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Analyses of Potential Ravine and Bluff Stabilization Sites Within the Blue Earth and Le Sueur River Basins

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Analyses of Potential Ravine and Bluff Stabilization Sites Within the Blue Earth and Le Sueur River Basins Minnesota State University, Mankato Cornerstone: A Collection of Scholarly and Creative Works for Minnesota State University, Mankato All Graduate Theses, Dissertations, and Other Graduate Theses, Dissertations, and Other Capstone Projects Capstone Projects 2015 Analyses of Potential Ravine and Bluff Stabilization Sites within the Blue Earth and Le Sueur River Basins Anna My-Tien T. Tran Minnesota State University - Mankato Follow this and additional works at: https://cornerstone.lib.mnsu.edu/etds Part of the Geographic Information Sciences Commons, Soil Science Commons, and the Water Resource Management Commons Recommended Citation Tran, A. M. T. (2015). Analyses of Potential Ravine and Bluff Stabilization Sites within the Blue Earth and Le Sueur River Basins [Master’s thesis, Minnesota State University, Mankato]. Cornerstone: A Collection of Scholarly and Creative Works for Minnesota State University, Mankato. https://cornerstone.lib.mnsu.edu/ etds/522/ This Thesis is brought to you for free and open access by the Graduate Theses, Dissertations, and Other Capstone Projects at Cornerstone: A Collection of Scholarly and Creative Works for Minnesota State University, Mankato. It has been accepted for inclusion in All Graduate Theses, Dissertations, and Other Capstone Projects by an authorized administrator of Cornerstone: A Collection of Scholarly and Creative Works for Minnesota State University, Mankato. Analyses of potential ravine and bluff stabilization sites within the Blue Earth and Le Sueur River Basins By Anna My-Tien T. Tran A thesis submitted in partial fulfillment of the requirement for the Master of Science in Environmental Science (in association with the Water Resources Center) Minnesota State University, Mankato Mankato, Minnesota 2015 ii Analyses of potential ravine and bluff stabilization sites within the Blue Earth and Le Sueur River Basins Endorsement Date: ______________________ This thesis, completed by Anna My-Tien T. Tran, has been examined and approved by the following members of the student’s committee. ___________________________________________ Dr. Shannon J. Fisher, Chair ___________________________________________ Dr. Phillip H. Larson, Committee Member ___________________________________________ Dr. Christopher T. Ruhland, Committee Member iii Acknowledgements I would like to express gratitude to my advisor, Dr. Shannon J. Fisher, whose advice, expertise, and encouragement added considerably to my graduate experience. I sincerely thank my committee members, Dr. Phillip H. Larson for the endless advice, assistance, and feedback that improved my thesis immensely, and Dr. Christopher T. Ruhland for the insight and understanding throughout this process. A very special thanks goes out to Rick Moore, for all of his expert advice in GIS. I would like to thank Dr. Alison Mahoney for her guidance and advice on the plant taxonomy. I also would like to thank all of the faculty and staff at Minnesota State University, Mankato, Department of Biology and Environmental Science and the Water Resource Center for furthering my knowledge in the natural resources field. I would also like to thank my family for the support they provided me throughout my entire life, and in particular, I would like to thank Quintin Mabanta for his continued patience, love and support, without whom I would have not finished this thesis. I would like to thank my fellow graduate students for the stimulating discussions and late nights working together in the office, and for all of the fun we had these past two years. Finally, I am truly grateful for the opportunity to conduct this research project. I recognize that this research would not have been possible without the financial assistance of the Lake Pepin Legacy Alliance, Minnesota State University, Mankato, and the Water Resources Center at Minnesota State University, Mankato, and express my sincerest gratitude to those agencies. iv Abstract Analyses of potential ravine and bluff stabilization sites within the Blue Earth and Le Sueur River Basins Anna My-Tien T. Tran Minnesota State University, Mankato 2015 The United States Environmental Protection Agency (USEPA) has listed much of the Upper Mississippi River (UMR) basin as impaired waters due to excessive turbidity, sedimentation, and nutrient loading. Of particular importance are the associated environmental problems (e.g. eutrophication, habitat and wetland loss, loss of biodiversity, and changes in water quality) that have developed within Lake Pepin, a popular recreational riverine lake of the UMR. Three major drainages contribute to these issues and empty in to the UMR near