External Land Forming Processes

Introduction and Definition of Weathering
Agents of Weathering

By the end of the lesson, the learner should be able to:
Define weathering as process of rock breakdown in situ
Explain denudation as collective term for external processes
Distinguish between weathering and other external processes
Identify weathering agents: heat, water, dissolved substances, plants and animals

Q/A session reviewing internal land forming processes from Form Two; Exposition of denudation concept and external processes; Definition of weathering and regolith formation; Discussion of weathering agents and their effects on rocks

Charts showing external vs internal processes, Rock samples showing weathering effects, Diagrams of weathering agents
Rock samples, Temperature demonstration materials, Water pH testing materials, Examples of plant root damage to rocks

Secondary Geography Form 3 Student's Book, Pages 41-42

External Land Forming Processes

Factors Influencing Weathering
Rock Structure, Texture and Physical Weathering Introduction

By the end of the lesson, the learner should be able to:
Explain how climate elements influence weathering rates
Analyze role of plants and animals in weathering processes
Describe how relief affects weathering on different slopes
Examine chemical composition effects: color differences and mineral composition

Brain storming on weathering factors; Discussion of climatic elements: sunshine, rain, frost, temperatures; Analysis of plant and animal contributions; Study of relief influence on weathering rates; Examination of rock color absorption and mineral composition effects

Climate charts, Relief diagrams, Rock samples of different colors and compositions, Examples from highland and lowland areas
Figures 3.1(a), (b), Rock samples showing different crystal sizes, Examples from Bunyore, Seme Hills, Sang'alo areas

Secondary Geography Form 3 Student's Book, Pages 44-45

External Land Forming Processes

Physical Weathering Processes - Block Disintegration and Exfoliation
Physical Weathering - Granular Disintegration, Frost Action and Crystal Growth

By the end of the lesson, the learner should be able to:
Describe block disintegration through temperature changes and diurnal ranges
Explain exfoliation as peeling off of rock surfaces
Identify formation of exfoliation domes
Analyze conditions leading to these weathering processes

Detailed discussion of block disintegration using Figure 3.3; Analysis of desert temperature conditions and rock expansion/contraction; Study of exfoliation process using Figure 3.4; Examination of exfoliation dome formation using Figure 3.5

Figure 3.3 rock blocks, Figures 3.4 and 3.5 exfoliation examples, Temperature demonstration materials, Examples from desert regions
Figure 3.6 granular disintegration, Figure 3.7 frost action, Figure 3.8 Ol Njorowa Gorge, Examples from East African mountains

Secondary Geography Form 3 Student's Book, Pages 47-48

External Land Forming Processes

Physical Weathering - Slaking and Pressure Release
Chemical Weathering Processes - Solution and Hydrolysis

By the end of the lesson, the learner should be able to:
Describe slaking as water uptake and loss in clay-containing rocks
Explain pressure release or unloading in exposed rocks
Identify areas experiencing these weathering processes
Analyze sheeting effects in granitic rocks

Discussion of slaking process in clay rocks during wet and dry seasons; Analysis of coastal Jurassic rocks examples: Miritini, Tudor, Port Reitz; Explanation of pressure release as denudation removes overlying rocks; Study of sheeting in granitic areas: Nyika plateau, Machakos, Maragoli, Bunyore

Examples from coastal Kenya, Granitic rock samples, Areas experiencing pressure release, Activity 3.4 practical demonstration
Chemical equation charts, Examples of salt pans, Rock samples containing feldspar, Areas showing hydrolysis: Wundanyi, Bunyore

Secondary Geography Form 3 Student's Book, Pages 50-51

External Land Forming Processes

Chemical Weathering - Oxidation, Carbonation and Hydration
Chemical Weathering Results and Biological Weathering

By the end of the lesson, the learner should be able to:
Explain oxidation process in iron-containing rocks
Describe carbonation affecting calcium carbonate rocks
Analyze hydration as water absorption causing rock expansion
Identify areas and examples of these weathering processes

