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```KASSU JET
GEOGRAPHY
PAPER 1
MARKING SCHEME
SECTION A
Answer all the questions in this section.
1. (a) State two reasons why Geography is a unique subject.
(i)
(ii)
(2 mks)
It emphasizes the spatial distribution of both physical and human features on the
earth surface and maps them to show their relationships and patterns.
Geography relates well with the other disciplines of earth science social science
and geometrical science, hence has a wide scope.
(b) The diagram below shows the relationship between geography and other disciplines.
Name the disciplines marked U, V, W and X.
U - Political
V - Demography
W - Geomorphology
X - Climatology
1
(4 mks)
2. (a) If a given parcel of air at 350C contains 15.5 gm/m3 of moisture and the given air can
hold a maximum of 20 gm/m3 at the same temperature, calculate the relative
humidity.
(2 mks)
R.H =
β΄
π¨πππππππ π―πππππππ
π»ππ πππππππ ππππππ ππ πππππ
πππ πππ πππππ ππππ ππ πππ ππππ ππππ
ππ.π ππ/ππ
ππ ππ/ππ
π πππ%
= 0.775 x 100 = 77.5%
(b) Draw a well labelled diagram to illustrate a mercury Barometer.
(3 mks)
3. (a) Study the diagram below showing mass wasting.
(i)
Name the mass wasting process in the diagram.
-
(ii)
Debris slide
Name the past marked J.
-
(1 mk)
Talus / scree
(b) State three effects of this process on the landscape.
(i)
(2 mks)
Causes slope retreat / steepness of the slope.
2
(3 mks)
(ii) Causes scars on the land / on the face of the slopes.
(iii) Lead to accumulation of debris at the base of the slopes.
4. (a) Define a lake.
(2 mks)
This is a mass of water in hollow depression on the earth surface.
(b) State three effects of a lake on the climate of the surrounding areas.
(i)
(ii)
(iii)
High evaporation of the lake causes high humidity.
High evaporation rates results into convectional rainfall.
The lake results into land and sea breeze which moderate the temperature.
5. (a) Name two surface features found in a Karst region.
(i)
(ii)
(iii)
(3 mks)
(2 mks)
Lime stone pavement / swallow holes
Grykes and clints, Karst windows
Blind valleys, Dolines / polje, uvalas
(b) State three conditions necessary for the formation of a Karst scenery. (3 mks)
(i)
(ii)
(iii)
(iv)
Moderate rainfall / humid climate
High temperature
A deep / low water table
Hard and well jointed rocks.
SECTION B
Answer question 6 and any other TWO questions from this section.
6. Study the map of Kitale 1:50,000 (sheet 75/3) provided and answer the following
questions.
(a) (i)
-
Name two districts found in the area covered by the map.
West Pokot
Trans-Nzoia
Elgeyo-Marakwet
(ii) What is the magnetic variation of the map?
2023β
3
(2 mks)
(1 mk)
(b) (i)
-
Convert the scale of the map into a statement scale.
(2 mks)
Map scale 1:50,000
i.e. 1cm represents 50,000 cm
100,000
= 0.5km
Statement scale: 1cm represents
0.5km/½km
(ii) Calculate the area of land to the North and North East of the Loose
Surface road C637 and B10/2 in the North Eastern corner of the map.
(2 mks)
Complete squares
Incomplete squares
=
=
Total complete squares =
Area =
11
14 = 7
2
11 + 7 = 17
17km2
(iii)Measure the distance of the Loose Surface Road C638 from grid reference
(2 mks)
9.6 km
(c) Explain three factors which have influenced the distribution of settlements in
the area covered by the map.
(6 mks)
-
The hilly areas along the forest have few or no settlements because the land
is steep/rugged which makes construction costly/difficult.
There are no settlements in the forest because it is a forest reserve where human
activities are prohibited.
Kitale municipality area is the most densely settled because it has a dense road
network for ease of movement and social amenities.
There are clusters of settlements in the plantations since the land is set aside for
farming.
