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Full-Text Articles in Engineering
Sensitivity Of A Distributed Watershed Simulation Model To Spatial Scale, Misgana K. Muleta, John W. Nicklow, Elias G. Bekele
Sensitivity Of A Distributed Watershed Simulation Model To Spatial Scale, Misgana K. Muleta, John W. Nicklow, Elias G. Bekele
Civil and Environmental Engineering
The results of distributed watershed models could be sensitive to spatial and temporal scales at which inputs and model parameters are aggregated. This paper reports findings of a detailed sensitivity analysis conducted on the U.S. Department of Agriculture’s distributed watershed simulation model, known as the Soil and Water Assessment Tool (SWAT). The Big Creek Watershed, located in southern Illinois, is used for the study. The model is calibrated to improve accuracy of its streamflow and sediment concentration predictions using observed data at two locations in the study watershed. Streamflow and sediment concentrations that are simulated by the calibrated model at …
Decision Support For Watershed Management Using Evolutionary Algorithms, Misgana K. Muleta, John W. Nicklow
Decision Support For Watershed Management Using Evolutionary Algorithms, Misgana K. Muleta, John W. Nicklow
Civil and Environmental Engineering
An integrative computational methodology is developed for the management of nonpoint source pollution from watersheds. The associated decision support system is based on an interface between evolutionary algorithms (EAs) and a comprehensive watershed simulation model, and is capable of identifying optimal or near-optimal land use patterns to satisfy objectives. Specifically, a genetic algorithm (GA) is linked with the U.S. Department of Agriculture’s Soil and Water Assessment Tool (SWAT) for single objective evaluations, and a Strength Pareto Evolutionary Algorithm has been integrated with SWAT for multiobjective optimization. The model can be operated at a small spatial scale, such as a farm …
Joint Application Of Artificial Neural Networks And Evolutionary Algorithms To Watershed Management, Misgana K. Muleta, John W. Nicklow
Joint Application Of Artificial Neural Networks And Evolutionary Algorithms To Watershed Management, Misgana K. Muleta, John W. Nicklow
Civil and Environmental Engineering
Artificial neural networks (ANNs) have become common data driven tools for modeling complex, nonlinear problems in science and engineering. Many previous applications have relied on gradient-based search techniques, such as the back propagation (BP) algorithm, for ANN training. Such techniques, however, are highly susceptible to premature convergence to local optima and require a trial-and-error process for effective design of ANN architecture and connection weights. This paper investigates the use of evolutionary programming (EP), a robust search technique, and a hybrid EP–BP training algorithm for improved ANN design. Application results indicate that the EP–BP algorithm may limit the drawbacks of using …
Evolutionary Algorithms For Multiobjective Evaluation Of Watershed Management Decisions, Misgana K. Muleta, John W. Nicklow
Evolutionary Algorithms For Multiobjective Evaluation Of Watershed Management Decisions, Misgana K. Muleta, John W. Nicklow
Civil and Environmental Engineering
The comprehensive and systematic management of watersheds is essential for reducing the adverse environmental impacts arising from anthropogenically caused erosion and subsequent sedimentation. This paper describes a computational methodology that is designed to serve as a watershed decision support system and is capable of controlling environmental impacts of non-point source pollution resulting from erosion. In the decision process, the methodology also accounts for other inseparable objectives such as economics and social dynamics of the watershed. This decision support tool was developed by integrating a comprehensive hydrologic model known as SWAT and state-of-the-art multiobjective optimization technique within the framework of a …
Watershed Management Technique To Control Sediment Yield In Agriculturally Dominated Areas, John W. Nicklow, Misgana K. Muleta
Watershed Management Technique To Control Sediment Yield In Agriculturally Dominated Areas, John W. Nicklow, Misgana K. Muleta
Civil and Environmental Engineering
Non-point source pollution is recognized internationally as a critical environmental problem. In Illinois, soil erosion from agricultural lands is the major source of such pollution. The erosion process, which has been accelerated by human activity, tends to reduce crop productivity and leads to subsequent problems from deposition on farmlands and in water bodies. Comprehensive watershed management, however, can be used to protect these natural resources. In this study, a discrete time optimal control methodology and computational model are developed for determining land use and management alternatives that minimize sediment yield from agriculturally-dominated watersheds. The solution methodology is based on an …