Desertification
Read Desertification and check the IELTS Reading answers. The world's great deserts were formed by natural processes interacting over long intervals of time. During most of these times, deserts have grown and shrunk independent of human activities. Paleodeserts, large sand seas now inactive because…
Passage preview
The world's great deserts were formed by natural processes interacting over long intervals of time. During most of these times, deserts have grown and shrunk independent of human activities. Paleodeserts, large sand seas now inactive because they are stabilized by vegetation, extend well beyond the present margins of core deserts, such as the Sahara. In some regions, deserts are separated sharply from surrounding, less arid areas by mountains and other contrasting landforms that reflect basic structural differences in the regional geology. In other areas, desert fringes form a gradual transition from a dry to a more humid environment, making it more difficult to define the desert border.
Vocabulary from this passage
10 words worth learning before you sit the test, each with the sentence it appears in.
- aridity noun
The state of being extremely dry, typically characterized by a lack of sufficient rainfall to support diverse plant growth.
The increasing aridity of the region has forced many agricultural communities to abandon their traditional farming practices.
- erratic adjective
Not even or regular in pattern or movement; unpredictable or inconsistent in its progression, timing, or general behavior.
The erratic advance of desert borders makes it difficult for scientists to map the precise rate of desertification.
- fragile ecosystem noun
A biological community that is easily disturbed or damaged by external changes, particularly those caused by human industrial activities.
The desert fringe is a fragile ecosystem where even minor human interference can lead to permanent land degradation.
- microclimate noun
The climate of a very small or restricted area, especially when it differs significantly from the surrounding regional climate.
Small hollows in the desert create a unique microclimate that allows specific types of vegetation to survive.
- misconception noun
A view or opinion that is incorrect because it is based on faulty thinking, incomplete information, or general misunderstanding.
It is a common misconception that drought is the sole cause of the desertification process in Africa.
- paleodesert noun
An ancient desert region that is now inactive and often stabilized by vegetation due to historical changes in climate.
Researchers study paleodeserts to understand how ancient climate shifts transformed lush landscapes into arid environments.
- percolation rate noun
The speed at which water moves through soil or porous rock, influencing the amount of erosion and moisture retention.
Heavy livestock traffic can compact the soil, significantly reducing the percolation rate and increasing surface water runoff.
- reclamation noun
The process of restoring land to a productive state or claiming something back from a state of neglect or decay.
The reclamation of desert land requires innovative irrigation techniques and the planting of hardy, sand-fixing vegetation.
- salinization noun
The process by which water-soluble salts accumulate in the soil, often reaching levels that are toxic to most plants.
Poor drainage in irrigated fields can lead to soil salinization, which eventually renders the land unsuitable for farming.
- vulnerable adjective
Susceptible to physical or environmental attack or harm; in ecology, at risk of significant degradation or eventual species extinction.
The vulnerable soil in arid regions requires careful management to prevent it from being swept away by wind.
Answers with explanations
- 14. E
The question refers to a **threat to people worldwide**. Paragraph E supports this by explicitly stating that **desertification presently affects millions of people in almost every continent**, which aligns perfectly with the global scope mentioned in the prompt.
- 15. C
The statement asserts it is **difficult to describe the process**. Paragraph C aligns with this by defining desertification as a **complex process** that **involves multiple causes, and it proceeds at varying rates**, highlighting its intricate and hard-to-describe nature.
- 16. C
The statement claims desertification can **alter local climates**. Paragraph C provides direct evidence for this, stating that desertification may **initiate a change in local climate**, confirming the specific environmental impact outlined in the question.
- 17. F
The prompt addresses **misconceptions regarding desertification origins**. Paragraph F explicitly tackles this by stating directly that **It is a misconception that drought cause desertification**, perfectly matching the idea that people hold incorrect beliefs about its causes.
- 18. D
The question mentions it is **hard to notice desertification** early on. Paragraph D confirms this by stating an area is brought to **public attention only after the process is well underway**, indicating that the problem goes unnoticed during its initial stages.
- 19. G
The statement says **straw grids diminish the swiftness** of wind. Paragraph G explains that the **Placement of straw grids** will also **decrease the surface wind velocity**, providing an exact match for the wind-diminishing mechanism described in the question.
- 20. NO
The statement claims **All desert borders are difficult to define**. The text contradicts this by stating that in **some regions, deserts are separated sharply**, while only in 'other areas' does a gradual transition make the border more difficult to define. Answer: NO.
- 21. NOT GIVEN
The statement definitively claims desertification is a **reversible process**. The passage states that **Scientists still question whether desertification** is permanent or **how and when it can be halted or reversed**. Because scientists are still questioning it, the text does not state it as a known fact. Answer: NOT GIVEN.
- 22. NO
The statement claims the area became a Dust Bowl **until almost 1950**. The text explicitly states it turned into the Dust Bowl **in the 1930's**, but notes that the term itself was not used until almost 1950. This contradicts the timing of the actual event. Answer: NO.
- 23. YES
The statement claims nomads **cannot get away** due to **current land-use methods**. The text affirms this, stating nomads are **trying to escape the desert, but because of their land-use practices, they are bringing the desert with them**, directly matching the claim. Answer: YES.
- 24. stabilize
The blank requires a verb explaining the effect of planting trees in oases. The text mentions that **Small plots of trees may also be scattered inside oases to stabilize the area**. Thus, 'stabilize' grammatically and factually completes the sentence.
- 25. salinization
The blank requires a noun related to a problem that needs prevention or control. The passage states that **efficient use of existing water resources and control of salinization** are effective tools. 'Salinization' fits correctly as the issue being controlled.
- 26. proper crop rotation
The blank requires a noun phrase describing what scientists are seeking to protect the soil. The text states research is focusing on **discovering proper crop rotation to protect the fragile soil**. The phrase 'proper crop rotation' perfectly matches the requirement.