Study of oxidation chemical equation and ferric oxide formation; Analysis of carbonation process using chemical equation; Discussion of limestone dissolution and calcium bicarbonate formation; Explanation of hydration process and spheroidal weathering; Examples from coastal limestone areas: Kambe, Bamburi, Kilifi

Chemical equation demonstrations, Rock samples showing oxidation effects, Limestone samples, Examples of spheroidal weathering in basalt
Figure 3.9 tors examples, Figure 3.10 tree root action, Examples of biological weathering in local environment, Human activity examples

Secondary Geography Form 3 Student's Book, Pages 53-56

External Land Forming Processes

Biological Weathering - Human Activities and Significance of Weathering

By the end of the lesson, the learner should be able to:
Identify human activities causing weathering: deforestation, blasting, industrialisation
Explain acid rain effects from industrial emissions
Analyze burning and irrigation contributions to weathering
Discuss significance of weathering in soil formation, construction, tourism and economics

Study of human weathering activities using Figure 3.11 quarrying; Discussion of industrialisation effects: Carbon IV Oxide, sulphur dioxide emissions; Analysis of acid rain formation and corrosive effects; Examples from Copper Belt Zambia, Webuye Kenya; Study of agricultural burning and irrigation effects

Figure 3.11 quarrying, Examples of industrial weathering, Acid rain demonstration materials, Local examples of human-induced weathering

Secondary Geography Form 3 Student's Book, Pages 58-60

External Land Forming Processes
Mass Wasting

Significance of Weathering and Economic Importance
Introduction, Definition and Factors Influencing Mass Wasting

By the end of the lesson, the learner should be able to:
Explain weathering importance in soil formation processes
Describe weathering role in quarrying and construction industries
Identify weathering creating tourist attractions
Analyze economic products from weathering: bauxite, kaolite, clay

Exposition of weathering as initial stage in soil formation; Discussion of quarrying importance for building and construction; Analysis of tourist attractions: Kit Mikayi, Crying Stone using Figure 3.12; Study of economic products: bauxite from hydrolysis, kaolite from granite rotting, clay for pottery and bricks

Figure 3.12 Crying Stone of Kakamega, Examples of weathering tourist sites, Economic product samples, Engineering consideration examples
Charts showing gravity effects, Slope demonstrations, Rock samples, Climate charts, Examples of human activities

Secondary Geography Form 3 Student's Book, Pages 60-61

Mass Wasting

Slow Mass Wasting Processes
Rapid Mass Wasting - Earthflows, Mudflows and Avalanches

By the end of the lesson, the learner should be able to:
Define soil creep as slow movement involving fine soil particles
Describe scree (talus) creep as angular waste rock movement on mountains
Explain solifluction as gravitational flow of water-saturated materials
Identify triggers, evidence and effects of slow mass wasting processes

Exposition of soil creep using Figure 4.1 showing effects and evidence; Discussion of triggering factors and infrastructure impacts; Study of scree creep using Figure 4.2 from mountain examples; Analysis of solifluction using Figure 4.3 in cold climates; Examples from Mount Kenya, Kilimanjaro, and local areas

Figures 4.1, 4.2, 4.3, Examples from mountains, Soil movement demonstrations, Cold climate examples
Figure 4.4 earthflows, Mudflow examples, Avalanche examples from temperate regions, Factor comparison charts

Secondary Geography Form 3 Student's Book, Pages 54-56

Mass Wasting

Landslides - Types and Characteristics
Effects of Mass Wasting on Physical and Human Environment

By the end of the lesson, the learner should be able to:
Explain landslides as sudden movement with small water content
Describe slump as intermittent movement with backward rotation
Distinguish debris slide, debris fall, rock fall and rock slide characteristics
Analyze examples from Kenya and East Africa: Fort Portal, Limuru-Longonot, road cuttings

