Desertification-one of ten threats to our earth
There is sixty percent global area is land, including 29% of area of deserts and desertification. It is said that 6 million hectares of land would transfer into desert each year with $423 billion of economic losses. The global arid and semi-arid lands are 5 billion hectares, of which 3.3 billion was threatened by desertification, leading to 6 million hectares of farmland and 9 million hectares of pastoral land lose their productivity. The cradle of human civilization, the Tigris and Euphrates have been turned fertile into desert. In China, the Yellow River basin also faces the serious situation of loss of soil erosion.
You cannot imagine that how big is the desert area on the earth. For example, the Sahara, the largest desert, except Antarctica is also one of the largest desert. Although we may not be able to imagine the Sahara, and you may think that it is not caused by human beings. However, it was a shock original river alluvial plain in a few thousand years ago. So how big is it now? The length of this desert is 4800 kilometres from east to west, and the width is 1300-1900 kilometres from south to the north, the total area is 9.06 million square kilometres which is almost same as China's area.
The immediate cause is the removal of most vegetation. This is led by a number of factors such as drought, climate shifts, tillage for agriculture, overgrazing and deforestation for fuel or construction materials. Vegetation plays a dominant role in determining the biological composition of the soil.
The urgent situation should be mitigate, or we will lose our land one day. Although we are not experts, but we should gain the awareness to protect our environment, to protect our vegetation.
Picture from the following website:
没有评论:
发表评论