Effects of Human Activities on the Hydrology And
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EFFECTS OF HUMAN ACTIVITIES ON THE HYDROLOGY AND ECOLOGY OF CHASSA DAMBO IN SINDA AREA, EASTERN PROVINCE, ZAMBIA by Khadija Mvula A dissertation submitted to the University of Zambia in partial fulfilment of the requirements of the degree of Master of Science in Geography University of Zambia Lusaka 2015 DECLARATION I, Khadija Mvula, declare that this dissertation represents my own work and that it has not been submitted for a degree, diploma or other qualification at this or any other University. Name: __________________________________________ Signature: _______________________________________ Date: ___________________________________________ ii COPYRIGHT All rights reserved. No part of this dissertation may be reproduced, stored in retrieval system, or transmitted in any form or by any means; electronic, mechanical, photocopying, recording, or otherwise, without the prior permission in writing from the Author or the University of Zambia. (C) Khadija Mvula 2015 iii APPROVAL iv ABSTRACT Dambos are depressions that are waterlogged and grass covered and these are surrounded by savanna woodland. In Zambia, there is no clear legislation on the protection, conservation and management of wetlands including dambos. Therefore, the aim of this study was to examine the physical characteristics of Chassa dambo in Sinda, Eastern Province of Zambia and assess how these characteristics have been affected by human activities for the purpose of finding a lasting solution. The objectives were to: (i) describe the physical characteristics of Chassa dambo in terms of geomorphology, morphology, soils, hydrology, ecology and vegetation cover; (ii) determine the uses of Chassa dambo and the agricultural activities in the area; (iii) assess the effects of human activities on the geomorphology, morphology, soils, hydrology, ecology and vegetation cover of Chassa dambo; and (iv) to assess ways for sustainable use of Chassa dambo. On methodology, primary data was collected through direct observation through section sampling in one metre depth pits for analysis of physical and chemical characteristics in order to determine fertility and sedimentation areas. Structured and Semi-structured interviews were administered to different stakeholders and local community members. A total of 80 heads of households (8.8%) out of 905 households were sampled. Secondary sources of data included maps and use of Google Satellite imagery for assessment of physical features of the dambo. Analysis of data revealed that Chassa dambo catchment had been cleared to pave way for commercial farming, subsistence farming and settlements. The dambo had been dammed for storage of water for irrigation and canalised for the purpose of diverting water to the dams and draining the middle and central parts of the dambo. Heavy machinery was used in commercial farming leading to soil compaction. Overall, the field evidence showed that physical characteristics of Chassa dambo have been adversely affected by human activities. Hydrologically, the dambo has deteriorated due to reduced soil moisture and increased overland flow attributed to tree and grass clearing and burning of vegetation. The ecology of the dambo revealed adverse effects of these activities which have affected the natural dambo ecosystem. The chemical analysis of the dambo soils showed an accumulation of nutrients in the lower dambo and the organic carbon being below the critical value thus, indicating degradation of the soil properties. It is concluded that human activities have affected the morphology, ecology and hydrology of Chassa dambo which suggest the need for legislation for the protection and sustainable use of dambos for the benefit of local communities. v DEDICATION To my children; Tukuza, Tackson Emmanuel, Mphaso, Chikondi and Daliso Chisomo vi ACKNOWLEDGEMENTS Writing this piece of work would not have been possible without the guidance and tolerance of my supervisors; the lecturers and other members of staff in the Department of Geography and Environmental Studies and; people from various institutions that assisted me with materials. I owe the indelible tutorship to Dr. Henry Sichingabula, my supervisor, and Mr. Gear Kajoba, co-supervisor, who ably supervised my work. My profound gratitude also goes to Mr. Brian Gondwe and Ms Mutinta Malambo of Mount Makulu Research Station for their assistance. Lastly, I would like to thank my husband, Mr. Jimmy M. Sakala for his encouragement and support throughout the period of my study. vii TABLE OF CONTENTS DECLARATION......................................................................................................... ii COPYRIGHT............................................................................................................. iii APPROVAL FORM................................................................................................... iv ABSTRACT................................................................................................................. v DEDICATION............................................................................................................. vi ACKNOWLEDGEMENTS........................................................................................ vii TABLE OF CONTENTS............................................................................................ viii LIST OF TABLES...................................................................................................... xiii LIST OF FIGURES.................................................................................................... xiv LIST OF APPENDICES............................................................................................. xvi ABBREVIATIONS AND ACRONYMS.................................................................. xvii 1.0 CHAPTER ONE: INTRODUCTION....................................................... 1 1.1 Introduction................................................................................................... 1 1.2 Theoretical basis............................................................................................ 1 1.3 Statement of the Research Problem.............................................................. 3 1.4 Aim of the Study........................................................................................... 4 1.5 Research Objectives...................................................................................... 4 1.6 Research Questions....................................................................................... 5 1.7 Significance of the Study.............................................................................. 5 1.8 Organisation of the Dissertation.................................................................... 6 2.0 CHAPTER TWO: LITERATURE REVIEW.......................................... 7 2.1 Introduction................................................................................................... 7 viii 2.2 Defining Wetlands and Dambos................................................................... 7 2.2.1 Definition of wetlands................................................................................... 7 2.2.2 Definition of Dambos.................................................................................... 8 2.3 Distribution of Dambos in Zambia............................................................... 9 2.4 Classification of Dambos.............................................................................. 9 2.5 Dambo Geomorphology................................................................................ 13 2.6 Dambo Morphology...................................................................................... 13 2.7 Dambos Soils................................................................................................ 14 2.8 Hydrology of Dambos................................................................................... 15 2.9 Ecology of Dambos....................................................................................... 17 2.10 Vegetation Cover in Dambos........................................................................ 18 2.11 Socio-economic Uses of Dambos................................................................. 18 2.12 Degradation of Dambos................................................................................ 20 2.13 Use of Pesticides on Dambo Wetlands......................................................... 23 2.14 Wetland Conservation and Sustainable Management................................... 24 2.15 Policy Framework in Zambia........................................................................ 24 3.0 CHAPTER THREE: STUDY AREA........................................................ 26 3.1 Introduction................................................................................................... 26 3.2 Location......................................................................................................... 26 3.3 Physical Characteristics of the Study Area................................................... 27 3.3.1 Climate.......................................................................................................... 28 3.3.2 Geomorphology............................................................................................. 29 3.3.3 Morphology................................................................................................... 29 3.3.4 Soils..............................................................................................................