J S S 3

BASIC SCIENCE 

1. Define environmental hazards

2. List the types of environmental hazards

3. Mention five causes of environmental hazards

4. Mention five ways of controlling environmental hazards.

5. List five ways to prevent environmental hazards.

Basic science note. 

Kindly copy it in your basic science note book. 

*Introduction*

Land serves various purposes and is

of great benefit to man. However, when it is abused and affected by human activities and natural disaster, it becomes deserted, we will study

desertification, the causes of

desertification, the geographical

zones prone to desertification in

Nigeria, the effects of a

desertification

on the people and environment, and

the methods of controlling desertification. We will also look into

depletion of ozone layer, the causes,

the effects of depletion, the importance of ozone layer and the

methods of controlling ozone layer

from depletion.

*Desertification*

Some human activities can lead to environmental disasters. Activities

like deforestation, overgrazing and

bush burning are the major causes of

gradual transformation of the

habitat into deserts. Research has

shown that if necessary measures

are not taken, many geographical

zones would be drastically depleted.

*Meaning of Desertification*

Desertification is a process of land degradation by which a region progressively drier until it subsequently turns to desert. Simply out, it is the process by which previously biologically productive and is transformed into wasteland. It can also be described as a type of land degradation in which a relatively dry land region becomes increasingly arid, typically losing its

bodies of water as well as vegetation and wildlife. 

Deserts are dry lands with very scanty vegetation. Deserts are found in some parts of Nigeria like Yola. Yobe, Borno and Soketo.

 Desertification is also the encroachment of desert by turning it into habitable land. It has affected many nations of the world like China, South Africa, etc.

*Causes of Desertification*

Desert encroachment can be caused by the following activities:

(i)Overgrazing (ii)Deforestation

(iii) Bush burning (iv) Destruction of plants in dry regions.

(v)Continuous farming activities.

(vi) Change in weather. (vii) Cultivation of soil that are fragile or exposed to erosion by wind or water.

 (vii) Over exploitation of woody resources, e.g. firewood. 

(ix) Agricultural practices that result in the net export of soil nutrients, leading to loss of the soil fertility, such as cropping. 

(x) Diversion of rivers to create irrigation schemes.

*Geographical Zones Prone to Desertification in Nigeria*

The zones prone to desertification are the zones that are closer to dry. lands (desert). Out of the two main geographical zones in Nigeria (tropical and savanna), savanna region is more prone to desertification than the other zones.

In Nigeria, we have areas like Sokoto, Kano, Kastina, Jigawa, Borno, etc. which are more prone to desertification.