There are no settlements on the seasonal and papyrus swamps because they are
poorly drained/marshy which discourage human activities.
There are many settlements in the South Easter and central parts of the area covered
by the map because the land is gently sloping which makes construction easy.
(d) Describe the relief of the area covered by the map.
-
The landscape is disserted by many river valleys.
There are many narrow river valleys.
There are numerous steep slopes in the North East/gentle slopes to the
East.
There are many interlocking spurs along the river valleys.
4
(4 mks)
-
There are many hills in the North East.
The main ridge is along the forest.
The area with the swamp is flat.
There are some broad valleys in the Eastern part of the area.
The highest altitude is 2362m/ the lowest is 1820m above sea level.
(e) Citing evidence from the map, explain three factors that favour cattle rearing in
Kitale area.
(6 mks)
-
The presence of scrub/scattered trees show that there is natural pasture
for cattle.
The presence of many rivers shows that there is adequate water for cattle.
The presence of many rivers show that there is adequate water for cattle.
The area has high attitude above 1820m which provides cool conditions
suitable for cattle rearing.
There is access to veterinary services shown by the presence of a cattle dip for treatment
of cattle.
Dense settlements provide market for cattle/cattle products.
Availability of transport shown by roads/tracks for movement of
cattle/cattle products.
The large tracts of land with few settlements in the Southern, Central and
Eastern parts show that there is extensive area available for grazing.
7. (a) (i)
What is faulting?
This is the fracturing / breaking of the earthβs crust.
(ii)
Apart from normal fault and reversed faults, name three other types of
faults.
(3 mks)
-
(b) (i)
Thrust fault
Tear / shear / slip fault
Anticlinal fault
Apart from tensional forces, explain two other causes of faulting.(4 mks)
-
Horizontal movements / tectonic forces may compress the crustal rocks
causing the rocks to fold.
Some parts of the folded rock develop fractures hence faulting.
Horizontal forces within the rocks moving past each other in opposite
directions
Rocks fracture as a result of teaching / shearing of racks in the region where
forces move past each other.
Vertical movements occur within the crust. They exert strain in the rocks
making them fracture.
5
(ii)
With the aid of well-labeled diagrams, describe how a rift valley was formed
by tensional forces.
(8 mks)
-
Layers of rocks within a region are subjected to the tensional forces.
-
Lines of weakness develop / two parallel lines f weakness called normal faults
form.
-
Further tension pull the side blocks of land to move apart while the middle
6
-
The subsided / down warped middle block forms the floor of the rift valley.
Diagram β 4
Explanation β 4
Total 8 mks
(c) Explain four effects of faulting on drainage.
-
(8 mks)
Vertical faulting across a river leads to formation of a waterfall / river rejuvenation /
knickpoint.
Rift faulting in basin forms depressions in which rain / river water / underground
water collect in them to form lakes.
Uplifting of the landscape may cause the river change / reverse direction of flow
Rivers may disappear into the ground through fracture / fault lines
Faulting may develop on the surface causing the river to flow along the fault hence
fault-guided drainage pattern.
7
8. (a) Explain how the following factors influence the distribution of vegetation. (2 mks)
(b)
(i)
Climate
Areas which have low temperatures have scarity/no
vegetation/areas which have moderate temperature have dense
vegetation.
Regions which receive high rainfall have dense vegetation
growth/areas which have low rainfall have scanty/scrub
vegetation.
Hot dry winds cause drought conditions which is responsible for
scanty/scrub vegetation/moist winds lead to increased
precipitation when they blow over a region hence dense vegetation.
Places which receive long hours of sunlight have many varieties of
lants/areas which receive less/short hours amounts of sunlight
have few/little variety of plants.
(ii)
Human beings
(2 mks)
Some human activities have led to clearing of natural vegetation
causing the establishment of deserts/semi natural vegetation.
Conservation measures geared towards protecting the existing
vegetation have led to establishment of forest/natural reserves.
The map below shows some vegetation zones of Kenya. Use it to answer
question (i).
