The Hydrological Cycle

Introduction and Definition

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

Secondary Geography Form 3 Student's Book, Pages 63

The Hydrological Cycle

Input and Output Processes

By the end of the lesson, the learner should be able to:
Identify precipitation as main input in various forms: dew, rainfall, mist, snow, fog
Explain evaporation as physical process of moisture loss to atmosphere
Describe transpiration as biological process of water loss from plants
Analyze factors affecting evaporation and transpiration rates

Exposition of precipitation forms and conditions for occurrence; Detailed discussion of evaporation process and factors: humidity, temperature, wind, sunshine hours, water characteristics; Analysis of transpiration through stomata and lenticles; Study of evapotranspiration as combined process

Precipitation examples, Evaporation demonstration materials, Plant samples showing stomata, Factor analysis charts

Secondary Geography Form 3 Student's Book, Pages 63-65

The Hydrological Cycle

Input and Output Processes

By the end of the lesson, the learner should be able to:
Identify precipitation as main input in various forms: dew, rainfall, mist, snow, fog
Explain evaporation as physical process of moisture loss to atmosphere
Describe transpiration as biological process of water loss from plants
Analyze factors affecting evaporation and transpiration rates

Exposition of precipitation forms and conditions for occurrence; Detailed discussion of evaporation process and factors: humidity, temperature, wind, sunshine hours, water characteristics; Analysis of transpiration through stomata and lenticles; Study of evapotranspiration as combined process

Precipitation examples, Evaporation demonstration materials, Plant samples showing stomata, Factor analysis charts

Secondary Geography Form 3 Student's Book, Pages 63-65

The Hydrological Cycle

Internal Transfer Processes

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

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

The Hydrological Cycle

Storage Processes and Significance

By the end of the lesson, the learner should be able to:
Identify surface water storage: seas, oceans, lakes, swamps
Describe ground water storage above impermeable rocks creating water table
Explain cryosphere as water stored in ice-covered regions
Analyze significance of hydrological cycle in ecological balance and distribution

Discussion of surface water storage through rivers to seas and lakes; Analysis of ground water formation through percolation and infiltration; Study of cryosphere as fresh water store; Examination of cycle significance: ecological balance, rainfall formation, atmospheric unity, oxygen-carbon cycle, water distribution

Water storage examples, Ground water table diagrams, Ice storage examples, Significance analysis charts

Secondary Geography Form 3 Student's Book, Pages 66-67

ACTION OF RIVERS

Definition of Terms Related to Rivers

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

KLB Secondary Geography Form 3, Pages 68-69

ACTION OF RIVERS

River Erosion Processes
River Transportation and Deposition

By the end of the lesson, the learner should be able to:
Explain hydraulic action, corrasion, attrition, and solution processes. Describe factors affecting erosion rate including stream volume, gradient, and bedrock nature.

Demonstration of erosion processes using water and materials. Discussion of factors affecting erosion with practical examples. Students observe erosion effects.

Water containers, sand, rock samples, demonstration materials
Containers, different sized particles, water, magnifying glasses

KLB Secondary Geography Form 3, Pages 69-72

ACTION OF RIVERS

Youthful Stage Features
Mature Stage Features

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

KLB Secondary Geography Form 3, Pages 74-80

ACTION OF RIVERS

Old Stage Features - Alluvial Fans and Flood Plains

By the end of the lesson, the learner should be able to:
Describe alluvial fan formation at highland-plain transitions. Explain flood plain development through erosion and deposition. Give examples like Ombei Fan and Kano Plains.

Drawing alluvial fan formation. Discussion of flood plain processes with Kenyan examples. Practical modeling of fan development.

Sand, water, modeling trays, maps showing flood plains, diagrams

KLB Secondary Geography Form 3, Pages 81-86

ACTION OF RIVERS

Old Stage Features - Meanders and Ox-bow Lakes
Old Stage Features - Levees, Braided Channels, and Deferred Tributaries

By the end of the lesson, the learner should be able to:
Explain meander formation through lateral erosion on concave banks. Describe ox-bow lake development from cut-off meanders.

Practical demonstration of meander formation using stream tables. Drawing meander development sequence leading to ox-bow lakes. Discussion of Kenyan examples.

Stream tables, sand, water, sequential diagrams, pictures of ox-bow lakes
Cross-section diagrams, aerial photographs, flood plain maps

KLB Secondary Geography Form 3, Pages 82-84

ACTION OF RIVERS

Delta Formation and Types

By the end of the lesson, the learner should be able to:
Explain delta formation when rivers enter seas/lakes. Describe arcuate, estuarine, and bird's foot delta types with examples (Tana, Rufiji, Lake Victoria deltas).

Drawing different delta types. Detailed discussion of Tana Delta distributaries. Analysis of delta formation conditions.

Maps of river deltas, diagrams of delta types, aerial photographs

KLB Secondary Geography Form 3, Pages 86-89

ACTION OF RIVERS

River Profile Summary

By the end of the lesson, the learner should be able to:
Summarize features along youthful, mature, and old stages. Compare dominant processes and resultant landforms at each stage.

Creating comprehensive river profile diagrams. Consolidation exercise comparing all stages. Tabulation of features by river stage.

Large drawing paper, colored pencils, summary charts, profile diagrams

KLB Secondary Geography Form 3, Page 89

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 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

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

KLB Secondary Geography Form 3, Pages 86-89

ACTION OF RIVERS

Drainage Patterns

By the end of the lesson, the learner should be able to:
Identify and describe dendritic, radial, centripetal, parallel, fault-guided, and trellis drainage patterns. Explain formation conditions and give Kenyan examples.

