Download nandi central joint examinations – 2009

NANDI CENTRAL JOINT EXAMINATIONS – 2009
312/ 1
GEOGRAPHY
PAPER 1
MARKING SCHEME.
SECTION A
1. a)
b)
2. a)
Glaciation
- Refers to the occupation, and sculpturing of the earth’s surface by the action of glaciers.
1x 1 = 1mk
Factors that determine the rate at which glaciers move.
Gradient of the land surface
Friction
Thickness and weight of glacier
Temperature variations.
4x1=4mks
Earth’s revolution
Direction ✓ 1
Orbit ✓ 1
Sun ✓1
Total 3 marks
b) Effects of Earths rotation.
Causes day and night
Causes deflection of winds and Ocean current
Cause variations in Ocean tides
Changes in time
3.a) Vegetation zones
i)
Q – Coniferous forest
ii)
R- Mountain vegetation
iii)
S – Desert vegetation
b) Tree species found in Q
Spruce
Douglas fir / fir
1
2 x 1 =2mks
3 x 1 = 3mks
Pine
Larch
2 x 1 = 2mks
4. a) Climate change
Establishment of new atmospheric / climatic conditions / climate in an area. 1 x 1 = 1mk
b) Human causes of climate change
Deforestation
Industrialization
Forest and grassland fires
Cloud seeding
4 x 1 =4mks
5. a) Difference between a spring and a well.
Spring is the point at which underground water finds its way onto the earths surface
naturally where as a well is deep hole dug in the ground often with the purpose of
getting water.
1x2=
2mks
b) Sources of underground water.
Rainwater
Meltwater
Lake and Seas water
Man matic / plutonic water.
SECTION B
6. a) i) Give the altitude of the lowest area or contour
3x1=2mks
- 1480m
ii) From the marginal information give the Magnetic variation as at January 1970.
2mks
1
2º31 west of true North
b i) Across – section ✓1 between grid reference 540700 and 610700
Scale 1 : 50 ✓1
5mks
c)
Describe the relief of the area covered by the map.
5mks
Generally it’s a high land area with highest contour . Lowest contour 1480m
Generally the land rises from the NW towards the SE.
The land slopes from the SE towards N/W
Presence of river valleys drained by major rivers like Timbil, Kimungu.
Presence of conical hills isolated.
Any relevant point ( 1x 5 ) 5mks
d) Citing evidence from the map, describe the climate of the area covered by the map 6mks
2
-
The area receives heavy rainfall evidence by presence of forest (South Western forest/
evidence by presence of Tea growing –Tea estates e.g. Sambret / presence of many
permanent River.
The area experience cool temp evidence e.g. Tea growing – Tilvet Tea estate
e) Economic activities
4mks
Activity
Evidence
Crop farming
Tea estate – Timbil
Trading
market e.g Kipsigirio market
Transportation
Roads e.g
Processing
Factory at Kericho tea estate
V .S
1 : 5000
VE 

H .S 1 : 50,000
1
50,000
X
 10
(bii) 
5000
1
V .E  10
7. a) Aridity
Process through which the soil experiences insufficient moisture leading to scanty
vegetation or barren land.
b) Reasons winds is a major agent of land sculpture in the desert.
Deserts mostly consist of Sand and dust that are easily transported and deposited by
wind.
Deserts often are barren hence no vegetation cover in most areas hence wind easily
picks the sand and dust.
Moisture in the desert is insufficient therefore the soil is loosely binded and can easily
be picked and transported by wind.
Most deserts are expansive hence enough room for erosion and formation of dunes.
3 x 1 = 3mks
c) Formation of features in the desert.
i)
Deflation hollows
Wind blows over the desert surface and picks the loosened materials like sand through
deflation.
Continuously the materials are removed by rolling and lifting lowering the desert
surface
Eddy currents caused by the lowered surface continue to erode the depression widening
it to form a deflation hollow.
Depression
begins to
forms
Direction
wind
Desert surface
before erosion
3
Eddy current
Deflation
hollow
Text
3mks
Diagram 2mks
Total
5mks
ii)
A barchan
Is a crescent shaped mound of sand deposit often found in deserts
Develops when sand accumulate on an intervening obstacle that lies in the
path of the wind.
Deposition starts with a Somali hill with prevailing wind to force some sand
to move forward forming.
Smooth gentle windward slope
The effect at the wind eddies cause the formation of a steep slope and horns
on the leeward side.
Obstacles
Prevailing
wind
Desert
surface
Sand
deposits
Prevailing
winds
Eddy
winds
4
Horn
Barchan
Text – 3mks
Diagram – 2mks
Total 5mks
d)
e)
f) i)
ii)
Characteristics of a seif dune
Are ridge shaped / steep 1000m
Lie parallel to the path at prevailing wind
Long and extend to over looking
Consists of corridors that are between 25 – 400m wide
Factors influencing the transportation of material in the desert
Strength and speed of wind
Intervening obstacles / vegetation
Nature of load
Water mass / moisture
weather changes
Erosion features observed
Rock pedestals
Mushroom blocks
Zeugeus
Yardangs
Deflation hollows
Ventifacts
Reasons for having a route map.
Attend to all areas of concerned
Avoid getting lost
Estimate the total distance to be covered
3x1
2x1
8. a)
Original Rock
Metamorphic Rock
Granite
Gneiss
Augite
Horn blende
Limestone
Marble
b)
i)
Name at least three rocks types that are found in Western Kenya.
