Kwame Nkrumah University of Science and Technology, Kumasi College of Engineering Department of Materials Engineering Assessing the Ecology of Wetlands in Kumasi and the Adaptations of the Communities to Floods BY ABDUL-RAZAK IDDRISU FEBRUARY, 2012 KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY, KUMASI COLLEGE OF ENGINEERING Assessing the Ecology of Wetlands in Kumasi and the Adaptations of the Communities to Floods By Abdul-Razak Iddrisu (BSc. Geodetic Engineering) A thesis submitted to the Department of Materials Engineering of the College of Engineering, in partial fulfilment of the requirement for the degree of Master of Science, in Environmental Resources Management. FEBRUARY, 2012 DECLARATION I, Abdul-Razak Iddrisu, hereby declare that the submission is my own work towards the award of MSc. Environmental Resources Management and that, to the best of my knowledge, it contains no material previously published by another person nor material which has been accepted for the award of any degree of the University, except where due acknowledgement has been made in the text. Abdul-Razak Iddrisu ………………………. ……………………… Candidate Signature Date Mr. B. B. Campion ……………………… .......……………………. Supervisor Signature Date Mr. G. Owusu-Boateng ……………………… .……………………....... Supervisor Signature Date Certified by: Prof. Samuel Kwofie ……………………… ………………….. Head of Department Signature Date ii ABSTRACT In an attempt to maintain wetland sustainability, it is important to manage anthropogenic activities on wetlands. Due to the ever increasing population, wetlands are abused by society leading to degradation. This research aimed at studying the ecology of wetlands in Kumasi and the adaptations of the wetland associated communities to flooding. The wetland areas namely Aboabo, Ahinsan, Atonsu, Asokore Mampong, Bantama and Kwadasu Estates and the associated land uses were delineated and their physicochemical and heavy metal characteristics analyzed using the Atomic Absorption Spectrometry. With the aid of questionnaire, the adaptations to flooding by wetland communities were studied. Results showed an increased trend for urban development (70%) with non-forested vegetation and wetlands suffering the consequences. High variation existed among some physicochemical parameters (TDS, temperature, conductivity, dissolved oxygen and salinity). pH was neutral to alkaline. The study showed that land use activities that take place in wetlands in Kumasi and its environs have negative effect on the functioning of the wetlands. Most of the streams are being used as waste disposal sites causing the wetland areas to flood in the least rain. The communities adapt to flooding by dredging the streams, creating embankment at the shoulders of the stream and sweeping away the flood water and in extreme cases vacate their home only to return after the flood subsides. It has become difficult if not impossible for city authorities to enforce the statutory laws of urban development and thus demolish buildings that flout these laws. iii ACKNOWLEDGEMENT In the name of Allah the Most Gracious, the Most Merciful, all praises and thanks are due to Allah the Lord of Aalamin (All that exist). I wish to express my sincere gratitude to my supervisors Mr. Benjamin Betey Campion and Mr. Godfred Owusu-Boateng of the Faculty of Renewable Natural Resources-KNUST, for their patience, support, valuable suggestions and guidance during the course of this thesis. For their priceless effort, this piece of work has seen the light of day surmounting all challenges and constrain of time. My greatest appreciation also goes to my brother Mr. Hamza Iddrisu, for his immeasurable assistance and moral support for which reason I started this program in the first place. My appreciation also goes to all the lecturers and staff of the Department of Materials Engineering, KNUST where this study was carried out, for their effort to impart us with rich and valuable teachings. Last but not least, my thanks go to all my friends and loved ones who contributed towards the successful completion of this course, most especially to Mr. Abdul-Latif Bavug of Ecobank - Accra, Mr. Iliasu Ewutomah and Mr. Augustus Ababio-Donkor (Department of Urban Roads) for all the „sorting out‟, I very much appreciate it. And finally, I am asking for God‟s blessings and success for all my future endeavours. iv TABLE OF CONTENT DECLARATION.......................................................................................................... ii ABSTRACT ................................................................................................................ iii ACKNOWLEDGEMENT .......................................................................................... iv TABLE OF CONTENT ............................................................................................... v LIST OF TABLES ...................................................................................................... ix LIST OF FIGURES ..................................................................................................... x LIST OF PLATES ...................................................................................................... xi LIST OF ACRONMY AND ABBREVIATION...................................................... xii CHAPTER ONE .......................................................................................................... 