Introduction to landslide causes and triggering factors; Study of slump development using Figures 4.5 and 4.6; Analysis of debris movements and rock movements; Examination of Kenyan examples: Kabarnet-Iten, Mwatate-Wundanyi, Kaseve roads; Discussion of infrastructure impacts and geological plane movements

Figures 4.5, 4.6 slump examples, Road cutting examples, Rock samples, Examples from Uganda and Kenya
Figures 4.9, 4.10, Soil fertility examples, Disaster case studies, Environmental conservation examples

Secondary Geography Form 3 Student's Book, Pages 57-60

The Hydrological Cycle

Introduction and Definition
Input and Output Processes

By the end of the lesson, the learner should be able to:
Define hydrological cycle as endless circulation of water from oceans to atmosphere to land
Explain role of sun as energy source driving the cycle
Identify components: inputs, outputs, transfers and storages
Describe hydrological cycle as complete balanced system

Q/A session using questions about water disappearance and return; Discussion of water circulation from sky to land to ocean; Exposition of hydrological cycle definition; Analysis of Figure 5.1 showing complete cycle; Study of system components and energy source

Figure 5.1 hydrological cycle diagram, Water circulation demonstrations, System component charts
Precipitation examples, Evaporation demonstration materials, Plant samples showing stomata, Factor analysis charts

Secondary Geography Form 3 Student's Book, Pages 63

The Hydrological Cycle

Internal Transfer Processes
Storage Processes and Significance

By the end of the lesson, the learner should be able to:
Explain interception as first contact of rain with vegetation
Describe runoff as overland flow when ground cannot absorb water
Define infiltration as vertical water absorption through soil pores
Distinguish percolation as movement through underlying rock layers

Study of interception storage and through fall processes; Analysis of surface storage and ground saturation; Discussion of runoff conditions and overland flow; Examination of infiltration capacity and factors; Study of percolation leading to underground water storage

Vegetation interception examples, Runoff demonstration materials, Soil infiltration samples, Percolation process diagrams
Water storage examples, Ground water table diagrams, Ice storage examples, Significance analysis charts

Secondary Geography Form 3 Student's Book, Pages 65-66

ACTION OF RIVERS

Definition of Terms Related to Rivers
River Erosion Processes
River Transportation and Deposition

By the end of the lesson, the learner should be able to:
Define rivers, source, mouth, tributaries, confluence, drainage basin, watershed, interfluves. Identify components of river systems on maps.

Q/A to review hydrological cycle. Explanation of river terminology with Kenyan examples. Drawing and labeling river system diagrams.

Maps of Kenya, river system charts, textbooks
Water containers, sand, rock samples, demonstration materials
Containers, different sized particles, water, magnifying glasses

KLB Secondary Geography Form 3, Pages 68-69

ACTION OF RIVERS

Youthful Stage Features
Mature Stage Features
Old Stage Features - Alluvial Fans and Flood Plains
Old Stage Features - Meanders and Ox-bow Lakes

By the end of the lesson, the learner should be able to:
Identify V-shaped valleys, waterfalls, rapids, gorges, potholes, interlocking spurs. Explain formation through vertical erosion dominance.

Drawing youthful stage features. Discussion of waterfall types with Kenyan examples (Thomson's Falls, Torok Falls). Modeling with clay.

Clay/plasticine, topographical maps, pictures of waterfalls, drawing materials
Comparison charts, cross-section diagrams, colored pencils
Sand, water, modeling trays, maps showing flood plains, diagrams
Stream tables, sand, water, sequential diagrams, pictures of ox-bow lakes

KLB Secondary Geography Form 3, Pages 74-80

ACTION OF RIVERS

Old Stage Features - Levees, Braided Channels, and Deferred Tributaries
Delta Formation and Types
River Profile Summary

By the end of the lesson, the learner should be able to:
Describe natural levee formation during floods. Explain braided channel development and deferred tributary formation.

Drawing levee cross-sections. Discussion of raised river beds and flooding problems. Analysis of braided patterns during dry seasons.

