LAND USE AND LAND COVER CHANGES IN THE CENTRAL HIGHLANDS OF ETHIOPIA: THE CASE OF YERER MOUNTAIN AND ITS SURROUNDINGS A THESIS SUBMITTED TO THE SCHOOL OF GRADUATE STUDIES, ADDIS ABABA UNIVERSITY IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE DEGREE OF MASTER OF SCIENCE IN ENVIRONMENTAL SCIENCE BY KAHSAY BERHE GEBREHIWET JUNE 2004 ADDIS ABABA UNIVERSITY SCHOOL OF GRADUATE STUDIES ENVIROMENTAL SCIENCE PROGRAMME LAND USE AND LAND COVER CHANGES IN THE CENTRAL HIGHLANDS OF ETHIOPIA: THE CASE OF YERER MOUNTAIN AND ITS SURROUNDINGS BY KAHSAY BERHE GEBREHIWET ENVIRONMENTAL SCIENCE PROGRAMME APPROVED BY EXAMINING BOARD: Signature Professor Zerihun Woldu __ Advisor Dr. Dagnachew Legesse Advisor Dr. Belay Semani External examiner Dr. Tesfaye Korme Internal examiner ii ACKNOWLEDGEMENTS This work would have not been completed without the contribution of many institutions and individuals, among which I am indebted to the International Livestock Research Institute (ILRI) for allowing me to carry out this study and research towards this Thesis. In addition, the International Water Management Institute (IWMI), through its Comprehensive Assessment Project funded part of this work and deserves acknowledgement. I am greatly indebted to my advisors Professor Zerihun Woldu, Dr. Dagnachew Legesse and Dr. Don Peden for their advice and sharing their invaluable time and ideas and for critically reading the earlier versions of this manuscript. I am especially indebted to Dr. Peden of ILRI, my supervisor, for his enormous support and kindness because without his help my endeavours would have been fruitless. He facilitated my study with Addis Ababa University and supplied all necessary materials and resources required for my study. His deeds are so special that they will remain in my mind. Dr. Girma Taddesse’s encouragement during the course of my study and facilitation towards finalising this research work was also special and deserves acknowledgment. Dr. Sonder’s technical support and friendly thoughts during data collection and the write up of this manuscript deserves acknowledgement. Ato Abiye Astatke, Dr. Berhanu Gebremedhin and Ato Abate Tedla all from ILRI are also acknowledged for their encouragements and sharing their ideas. I would like to thank Dr. Fernandez-Rivera, ILRI, for assistance rendered in calculating daily dry matter livestock requirements. The assistance from Ato Alemayehu Mamo, Woody Biomass, was so much that without his support the GIS related works could have not been completed on time. He devoted much of his valuable time in helping me finalise this work. He has a special place in my mind for his contributions were so much. Mr. Sutcliffe of Woody Biomass also made comments on the earlier version of this manuscript and shared his ideas and resources. iii My special thanks also go to Adaa Liben, Gimbichu, Bereh Aleltu and Akaki wereda Bureaus of Agriculture for their collaboration and facilitation during the study are also cordially acknowledged. The Development Agents of all ten Peasant Associations, where the survey was conducted are also acknowledged. All the enumerators who worked with me during the survey also deserve acknowledgement, but particularly Degefa Birru, ILRI, contributed immensely towards the completion of the survey work and deserves acknowledgement. My other ILRI colleagues Ato Solomon Gebreselassie, Ato Aklilu Bogale and Ato Abebe Misgina, who helped during the analysis of the socio-economic data, deserve special acknowledgement. All colleagues of the then “Mountains Project” of ILRI are all acknowledged, but W/o Genet Delelgne is especially thanked for her keen interest in my carrier development. In addition, Ato Aklilu Alemu of ILRI, Debre Zeit walked with me during gully assessment and deserves acknowledgement. The ILRI library staffs W/o Azeb Abraham, Goshu Chernet and Hailu Birbo are all acknowledged for their assistance during search for literature. My classmates are all acknowledged for their friendship and support during my enrolment at Addis Ababa University, but especially that of Elias Gugsa was so special he deserves special thanks. It would be a mistake not to mention the role of the sample farmers in this study who kindly spared their time and effort and responded tirelessly to the lengthy process of the interview. Finally, the unfailing encouragement, tolerance and support rendered from my wife Meaza Tsehay, our children and all my families deserves particular thanks. The prayers of my mother have contributed to the success of my work. iv TABLE OF CONTENTS ACKNOWLEDGEMENTS ..................................................................................................III TABLE OF CONTENTS ........................................................................................................V LIST OF FIGURES............................................................................................................VIII APPENDICES.....................................................................................................................VIII LIST OF ACRONYMS .........................................................................................................IX ABSTRACT..............................................................................................................................X CHAPTER ONE INTRODUCTION 1.1 BACKGROUND .................................................................................................................. 1 1.2 STATEMENT OF THE PROBLEM........................................................................................... 7 1.3 OBJECTIVES OF THE STUDY ............................................................................................. 10 1.4 APPROACHES USED IN THE STUDY................................................................................... 10 1.5 ORGANISATION OF THE THESIS ....................................................................................... 11 1.6 OVERALL EXPECTATIONS FROM THE STUDY.................................................................... 12 1.7 LIMITATIONS OF THE STUDY ........................................................................................... 13 CHAPTER TWO REVIEW OF LITERATURE 2.1 LAND-USE AND LAND-COVER DYNAMICS AND LINKS .................................................... 14 2.2 POPULATION INCREASE AND NATURAL RESOURCES ........................................................ 16 2.3 STUDIES ON LONG TERM CHANGES IN LULC IN ETHIOPIA .............................................. 18 2.3.1 Land cover changes and its impacts in Ethiopia .................................................... 19 2.3.1.1 Crop production and land degradation............................................................. 19 2.3.1.2 Livestock resources and land degradation....................................................... 22 2.3.1.3 Forest resources degradation ........................................................................... 25 2.3.1.4 Land Use and Land Cover change and biodiversity........................................ 28 2.3.1.5 Land Use and Land Cover changes and the hydrological cycle...................... 29 2.3.1.6 Land Use and Land Cover changes and climate change ................................. 29 CHAPTER THREE GENERAL DESCRIPTION OF THE STUDY AREA 3.1 LOCATION....................................................................................................................... 31 3.2 TOPOGRAPHY, GEOLOGY AND SOILS ............................................................................... 31 3.3 WATER RESOURCES OF THE STUDY AREA........................................................................ 35 3.4 CLIMATE......................................................................................................................... 37 3.4.1 Rainfall.................................................................................................................... 37 3.4.2 Temperature............................................................................................................ 39 3.5 SHEET EROSION............................................................................................................... 39 3.6 GULLY EROSION.............................................................................................................. 40 3.7 THE MIXED CROP-LIVESTOCK FARMING SYSTEMS ........................................................... 42 3.8 SOCIO-ECONOMIC CHARACTERISTICS OF THE STUDY AREA ............................................. 43 3.8.1 Social organisations ............................................................................................... 43 3.8.2 Settlement patterns.................................................................................................. 45 3.8.3 Farm activities ........................................................................................................ 46 3.8.4 Labour requirements .............................................................................................. 48 3.8.5 Demographic features of the study area................................................................. 49 3.9 VEGETATION................................................................................................................... 49 3.10 WILD LIFE ..................................................................................................................... 50 CHAPTER FOUR MATERIALS AND METHODS 4.1.SOCIO-ECONOMIC STUDY...............................................................................................