1 INTRODUCTION........................................................................................................ 1 1.1 BACKGROUND ND JUSTIFICATION OF STUDY ........................................ 1 1.2 PROBLEMS WITH WETLANDS DEGRADATION AND FLOODS IN KUMASI ............................................................................................................ 4 1.3 AIM AND OBJECTIVES .................................................................................... 5 1.4 RESEARCH QUESTIONS .................................................................................. 6 1.5 SCOPE OF THE RESEARCH ............................................................................. 6 CHAPTER TWO ......................................................................................................... 7 LITERATURE REVIEW ........................................................................................... 7 2.1 METHODS OF GATHERING WETLAND DATA ........................................... 7 2.2 DEFINITION AND IMPORTANCE OF WETLANDS ..................................... 8 2.3 AFRICAN WETLANDS ................................................................................... 10 2.4 BIODIVERSITY OF WETLAND ..................................................................... 12 2.4.1 DIVERSITY AND PRODUCTIVITY OF WETLAND PLANTS ............. 13 2.4.2 DIVERSITY OF ANIMALS IN WETLANDS........................................... 14 2.5 THE RAMSAR CONVENTION AND ITS ROLE IN CONSERVATION AND WISE USE OF WETLAND BIODIVERSITY................................................ 15 v 2.5.1 WISE USE OF WETLANDS ...................................................................... 16 2.6 DELINEATION AND MAPPING OF WETLANDS ....................................... 20 2.7 CLASSIFICATION OF WETLAND TYPES ................................................... 22 2.8 WETLAND HYDROLOGY .............................................................................. 23 2.8.1 WATER BALANCE ................................................................................... 24 2.8.2 EVAPORATION ESTIMATION ............................................................... 24 2.8.3 WETLAND RIVER INTERACTION......................................................... 25 2.9 WETLAND AND CLIMATE CHANGE .......................................................... 26 2.9.1 WETLAND CARBON STOCKS ............................................................... 27 2.9.2 WETLANDS AS SINKS AND SOURCES ................................................ 28 2.10 URBANIZATION AND LAND USE ............................................................. 29 2.11 MODELS USED IN STUDYING WETLANDS ............................................ 30 2.12 ENVIRONMENTAL CONSEQUENCES OF URBANIZATION ................. 31 2.13 WETLAND MANAGEMENT IN GHANA.................................................... 34 CHAPTER THREE ................................................................................................... 37 MATERIALS AND METHODS .............................................................................. 37 3.1 DESCRIPTION OF STUDY AREA ................................................................. 37 3.1.1 DEMOGRAPHY ......................................................................................... 38 3.1.2 CLIMATIC CONDITIONS ........................................................................ 39 3.1.3 TOPOGRAPHY, GEOLOGY AND SOIL TYPE ...................................... 40 3.1.4 THE DRAINAGE SYSTEM IN KUMASI ................................................. 41 3.1.5 LAND USE AND VEGETATION ............................................................. 42 3.2 RECONNAISSANCE SURVEY OF WETLANDS IN KUMASI AND SELECTION OF STUDY SITES .................................................................... 42 3.3 DATA COLLECTION ....................................................................................... 44 3.4 ON-GROUND INVENTORY OF WETLANDS IN KUMASI ........................ 44 3.4.1 SEDIMENT SAMPLING ............................................................................ 44 vi 3.4.2 SOIL PREPARATION AND