(a)

—Passing star theory.

—Nebula cloud theory.

(b)

—Gravitational force-The earth is maintained in the orbit./things on the earth don’t fall off.

—Centrifugal force-This causes bulging of the earth at equator.

—Centripetal force-Causes flattening of the earth at the poles.

(a)

E—Surface run off.

F—Evaporation.

H—Precipitation.

G−Condensation.

(b)

(i) —This refers to the source of most rivers e.g. forested mountain area where a river draws its waters.

(ii) —River regime is seasonal fluctuation in river discharge.

(a)Factors making weather datas to be inaccurate.

—Use of defective weather instruments.

—Occurrence of extreme weather conditions.e.g Elnino.

—Human errors when reading.

—Natural calamities.

—Poor siting of the weather station.

(b)Role of Stevenson screen.

—To protect the delicate weather recording instruments.

—To provide shade conditions for accurate temperature and humidity readings.

(c)

—Sides made up of Louvers to ensure air circulation.

—Should be painted white to reflect much heat.

—Raised from the ground 1.2 m high to ensure free flow of air.

—Metallic legs to prevent it from being eaten by termite.

—Roof should have double boarding to prevent heat reaching inside.

(a)

—Hydrosphere.

—Atmosphere.

(b)

—Made of iron.

—Believed to be in solid state.

—Density of 16-17g/cm3

—Has a temperature of about

(b)

—Soil is light in colour.

—They are sandy.

—They are loose in texture.

—They are thin.

—They have low moisture content.

(a)

(i)Six figure grid reference of the road junction at M. 344142.

(ii)Magnetic variation of the area when the map extract was drawn. 20231

(iii)Three districts covered by the map extract.

i. West Pokot.

ii. Trans Nzoia.

iii. Elgeyo Marakwet.

(b) (i)Gradient of the district boundary from 3932 to 5027.

(ii)Four economic activities carried out in the area by the sketch map.

—Transport and communication-there are tarmac and telephone lines.

—Agriculture-coffee plantations.

—Trade-municipality/Kitale town.

—Lumbering-forest nursery.

(d)Factors influencing vegetation distribution.

—Drainage-poorly drained areas like swamps have marshy vegetation.

—Relief-highland have woodland and scrub vegetation.

—Climate-areas with high rainfall have dense forests, Riverrine treos have developed along river valleys.

—Human activities-natural vegetation has been replaced by estates and settlements.

(a)Vulcanicity is the process by which solid liquid or gaseous materials are forced out of the interior into the earth’s crust on onto the surface of the earth.

(b)Characteristics of acidic magma.
—Viscous.

—Sticky.

—solidifies quickly.

—High silica concentration that exceeds 65 %.

(c) (i)Formation of Batholiths.

—This is a plutonic mass of magma which intruded the country rock.

—The magma is so hot that it metamorpho.

—It is generally composed of granite dome shaped and form at a great depth.

—Batholiths appear to have replaced rather displaced the country rock. Some country rock may have melted or sank into magma.

(ii) Composite/complex. Volcanoes

—.Due to earth movement the crustal rock is distributed leading to formation of a vent.

—The underlying molten rock escaped through a central vent to the surface.

—There were successive violent vent eruption which first ejected solid materials (dust cinder & pyroclast).

—These pyroclasts settled around the vent.

—The next eruption ejected huge mass of acid/intermediate lava which cooled and solidified over the layer of pyroclast to form alternative layer of lava. —When another eruption occurred the pressure inside caused the solidified magma in the vent to break into pieces which were thrown out to form another layers of pyroclasts.

—Mass of lava followed and spread over the layer of pyroclast.

—This process is repeated leading to formation of volcanic cone.

(iii) Characteristics of composite volacano.

—Has a vent.

—It has side vents.

—It is composed of alternative layers of ash pyroclast and lava.

—It is conical shaped.

—It has steep sides.

—It has cone letes/parasitic cones.

—It has a crater.

—Consits of andesite(intermediate rock)

(d)

—Resultant features such as volcanoes, Geysers volcanic plugs offers scenic beauty which attract tourist bringing foreign exchange.

—Hot springs & geysers are harnessed to produce geothermal power for both domestic and industrial use.

