THE OPEN UNIVERSITY OF TANZANIA Institute of Continuing Education FOUNDATION PROGRAMME OFP 012 Geography Published by: The Open University of Tanzania Kawawa Road, P. O. Box 23409, Dar es Salaam. TANZANIA www.out.ac.tz First Edition: 2013 Second Edition: 2017 Copyright © 2013 All Rights Reserved ISBN 978 9987 00 252 8 2 Contents GENERAL INTRODUCTION ....................................................................................................... 6 PART 1 EARTH’S STRUCTURE AND MATERIALS OF EARTH Lecture 1: The Meaning and Branches of Geography ................................................................... 8 1.1 Introduction ............................................................................................................... 8 1.2 Geography: An Overview .......................................................................................... 8 Lecture 2: Structure of Earth ....................................................................................................... 12 2.1 Introduction ............................................................................................................. 12 2.2 The Structure of Earth .............................................................................................. 13 Lecture 3: Origin of Earth ............................................................................................................ 16 3.1 Continental Drifting Theory ..................................................................................... 16 3.2 The Plate Tectonic Theory ....................................................................................... 16 3.3 Movement of Plates and Resulting Landforms .......................................................... 17 Lecture 4: Classification of Rocks ................................................................................................. 21 4.1 Introduction ............................................................................................................. 21 4. 2 Types of Rocks ........................................................................................................ 21 4.3 Rock cycle ............................................................................................................... 22 PART 2 EARTH’S MOVEMENT AND INTERNAL GEOMOPHIC PROCESSES Lecture 5: Internal Geomorphic Processes: Volcanicanism and Landforms .............................. 26 5.1 Introduction ............................................................................................................. 26 5.2 Earth Movements ..................................................................................................... 26 5.3 Effects of Tension and Compression Forces ............................................................. 28 5.4 Volcanic Activity ..................................................................................................... 29 5.5 Lifecycle of a Volcano ............................................................................................. 32 5.6 Importance of Volcanic Activity to Man................................................................... 32 5.7 Volcanic Activity as a Hazard .................................................................................. 33 PART 3 EXTERNAL GEOMORPHIC PROCESSES Lecture 6: External Geomorphic Processes Weathering and Mass Movement ........................... 36 6.1 Introduction ............................................................................................................. 36 6.2 Weathering .............................................................................................................. 36 6.3 Factors Affecting the Type and Rate of Weathering.................................................. 40 6.4 Mass Movement....................................................................................................... 40 Lecture 7: River Action and Landforms Produced ...................................................................... 44 7.1 Introduction ............................................................................................................. 44 7.2 Erosion and Deposition by Running Water ............................................................... 44 7.3 Factors Which Reduce Energy of a River ................................................................. 45 7.4 Features Produced in the Upper Course of River Valley ........................................... 46 3 7.5 Features Produced in the Middle Course of a River Valley ....................................... 47 7.6 Features of a Lower Course of a River Valley .......................................................... 49 7.7 Types of delta .......................................................................................................... 50 Lecture 8: Erosion and Deposition by Action of Waves ............................................................... 54 8.1 Introduction .................................................................................................................. 54 8.2 Features Produced by Wave Erosion ........................................................................ 55 8.3 Features Produced by Wave Deposition ................................................................... 56 Lecture 9: Erosion and Deposition by Wind Action ..................................................................... 59 9.1 Introduction ............................................................................................................. 59 9.2 Processes of Wind Erosion ....................................................................................... 59 9. 3 Wind Erosional Landforms ...................................................................................... 60 9.4 Features Produced by Wind Deposition .................................................................... 62 9.5 Types of Desert ........................................................................................................ 64 Lecture 10: Glacial Erosional and Depositional landforms ......................................................... 66 10.1 Glacial Types and Processes..................................................................................... 66 10.2 Glacial Erosional Landforms .................................................................................... 66 10.3 Glacial Depositional Landforms ............................................................................... 68 Lecture 11: The Study of Soil ........................................................................................................ 72 11.1 Introduction ............................................................................................................. 72 11.2 Soil Profile ............................................................................................................... 73 11.3 Constitutes of Soil .................................................................................................... 74 11.4 Factors for Soil Formation ....................................................................................... 75 11.5 Physical Characteristics of Soil ................................................................................ 76 11.6 Soil Fertility ............................................................................................................. 78 11.7 Soil Erosion, Conservation and Sustainability .......................................................... 78 PART 4 HUMAN GEOGRAPHY Lecture 12: Constituents of Human Geography ........................................................................... 83 12.1 Introduction ............................................................................................................. 83 12.2 Main Concerns of Human Geography ...................................................................... 83 12.3 People and Environment .......................................................................................... 85 12.4 Major Environmental Problems in Tanzania ............................................................. 85 12.5 Human Impacts on the Environment......................................................................... 88 Lecture 13: Population and Development..................................................................................... 90 13.1 Introduction ............................................................................................................. 90 13.2 Population Terms ..................................................................................................... 90 13.3 Population Distribution ............................................................................................ 93 13.4 Population Density ................................................................................................... 93 13.5 Overpopulation ........................................................................................................ 94 13.6 Population Controls ................................................................................................. 94 13.7 Population Migration ............................................................................................... 95 13.8 Factors for Migration ............................................................................................... 95 13.9 Consequences of Migration in Area of Origin and Area of Destination ..................... 97 4 PART 5 ENVIRONMENT AND EXPLOITATION OF NATURAL RESOURCES Lecture