KCSE 2024 Geography Paper 1 Marking Scheme

1 a) What is Geography?

Geography is the study of the relationship between human beings and the environment/ the study of the distribution and interdependence between nature and human aspects on the earth surface./ study of the Earth as a home of humankind

b) State three ways in which Geography is related to Mathematics.

Geographical information can be analysed through the application of Mathematical techniques.

Mathematical principles/formulae are used in Geography to calculate area/ distance/ population density.

Geographical concepts are applied in calculating direction/bearing in mathematics.

Geographical information can be presented by applying mathematical techniques.

2. State five factors that have led to the decline of natural grasslands in Kenya.

Human encroachment and replacement by settlements/ for Agriculture.

Frequent bush fire outbreaks that destroys grass/vegetation.

Pests such as army worms and locusts destroy grass/vegetation.

Wild and domestic animals overgrazing and destroying grass.

Replacement/planting of grass/ Lucerne/ lawn grass.

Prolonged drought/desertification.

Soil degeneration.

3. A Form One Class visited a nearby weather station. While there, one of the students asked the importance of the Stevenson's screen.

Give four responses that the weather station personnel would have given.

The screen provides the thermometer with free flow of air that allows for accurate temperature reading.

It ensures the safety of the delicate instruments kept in it.

It provides shade/shelter from the rain/direct rays of the sun.

It is raised from the ground protecting the instruments from contact with direct radiation from the earth's surface.

4. (a) Give the two types of ocean movements.

Vertical movement.

Horizontal movement.

b) State four causes of pollution in the Indian Ocean.

Deposition of silt and sediments from the hinterland.

Deposition of industrial wastes from industries into the oceans.

Solid wastes are dumped at the beaches and find their way to the ocean.

Herbicides and pesticides from agricultural farms carried by rivers from hinterlands to the ocean.

Discharge of warm water used to cool machines/industrial plants.

Spillage of from oil ships/tankers into the ocean waters.

5. (a) Name two types of deserts by the nature of their surfaces.

Sandy (Erg/Koum)

Stony (Reg/Srir/Sai)

Rocky (Hamada)

Badlands.

b) Give three features associated with inland drainage basins in arid areas.

Alluvial fans/Alluvial cones

Playas/Sobkhas

Salinas/Salar

Bajadas/Bakada

Pediments

Ephemeral rivers/streams

6. Study the map of Tambach (1:50,000) (sheet 90/3) and answer the following questions.

(a) (i) What is the bearing of Air photo principal point at grid square 0180 from the Trigonometrical station 90S5 at grid square 0475?

324° ± 1° / N36°W ± 1° (323° - 325°) (N 35°W - N37°W)

(ii) Identify two physical features found in grid square 9581

Gently slope.

River.

Valley.

Seasonal swamp.

Scrub.

Scattered trees.

(iii) Calculate the area of the planted forest at Kapchemutwa. Give your answer in square kilometers.

8 km² ± 0.5

7.5 km² - 8.5 km²

(2 marks)

(b) Using a scale of 1 cm to represent 40 metres draw a cross-section from grid reference 830650 to 910650.

On it mark and name the following:

(i) Dry weather road. (ii) Gentle slope. (iii) Seasonal swamp. (iv) River Kerio.

A CROSS-SECTION FROM GRID REFERENCE 830650 TO 910650

(i) Dry weather Road 1MK

(ii) Gentle slope 1MK

(iii) Seasonal swamp 1MK

(iv) River Kerio 1MK

(v) Correct trend 1MK

(vi) Title 1MK

(vii) Start and end points 1MK

Total (7 marks)

c) Explain how relief has influenced the distribution of settlement in the area covered by the map.

There are many settlements in the Northwest and Southwest because the land is gently sloping.

There are no settlements on some of the slopes on the Eastern side/North Eastern side because they are steep.

There are few settlements on Elgeyo escarpment because the area has steep slopes.

There are few settlements on the floor of Kerio Valley because it is low lying.

There are settlements at the foot of some of the hills on the eastern side of the area because they are gently sloping

there is no settlement on the hills on the north eastern side because they are steep

(d) Citing evidence from the map, give three economic activities carried out in the area covered by the map.

7. The diagram below represents features formed through faulting. Use it to answer question a(i) and (ii)

Formation by compressional forces.

The rocks of the crust are subjected to compressional forces.

This leads to formation of 2 parallel reversed faults.

Continued compressional forces lead to vertical tectonic forces which push up the middle block along the fault lines.

The side blocks remain at a lower position.

The raised block forms an elongated upland bordered by steep slopes on either sides where a block mountain/horst.

Name the part labeled L - Escarpment

(ii) Describe how the feature marked J is formed.

The rocks of the earth’s crust in a region are subjected to forces of compression.

The forces cause reverse faults to form.

Tensional forces pull away the blocks of land on either side of the faults.

The side blocks subside/sink along the faults.

The middle block is left standing.

(b)(i) Give the four sections of the Great Rift Valley.

The Lake Turkana/Stephanie section/Ethiopian

The Eastern/Gregory Rift Valley.

The Western Rift Valley/Albertine

The Malawi Rift Valley.

(ii) Describe three physical characteristics of the Great Rift Valley.

The width of the Rift Valley varies/ at the Aberdare ranges the Rift Valley is 100 km, while at Lake Magadi it is 50 km.

The height of the scarp/escarpments varies/ the Aberdare ranges scarp rises to 2000 M above sea level while around Lake Magadi it is 600 m.

The floor of the Rift Valley is uneven/ has depressions and mountains.

Some parts have volcanic features.

Step faulting is also common.

It is elongated.

The floor has many minor faults.