—Vulcanicity leads to metamorphism which produces valuable minerals from mining e.g Diamond, copper and gold. These are sold to earn revenue. —Volcanic rock weathers to produce fertile soils suitable for farming.

—Volcanic rocks are used for building stones and road construction.

—Wind ward side of volcanic mts receives heavy rain which encourage farming and settlement.

—Some volcanic mts are forested and ice capped hence are catchment areas for used for domestic and irrigation.

(a)Types of deserts surfaces.

—Sandy deserts.

—Stony deserts.

—Rocky deserts.

(b)Processes of wind erosion.

i. Deflation-This is where the eddies of wind scoop out loose dry unconsolidated materials like dust, fine sand particles from the surface. The materials are lifted in.

ii. Abrasion-The materials (sand grains) carried by wind are used to grind scrape and polish the desert surface. The material knock against the rocks wearing them.

iii. Attrition. The materials which are airborne constantly knock against each other hence becoming progressively smaller in size.

(c)(i) Deflation Hollows.

—Physical weathering and abrasion lead to production of unconsolidated materials of dust and sand particles.

—Loose materials are then scooped/removed by wind through deflation formation of shallow depression.

—The basin is widened and deepened through continued abrasion and deflation forming a depression called deflation Hollow.

(ii)Rock pedestal.
—Rock of alternative hard and soft rock lies on the path of moving wind.

—Wind Abrasion wear out the softer layer rapidly than the hard layer resulting to formation of irregular mass of rock.

—Wind Abrasion make the base to have small neck and a broad top due to less abrasion.

(iii)Barchan.
—An obstacle lies along the path of sand laden wind.

—The obstacle force the wind to deposit sand around it forming a low hill.

—As this continue the mound of sand grow bigger.

—Eddies current on the leeward side more the sand to form horns.

—Eventually the barchans is formed.

(d)

(i)D—Zone of permanent saturation.√ C—Zone of intermittent saturation√

E—Zone of Non-saturation.√

(ii)Well A.

This is because it contains water in both wet and dry seasons.

(iii)

—Grikes and clints.

—Dry valleys.

—Blind valleys.

—Limestone gorge.

—Dolines.

—Vivalas.

—Poljes.

—Limestone pavements.

(e) —Underground water found in Limestone areas is important to people because it provide with water for both domestic. e.g. Mzima spring provide water to Mombasa.

—Springs are a source of many rivers.

—Limestone blocks are used to build houses.

—The scrub and shrub vegetation support sheep farming.

—Underground and surface features of Karist landscape forms Scenic beauty which attract tourist hence bringing foreign exchange.

—Limestone materials are used in the manufacture of cement.

—Large amount of limestone are used as a flux iron and steel industry. During smelting of iron ore, limestone combine with impurities in the ore thus allowing iron content to be separated from wastes.

(a)How the following factors influence the type and distribution of vegetation.

(i)Aspect.

—Affect sunlight, temperature and rainfall amount.

—Windward slopes are wetter than leeward slopes therefore have luxuriant vegetation and forests.

—Leeward slopes favour the growth of grass and shrubs due to less rainfall.

—In temperate lands, in the northern hemisphere, sloping facing south are warmer than north facing slopes.Threrefore they are good condition for the growth of forests vegetation.

(b)

(i)Name of vegetation zones.

a. -Heath and moorland

b. –Bamboo forest.

c. –Rainforest.

d. Savannah grassland.

(ii)Two reasons why these is no vegetation on top of the mountain.

—Too cold for plant growth and survival.

—Covered by snow.

—Absence of soil (bare rock).

(c)(i)Three characteristics of tropical rainforest.

—Trees have broad leaves (broad-leaved) to provide surface area for transpiration.

—Have shiny/glossy leaves to reflect the high intensity of in solation.

—Have three canopies i.e. top layer (30-60m), middle layer (15-30m) and bottom layer (515m) tall.

—Trees are at different stages of development since there are no seasons. Some may be flowing, fruiting and leaf-fall at the same time.

—Trees are evergreen and shed leaves at different times of the year.

—Trees are tall, straight with smooth trunks due to competition for sunlight.

—Little or no undergrowth due to limited sunlight on the ground.

—Trees have thick buttressed roots for support/anchorage since they are large and tall.

—Most trees have shallow and extensive roots to tap nutrients near the ground surface.

—Have a wide variety of species growing together i.e. mixed strands.