Cross-section diagrams, aerial photographs, flood plain maps
Maps of river deltas, diagrams of delta types, aerial photographs
Large drawing paper, colored pencils, summary charts, profile diagrams

KLB Secondary Geography Form 3, Pages 84-85

ACTION OF RIVERS

River Capture

By the end of the lesson, the learner should be able to:
Define river capture, pirate river, misfit river, elbow of capture, wind gap. Describe capture process and conditions. Explain Kenyan examples: Tiva-Galana and Sondu-Miriu captures.

Drawing river capture process step-by-step. Detailed case study of Kenyan river captures. Map analysis of capture sites and resultant features.

Maps of Kenya, capture process diagrams, case study materials

KLB Secondary Geography Form 3, Pages 85-86

ACTION OF RIVERS

River Rejuvenation
Drainage Patterns

By the end of the lesson, the learner should be able to:
Define river rejuvenation and distinguish dynamic vs static rejuvenation. Describe resultant features: river terraces, incised meanders, rejuvenation gorges, knick points.

Discussion of rejuvenation causes (base level changes, increased discharge). Drawing rejuvenation features with examples from coastal Kenya rivers.

Rejuvenation feature diagrams, pictures of incised meanders, maps of coastal Kenya
Pattern diagrams, maps of Mt. Kenya and Rift Valley, colored pencils

KLB Secondary Geography Form 3, Pages 86-89

ACTION OF RIVERS

Drainage Systems
Significance of Rivers - Positive Effects

By the end of the lesson, the learner should be able to:
Distinguish accordant, discordant (antecedent, superimposed), and back-tilted drainage systems. Explain formation and give examples.

Discussion of drainage development relative to geological structure. Analysis of Rift Valley antecedent drainage and Yatta Plateau back-tilting.

Geological maps, drainage system diagrams, cross-sections
Maps of water systems, pictures of dams and ports, economic activity charts

KLB Secondary Geography Form 3, Pages 92-94

ACTION OF RIVERS
LAKES
LAKES

Significance of Rivers - Negative Effects and Water Conservation
Definition of a Lake
Lakes Formed by Tectonic Movements - Rift Valley Lakes

By the end of the lesson, the learner should be able to:
Describe flooding problems, communication barriers, waterborne diseases. Explain Water Act provisions for conservation and access.

Discussion of flood disasters and health issues. Analysis of communication problems caused by rivers. Review of water resource management principles.

Pictures of floods, case study materials, Water Act summary
Chalkboard, textbooks, wall map of Kenya
Chalkboard, chalk, exercise books, wall map of East Africa

KLB Secondary Geography Form 3, Pages 96-97

LAKES

Lakes Formed by Tectonic Movements - Downwarped Lakes
Lakes Formed by Volcanic Activity
Lakes Formed by Glaciation
Lakes Formed by River and Wave Deposition

By the end of the lesson, the learner should be able to:
Explain formation through crustal warping and tilting. Describe Lakes Victoria and Kyoga formation during drainage evolution. Analyze back-tilted rivers (Kagera, Katonga, Kafa) contributing to lake formation.

Drawing crustal warping diagrams on chalkboard. Discussion of drainage reversal and back-tilting. Students draw formation sequence in notebooks.

Chalkboard, chalk, exercise books, atlas
Chalkboard, chalk, exercise books, textbooks
Basin, clay/soil, water, chalkboard, chalk, exercise books

KLB Secondary Geography Form 3, Pages 102-103

LAKES

Other Lake Types - Wind Erosion, Solution, and Human-made
Landslide and Meteorite Lakes
Lake Classification Summary and Regional Examples

By the end of the lesson, the learner should be able to:
Describe wind erosion lakes through deflation to water table. Explain solution lakes in limestone areas (sink holes). Identify human-made lakes behind dams (Masinga, Volta, Kariba, Nasser).

Discussion of oasis formation through wind erosion. Explanation of solution processes in limestone using chalk demonstration. Review of major African dams and their lakes.

