Urgently ask for 2 pieces of junior high school student investigation report about 200 words Xie

In environmental science, it is generally believed that environment refers to the space around people and the various natural factors in it that can directly affect human life and development. In the course of millions of years of human history, the environment has played a huge role in the creation of human civilization and progress. The atmosphere, water, land, and grasslands are the material basis for human survival. Forests, minerals and other resources provide materials for the continuous development of human beings, creating a high degree of human civilization on the earth.

However, while human beings are developing and utilizing environmental resources, they have also produced a series of environmental problems for their own sub-living environment. To that end, I conducted my investigation.

1。The ozone layer is destroyed. The ozone layer accounts for 1/100,000 of the total stratosphere, and although the content is very low, it can absorb ultraviolet rays, but due to human destruction, the ozone layer is rapidly depleted and extremely damaged.

Such as the ozone hole in Antarctica. In 1994, 24 million square kilometres of the ozone layer over Antarctica were destroyed. The ozone layer over Antarctica was formed over 2 billion years, but it has been destroyed by 60% in the last century.

With an average reduction of 10 to 15 per cent of the ozone layer over Europe and North America, and even 35 per cent over Siberia, scientists warn that the ozone layer over the planet is being destroyed far more than the average person thinks.

2。Freshwater crisis. Although the Earth's ground2 3 is covered by water, 97% of the Earth's surface is undrinkable seawater, and less than 3% is freshwater, but 2% of this is sequestered in polar glaciers.

Of the only 1% of freshwater, 25% is used for industry, 70% is for agriculture and only 5% is available for drinking and other domestic purposes. At present, more than 100 countries and regions in the world are short of water, and 28 of them are classified as countries and regions with severe water shortage. According to statistics, the total area of water shortage in northern China is 580,000 square kilometers, and more than 300 of China's more than 500 cities are short of water, with an annual water shortage of 5.8 billion cubic meters.

Due to the destruction of human beings, the earth's water resources are limited, and many large rivers such as the Colorado River in the United States and the Yellow River in China are no longer majestic.

3。Desertification of land. At present, the phenomenon of desertification in the world is still intensifying.

More than 1.2 billion people are currently under direct threat of desertification, and 100 million of them are at risk of losing their land in the short term. By 1996, the global desertification of land has reached 36 million square kilometers, accounting for 1 4 of the entire earth's land area, equivalent to the total land area of Russia, Canada, China and the United States, there are more than 100 countries affected by desertification in the world, and desertification is expanding at a rate of 5-70,000 square kilometers per year, which is equivalent to the area of Ireland. For people threatened by desertification, desertification means that they will lose the most basic basis for survival - the disappearance of productive land.

Postscript: There are many crises that people will face, and if humanity continues to destroy the environment, then humanity will become extinct and the earth will become a distant history in the universe.

Now junior high school students, post-90s! It's very tricky, it's oversized. ok！