The Frequency and Magnitude of Flood Discharges and Post-Wildfire Erosion in the Southwestern U.S
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The frequency and magnitude of flood discharges and post-wildfire erosion in the southwestern U.S. Item Type text; Electronic Dissertation Authors Orem, Caitlin Anne Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 11/10/2021 06:19:17 Link to Item http://hdl.handle.net/10150/333119 THE FREQUENCY AND MAGNITUDE OF FLOOD DISCHARGES AND POST- WILDFIRE EROSION IN THE SOUTHWESTERN U.S. by Caitlin Anne Orem ___________________ A Dissertation Submitted to the Faculty of the DEPARTMENT OF GEOSCIENCES In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College of THE UNIVERSITY OF ARIZONA 2014 2 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE As members of the Dissertation Committee, we certify that we have read the dissertation prepared by Caitlin Orem, entitled Floods, Erosion Rates, and the Effect of Wildfire on Erosion Regimes in the Southwest and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy. _______________________________________________________________________ Date: 5/23/14 Jon Pelletier _______________________________________________________________________ Date: 5/23/14 Victor Baker _______________________________________________________________________ Date: 5/23/14 Steve DeLong _______________________________________________________________________ Date: 5/23/14 Craig Rasmussen _______________________________________________________________________ Date: 5/23/14 Jennifer McIntosh Final approval and acceptance of this dissertation is contingent upon the candidate’s submission of the final copies of the dissertation to the Graduate College. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation requirement. ________________________________________________ Date: 5/23/14 Dissertation Director: Jon Pelletier 3 STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: Caitlin A. Orem 4 ACKNOWLEDGEMENTS This research was funded by the National Science Foundation Santa Catalina and Jemez River Basin Critical Zone Observatory (CZO) at the University of Arizona. Additional funding was obtained through the Geological Society of America Student Research Grant. This research would not have been possible without numerous discussions with my advisor, Jon Pelletier, as well as my other committee members Vic Baker, Craig Rasmussen, Steve DeLong, and Jennifer McIntosh. I am also thankful for access to laboratory space provided by Andy Cohen, Jay Quade, and Jonathan Overpeck and their students. Assistance and data from, as well as conversations with, fellow graduate students including Rebecca Lybrand, Kat Compton, Xavier Zapata-Rios, Claire Stielstra, Kendra Murray, Jill Onken, Matt Dettinger, Cody Routson, Sarah Truebe, Luke McGuire, Nick McKay, Zack Williams, Jordon Bright, Diane Thompson, Russ Edge, Adam Hudson, Drew Laskowski, Devon Orme, Kate Metcalf, Shaunna Morrison, and Jared Olyphant were also extremely helpful to me during my research period. 5 DEDICATION This dissertation is dedicated to my family and to all the teachers, professors, and advisors who guided me during my academic pursuits. 6 TABLE OF CONTENTS LIST OF FIGURES .............................................................................................................9 LIST OF TABLES.............................................................................................................10 ABSTRACT.......................................................................................................................11 1. INTRODUCTION .........................................................................................................13 2. PRESENT STUDY........................................................................................................17 3. REFERENCES ..............................................................................................................21 4. APPENDICES ...............................................................................................................25 APPENDIX A: CONSTRAINING FREQUENCY-MAGNTITUDE-AREA RELATIONSHIPS FOR PRECIPITATION AND FLOOD DISCHARGES USING RADAR-DERIVED PRECIPITATION ESTIMATES: EXAMPLE APPLICATIONS IN THE UPPER AND LOWER COLORADO RIVER BASINS, U.S.A..............................26 Abstract .............................................................................................................................27 1. Introduction ...................................................................................................................28 1.1 Flood-Envelope Curves .............................................................................................28 1.2 Study Area .................................................................................................................30 2. NEXRAD Data .............................................................................................................33 3. Methods .........................................................................................................................34 3.1 NEXRAD Data Conversion and Sampling ...............................................................34 3.2 Precipitation and Flood Calculations ........................................................................36 3.3 Recurrence Interval Calculations ..............................................................................41 3.4 Estimation of Uncertainty .........................................................................................42 3.5 Testing the Effect of Climate Variability ..................................................................43 4. Results ...........................................................................................................................44 4.1 Channel Characteristics and Runoff Coefficients......................................................44 4.2 Trends in Precipitation Intensity ...............................................................................45 4.3 Trends in Qp ..............................................................................................................46 4.4 Trends in Qfd .............................................................................................................47 4.5 The Effect of ENSO on Precipitation .......................................................................48 5. Discussion .....................................................................................................................49 5.1 Use and Accuracy of NEXRAD Products .................................................................49 7 5.2 Comparison of the FMAC method to Previous Studies ............................................51 5.3 Comparison of FMACs to Published FECs ..............................................................52 5.4 Precipitation Controls on the Form of the FEC ........................................................54 5.5 Climate Variability in the NEXRAD Data ...............................................................55 6. Conclusions ...................................................................................................................57 Acknowledgements ...........................................................................................................60 References .........................................................................................................................61 APPENDIX B: QUANTIFYING THE TIME SCALE OF ELEVATED GEOMORPHIC RESPONSE FOLLOWING WILDFIRES USING MULTI-TEMPORAL LIDAR DATA: AN EXAMPLE FROM THE LAS CONCHAS FIRE, JEMEZ MOUNTAINS, NEW MEXICO ...........................................................................................................................81 Abstract .............................................................................................................................82 1. Introduction ...................................................................................................................83 2. Study Site ......................................................................................................................88 3. Methods .........................................................................................................................90 3.1 Airborne Laser Scanning (ALS) ...............................................................................90 3.2 Terrestrial Laser Scanning (TLS) .............................................................................91