Drawing different drainage patterns. Analysis of Mt. Kenya radial drainage and Rift Valley centripetal patterns. Pattern recognition exercises.

Pattern diagrams, maps of Mt. Kenya and Rift Valley, colored pencils

KLB Secondary Geography Form 3, Pages 90-92

ACTION OF RIVERS

Drainage Systems

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

KLB Secondary Geography Form 3, Pages 92-94

ACTION OF RIVERS

Drainage Systems

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

KLB Secondary Geography Form 3, Pages 92-94

ACTION OF RIVERS

Significance of Rivers - Positive Effects

By the end of the lesson, the learner should be able to:
Explain rivers' roles in water supply, irrigation, transport, HEP generation, port facilities, building materials, boundaries, fishing, tourism.

Discussion of urban water supplies from rivers. Analysis of HEP projects and irrigation schemes. Review of river-based economic activities.

Maps of water systems, pictures of dams and ports, economic activity charts

KLB Secondary Geography Form 3, Pages 94-96

ACTION OF RIVERS

Significance of Rivers - Negative Effects and Water Conservation

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

KLB Secondary Geography Form 3, Pages 96-97

LAKES

Definition of a Lake

By the end of the lesson, the learner should be able to:
Define a lake as a large mass of water occupying a depression. Distinguish between fresh water and salt water lakes. Explain reasons for lake salinity including lack of outlets, high evaporation, and underground salt sources.

Q/A to review hydrological cycle and water bodies. Discussion of lake characteristics with examples from Kenya. Listing fresh vs salt water lakes on chalkboard.

Chalkboard, textbooks, wall map of Kenya

KLB Secondary Geography Form 3, Pages 99-100

LAKES

Lakes Formed by Tectonic Movements - Rift Valley Lakes
Lakes Formed by Tectonic Movements - Downwarped Lakes

By the end of the lesson, the learner should be able to:
Describe formation of faulted/rift valley lakes through earth movements. Explain characteristics: narrow, steep-sided, alkaline, long, deep. Give examples from Kenya (Turkana, Baringo, Nakuru, Naivasha) and other African rift valleys.

Drawing rift valley formation diagrams on chalkboard. Discussion of Kenyan Rift Valley lakes with their characteristics. Students copy diagrams in exercise books.

Chalkboard, chalk, exercise books, wall map of East Africa
Chalkboard, chalk, exercise books, atlas

KLB Secondary Geography Form 3, Pages 100-102

LAKES

Lakes Formed by Volcanic Activity
Lakes Formed by Glaciation

By the end of the lesson, the learner should be able to:
Describe crater lake formation in volcanic craters. Explain lava dammed lake formation when lava blocks river courses. Give examples: crater lakes (Simbi, Paradise, Chala) and lava dammed lakes (Bunyonyi, Kivu, Tana).

Drawing crater lake formation on chalkboard. Discussion of lava dam formation across rivers. Students sketch volcanic lake types in exercise books.

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

KLB Secondary Geography Form 3, Pages 103-106

LAKES

Lakes Formed by River and Wave Deposition

By the end of the lesson, the learner should be able to:
Explain ox-bow lake formation from cut-off meanders. Describe lagoon formation through longshore drift and delta processes. Give examples from Kenyan rivers (Tana, Yala, Nyando) and Lake Victoria shores.

Simple demonstration of meander cut-off using clay/soil and water in basin. Drawing ox-bow lake formation sequence on chalkboard. Discussion of lagoon formation.

Basin, clay/soil, water, chalkboard, chalk, exercise books

KLB Secondary Geography Form 3, Pages 107-108

LAKES

Other Lake Types - Wind Erosion, Solution, and Human-made
Landslide and Meteorite Lakes

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)

KLB Secondary Geography Form 3, Pages 108-109

LAKES

Lake Classification Summary and Regional Examples

By the end of the lesson, the learner should be able to:
Consolidate all lake formation types. Compare characteristics of different lake types. Analyze distribution patterns of lakes in East Africa and beyond.

Creating comprehensive classification table on chalkboard. Students copy into exercise books. Group discussions on different lake formation processes.

Chalkboard, chalk, exercise books, atlas

KLB Secondary Geography Form 3, Pages 100-109

LAKES

Significance of Lakes - Economic Importance

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

Significance of Lakes - Social and Environmental Benefits

By the end of the lesson, the learner should be able to:
Describe lakes as tourist attractions and recreational facilities. Explain climate modification effects of large water bodies. Analyze lakes as sources of rivers and building materials.

Discussion of Lake Nakuru National Park and flamingo tourism. Analysis of Lake Victoria's influence on regional climate. Review of recreational activities (boating, sport fishing).

Chalkboard, chalk, textbooks, exercise books

KLB Secondary Geography Form 3, Page 111

LAKES

Significance of Lakes - Social and Environmental Benefits

By the end of the lesson, the learner should be able to:
Describe lakes as tourist attractions and recreational facilities. Explain climate modification effects of large water bodies. Analyze lakes as sources of rivers and building materials.

Discussion of Lake Nakuru National Park and flamingo tourism. Analysis of Lake Victoria's influence on regional climate. Review of recreational activities (boating, sport fishing).

Chalkboard, chalk, textbooks, exercise books

KLB Secondary Geography Form 3, Page 111

LAKES

Negative Effects of Lakes

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

KLB Secondary Geography Form 3, Page 111