Download COMA JOINT EXAM 2014 GEOGRAPHY PAPER 1 MARKING

COMA JOINT EXAM 2014
GEOGRAPHY PAPER 1
MARKING SCHEME
SECTION A
1.
(a)
(b)
2.
(a)
(b)
3.
(a)
Name three types of coral reefs.
Barrier reef
Fringing reef
Atolls reef
(3 x 1 =3 marks)
What are the benefits of coral reefs in the areas they have developed?
Sheltered water encourages growth of plankton /fish food.
Shallow Corals are a tourist attraction earning a country foreign exchange.
Corals form a base of mining of limestone used in cement manufacture. (2 x1 = 2 marks)
The diagram below represents features of intrusive vulcanicity.
Name the features marked P,Q and R
P-Batholith
Q -Laccolith
R -Lopolith
(3x1=3mks)
How is a caldera formed?
- As a result of subsequent violent eruptions leaving an enlarged crater
- Subsidence where the weight of the cone collapses into magma chamber (2x1=2mks)
Name the three main layers of the atmosphere from the earth’s surface upwards.
Troposphere
Stratosphere
Mesosphere
(Accept in this order) (3x1=3mks)
(b)
What is temperature inversion?
4.
(a)
-A condition in the atmosphere where upper layer of air is warmer than the lower layer
(2mks)
Highlight any three factors that necessitate the occurrence of an artesian basin.
5.
The aquifer must lie between two impermeable rocks
The aquifer must outcrop in a region which is a source of water
The aquifer must dip from a region of water intake and the rock layers must form a broad
synchine or basin.
The mouth of the well must be lower than the intake area
(3x1=3mks)
(b)
Apart from lakes rivers and sea, name any other two sources of underground water
Rain water
Melt water
Manmatic water
(a) Below is a diagram showing the structure of the atmosphere
a. – Troposphere
b. - Stratosphere
c. - Thermosphere /ionosphere.
(b) State the reasons for the behavior of graph at zones b and c.
(3x1=3mks)
a. – Temperature increases with altitude.
b. – There is no change in temperature with increase in height.(isothermal zone).
(2x1=2mks)
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SECTION B
Answer question Six and any other two questions from this section.
6.
(a) Study the map of Nkubu provided and answer the questions that follow.
(i) Six- figure grid reference. 512931
(1 mark)
(ii) Approximate height of Rurie swamp 1320m. 
(1 mark)
(iii) Magnetic declination at the time the map was drawn. 1o 25’ 
(1 mark)
(b)
(i) Bearing of the airphoto principle point at Kaguma from the trig. station(5294) North of

Thingithu river is = 300o 
(2 marks)
(c)
7.
(a)
(b)
(c)
(ii) Economic activities that the local people engage in :
Coffee growing  evidence coffee factories. 
Dairy farming  evidence cattle dips. 
Quarrying evidence quarries. 
Trading  evidence shops /markets
N.B Mark activity+ evidence (3x2=6mks)
(i)Relief of the area covered by the map
 The area is generally a highland. 
 Has several ridges. 
 The lowest part is about 940m  to the east of the map while / the highest is 2640m to
the west of the map.
 There are steep slopes the west of the map /while the gentle slopes are found to the
far south of the map.
 There are many river valleys. The most conspicuous is that which is occupied by
River Iraru.
 There are several cinical hills like Nduguru, Kanje, Kirui and Thunguru.
 The landscape is dissected by rivers.
(5 x 1 = mks)
(ii) Factors influencing settlement in the area covered by the map.
 On the Western part of the map, there is government protected forest hence no human
settlement. 
 River valleys and swampy areas are avoided due to flooding. 
 There is dense population /clustered settlement on the gentle slopes. 
 Within and around trading centres like Nkubu and Kanyakine there is high concentration
of settlements. 
(3x 2 = 6mks)
(d)
(i) Adjoining map extract - mitunguu ( 1mk)
(ii) The area of the forest = ( Full Sq= 48+ Half Sq=40/2)=68km2 . 
(2 mks)
(i) Define wind abrasion.
-Action of wind using its load (sand particles) to break off parts of surface layer of
rocks, grind, scour, polish rock surface.
(2mks)
(ii) Name two processes of wind transportation.
-Saltation
-Suspension
-Surface creep
(2mks)
Give one difference between a rock pedestal and a mushroom block.