Pieces of chalk, water container, chalkboard, atlas
Sand tray, small stones, chalkboard, internet access (if available)
Chalkboard, chalk, exercise books, atlas

KLB Secondary Geography Form 3, Pages 108-109

LAKES

Significance of Lakes - Economic Importance
Significance of Lakes - Social and Environmental Benefits

By the end of the lesson, the learner should be able to:
Explain lakes as sources of fish, water supply, and irrigation. Describe hydroelectric power generation from lakes. Analyze transport and navigation benefits. Discuss mineral extraction (soda ash, salt) from lakes.

Discussion of Lake Victoria fisheries and water supply to cities. Analysis of Owen Falls and Seven Forks power generation. Case study of Lake Magadi salt and soda ash mining using textbook examples.

Chalkboard, chalk, textbooks, exercise books

KLB Secondary Geography Form 3, Pages 109-111

LAKES
OCEANS, SEAS AND THEIR COASTS
OCEANS, SEAS AND THEIR COASTS

Negative Effects of Lakes
Distinction Between Oceans and Seas
Nature of Ocean Water - Salinity and Temperature

By the end of the lesson, the learner should be able to:
Identify disease vectors (mosquitoes, snails) around lakes causing malaria and bilharzia. Describe dangerous wildlife habitats (crocodiles, hippos). Explain displacement issues from human-made lakes.

Discussion of health challenges in lake regions. Analysis of human-wildlife conflict around lakes. Case study of resettlement during dam construction projects using textbook examples.

Chalkboard, chalk, textbooks, exercise books
Chalkboard, world map, atlas, exercise books
Chalkboard, chalk, exercise books, thermometer for demonstration

KLB Secondary Geography Form 3, Page 111

OCEANS, SEAS AND THEIR COASTS

Nature of Ocean Water - Ocean Life and Topography
Islands and Ocean Pollution
Water Movement - Vertical Movement

By the end of the lesson, the learner should be able to:
Describe ocean life including plankton, nekton, and benthos. Explain ocean topography features: continental shelf, slope, abyssal plain, ridges, and trenches.

Discussion of marine organisms and their habitats. Drawing ocean floor profile on chalkboard showing topographical features. Students sketch ocean life zones.

Chalkboard, chalk, exercise books, textbooks
Chalkboard, chalk, exercise books, atlas
Containers, warm and cold water, chalkboard, atlas

KLB Secondary Geography Form 3, Pages 117-119

OCEANS, SEAS AND THEIR COASTS

Water Movement - Ocean Currents
Major Ocean Currents
Tides - Formation and Causes
Types of Tides

By the end of the lesson, the learner should be able to:
Explain ocean current formation by winds, earth's rotation, land masses, and temperature. Describe Coriolis effect and its impact on current direction. Distinguish between warm and cold currents.

Drawing ocean current formation diagrams on chalkboard. Discussion of Coriolis effect using globe demonstration. Students identify current types on world map.

Chalkboard, chalk, globe, world map, exercise books
World map, atlas, chalkboard, exercise books
Chalkboard, chalk, exercise books, stones for demonstration
Chalkboard, chalk, exercise books, textbooks

KLB Secondary Geography Form 3, Pages 122-124

OCEANS, SEAS AND THEIR COASTS

Wave Formation and Types
Wave Erosion Processes and Features

By the end of the lesson, the learner should be able to:
Explain wave formation through wind friction on water surface. Describe wave components: crest, trough, wavelength, height. Distinguish between constructive and destructive waves.

Simple demonstration of wave formation using water basin and fan/breath. Drawing wave diagrams showing crest and trough. Discussion of wave breaking processes.

Water basin, chalkboard, chalk, exercise books
Chalkboard, chalk, exercise books, pictures from textbook

KLB Secondary Geography Form 3, Pages 128-130

OCEANS, SEAS AND THEIR COASTS

Wave Transportation and Deposition

By the end of the lesson, the learner should be able to:
Explain longshore drift process and material transportation. Describe factors influencing coastal deposition. Identify transportation mechanisms along coasts.

