Objective:Understand the processes that are leading to soil degradation and be able to describe the impacts that this is having on the environment and human populations.
Definition: A severe reduction in the quality of soils. The term includes soil erosion, salinization and soil exhaustion (loss of fertility)
"It takes such a long time for soil to form – some 10-12,000 years to build up to depths we might describe as productive land. First, the rocks that have made it from the Earth's interior to the surface must be "weathered" by wind and rain, a disintegration that is assisted by microorganisms, insects and lichen. This organic matter decays, feeding more organisms, including, in time, plants. It is the accumulation of hundreds of years of this organic matter, living organisms and minerals that we call soil. It takes a few hundred years to produce each centimetre of soil (although it is a little faster in the tropics), but it can be lost in a matter of hours."
Causes & Implications of soil degradation
Read this Guardian article
Read this BBC article.
Solutions to Soil Degradation
Describe how the following methods can help reduce soil degradation
Physical Water Scarcity
Definition: where water resource development is approaching or has exceeded unsustainable levels; it relates water availability to water demand and implies that arid areas are not necessarily water scarce.
Economic Water Scarcity
Defnition: where water is available locally but not accessible for human, institutional or financial capital reasons.
Read the following articles and make notes about why Ethiopia faces economic water scarcity:
Figure 1.7: Water Scarcity Map. source: http://www.grida.no/
Example: Mexico City
Great article about physical and economic water scarcity and its impacts in Mexico City. Guardian 2014
On the printed version(or get a digital copy) highlight in different colours:
Exam style question
Should developing countries focus on improving the quantity or quality of the supply of potable water. Discuss (10 marks)
Case Study: Paua New Guinea
Rainforest destruction & sustainability