-Rock pedestal has alternating layers of hard and soft rock (heterogenous) while a
mushroom block has the same rock hardness (homogenous)
(2mks)
(i) Explain a factor that makes wind an effective agent of erosion in arid areas.
-High wind velocities due to lack of vegetation cover/land surfaces flat with few/no
obstacles hence wind blows with great speed
-Soils are loose and unconsolidated so are easily removed by wind
(2mks)
(ii) Give three characteristics of barchans.
-Lie at right angles to prevailing winds
-Have two horns
-Windward side is gentle, while lee ward side is steep
2
(d)
-Occurs in groups
-Migrate in direction of prevailing wind
Using well illustrated diagrams, explain how Mesas and Buttes form.
(3mks)
Mesa
Butte
(e)
8.
(a)
(b)
-Many rivers flow over an upland or plateau in a desert
-Rivers erode deep valleys (through abrasion and hydraulic action)
-Vertical erosion deepens the valley
-During the dry season, the valleys are deepened by wind abrasion and deflation
-With time, remnant hills separated from each other by deep valleys are formed
-The large hills are known as Mesas, the smaller ones are buttes
N.B Text - 6, diagram - 2= (8mks)
You are to carry out a field study in the arid north of Kenya:
(i) Mention three preparations you would make before the study.
-Prepare stationery/tools
-Read from secondary sources on topic
-Prepare working schedule
-Seek permission/escorts
(3mks)
(ii) Mention three problems you are likely to face during the field study.
-High temperatures causes discomfort
-Thirst
-Problem walking through stony/sandy terrain
(3mks)
(i) Define natural vegetation
Natural vegetation is a plant cover that grows and spreads through natural means of
seed dispersal without interference of external modifying influence
(1x1=1mk)
(ii) State four characteristics of natural vegetation found in tropical rain forests.
-Forest consists of mixed variety of the species
-Trees are evergreen
-Trees are tall
-Trees have large trunks
-Trees have broad leaves.
-Trees take long-time to mature
-Trees are hardwoods
-Trees are close to each other
-Forests have little/no undergrowth
-Trees have buttress roots
-Forests have three distinct layers/canopies
-They have ephiphytes-climbing plants
-Straight with smooth trunks
-Have some low growing plants-saprophytes
(4x1=4mks)
Four ways in which vegetation found in arid areas adapts to the environmental
conditions.
-Some plants have thick (fleshy) succulent leaves to store water
-Some plants have long roots to tap water from underground water
-Some plants have spuky /thin/waxy needle like leaves to reduce rate of transpiration
3
-Plants seeds remain dormant awaiting the short rains/short-lived plants
-Some plants have thick /hard barks to reduce transpiration/protection against sand
blasts.
-Some plants are stunted due to harsh conditions
-Some plants are quick in sprouting to take advantage of little rainfall
-Dense cell fluids,complex sunken stomata
-Salt-tolerant (halophytes)
-Deciduous
(3x1=3mks)
(c)
Names of the grasslands in the following areas.
(i)
East Africa-Savanna
(ii)
Canada-prairies
(iii) Argentina-Pampas
(d)
(ii)
(e)
9.
(a)
(3x1=3mks)
(i) Give Reasons why Tundra region has scanty vegetation.
The ground is frozen most of the year
-Area has very short growing season/short summer
-The area has thin soils
-Some parts are poorly drained/bog-wet,spongy ground
-Area has low precipitation
-Very strong winds which intefere with seed dispersal
(2x1=2mks)
Two topographical factors that influence vegetation distribution.
-Relief
-Drainage
-Aspect
(2x1=2mks)
Five economic importance of vegetation.
Medicinal value
-For aesthetic value/beauty
-Habitat for wild animals
-Sources of building /construction materials e.g timber
-Source of fodder/feeding of animals/food for man
-Control of soil erosion
-Influence of rainfall formation
-Source of raw materials for industries e.g pulp and paper industries
-Forests protect water catchments areas
A glaciated upland area diagram
R
S
T
(i)
(ii)
The parts labeled R,S and T
R – Pyramid peak
S – Arete
The distinctive characteristics of a fiord
-Has steep walls
-Is a narrow sea inlet
-Is U-shaped
-Has hanging valley
-Has deep waters
-Is shallower seawards/deep landwards
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T – Corrie lake/Tarn
(3x1=3mks)
(2x1=2mks)
--
(b) With aid of well labeled diagrams, describe the formation of the following
features;
(i) A Cirque
-Snow accumulates in a shallow pre-existing depression on a mountain side
-The snow gets compacted into ice to form a cirque glacier
-The ice erodes the bottom of the hollow by abrasion, making it deeper
-Frost action and the plucking process operate on the sides of the hollow, making it
wider.
