Question 1
- What is desertification
- State three human activities that lead to desertification.
Answer
- - Desertification is the encroachment of large areas of barren land, uncultivatable and lacking vegetation to the more productive and habitable regions
-
- Clearing of vegetation to create room for settlement, agriculture, industry and for fuel.
- Poor agriculture practices, ploughing down slope etc.
- Industrialization
Question 2
- Give three examples of mechanically formed sedimentary rocks.
- State two changes that occur in sedimentary rocks when they are subjected to intense heat and pressure
Answer
-
- Sandstone . Clay stone/silt stone
- Mudstone -
- New minerals are formed
- Rock particles become compacted
Question 3
- Why is ocean salinity higher in the tropical regions than at the equator
- Name three types of ocean tides
Answer
-
- Heavy rainfall and high humidity along the equator dilutes the sea salt and the heavy cloud cover reduces evaporation of the sea water.
- In the tropics the temperatures are very high leading to increased evaporation of water and a higher concentration of the salts. -
- Perigean
- Apogean
- Spring
Question 4
- When local time is 2.00 p.m. at longitude 600E.What is the longitude of a place whose local time is 5.00 p.m.
- Give two effects of the oval shape of the orbit of the earth
Answer
-
change in time:
5.00pm - 2.00pm = 3 hrs
3 × 60 mins = 180 mins
Change in degrees
180 ⁄ 4 = 450
- since 5.00 p.m is on the eastside of 2.00pm.Add degrees 600E + 450 = 1050E -
- Change of tides
- Change of energy/heat
Question 5
- Apart from river and wave deposition state three ways in which lakes may be formed
- Name two lakes in Kenya where formed through river deposition.
Answer
-
- Formed through tectonic movements
- Formed by glaciations
- Formed by wind erosion -
- Lake Shakababu along Tana river
- Lake Gambi along Tana river