Ch10 Taming the sand

Question 1

What is desertification?

Answer 1

They are areas with low precipitation and a high evaporation rate. The dry condition only supports vegetation such as grass, shrubs and scattered trees. Grassland and Savanna are examples of drylands.

Question 2

What happens when physical or human causes lead to a decrease in vegetation cover?

Answer 2

Persistent land degradation. The topsoil without vegetation cover is exposed to erosion by wind and water -> loss of soil fertility-> loss of vegetation cover-> desertification, land loses its productivity and supports less vegetation.

Question 3

Where are the areas at high risk of desertification?

Answer 3

Xinjiang, Ningxia, Shanxi, Neimongol

Question 4

Where are the areas most vulnerable for desertification “

Answer 4

At the fringe of the major deserts.

Question 5

What are the physical causes in terms of climatic factors?

Answer 5

There areas are in the inland of China and they have low annual rainfall. The absence of cloud cover increases the radiation cooling at night and the daily range of temperature increases. Evaporation rate is high. In summer, not much moisture brought by summer monsoons can reach the inland. In winter, the cold and dry monsoons does not favour the formation of rain. Frequent strong winds in spring and winter facilitate soil erosion.

Question 6

What are the physical causes in terms of relief factors of desertification?

Answer 6

They are mainly mountainous, in places that have many mountains or highlands and many large deserts like Takla Makan Desert and the Gobi Desert.

Question 7

What sets of the process of land degradation?

Answer 7

Soil is sandy, wet and poor with a dry climate -> sparse vegetation -> land productivity in northern China is low -> land degradation

Question 8

What are the process of human induced climate change?

Answer 8

Global warming -> relative humidity decreases -> hinder the formation of rain and clouds -> precipitation-> drought become frequent -> decrease of vegetation cover-> soil erosion increases and land degradation is resulted.
Global warming -> evaporation rate increases -> soil erosion increases and land degradation is resulted.
Global warming -> lowers the relative humidity-> evapotranspiration decreases -> vegetation cover decreases -> soil erosion and land degradation is resulted.

Question 9

How the population growth affects the dryland?

Answer 9

Rapid increases in population in drylands -> the demand for food and other resources increases > people have to use the land aggressively-> misuse the dryland resources like overgrazing -> low land productivity in the northern China -> set of the process of land degradation

Question 10

What are the names of the misuse of land resources processes?

Answer 10

Overgrazing, over-cultivation, over-irrigation, over-cutting of trees and shrubs

Question 11

Explain on the term of overgrazing.

Answer 11

Herders rear too many livestock which exceeds the carrying capacity of the pastureland. The pasture is used up quickly than it can regrow. Animals trample the soil and vegetation dies. Soil is left barren and soil erosion occurs.

Question 12

Explain on the term of over-cultivation

Answer 12

Farmers grow too many crops in poor soil year after year and shorten the fallowing period. Soil moisture and nutrients are used up too quickly. Crops cannot grow and the land loses productivity and farmers abandon the land. They open up more drylands and the vicious cycle continues. Therefore, the loss of vegetation cover -> soil erosion increases -> land degradation

Question 13

Explain on the term of over irrigation.

Answer 13

Tapping too much groundwater for irrigation -> water table drops -> soil moisture decreases and the soil becomes dry.
Applying too much irrigation water.
Irrigation water dissolves salts in soil -> strong evaporation under the hot and dry climate -> dissolved salts are drawn up and accumulate on the surface. This is known as salinisation which increases the salt levels in the soil. The land becomes salty and loses productivity.

Question 14

Explain on the term of over-cutting of trees and shrubs.

Answer 14

Cut more trees and shrubs for cooking and building materials. Deforestation occurs and soil is left barren and soil erosion occurs.

Question 15

How does desertification affect people and the natural environment in China?

Answer 15

Economic losses, relocation of people, affecting the natural environment, increase in the frequency of sandstorms and dust storms.

Question 16

What has been done to keep desertification in check?

Answer 16

Increasing vegetation cover in Northern China (Afforestation scheme), restoring vegetation cover, preventing it from further loss.

Question 17

What sorts of trees are suitable for planting in drylands?

Answer 17

fast-growing, drought resistant and have extensive root systems

Question 18

What are the two large scale projects introduced by the Central Government?

Answer 18

The Three-North Shelter-belt Project, Beijing Tianjin Sandstorm source control project.

Question 19

What are used to fix the land in some sandy drylands where it is too dry for planting trees and grass directly?

Answer 19

Straw checkerboards. It allows the planting of vegetation in the future when the soil condition has improved. Sand soil and moisture are kept inside the squares. Plants grow when there is enough soil and moisture. The wheat straw slows down the wind speed.

Question 20

What are the control grazing activities?

Answer 20

The Central Government has carried out the Returning Grazing land to Grass Land project in northern, western and north-eastern in 2003 to control grazing activities.
Measures are also adopted to prevent overgrazing like prohibit grazing on seriously graded land and fix the size of the livestock reared on each plot on the grassland where grazing is allowed.
Seasonal grazing and rotational grazing allows the fallowing and pastures to regrow.

Question 21

What are the control farming activities?

Answer 21

Grain for Green project. It encourages farmers to give up farming in degraded farmland on steep slopes and plant trees or grass instead. Provide farmers with food and money as subsidies. Hence, the land pressure from over-cultivation decreases and restores the productivity of degraded land.
Prohibit farming in areas that are unfavourable for cultivation. This prevents the soil from losing nutrients.
Encourage farmers to use drip irrigation method. Encore farmers to grow drought resistant crops. This can prevent the accumulation of salt and conserve, avoid the water wastage.
All these methods can decrease the loss of vegetation cover and soil erosion decreases

Question 22

What are the other sources of income?

Answer 22

Providing job in the factories related to agribusiness. Grow cash crops. Developing ecotourism.