"Water on Earth" PPT courseware

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"Water on Earth" PPT courseware

Part One: Water is the source of life!

One of the main features that distinguishes the Earth from other planets: abundant water!

Where can we get water?

Classification according to accumulation situation

ocean water

land water

atmospheric water

biological water

water cycle

1. Concept: the continuous transformation between ocean water, land water, and atmospheric water on the earth

2. Area of ​​occurrence: between ocean and land

between land and land

Between the ocean and the sky above the ocean

Importance of water cycle:

(a) The water cycle is the interconnection between water bodies on the earth, making the hydrosphere a dynamic system.

(b) Through the water cycle, the ocean continuously supplies fresh water to the land, nourishing the land and nurturing life.

Water on Earth PPT, Part 2: What are the characteristics of the distribution of water resources in my country?

Spatially: more in the east and less in the west, more in the south and less in the north

In terms of time: abundant in summer, lacking in winter, large inter-annual changes

Think about it: Based on the current situation of my country’s water resources, in what ways do you think the water shortage problem can be alleviated?

The vast majority of this precious fresh water is glaciers (mainly in the Antarctic and Arctic regions) and groundwater deep in rock formations that are not easily utilized by humans. Together, they account for about 99% of all fresh water resources on the earth.

Freshwater that can be utilized by humans exists in rivers, lakes and swamp soil, which accounts for only 0.3% of all freshwater resources on the earth!

Water on Earth PPT, Part 3: Plants contain water

1. Aquatic plants have higher water content than terrestrial plants;

2. Parts with vigorous life activities have high water content;

(Root tips, buds, seedlings 60%-90%; trunk 40%-50%; air-dried seeds 10%-40%)

The water in the human body accounts for about 60% of the body weight. Calculate how much water is in your body?

The water content in the body of children can reach 4/5 of body weight; in adults it is 2/3.

Water on Earth PPT, Part 4: Which is more important, water or food?

A person who goes on hunger strike for 1-2 weeks can survive as long as he drinks water, but if he goes without water, he can only survive for a few days. According to research, the human body cannot survive if it loses 20-22% of water. Therefore, water is the most abundant and most important substance in the human body.

A healthy adult needs about 2-2.5 liters of water per day on average

Adaptation of organisms to their environment

In order to adapt to a water-scarce environment, what kind of special structure does the cactus have to maintain the water content in the body?

Do you know how the camel, known as the ship of the desert, stores water?

roots exposed to air

Tropical rainforests have a lot of rainfall, high temperatures, and hot and humid air. The aerial roots have a breathing function and can absorb moisture from the air.

Keywords: Zhejiang Education Edition eighth grade science PPT courseware free download, water on earth PPT download, .PPT format;

For more information about the "Water on Earth" PPT courseware, please click on the "Water on Earth" ppt tag.

"The Movement of Sea Water" Water on Earth PPT courseware:

"The Movement of Sea Water" Water on Earth PPT Courseware Part One: Explanation of Course Standards 1. Combined with materials, analyze the main causes and effects of waves, tides, and ocean currents. (Comprehensive thinking) 2. Combined with the ocean current distribution map, master the distribution patterns and names of ocean currents in the world's oceans.

"The Movement of Sea Water" Water on Earth PPT:

"The Movement of Sea Water" Water on Earth PPT Part One Content: Learning Objectives: 1. Understand the main forms and characteristics of sea water movement. 2. Understand the main influencing factors of waves and their impact on human activities. 3. Understand the causes of tides and their application characteristics. 4...

"The Nature of Seawater" Water on Earth PPT courseware:

"The Nature of Seawater" Water on Earth PPT courseware Part 1: Explanation of course standards 1. Combined with the chart information, understand the main factors that affect the temperature, salinity and density of seawater. (Comprehensive thinking) 2. Use chart data to summarize the time of seawater temperature, salinity, and density..

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Update Time: 2024-11-25

This template belongs to science courseware Zhejiang Education Edition Eighth Grade Science Volume 1 industry PPT template

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