Simple demonstration of longshore drift using sand and water. Discussion of sediment sorting and deposition patterns. Students draw longshore drift diagrams.

Sand, water container, chalkboard, chalk, exercise books

KLB Secondary Geography Form 3, Pages 134-135

OCEANS, SEAS AND THEIR COASTS

Coastal Depositional Features - Beaches and Spits
Coastal Depositional Features - Bars and Other Features

By the end of the lesson, the learner should be able to:
Describe beach formation and characteristics. Explain spit formation at coastline direction changes. Identify beach features: ridges, cusps, berms, beach rock.

Discussion of beach formation conditions and processes. Drawing spit formation diagrams showing longshore drift effects. Students identify local beach examples.

Chalkboard, chalk, exercise books, sand for demonstration
Chalkboard, chalk, exercise books, textbooks

KLB Secondary Geography Form 3, Pages 135-137

OCEANS, SEAS AND THEIR COASTS

Types of Coasts - Concordant and Discordant
Submerged Coasts - Highland and Lowland

By the end of the lesson, the learner should be able to:
Distinguish between concordant and discordant coasts. Explain factors determining coast types: wave action, tidal currents, rock nature, alignment.

Discussion of coast types with Kenya examples (Malindi-Lamu vs Mombasa). Analysis of factors affecting coastal development. Students identify coast types on maps.

Atlas, chalkboard, chalk, exercise books
Chalkboard, chalk, exercise books, maps of Kenya coast

KLB Secondary Geography Form 3, Pages 139-140

OCEANS, SEAS AND THEIR COASTS

Emerged Coasts
Coral Coasts and Reef Formation

By the end of the lesson, the learner should be able to:
Describe emerged coast formation through sea level fall. Identify upland features: raised beaches, notches, wave-cut platforms. Explain lowland features: fall-lines, gentle coastal plains.

Discussion of emergence processes and resultant features. Analysis of Kenya coast examples (Mama Ngina Drive, Oceanic Hotel). Students draw emerged coast profiles.

Chalkboard, chalk, exercise books, local examples
Chalkboard, chalk, exercise books, world map

KLB Secondary Geography Form 3, Pages 142-143

OCEANS, SEAS AND THEIR COASTS

Types of Coral Reefs
Coral Reef Formation Theories

By the end of the lesson, the learner should be able to:
Distinguish between fringing reefs, barrier reefs, and atolls. Explain formation processes and characteristics of each reef type. Give examples from East Africa and globally.

Drawing coral reef formation diagrams on chalkboard. Discussion of Great Barrier Reef and local examples. Students sketch reef formation sequences.

Chalkboard, chalk, exercise books, atlas
Chalkboard, chalk, exercise books, textbooks

KLB Secondary Geography Form 3, Pages 144-146

OCEANS, SEAS AND THEIR COASTS

Significance of Oceans - Economic Importance
Significance of Coasts and Coastal Features

By the end of the lesson, the learner should be able to:
Explain ocean significance for climate modification, fishing, transport, and mineral extraction. Describe HEP generation from tides and tourism benefits.

Discussion of ocean economic activities and benefits. Analysis of global fishing grounds and shipping routes. Students list ocean economic uses.

Chalkboard, chalk, exercise books, world map
Chalkboard, chalk, exercise books, maps of Kenya

KLB Secondary Geography Form 3, Pages 148-149

OCEANS, SEAS AND THEIR COASTS

Unit Assessment

By the end of the lesson, the learner should be able to:
Assess understanding of ocean characteristics, water movements, coastal processes, and significance. Evaluate achievement of all learning objectives.

Written assessment covering all unit topics. Practical identification of coastal features from descriptions. Map work exercises using atlas.

Assessment papers, atlas, exercise books, maps

KLB Secondary Geography Form 3, Pages 113-150