Y
Y
X
8
(i)
Name the vegetation zone marked X and Y.
X
Woodland and grassland
Y
Swamp vegetation
(2 mks)
(ii)
Give two uses of Savannah vegetation.
(2 mks)
(iii)
(c)
Commercial ranching/grazing is practiced in some parts of the
grassland.
Are home to wild animals.
The trees are habitats for bees which provide honey.
Some of the shrubs/herbs are used for medicinal purposes.
Some of the wild fruits/berries are consumed as food.
Describe the characteristics of Mediterranean type of vegetation.
(5 mks)
Some plants have small/thick-skinned/leathery leaves/spiny leaves.
Some plants have long roots.
Some plants have thick barks.
Some plants have large fleshy bulbous roots.
Some plants have shiny/waxy leaves.
Some trees are deciduous
Some plants are evergreen.
The vegetation is adapted to the long hot and dry summers.
Some plants have fleshy leaves.
Grasses dry off during summer and germinate during winter.
Shrubs/thickets/bush/thorny bush/marquise/machia/
chaparral/malle are common.
Woody scrub is common in very dry areas.
Explain three ways in which desert vegetation adapts to climatic conditions.
(6 marks)
Some plants have thick/fleshy/succulent leaves/barks to enable them store
water.
Some plants have long roots to tap the underground water.
Some have no leaves/have thin/spiky/waxy/needle like leaves to reduce
transpiration.
Some plant seeds remain dormant awaiting the short rains.
Some plants have thick/hard barks to reduce transpiration.
Some plants with in the absence of moisture but have quick recovery
ability.
Some plants have thorns to protect themselves from browsing animals.
Some plants have underground bulbs to store water.
Most plants are stanted/dwarf like due to the harsh conditions.
Some plants are quick sprouting to take advantages of the short-lived
desert rains.
9
(d)
You are planning to carry out a field study of the vegetation within the local
environment.
(i)
State three preparations you will make for the field study. (3 marks)
Formulate objectives/hypotheses for the study.
Carry out reconnaissance of the area of study.
Seek permission from the relevant authorities.
Acquire appropriate stationery/tools/equipment.
Prepare a working schedule.
Divide students into groups and assign work to each group
(ii)
9. (a) (i)
How will you identify the different types of vegetation? (3 marks)
By their appearance
Their colour
By their age
By their leave size/pattern type
By the nature of their barks
By the texture of their leaves.
By their system of the roots.
Distinguish between river discharge and river regime.
(2 mks)
River discharge is the amount of water passing through a particular point at a
river course while river regime is the seasonal fluctuation in the volume of a
rivers water.
(ii)
Describe how a river erodes through the following processes:Abrasion
(3 mks)
-
The load carried by the river is used as a tool for scouring, scrapping ,
scratching and grinding.
The load is hurled by the river water against the bank or dragged along the
river bed
The load chips off the rock on the bank and floor.
The load being dragged smoothens the river bed through grinding and
scraping.
Rolling of some load on the river bed lead to formation of potholes.
Any 3 x 1 = 3 mks
Solution
-
(2 mks)
The rocks of the river channel can dissolve in water e.g. gypsum, dolomite.
As water flows it dissolves soluble rocks / minerals and transports the
minerals within the water current.
10
(b) Describe how the following features are formed:
(i)
Gorge, when a waterfall retreat
(4 mks)
- Vertical erosion occurs at the waterfall point.
- This is due to increase in gradient and the force of falling water.
- The position of waterfall shifts upstream as resistant rocks are slowly eroded
by abrasion and hydraulic action to form a deep narrow valley.
- This leads to the formation of gorges below a waterfall.
(ii)
River braids
(4 mks)
- The river flows in the middle or old stage where the valley is wide and gently
sloping.
- River carries a large load in a wide shallow channel.
- The gradient is low hence making the river to flow sluggishly / low velocity
- The river deposits its load on the bed.
- The river bed is gradually raised blocking the flow due to accumulation of
sediments into features called shoals.
