Vegetational Change and Land Degradation in the Lake Baringo
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Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2006 Vegetational Change and Land Degradation in the Lake Baringo Area, Kenya, During the Late Holocene: Evidence from the Paleorecord and Remote Sensing Lawrence Morara Kiage Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Social and Behavioral Sciences Commons Recommended Citation Kiage, Lawrence Morara, "Vegetational Change and Land Degradation in the Lake Baringo Area, Kenya, During the Late Holocene: Evidence from the Paleorecord and Remote Sensing" (2006). LSU Doctoral Dissertations. 1979. https://digitalcommons.lsu.edu/gradschool_dissertations/1979 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. VEGETATIONAL CHANGE AND LAND DEGRADATION IN THE LAKE BARINGO AREA, KENYA, DURING THE LATE HOLOCENE: EVIDENCE FROM THE PALEORECORD AND REMOTE SENSING A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements of the degree of Doctor of Philosophy in The Department of Geography and Anthropology by Lawrence Morara Kiage B. Ed., Kenyatta University, 1995 M. A., Kenyatta University, 1998 May, 2007 To Precious for the spirit she displayed ii ACKNOWLEDGEMENTS I would like to thank my major professor, Dr. Kam-biu Liu, for his enormous support throughout my graduate career. He basically opened up the horizons of the fields of biogeography and palynology to me and taught me the finer tricks of excellent research that transformed my career. He is endowed with large reserves of patience, guidance, and friendship, which he graciously shared with me and the results are obvious in this dissertation. I thank him for his excellent mentorship. There are two other individuals who ensured that I remain in school and have peace of mind while I pursue my doctorate studies at LSU. Dr Oscar K. Huh and Dr. Nan D. Walker will always be a big and pleasant chapter in my life and career. They offered me a research assistantship position at the state-of-the-art Earth Scan Laboratory and inspired excellence in me. I owe much of my remote sensing skills to the two individuals. I thank them for their grace and undying support, and for making me realize that not all angels have wings. I would like to thank Dr Nina Lam for her support and advice during my entire graduate program, and for serving on my committee. Her guidance is excellent; she is a great teacher, and good friend. She sharpened my tools in remote sensing and GIS and I will always be indebted to her. Special thanks also to Dr Michael Leitner for being a great individual, an excellent teacher, good friend, and for agreeing to serve on my committee. The excellent cartographic work in this dissertation was performed by Clifford Duplechin and Mary Lee Eggart and they are thanked for their professionalism. I must thank Dr. Terry Brncic of the Oxford Long-term Ecology Laboratory, Oxford iii University Centre for the Environment, for sharing with me a collection of African pollen pictures that were invaluable in the pollen identification process. I thank my colleague Jason T. Knowles for agreeing to temporarily suspend reason and engage the crocodiles and hippopotamus of Lake Baringo in coring exercises. I also thank my brother James N. Kiage for joining Jason and myself for fieldwork. John Omonywa is thanked for driving the research team on the treacherous road to Lake Baringo and around its drainage basin. His driving made us want to finish the exercise sooner. I thank my colleagues at the Global Paleoecology Laboratory; Terry McCloskey, Jennifer Hathorn, Jonathan Breaux, Tom Bianchette, and Yun Huang for making life in the laboratory livable. Special thanks to the entire Earth Scan Laboratory crew, especially Ric Haag and Shreekanth Balasubramanian for teaching me how to track satellites using the X-band antenna and look for an excuse to party. I received a lot of moral and spiritual support from my friends, Dr. Larry and Veronica Henry, Dr Pius and Caroline Egbelu, Hector Casillas, Dr. Jepkoech Tarus, Drs. Daniel and Cate Moriasi, Pr. Reggie Phillips, Remy Kasili, Douglas Miano and his family, and many others that I will not enumerate. I thank them all because I could not have made it without their support. I thank my wife Lilian and my son Dean for their patience, support, and encouragement throughout my time as a graduate student. Special thanks to my parents, Hellen and George Kiage, my brothers Patrick and James, and sisters Cathy, Betty and Jenny for encouraging me to pursue excellence. This dissertation project was facilitated through generous grants from the National Science Foundation, The Geological Society of America, The Sigma-Xi National iv Research Society, and two R. J. Russell grants from the Department of Geography and Anthropology, Louisiana State University. Finally, and most important, I thank God for life and health without which nothing would have been possible. v TABLE OF CONTENTS DEDICATION.