Lesson 2:

Causes of Land Degradation

What you should know by the end of this lesson:

at least 3 causes of Rural Land Degradation
Understand the impact that Wind and Rain has on Land Degradation

Background

Land degradation is when soil reduces infertility and will support fewer vegetation, animals and people.

Arid

A region with a lack of water

Land Degradation

Loss of healthy Soil

Desertification

Land turning to desert

Digital Workbook and Paper Jotter

Take notes on all the different reasons for Rural Land Degradation

Soil Erosion

Reminder!

Erosion is when the material is broken down and carried or transported away by wind or water

by the wind

Dried out soil is very loose and falls apart to its individual granules. Any wind can move this bare soil about as it is not being held together or protected by vegetation. In times of heavy winds, this can create sand and dust storms that blow large amounts of soil away from an area.

by water

A small amount of water in the soil will actually do a good job of turning the soil to mud and stopping it from being blown away by the wind.

However, rainfall in the Sahel is infrequent and can be heavy when it does come. Dry hard soil will act like concrete and not allow the water to infiltrate (soak in) quickly. Water then flows over the top of the soil carrying soil particles away with it.

5 causes of land degradation

Deforestation

Demand for wood (for houses, furniture and fuel) removes tree roots that hold the soil together and protect it from the elements. Removing trees exposes the soil to the wind and rain.

Overcultivation

Too much farming of the same crop

means nutrients are removed and does

not allow the soil to recover. Continually

planting and harvesting crops does not

allow the soil to recover which produces

less food.

Over Irrigation

Irrigation is the process of storing water and using it in controlled amounts on crops.

This leads to salinisation (increase in salt) of the soil, reducing fertility and either leading to the need for salt/tolerant plants or further degradation occurs.

Over Grazing

Too much farming of the same crop means nutrients are removed and does not allow the soil to recover. Continually planting and harvesting crops does not allow the soil to recover which produces less food.

Over Population

More people need space and food. Making all of the other causes worse as there is more cattle, more crops and more space needed.