Here is the 2017/2018 WAEC Geography Answers.
4a)
i)Rarely has fossils
ii)React with acid
iii)have alternate bands of light and dark minerals
4b)
i)formed through the action of heat and pressure
ii)formed from clay
iii)formed from limestone
4c)
i)rocks are source of minerals eg gold,silver,petroleum etc
ii)rocks are source of materials for construction
iii)rocks serves as raw materials for industry eg cement industry
3a)
Erosion is the process of eroding or being eroded by wind, water, or other natural agents. While Mass movement is the movement of surface material caused by gravity.
3b)
i)runing water
ii)winds
iii)waves
vi)glaciers
3c)
i)Water
-rainwater acts as a lubricant to weathered materials.
ii)Vegetation
-lack of vegetation cover to hold the
loose particles.
iii)Rock structure
-joints dipping downslope usually assists landslides, rockfalls, rockslide, rock creep.
7a)
i)Agricultural Pollution
ii)Oil Pollution.
iii)Radioactive Substances polution
iv)River dumping pollution
v)Marine Dumping pollution
7b)
i)A regular qualitative and quantitative monitoring of fresh water resources.
ii)Construct proper sanitary landfill
sites.
iii)Investigate ground water quality.
iv)Provide government help for waste management by industries.
v)Throw refuse into garbage cans. Visitors who throw garbage into pools, lakes, ponds, and even along the beaches pollute recreational sites on a daily basis.
1a)
Scale 1:25,000
1b)
i)it has few social amenities
ii)it is a feature of rural settlements
iii)they are only motivate in primary activities like farming lumbering fisht etc
1bii)
i)water transport
1c)
i)dentritic pattern
6a)Soil can be defined as the organic and inorganic materials
on the surface of the earth that provide the medium for plant
growth.
6bii Clay soils with 25-40% clay
These soils have a good ability to transport water by
capillary action from deep layers but the rate is slow, so plant
water requirements are not met through capillary water.
2 These soils are darker in colour and soil aggregation is more
distinct
a) *
Causes of Desert Encroachment*
1. Human activities: such activities such as over-grazing, over-
cultivation, bush burning, and excessive cutting of firewood
greatly reduce the vegetative cover and expose the land to
drought and desertification. Examples of areas with desert
encroachment are the Sahelian zones of Nest Africa, Ethiopia,
Somalia and Sudan.
2. Change in Weather: The frequent and prolonged dry
weather increases the aridity of affected areas.
3. The southward movement of the dry sub-tropical high
pressure belt results in severe drought in semi-arid regions.
b) *
Effects of Desert Encroachment*
1. Large scale disruption of socio-economic life arising from
crop failure and shortage of water and pasture for livestock.
2. Widespread malnutrition and diseases such as kwashiokor
and marasmus.
3. Migration of people from drought areas to more humid
areas.
4. Large refugee population, that are made up of victims of
drought and social insecurity in the semi-arid areas.
5. Disruption of ecological balance and loss of vegetation, soil
and water resources.
c) *
Preventive Measures of Desert Encroachment*
1. Conservation of existing vegetation through legislation
against indiscriminate exploitation and felling of forests and
trees.
2. Legislation and strong control against bush burning.
3. Improved grazing practices.
4. Establishment of shelter belts to protect the soil and arrest
the effect of desertification.
5. Afforestation programs.
6. Integrated rural development.
Factors that affect Mass Movement
It is very clear, that mass movement or mass wasting is
movement of weathered material with the aid of gravity,
there are many factors that affect this movement. I shall tell
you about 6 main factors as follows:
1. Where permeable rocks alternate with impermeable rocks,
the permeable rocks are more more prone to mass wasting
than the impermeable rocks.
2. Mass movement is pronounced in areas with steep slopes
where the weathered layer is deep and the weathered
materials are loose. Naturally, the rate of movement of
weathered materials is faster on steep slopes than on gentle
slopes.
3. Mass movement is encouraged if there are earthquakes and
volcanic eruptions.
4. Areas with a high annual range of temperature and a high
frequency of freezing and thawing will encourage soil creep
while areas with a high temperature and occasional torrential
rainfall encourage mudflow.
5. Mass movement is also encouraged if there is no vegetation.
6. The activities of man like mining and herding of animals
encourage the production of mass movement or mass
wasting. This are the factors that affect Mass movement or
wasting.