(c) (i) Apart from a parasitic cone, give five other volcanic features found in the Rift Valley:

Fumaroles/Solfatara/Moffette

Hot springs/geysers/fumaroles/solfataras/steam Jet

Craters/caldera

Volcanic mountains/lava plains

Ash and cinder cones

Plug domes/plug volcano/Siping

Composite volcano/Strato volcano/Complex volcano

Shield volcano/Basic lava dome/cone

(ii) With the aid of a well labelled diagram, describe how a parasitic cone is formed.

The upper part of the main vent/pipe of a composite volcano is blocked.

The magma from the interior of the earth cannot make its way to the top of the volcano.

Pressure builds up and the magma escapes through a side vent.

The successive outpourings of magma through the side vent builds alternating layers of ash and lava to form a conelet on the side of the composite volcano.

The resultant feature (conelet) formed is a parasitic cone.

8 (a) What is weathering?

Weathering is the breaking/disintegration and decomposition of rocks on/below the earth's surface in situ without movement.

(ii) Explain four ways in which water influences weathering.

Some minerals in rocks can directly dissolve in water changing the rock from solid to solution.

Rain water dissolves carbon dioxide to form carbonic acid which reacts with limestone rocks to form calcium bicarbonate. This dissolves in water leading to break up of rocks in limestone areas.

Hydrogen in water reacts and combines with the minerals in rocks.

The rocks are decomposed and soften leading to break up/swelling.

b) Explain the significance of weathering on human activities.

Weathering leads to formation of soils which are used in agriculture.

Weathering results in development of different types of soils used as raw material in various industries/pottery/building/Bauxite as an aluminum-ore.

Weathering weakens rocks making exploitation of minerals easy.

Some weathered rocks form tourist attractions earning foreign exchange.

Weathering can damage/weaken structures/roads.

9 a (i) Give two sources of rivers

Sources of rivers:

Lakes

Melt waters

Springs

Swamps / Marshes

(ii) Describe the following drainage patterns

Trellis:

It develops where soft and hard rocks alternate vertically.

The tributaries join the main river at right angles.

The minor tributaries also join the tributaries at right angles.

The consequent streams are parallel to main River.

The obsequent streams flow to the opposite direction from main river.

The river and tributaries form a rectilinear pattern.

Dendritic:

It develops in rocks of uniform structure/homogeneous.

The direction of flow is influenced by slope.

The tributaries join the main river at acute angles.

The tributaries converge on the main river forming a shape like that of a tree and its branches.

9 (b) (i)With the aid of a well labelled diagram, describe how a natural levee is formed.

It forms when a river floods.

The river bursts its banks and the velocity is reduced.

Deposition takes place on the river bed and banks.

The coarse/heavy materials are deposited on the river banks.

The finer materials/alluvium are carried further into the flood plain.

During dry season, alluvium is deposited on the river bed when river water drains back to its channel.

This type of deposition occurs repeatedly every season causing river banks to be raised.

The raised river banks are the levees

(ii) State four characteristics of the middle stage of a river.

It forms truncated spurs.

It has a wide valley/open V-shaped cross section.

It has increased discharge.

Its gradient is gentle/river flow is slower.

Lateral erosion is dominant.

Deposition begins to take place along some sections of this stage.

The river bends become more pronounced.

River forms bluffs/slip-offs/ep

It has several tributaries.

(c) You intend to carry out a field study on features found in the youthful stage of a river within the school vicinity.

(i) State four ways in which you would prepare for the study.

Pre-visit the area of study.

State objectives/formulate hypothesis.

Decide on suitable methods of data collection.

Prepare a working schedule.

Seek permission from the relevant authority.

Read relevant materials/content analysis.

(ii) Give three methods you would use to collect information during the study.

Take photographs/videos.

Interview resource persons.

Measure volume/depth of water.

Observe features.

10 (a) Outline how the process of plucking takes place in glacial erosion.

It occurs when pressure from overlying mass of ice causes freeze-thaw action.

The melt waters fill cracks/joints in bedrocks.

As water freezes it exerts pressure in the cracks enlarging them.

The enlarged cracks lead to disintegration of the rocks.

As ice moves forward the pieces of loose rocks are pulled along and dislodged from the rest of the rock mass.

(b) Describe how a hanging valley is formed.

Initially there is a main valley and its tributaries.

Ice occupies these valleys.

As ice gets heavy / thick it begins to flow down the slope.

The valley gets eroded through abrasion and plucking.

The main valley is deepened and widened more than the tributary valley.

When ice melts away the tributary valley is left hanging at a higher level than the main valley forming the hanging valley.

(c) The diagram below represents features resulting from glacial deposition in a lowland area.

Use it to answer question c(i) and c(ii):

(c) (i) Name the feature marked.

M - Esker

N – Drumlin

(c) (ii) Describe how the feature marked P is formed.

Moving ice carries solid material/moraine.

It then stagnates at a point.

Ice melts at the snout/tip.

Melt ice releases its load.

Gradually the load piles into the ridge.

Overtime the ridge forms a block of solid material at its tip called terminal moraine.

(d) (i) What is meant by the term ice sheet?

An ice sheet is a continuous mass of ice covering an extensive/large area usually in a glaciated lowland.

(ii) Explain three positive effects of upland glaciated features to human activities.

Most fiords form deep well sheltered natural harbours & good fishing grounds.

Warm glaciated upland valleys are suitable for livestock farming / agriculture.

Glaciated uplands have magnificent features that attract tourists for recreational activities.

Some U-shaped valleys form good natural route ways/settlement.

Waterfalls that form at hanging valleys can be exploited for production of HEP.