Lake Pepin - the Minnesota River Basin (MRB), St. Croix River, and UMR. The MRB makes up approximately one-third of the drainage area above Lake Pepin, but has been found to contribute approximately 85-90% of all sediment entering the lake – both in the past and present. A major tributary system of the MRB, the Blue Earth River Basin (BERB) and its subbasins, contribute as much as half of the sediment exiting the Minnesota River, despite accounting for only one-fifth of the MRB drainage area. The tremendous sediment yields from this basin are a result of both post-glacial landscape evolution and contemporary land-use practices. Recent radioisotopic fingerprinting of these sediments has helped narrow the focus of mitigations strategies v as they indicate that the majority of the sediment originates from near-channel sources in the MRB, specifically ravines and bluffs. Significantly, it was also found that the rate of sedimentation has increased ten-fold over the past 150 years. Thus, mitigations strategies to curtail the sediment yields arriving downstream should focus on the near- channel sources of the BERB and its subbasins. Unfortunately, the resolution of radioisotopic methods is inadequate in locating of specific near-channel sources on which to implement mitigation strategies. Therefore, a crucial first step of an effective mitigation strategy to reduce erosion is to develop a methodology that aids in identifying the precise geographic position of ravines and bluffs with high erosion potential. This study uses Geographic Information Systems (GIS) to compile county Light Detection and Ranging (LiDar) and elevation, watershed and stream network, county infrastructure (private and public buildings and roads), county and watershed soil, county and watershed land use data in the BERB and its subbasins, to attempt to locate precise locations of ravines and bluffs with high erosion potential. Using two LiDar data sets taken in 2005 and 2012, and incorporating net sediment loss, slope grade, soil material, soil texture, connectivity to river, distance to river, surrounding adjacent land use, proximity and threat to roads, proximity and threat to public and private buildings, accessibility from roads, visibility from stream, and visibility from roads; 14 ravines and 10 bluffs were identified in the BERB, and 18 ravines and 29 bluffs were identified in the BERB, the Le Sueur River Basin (LSRB). These ravine and bluff sites exhibited an vi abundant amount of erosion between 2005 and 2012. As a baseline study, a comprehensive review of hydrologic and sediment transport models and stabilization techniques were completed to provide natural resource managers tools to stabilize and effectively manage these erosive sites. Preliminarily, this thesis study provides an effective protocol for identifying potential mitigation/stabilization sites that are not readily accessible with conventional surveying equipment. The models and stabilization techniques reviewed are effective strategies for watershed management in highly geomorphically active regions. Moving forward, a future LiDar dataset is recommended for further temporal and spatial analysis of the identified sites. Moreover, long-term monitoring of selected sites are recommended in order to isolate parameters to model erosion events, determine rates of change, and further understand the evolution of the landscape for effective watershed management. vii Table of Contents Acknowledgements iii Abstract iv Abbreviations ix List of Tables xi List of Figures xv List of Appendices xvii Introduction 1 Research Objectives 6 Literature Review 7 Geomorphology of the Minnesota River Basin 7 Erosion and Sediment Sources in the MRB 12 Contributing Factors of Increased Discharge, Surface Runoff, and Sedimentation 13 Impacts from Increase Discharge and Surface Runoff 16 Impacts from Increased Sedimentation 18 Lake Pepin 21 Objective 1: Using multi-temporal LiDar datasets to identify a complete inventory of ravines and bluffs within the BERB and LSRB 25 Study Area 25 Geographic Information Systems (GIS) and Remote Sensing (RS) 27 LiDar Data 28 2005 LiDar data 28 2012 LiDar data 29 Data Discrepancies 30 Criteria Influencing Sediment Transport 35 Methodology 39 Objective 2: Review of hydrological and sediment transport models to provide a foundation for natural resources management within watersheds 61 Universal Soil Loss Equation Family 62 Universal Soil Loss Equation (USLE) 62 Modified Universal Soil Loss Equation (MUSLE) 63 Revised Universal Soil Loss Equation 1 (RUSLE1) 64 Revised Universal Soil Loss Equation 2 (RUSLE2) 65 Better Assessment Science Integrating Point and Nonpoint Sources Family 66 Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) 66 Soil and Water Assessment Tool (SWAT) 68 Ephemeral Gully Erosion Model Family 70 Ephemeral Gully Erosion Model (EGEM) 70 Revised Ephemeral Gully Erosion Model
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