1) ◽  
pp. 21-36
Author(s):  
Steen Christensen
Keyword(s):  
Case Studies ◽  
Statistical Methods ◽  
Specific Capacity ◽  
Joint Model ◽  
Model Parameters ◽  
The Third ◽  
Predictor Models ◽  
Physically Based ◽  
Physically Based Models ◽  
Single Predictor

Two physically based models are derived that can be used to predict the log-transmissivity from the lithology, e.g. as logged in boreholes. The first model uses the lithology as the only predictor, whereas the second model uses the lithology and the specific capacity as simultaneous predictors. The model parameters can be estimated by statistical methods from actual observations. The methods are applied to three case studies. A comparison with Christensen (1995) shows that the lithology in some cases is a better single predictor of log-transmissivity than the specific capacty; in other cases the opposite is true. This suggests that the proposed joint model is preferable to either of the single predictor models. In two cases the joint model improves the prediction considerably when compared with the single predictor models; in the third case the joint model is at least as good as the single predictor models.

scholarly journals Evaluating performances of simplified physically based models for landslide susceptibility

2015 ◽  
Vol 12 (12) ◽  
pp. 13217-13256 ◽  
Author(s):  
G. Formetta ◽  
G. Capparelli ◽  
P. Versace
Keyword(s):  
Landslide Susceptibility ◽  
Goodness Of Fit ◽  
Shallow Landslides ◽  
Model Parameters ◽  
Test Case ◽  
Susceptibility Analysis ◽  
Physically Based ◽  
Private And Public ◽  
Physically Based Models

Abstract. Rainfall induced shallow landslides cause loss of life and significant damages involving private and public properties, transportation system, etc. Prediction of shallow landslides susceptible locations is a complex task that involves many disciplines: hydrology, geotechnical science, geomorphology, and statistics. Usually to accomplish this task two main approaches are used: statistical or physically based model. Reliable models' applications involve: automatic parameters calibration, objective quantification of the quality of susceptibility maps, model sensitivity analysis. This paper presents a methodology to systemically and objectively calibrate, verify and compare different models and different models performances indicators in order to individuate and eventually select the models whose behaviors are more reliable for a certain case study. The procedure was implemented in package of models for landslide susceptibility analysis and integrated in the NewAge-JGrass hydrological model. The package includes three simplified physically based models for landslides susceptibility analysis (M1, M2, and M3) and a component for models verifications. It computes eight goodness of fit indices by comparing pixel-by-pixel model results and measurements data. Moreover, the package integration in NewAge-JGrass allows the use of other components such as geographic information system tools to manage inputs-output processes, and automatic calibration algorithms to estimate model parameters. The system was applied for a case study in Calabria (Italy) along the Salerno-Reggio Calabria highway, between Cosenza and Altilia municipality. The analysis provided that among all the optimized indices and all the three models, the optimization of the index distance to perfect classification in the receiver operating characteristic plane (D2PC) coupled with model M3 is the best modeling solution for our test case.

scholarly journals Calibration of physically based models: back to basics?

2003 ◽  
Vol 5 (4) ◽  
pp. 233-244 ◽  
Author(s):  
Vincent Guinot ◽  
Philippe Gourbesville
Keyword(s):  
Hydrological Model ◽  
Flash Flood ◽  
Model Parameters ◽  
Model Structure ◽  
Ungauged Catchments ◽  
Model Response ◽  
Physically Based ◽  
Physically Based Models ◽  
Extreme Hydrological Events ◽  
Main Factor

The modelling of extreme hydrological events often suffers from a lack of available data. Physically based models are the best available modelling option in such situations, as they can in principle provide answers about the behaviour of ungauged catchments provided that the geometry and the forcings are known with sufficient accuracy. The need for calibration is therefore limited. In some situations, calibration (seen as adjusting the model parameters so that they fit the calculation as closely to the measurements as possible) is impossible. This paper presents such a situation. The MIKE SHE physically based hydrological model is used to model a flash flood over a medium-sized catchment of the Mediterranean Alps (2820 km2). An examination of a number of modelling alternatives shows that the main factor of uncertainty in the model response is the model structure (what are the dominant processes). The second most important factor is the accuracy with which the catchment geometry is represented in the model. The model results exhibit very little sensitivity to the model parameters, and therefore calibration of these parameters is found to be useless.

scholarly journals Hydrometeorological monitoring for water balance determination at plot scale

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
A. Sommella ◽  
Mario Palladino ◽  
A. Comegna ◽  
A. Coppola
Keyword(s):  
Model Parameters ◽  
Hydraulic Characteristics ◽  
Experimental Site ◽  
Resources Management ◽  
Soil Variables ◽  
Basilicata Region ◽  
Physically Based ◽  
Physically Based Models ◽  
Soil Hydraulic ◽  
Set Up

To provide adequate answers to recurring problems in land and water resources management, nowadays the use of physically based models is widespread. The reliability of the responses of this kind of model is closely linked to the precision with which model parameters are determined, such as soil hydraulic characteristics and meteorological variables. In this work, we set up a complete station for the monitoring of both meteorological and soil variables, as well as a soil hydraulic characterization. The experimental site shows vertic characteristics and is in Guardia Perticara, Basilicata region, Italy.

