Modelling The Great Lakes Hydrologic Hydraulic System

Author : Daniel Thomas Latimer Myers
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.4/5 (387 download)

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Download or read book Improved Hydrological Modeling of Great Lakes Basin Including Calibration Period Selection and Rain-on-snow Simulation written by Daniel Thomas Latimer Myers and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrological models relate landscape and climate characteristics with the water cycle, extreme events, and the availability of freshwater. However, the use of these models can be impaired by common pitfalls including the arbitrary choice of calibration periods and the omission of physical processes such as rain-on-snow melt, making the models less reliable when used where climate or landscape changes are occurring. This dissertation had three objectives: 1) Assess how much water balance simulations can be influenced by the choice of calibration and validation periods, 2) Analyze the influence of rain-on-snow melt of winter floods and summer hydrological droughts in North America's Great Lakes Basin using a modified Soil and Water Assessment Tool (SWAT) hydrological model, and 3) Investigate the influence of climate change on rain-on-snow melt and hydrology of the Great Lakes Basin.We found that the arbitrary selection of calibration periods can substantially influence simulations of water balance components such as snowmelt, surface runoff, and soil water storage. Thus, modelers using this split-sample approach should choose calibration and validation time periods selectively based on knowledge of changes in climate and hydrological characteristics and document the reasons for their choice. We also found that modifying SWAT to include rain-on-snow led to more extreme simulations of winter floods and summer hydrological droughts in the Great Lakes Basin and improved model performance. The unmodified SWAT could be underestimating hydrological extremes in areas where rain-on-snow events occur. Further, the hydrology of the Great Lakes Basin is expected to change throughout the 21st century, including a decrease in annual rain-on-snow melt amount due to reduction in snowpack. Parts of the basin with mean winter/spring air temperatures around freezing were most sensitive to changing rain-on-snow melt. As the threats of climate change and extreme hydrological events become more severe, it is increasingly important for hydrological modelers to best simulate physical processes such as rain-on-snow melt and avoid common pitfalls with the selection of calibration periods.