—Most trees are hardwoods which take long to mature.

—Difficult to exploit due to thickness of the forest, buttress roots and the logs are heavy and bulky with zone not floating in water.

—Have a wide variety of lianas, climbing plants, creepers, and vines e.t.c.

(ii)Three uses of Savannah vegetation.

—Grazing-have abundant tall and short grass for domestic and wild animals.

—Help reduce soil erosion-soil cover.

—Habitat for bees and wild animals which provide honey, beeswax, hides and skins.

—Some shrubs and herbs have medicinal value.

—Source of fuel-provide wood fuel for the people in the tropics.

—The grass increases humus content of the soil making suitable for cereal farming.

—Tourist attraction-habitat for wild animals that attract tourists.

(d)(i)Preparations to be made before the actual field study.(Two)

—Prepare objectives.

—Formulate hypothesis.

—Collect required tools, materials, equipments etc.

—Seek permission from relevant authorities e.g. school head, forest officers/guards e.t.c.

—Prepare a road map.

—Prepare a work schedule.

—Discuss the topic in class.

—Divide the class into work groups.

—Conduct a pre-visit.

—Read through relevant material on forests.

(ii)Problems facing the man forest. (Two)

—Fire outbreaks.

—Clearing of forests for settlement, lumbering and agriculture.

—Forest destruction by wild animals and livestock.

—Illegal settlement of forest land.

—Drought-related problems e.g drying of young trees.

(iii)Solutions to the above problems.

—Eviction of illegal settlers in the forest.

—Control the number of animals.

—Demarcating the forest area.

—Control the cutting of trees by employing forest guards/warders.

—Enhancing community awareness and responsibility so as to conserve and control the use of forests and forest products.

—Encourage the shamba system to improve afforestation programmes.

—Afforestation and reafforestation programmes.

(a) Three ways in which ice may be formed.

i. When sea or ocean water freezes.

ii. When water vapour condenses quickly and directly to solid.

iii. Due to compaction of snow and the subsequent freezing.

iv. Due to seepage of water into snow and the subsequent freezing.

(b) Distinction between an ice cap and an iceberg.

—An ice cap is a small but permanent ice/mass of ice which cover limited areas of plateaus or high mountain tops while an ice-berg is a floating mass of ice on the sea which has broken off from the main ice sheet.

(c)(i) Movement of ice through extrusion flow.

—It affects ice sheets in lowland areas.

—When ice accumulates, it builds up to great thickness at the centre.

—The resultant weight compresses the layers of ice beneath forcing them to spread outwards where there is less pressure.

—Due to the immense weight of overlying ice, individual ice crystals align themselves into layers and slide over each other.

—The melt water lubricates the base of the glacier mass which slides over the bedroll outwards by gravity. (ii) Three processes of ice movement other than extrusion flow. i. Basal slip.

ii. Plastic flowage. iii. Internal shearing.

(d) Formation of a pyramidal peak.

—Snow accumulates in shallow depressions on a mountain side.

—Ice exerts pressure on the cracks and the hollow thereby enlarging the depression.

—The back walls are steeped by plucking leading to formation of cirques round mountain top.

—Frost action cause blocks of rocks to be broken from the back walls of the cirques.

—As the cirques enlarge, the block of rock between them becomes narrower.

—These create so formed leave a jagged peak standing out.

—The sharp steep-sided peak formed is the pyramidal peak.

(e) Three features found in glaciated lowlands.

—Ice-eroded plains.

—Depressions.

—Roche montanee.

—Crag and tail.

(f) Three positive effects of glaciation.

—The glaciated highlands are sources of rivers which are used for irrigation, industrial and domestic purposes.

—The glacial troughs and lakes form excellent route-ways helping in transport and communication network. e.g. the Great Lakes of North America. —The overdeeping of glacial troughs and glacial valleys may expose minerals making it easy to exploit them.

—The waterfalls from hanging valleys are ideal sites for generation of HEP.

—Boulder clay, outwash plains and old glacial lake beds are very fertile and good for agriculture and growth of natural pasture.

—Glaciated highlands and mountains are tourist attraction sites e.g The Alps.

—Sand for building and construction may be extravated from outwash plaine, eskers and kanes.

—The sheltered waters in the fiords provide suitable breeding grounds for fish and natural harbours.