- The river sub-divides into channels distributaries / braids across the deposits
as the river attempts to flow around the obstacle.
- Channels created by this process are called river braids.
(c) State four characteristics of a river in the old stage.
-
River flows very slowly / reduced velocity
Great deposition of aluminum hence constructive work
Lateral erosion occurs
Seasonal floods are common
River has large volume of water
River has differed tributaries
Has ox-bow lakes
Carried a large load/ silt/ alluvium
(d) Explain three significance of a river to human activities.
-
(4 mks)
(6 mks)
Some rivers provide water for domestic and industrial use
Fresh water rivers are used for irrigation in dry areas for crop production
Navigable rivers or their sections provide cheap transport routes.
Some rivers are rich in fish hence are fishing grounds
Some rivers have been damned to produce hydro electricity power to run machines.
Some river beds and valley are sources of building materials
Some alluvial sediments contain valuable minerals which are mined and sold to earn
income
Features formed by rivers e.g. waterfalls attract tourists which earn foreign exchange.
Flooding deposits alluvium on source river valleys, deltas, plains which create fertile
soils which encourage agriculture.
Any 6 x 1 = 6 mks
11
10. (a) What is soil profile?
(1 mk)
This is a vertical arrangement / cross-section of different layers of soil from the surface to
the bedrock.
(b) The diagram below shows a soil catena.
(i)
Name the type of soils found in position R and U.
(2 mks)
R β Lateritic soils / laterites
U β Peat / Bog
(ii)
State two characteristics of soils found in section marked.
I.
R
Laterite soils
- Red in colour
- Acidic
- Rich in iron and alluminium oxides
- Have low humus content / organic matter
- Are sticky soil
- Have developed soil profile
- Are mature soil
- Are of low agricultural value.
Any 2 x 1 = 2 mks
12
(2 mks)
II.
(c) (i)
Name two components of soil.
-
(ii)
U
Peat / Bog Soils
Poorly Drained / Water Logged
Grey / Blue In Colour
Are Acidic
Have Poorly Developed soil profile
(2 mks)
(2 mks)
Air
Water / moisture
Organic matter / humus
Inorganic matter / minerals
Differentiate between soil structure and soil texture.
(2 mks)
Soil structure refers to the way soil particles are grouped together into larger
particles while soil texture is the size of the individual soil particles.
Or
Soil structure refers to the grouping / arrangement of soil particles / aggregates
while soil texture refers to the size of soil particles / degree of fineness or
coarseness of soil particles.
(d) Explain how the following factors influence soil formation.
(i)
Climate
ο§
ο§
ο§
ο§
ο§
(4 mks)
Rainfall affects the rate at which some soil forming processes e.g. leaching
occur.
Rainfall provides water which makes it possible for rocks to decay /
disintegrate to form soil.
Seasonal variation of rainfall can cause the accumulation/ concentration of
salts in the soils.
Erosion by water, ice and wind cause formation of thin soils
Decomposition of the eroded materials by water, ice, wind lead to formation
of new soils / alluvial soils.
High temperatures increases the rate of weathering and also accelerate
bacterial activities which generate some of the organic matter in soil.
13
Vegetation
ο§
ο§
(4 mks)
Vegetation provide humus which result from decomposition of plant remains.
Plant roots penetrate and break up soils and allow water to pass through or
help the soil become porous.
(e) Explain how the following practices cause soil degeneration.
Burning
ο§
ο§
ο§
(2 mks)
Burning expose soils to agents of soil erosion
Burning kills the micro-organisms thus robbing the soil of its organic matter resulting
in deterioration of soil structure
Burning dries up the soil because if causes lose of soil water.
Leaching
ο§
(2 mks)
Leaching dissolves soluble minerals in the top soil and the same substances in moved
and deposited is the lower payers.
Over-application of fertilizers
ο§
ο§
(2 mks)
Causes changes in the soil PH by increasing acidity
Over-application of the fertilizer affect the soil microorganism thus reducing the
ability of soil nutrients.
14
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