Behaviour of 4H-SiC pin Diodes Studied by Numerical Device Simulation

2007 ◽  
Vol 556-557 ◽  
pp. 905-908
Author(s):  
Dorothea Werber ◽  
P. Borthen ◽  
Gerhard Wachutka
Keyword(s):  
Empirical Relation ◽  
Mobility Model ◽  
Model Parameters ◽  
Temperature Dependent ◽  
Pin Diodes ◽  
Carrier Lifetimes ◽  
Physically Based ◽  
Physically Based Models ◽  
Numerical Device ◽  
Best Fit

We simulated and measured the forward characteristics of 4H-SiC pin diodes in a wide temperature range from 300K to 700K. Our simulations are based on the stationary drift-diffusion model including a model for incomplete ionization of the dopants. Physically based models for Auger recombination and Shockley-Read-Hall recombination are used as well. For the mobility model the empirical relation of Caughey-Thomas is used. The model parameters to be calibrated in the simulation are the electron and hole minority lifetimes and the electron and hole bulk mobilities. Employing temperature-dependent carrier lifetimes we achieved very good agreement between simulations and measured data. For the temperature- and doping-dependent carrier mobilities we found that the best fit is obtained for a bulk mobility value much smaller than that suggested by standard parameters for 4H-SiC. With the calibrated parameters we simulated the internal carrier distributions for temperatures up to 700 K and for different carrier lifetimes.

scholarly journals Evaluating performance of simplified physically based models for shallow landslide susceptibility

2016 ◽  
Vol 20 (11) ◽  
pp. 4585-4603 ◽  
Author(s):  
Giuseppe Formetta ◽  
Giovanna Capparelli ◽  
Pasquale Versace
Keyword(s):  
Landslide Susceptibility ◽  
Model Performance ◽  
Shallow Landslides ◽  
Model Verification ◽  
Sensitivity Analyses ◽  
Model Parameters ◽  
Parameter Calibration ◽  
Susceptibility Analysis ◽  
Physically Based ◽  
Physically Based Models

Abstract. Rainfall-induced shallow landslides can lead to loss of life and significant damage to private and public properties, transportation systems, etc. Predicting locations that might be susceptible to shallow landslides is a complex task and involves many disciplines: hydrology, geotechnical science, geology, hydrogeology, geomorphology, and statistics. Two main approaches are commonly used: statistical or physically based models. Reliable model applications involve automatic parameter calibration, objective quantification of the quality of susceptibility maps, and model sensitivity analyses. This paper presents a methodology to systemically and objectively calibrate, verify, and compare different models and model performance indicators in order to identify and select the models whose behavior is the most reliable for particular case studies.The procedure was implemented in a package of models for landslide susceptibility analysis and integrated in the NewAge-JGrass hydrological model. The package includes three simplified physically based models for landslide susceptibility analysis (M1, M2, and M3) and a component for model verification. It computes eight goodness-of-fit indices by comparing pixel-by-pixel model results and measurement data. The integration of the package in NewAge-JGrass uses other components, such as geographic information system tools, to manage input–output processes, and automatic calibration algorithms to estimate model parameters. The system was applied for a case study in Calabria (Italy) along the Salerno–Reggio Calabria highway, between Cosenza and Altilia. The area is extensively subject to rainfall-induced shallow landslides mainly because of its complex geology and climatology. The analysis was carried out considering all the combinations of the eight optimized indices and the three models. Parameter calibration, verification, and model performance assessment were performed by a comparison with a detailed landslide inventory map for the area. The results showed that the index distance to perfect classification in the receiver operating characteristic plane (D2PC) coupled with the model M3 is the best modeling solution for our test case.

NEW TECHNOLOGIES AND PRACTICES FOR WASTE MINIMIZATION IN THE CHEMICAL AND PETROCHEMICAL INDUSTRIES : FINDINGS OF THE SALVADOR, BRAZIL, 1993 CONFERENCE

1994 ◽  
Vol 30 (3) ◽  
pp. 1-9
Author(s):  
Francisco Fontes Lima ◽  
Francisco Alves Pereira
Keyword(s):  
Waste Management ◽  
Environmental Protection ◽  
Case Studies ◽  
New Technologies ◽  
Waste Minimization ◽  
Source Control ◽  
International Conference ◽  
The Third ◽  
Control Programmes ◽  
Petrochemical Industries

This paper describes the findings of the “Third International Conference on Waste Management in the Chemical and Petrochemical Industries,” held in Salvador, Brazil, October 20-23, 1993. A summary of the 74 technical papers, divided into six major categories, is presented together with comments on the more stringent legislation concerning source control programmes. Case studies of two large chemical complexes that have been developing successful waste minimization programmes are described in detail: CETREL-Environmental Protection Company in Camaçari, Brazil, and BASF AG in Ludwigshafen, Germany.

