"The Impact of Human Activities on the Earth's Surface" Changes in the Earth's Surface PPT Courseware 2

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"The Impact of Human Activities on the Earth's Surface" Changes in the Earth's Surface PPT Courseware 2

Thinking: What human activities are constantly changing the surface morphology?

Follow the laws of nature to change the surface form.

For example:

Reclamation of land, excavation of rivers, construction of reservoirs, and greening of deserts;

Building construction, developing earthwork, changing the landscape, especially regional development are obvious;

Water conservancy construction changes the flow direction and volume of water bodies, thereby changing the surface ecological environment;

By opening up wasteland and creating farmland, the natural ecology is transformed into an agricultural ecological environment.

Benefits of building a reservoir

Main functions: flood control and drought relief/flood control and drought relief, power generation

Secondary functions: irrigation, water supply, shipping, fishery, tourism, etc.

Changes in the Loess Plateau

my country's ancient civilization first appeared on the Loess Plateau, which reflects from one aspect that the Loess Plateau has a good ecological environment and is suitable for human life.

The Loess Plateau is the birthplace of the Zhou and Qin people. The Zhou and Qin people are both agricultural peoples. In the process of reclaiming farmland and building palaces and tombs, they cut down a large amount of forests and almost all the trees were cut down. The result was It has caused water and soil erosion, resulting in a landscape with broken surface tributaries and crisscrossed ravines, which is difficult to remediate.

It violates the laws of nature and destroys the surface form. For example:

War, destruction of buildings, and even atomic bombs that left an area barren of vegetation;

The amount of garbage increases and is piled on the surface, or the landfill is not up to standard, and the filtrate seeps down, affecting surface vegetation;

Oilfield drilling, mining of various minerals, and excessive exploitation of groundwater have an impact on the earth's crust, easily causing earthquakes or causing surface subsidence;

Excessive sewage discharge exceeds the self-purification capacity of the water body, leading to swamping of lakes;

Indiscriminate logging and desertification of the soil.

Due to human activities, the health of the earth is facing increasingly severe challenges.

Scientists have found that the average area of ​​the ozone layer hole over Antarctica this year is about 27.45 million square kilometers, which is larger than the area of ​​North America. It will take 60 years to completely repair.

As chemical fertilizers, feces, sewage, etc. are discharged into the sea, they provide sufficient nutrients for some algae, stimulating the crazy growth of these seaweeds. Coupled with air pollution factors, some "low oxygen zones" and "hypoxic zones" are formed in the sea. Not only Fish, shrimp, and shellfish cannot survive in low-oxygen or anoxic conditions, and even seagrass cannot survive. Therefore, the "low-oxygen zone" and "hypoxic zone" are also called "dead zones."

As many as 200 "dead zones" have appeared in the world's oceans.

Humans are destroying the earth at an unprecedented rate

Over the past 50 years, population growth has caused pollution and overexploitation of two-thirds of the ecosystems on which humans depend, including air and water.

Between 10% and 30% of mammals, birds and amphibians are on the verge of extinction.

Future changes in ecosystems may cause disease outbreaks, and the African Great Lakes region may become a hotbed for the spread of cholera due to climate change.

my country’s five largest freshwater lakes

Poyang Lake 3914 square meters, Jiangxi

Dongting Lake 2920 square meters, Hunan and Hubei

Taihu Lake 2250 square meters, Jiangsu

Hongze Lake 2069 square meters, Jiangsu

Chaohu 2063 square meters, Hefei

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"The Impact of Human Activities on the Earth's Surface" Changes in the Earth's Surface PPT Courseware 3:

"The Impact of Human Activities on the Earth's Surface" Changes in the Earth's Surface PPT Courseware 3 What effects have you found of human activities on the Earth's surface? How has the landscape changed? What benefits do urban development and changes bring to us? Do they have any adverse effects? The big rivers in China are like the Yellow River...

"The Impact of Human Activities on the Earth's Surface" Changes in the Earth's Surface PPT Courseware:

"The Impact of Human Activities on the Earth's Surface" Changes in the Earth's Surface PPT Courseware Human activities are constantly changing the morphology of the Earth's surface. In how many ways have humans continued to change the surface morphology? Release a large amount of carbon dioxide and cause soil erosion. So, we understand a truth...

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Update Time: 2024-11-22

This template belongs to science courseware People's Education Press Fifth Grade Science Volume 2 industry PPT template

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