- Granite, Gneisss, Sandstone, Mudstone
1x3= 3mks
c)
Describe the formation of mechanically formed sedimentary rocks
5mks
Pre – existing rocks are weathered to form sediments
Sediments are then transported and deposited on land or on sea by water, wind or ice.
Over a period of time they are consolidated into a hard rock due to pressure from the
overlying material
The layers of strata occur because of the change of composition of materials,
particularly
the size of the particles.
2 x 4 = 8mks
d)
Significances of rocks to man
6mks
Some rocks form beautiful scenarier that attract tourists and hence earning country
foreign exchange.
Some rocks are used in building and construction e.g, limestone and granite.
Some are raw materials e.g limestone to the cement industry, trona – Magadi
Sand is a source of building material
5
Fossil fuel- coal is associated with sedimentary rocks.
Any relevant point 6mks
e)i) Methods of data recording
2mks
Photograph taking
Drawing sketches
Filling in tables / tabulation
Writing notes
Any relevant 1 x 2 = 2mks
ii) Importance of a route map
3mks
To save time
To ensure every activity is given ample time.
Estimate the cost of the study
9.a) Folding
-Process of crustal distortion that often causes rocks to bend upwards or downwards.1x1mk
b) Major fold mountains of the world
A – Appalachians mts
1x1
B- Rochies
1x1
C – Ural mts
1x1
D- Caps ranges
1x1
c) Formation of fold mountains under the following theories.
i) Contraction theory
Initial cooling of the earth, the outer surface cooled and contracted faster than the
interior
Surface rocks started wrinkling inorder to fit on the cooling and contracting rocks of
the interior.
These wrinkles formed the present fold mountains
3 x1 mks
ii) Convectional currents theory
Movement of convectional currents in the mantle horizontally causes a
frictional drag on that crustal rocks forcing them to move.
When continental coast are pulled towards each other they force sediments
between them to fold
Folding of such sediments leads to formation of folds that have often caused
the formation of fold mountains.
(3x1marks)
d)
Significance of folding to look physical and human environment.
Fold mountains often facilitate the formulation of relief rainfall hence windward sides
of such mountains experience heavy rainfall while the lee ward often relieve little or no
rainfall.
Most fold mountains often act as water catchments areas as some contain glaciers, that
can lead to melt water whereas others are sources of rivers especially on the windward
side.
In some fold mountains Katabatic winds often are cold and cause harm to crops
especially in the lower valleys and slopes.
Process of folding could bring minerals to the surface marking the exploitation of such
minerals cheap.
Fold mountains provide unique scenery that act as a tourist attraction hence as the
country earns foreign exchange
Fold mountains at times act as barriers to transport and communication especially if it
lacks passes.
Mountains areas often dissauge settlements hence most f such areas are un inhabited.
6
Any 3 x 2 mks
c)
Formation of Rift Valley by tensional forces.
Crustal rocks are subjected to tensional forces
Tensional forces
Continued subjection of tensional forces to crustal rocks leads to development of normal fault
lines.
Fault line
Fault line
Development of two faulting divides the crustal rocks into three major blocks. The centre block
subsides as the two side blocks are pulled by tensional forces.
This results to the formation of a trough called a rift valley.
Rift Valley
Diagram – 3mks
Text – 3mks
T – 6mks
d)
Features resulting from faulting
Rift valley
Escarpment / faultscape
Fault blocks or
Block mountains
Tilt blocks
Any 2 x 1 mks
10.
i) Define the term mass – wasting
1mk
Mass – wasting is the downward movement of weathered material under the
influence of gravity.
ii) Three types of rapid mass – wasting
3mks
Rock slump, Rock slide, Rock slide, Rock fall, and avalanche.
b)
Three ways in which soil creep occurs
6mks
Due to temperature changes soil particles expand and contract hence shift position
down slope
Moisture in the soil causes it to become wet and compact on drying, the particles loosen
and shift position down slope.
Frost hearing beneath soil particles lifts particles at high angles to the slope but they fall
back perpendicularly under gravity
7
c)
d)
Extend forces like earth quakes, explosives in mining or heavy vehicles trigger off the
movement.
2x3
Identify four underground features found in a karst Scenery
4mks
Stalagmite, stalactite, pillars, caves
1 x 4 = 4mks
Formation of stalagmite
6mks
Diagram – 3mks
Text – 4mks
Limestone
rock
Under ground
stream
Stalegmite
Rainwater dissolves carbon dioxide as it passes through the car to form
weak carbonic acid.
The rainwater dissolves calcium carbonate as it percolates through
limestone joints
The solution in form of calcium hydrogen carbonate drips to the floor of the
cave.
Some of the water and carbon dioxide are released leaning behind deposits
of calcium carbonate.
The calcium carbonate deposits grow upwards from the floor of the caves to
form finger like projections called stalagmite.
Conditions necessary for the formation of Karsts scenery
5mks
The rock below should be limestone, chalk or dolomite.
The rock should be well jointed soluble allowing solution to occur along
the joints.
The region should receive moderate high rainfal to facilitate solution process.
The watch table should be deep to allow water percolation and sub sequential
erosion
Warm / hot climate.
-
e)
8