-The plucking process is effective on the back-wall, making it steeper
-Eventually, a deep arm chair-shaped depression is formed. This depression is called
a cirque.
Mountain top
Cirque glacier
Bergschrund
Crevases
Plucking
Abrasion
Ice accumulates in hollow
Hollow is deepened and extended downwards
Steep plucked
backwall
A cirque
Rock threshold
with moraine
Over-deepened hollow forms a cirque
(ii) A hanging valley
-Initially, there is a main valley and tributary valleys
-Ice occupies these valleys
-The valleys get eroded by the ice through abrasion and plucking
-The main valley is eroded more because it contains more ice than the tributary valleys
-When ice eventually retreats by melting, the tributary valleys are left at a higher level
than the main valley
-They appear to hang above it and so are called hanging valleys.
(c) Two factors that may lead to glacial erosion in upland areas .
-Nature of underlying rocks well jointed /faulted rocks facilitate plucking When water
gets into rocks compared with rocks without joints/Abrasion is more effective on softer
rocks than harder ones.
-The speed of the glacier. A fast-flowing glacier erodes more for it has greater energy to
erode.
-The thickness and weight of the ice. The rock debris beneath the ice is more effective in
scrapping the ground by abrasion when the ice is very heavy.
5
-Availability of debris. The more the debris that is embedded in the ice, the more effective
that abrasion will be for debris acts as a tool for abrasion.
(2x2=4mks)
10.
(d) A filed study on a glaciated upland;
(i) Two types of moraine you are likely to identify:
-Medial moraine
-Lateral moraine
-Terminal moraine
-Ground/sub-glacial moraine
-Englacial moraine
(2x1=2mks)
(ii) Four reasons why one would need the map of the area
(4mks)
- To show the extent of size/ area of the landscape
-To show the distribution of erosion /depositional features in the area
-To show the variation of relief of the area
-To help in estimating distances to be covered during the study
-To estimate the time required for the study
-To be able to plan for work schedule
-To decide on other techniques of data collection
(4x1=4mks)
(a)(i) Name the climatic Regions marked A,B and D.
A-Tropical monsoon climate
B-Mediterranean climate
C-Equatorial climate
D-Tundra climate
(1x4=4mks)
(ii) State any four characteristics of the climate marked C
-Experience high temperatures (24-27oC)
-Experience small annual range of temperature of 3oC
-Mean annual rainfall exceeds 1500mm and is evenly distributed through out the year
-It receives double maxima rainfall regime after the equinox
-Low diurnal range of temps. of approx. 60C
-High humidity due to heavy rainfall & high evaporation rates
-Major winds due are trade winds
-Thick cloud cover throughout the year
-Low pressure all year round
-Rainfall mainly convectional but orographic is common in Mt.areas.
(4x1=4mks)
(b)(i) Identify any three types of cold climates.
-Tundra climate
-Cold temperature eastern margin
-Cold temperature continental
-Polar climate
(1x3=3mks )
(i) Briefly explain microclimate.
Micro climate is climate which is experienced within a small or localized area and
slightly modified or different from the general climate of a region
(1x4=4mks)
(c)
(i) What is climate change?
-It is the long term response to average variations in the conditions of the atmosphere. (ii)
(a)
Calculating the mean annual temperature
M.A.T=(Total monthly temperature)
12 month
= 297/12 =24.75oC
(b) Mean annual rainfall
=(Total monthly Rainfall)
12months
=1522/12=126.83mm 
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(c) State any one characteristics of the type of climate in the station.
-It experiences high amount of rainfall pa over 1500mm
-It experiences high temperatures i.e. mean annual temperature of over 24oC
(1x1=1mk)
(d)(i) Explain any two causes of Global warming.
-Depletion of ozone layer exposing the earth to short energy radiation rays e.g.
Ultra violet
-Deforestation
(2x2=4mks)
(ii) Name any one Greenhouse gases.
-Carbon dioxide
-Chloro fluorocarbon
(1x1=1mk)
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