………………………………………...………………………………….ii ACKNOWLEDGEMENTS …………………...…………………………………………iii ABSTRACT ...………………………………………………………………………….viii CHAPTER 1 INTRODUCTION ...………………………………………………….......1 1.1 Expected Significance……………………………………………………..5 1.2 References…………………………………………………………………6 CHAPTER 2 REVIEW OF LATE QUATERNARY PALEOENVIRONMENTAL CHANGES IN EAST AFRICA.………………………………………………………11 2.1 Introduction....……………………………………………………………11 2.2 Modern Climate and Vegetation Patterns..………………………………12 2.3 Pollen Records from East Africa...………………………………………18 2.4 The Paleoenvironment of East Africa ……...……………………………21 2.4.1 42,000 to 30,000 14C yr BP………………………………………21 2.4.2 30,000 to 21,000 14C yr BP………………………………………24 2.4.3 21,000 to 12,500 14C yr BP………………………………………25 2.4.4 12,500 to 10,000 14C yr BP………………………………………30 2.4.5 Early to Middle Holocene………………………………………..32 2.4.6 Middle to Late Holocene…………...……………………………34 2.4.7 The Last Millennium…………………………………………….36 2.5 Synthesis…………………………………………………………………39 2.6 References………………………………………………………………..47 CHAPTER 3 STRATIGRAPHIC EVIDENCE OF CLIMATE CHANGE AND LAND DEGRADATION IN THE LAKE BARINGO AREA, KENYA, EAST AFRICA, OVER THE PAST 350 YEARS……………………………………………………….60 3.1 Introduction………………………………………………………………60 3.2 Background………………………………………………………………63 3.3 Methods…………………………………………………………………..68 3.4 Results ……………………………………………………………………72 3.4.1 Core LB-5………………………………………………………..72 3.4.2 Core LB-6………………………………………………………..76 3.4.3 Core LB-4………………………………………………………..79 3.4.4 Core LB-3…………………………………………………..……81 3.5 Stratigraphic Correlation of the Cores...…………………………………83 3.6 Interpretation and Discussion...………………………………………….85 3.6.1 Evidence of Droughts in the Stratigraphic Record...…………….85 3.6.2 High Sedimentation Rates..………………………………………94 3.7 Conclusion……………………………………………………………...104 vi 3.8 References………………………………………………………………105 CHAPTER 4 PALYNOLOGICAL EVIDENCE OF CLIMATE CHANGE AND LAND DEGRADATION IN THE LAKE BARINGO AREA, KENYA, EAST AFRICA, OVER THE PAST 350 YEARS……………………………………………………...114 4.1 Introduction……………………………………………………………..114 4.2 Background……………………………………………………………..117 4.3 Materials and Methods………………………………………………….119 4.4 Results and Discussion…………………………………………………122 4.4.1 Vegetation Response to Climate Variability……….…………..127 4.4.2 Human Impact on Vegetation ………………………………….133 4.5 Conclusion……………………………………………………………...142 4.6 References………………………………………………………………144 CHAPTER 5 RECENT LAND-COVER/USE CHANGE ASSOCIATED WITH LAND DEGRADATION IN THE LAKE BARINGO CATCHMENT, KENYA, EAST AFRICA: EVIDENCE FROM LANDSAT TM AND ETM+ …..………………………………151 5.1 Introduction……….…………………………………………………….151 5.2 The Study Site.………………………………………………………….156 5.3 Methods.……………………………………………...…………………157 5.3.1 Data Acquisition and Initial Processing...………………………159 5.3.2 Change Detection Techniques………...…..……………………161 5.3.2.1 Radiometric Preprocessing...…………………………...161 5.3.2.2 Data Transformation Methods…..……………………...162 5.3.2.3 Classification……………………………………………165 5.3.3 Accuracy Assessment...………………………………………...169 5.4 Results and Discussion...……………………………………………….173 5.5 Conclusion……………………………………………………………...188 5.6 References………………………………………………………………189 CHAPTER 6 SUMMARIES AND CONCLUSIONS..……………………………….197 6.1 Directions Future Research…………………………………………………203 APPENDIX A: POLLEN NOTES.……………………………………………………..205 APPENDIX B: LETTER OF PERMISSION FROM SAGE PUBLICATIONS………...……………………………………………………………..227 APPENDIX C: LETTER OF PERMISSION FROM INTERNATIONAL JOURNAL OF REMOTE SENSING..…………………………..229 VITA……………………………………………………………………………………230 vii ABSTRACT This dissertation investigates the history of vegetational changes and land degradation in the Lake Baringo area, Kenya, East Africa, during the Late Holocene. It uses 14C -and 210Pb-dated fossil pollen, fungal spores, microscopic charcoal, and stratigraphic record from lake-sediment cores to reconstruct the paleoenvironment in the East African region. More recent changes in the Lake Baringo are examined using remote sensing imagery. These data provide one the first high-resolution late Holocene pollen records from the semi-arid region of Kenya (and one of only a handful from East Africa in general). Lake Baringo records a sedimentation