Conclusion

2018 ◽  
Author(s):  
John West
Keyword(s):  
Eighteenth Century ◽  
Case Studies ◽  
Literary History ◽  
The Political ◽  
The Third ◽  
Religious Differences

Literary history often positions Dryden as the precursor to the great Tory satirists of the eighteenth century, like Pope and Swift. Yet a surprising number of Whig writers expressed deep admiration for Dryden, despite their political and religious differences. They were particularly drawn to the enthusiastic dimensions of his writing. After a short reading of Dryden’s poem to his younger Whig contemporary William Congreve, this concluding chapter presents three case studies of Whig writers who used Dryden to develop their own ideas of enthusiastic literature. These three writers are Elizabeth Singer Rowe, John Dennis, and the Third Earl of Shaftesbury. These case studies are used to critique the political polarizations of seventeenth- and eighteenth-century literary history and to stress instead how literary friendship crossed political allegiances, and how writers of differing ideological positions competed to control mutually appealing ideas and vocabularies.

scholarly journals On the residual strength of aging cast iron trunk mains: Physically-based models for asset failure

2016 ◽  
Vol 663 ◽  
pp. 204-212 ◽  
Author(s):  
Azadeh Fahimi ◽  
Timothy S. Evans ◽  
Jeff Farrow ◽  
David A. Jesson ◽  
Mike J. Mulheron ◽  
...  
Keyword(s):  
Cast Iron ◽  
Residual Strength ◽  
Physically Based ◽  
Physically Based Models

A Social Sonic Paradigm

2021 ◽  
pp. 540-554
Author(s):  
Tegan Bristow ◽  
João Orecchia Zúñiga
Keyword(s):  
Case Studies ◽  
Southern Africa ◽  
Political Engagement ◽  
Sound Art ◽  
Intellectual Engagement ◽  
The Third ◽  
Primary Focus ◽  
Definition Of ◽  
Forms Of Knowledge

This chapter presents an examination of why—in contemporary Africa, with Southern Africa as the primary focus—there are very few artists working with sound in a manner that fits the paradigm of sound art as it is known in Euro-America. Emphasis is not placed on a lack of intellectual engagement, which is significant in the Euro-American definition of sound art. What is presented does not aim to deviate from this, but rather acts to affirm an engagement with alternative forms of knowledge and mechanisms of sound found in the South. Three areas are explored; these however are interlinked and do not stand alone. The first is an understanding of the practice of interdisciplinarity as political engagement. The second explores the role of community and communal interaction with sound and how this is fundamental to form in the region. The third extends this by showing how the histories of knowledge and power are fundamental to these explorations in the region, emphasizing how contemporary explorations of sound are used to both contain and shift these histories. The chapter takes shape with the use of case studies and draws on interviews conducted by the authors.

scholarly journals Public and Private Ownership in the Iranian Constitution: Principle 44, A Barrier for Development

2017 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Ahmad Torabi
Keyword(s):  
Case Studies ◽  
Economic Impacts ◽  
Private Ownership ◽  
Public Ownership ◽  
Public And Private ◽  
The Third ◽  
Public Property ◽  
Legal Challenges ◽  
The Law ◽  
The Government

The Iranian legislator has sought to protect public property and public ownership in the Iranian Constitution in accordance with Islamic principles, terms and procedures. There are a number of principles that have been directly applied to this purpose; however, one principle has had a very significant impact on government domination of the economy of Iran: principle 44. This principle does not directly describe public property; rather, it aims to determine the areas that are under public ownership and are administered by the government. However, the principle has some contradictions and legal challenges in itself. In addition, the supplementary law that has been enacted to provide the areas for the enforcement of principle 44 fails to secure the aims of the legislator. Therefore, this paper analyses legal challenges of the principle, as well as its supplementary law, and gives suggestions to solve the challenges.This paper is divided into four sections. The first section provides an analysis of the principle itself, and its relationship and consistency with other principles of the constitution. In the second section, the Law of Implementation of Principle 44 and the legal challenges that arise from it will be discussed. The third section focuses on the negative economic impacts of this law, as well as case studies of it. Lastly, the paper provides a summary of suggestions to amend this law.

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