Text Editor|Yi Xiansen
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Preamble:
In the early 80s, a northern Shaanxi folk song is still sung into the hearts of many people today. This song is written about one of the four major plateaus in the north-central part of the mainland, that is, the "Loess Plateau" loess area.
The total area of loess can be reached, crisscrossed with indiscriminate. The thickness of these disorderly ravines and small slopes can reach tens of meters, and some can reach hundreds of meters.
However, in some areas, there are many serious ecological crises such as land subsidence, groundwater system destruction, and environmental pollution. According to relevant data, based on the annual loss of 1.6 billion tons of soil, a total of about 3,800 tons of ammonium nitrogen, total phosphorus and total potassium are lost.
Don't think that these soil erosions have nothing to do with us, in fact, these losses are all the mainland's non-renewable energy wealth, and China at that time could only watch.
After an American journalist visited here in 1936, in.
Therefore, China's "Loess Plateau" is famous in the world.
Here, there is no green vegetation on the bare surface, and there is no life in sight of desolation.
At a conference 70 years ago, even the United Nations admonished us. Probably speaking, according to the economic situation of your country at that time, it was almost impossible to change such a large area of yellow earth, so don't waste manpower, material and financial resources if you are poor, can you rely on a few hoes?
At that time, the geography of the place was, in the eyes of foreigners, impossible to meet the basic needs of human habitation. These words vividly illustrate that "birds don't poop" there, and it is a barren and barren land.
As everyone knows, the mainland lives on this Loess Plateau, and at the same time, it is also an important birthplace of the Chinese nation.
At this point, there was a determination to start the transformation and management of the Loess Plateau, since it is a national land, it can be turned into a suitable place for human habitation. In recent years, I have understood why the mainland has to fight to the end with such a desolate place, it turns out.
The land resources of the Loess Plateau were originally relatively fertile soil, but due to serious soil erosion, it became very barren, and although the population was large, the grain yield was very low.
Around the sixties and seventies, a vicious circle of "" was formed. It is because of the problem of soil erosion that it has become an important factor restricting the healthy economic development of the Loess Plateau.
Now that 70 years have passed, and the United Nations has suggested that we should ignore it, we will prefer it, so what is the current situation of the Loess Plateau and the results of governance?
The yellow earth that has been desolate for thousands of years
Loess Plateau in China,,。 It starts from the Great Wall in the north, reaches the Qinling Mountains in the south, reaches the Wusheling Mountains in the west, and reaches the Taihang Mountains in the east. Among them, it spans seven larger provinces, including Shanxi, Shaanxi, Gansu, Ningxia, Qinghai, Henan, and Inner Mongolia.
Therefore, the Loess Plateau is also an important birthplace of the Chinese nation, and with the concept of "backwardness will be beaten", we want to turn this barren land into an oasis!
The classical "Zizhi Tongjian" records the Shaanxi and Gansu regions in the Tang Dynasty, just like "Lu Yan looks at each other, mulberry and hemp are wild, and the rich people in the world are not as good as Longyou". For a long time, the vegetation coverage rate is high and the ecological environment conditions are superior. The so-called "beautiful mountains, forests, rivers and valleys, and many geniuses" describes the natural features of the Yellow River Basin.
Archaeologists have found prehistoric humans in the western part of the Loess Plateau 5,500 years ago.
No matter how beautiful the place is, it will disappear, after all, even the age of dinosaurs has been extinct, and with the passage of time, due to the intermittent continuous rise of the mountains, the slopes and hills are gradually covered, and the current topography of the Loess Plateau has been formed.
These tens of thousands of gully soil layers, these accumulation and precipitation of dry yellow soil, are the products of the accumulation of rocks from other regions under the action of external forces such as wind, flowing water, and organisms, so it is said that this is the wealth blown by the wind.
It is the world's largest loess accumulation area, with an overall altitude of 800 to 3,000 meters.
Don't look at it as an area where birds don't poop, but here it has given birth to the unique ethnic customs and culture of the Loess Plateau, and has produced folk houses represented by "caves", and folk art represented by Xintianyou and Ansai waist drums.
Loess is an aeolian accumulation that is blown and transported under the power of the wind, and accumulates in an arid and semi-arid environment.
With the exception of a few stony mountain areas, the loess thickness of the small slopes of the ravines is between 50 and 80 meters, and the thickest can reach 150 to 180 meters. Here's it, among them.
In terms of chemical composition, the content of soluble chemical components in loess is relatively high, so it is also an important energy and chemical base in the mainland.
Why did the oasis in the Tang Dynasty become a loess slope where birds don't poop now?
It's not because of human farming for a long time. In particular, the Ming Dynasty and Qing Dynasty in modern history, etc., caused the natural forests and grassland plants in the Loess Plateau area to be almost destroyed.
After the ecological environment was seriously damaged, there was very serious soil erosion in northwest China such as Shaanxi and Gansu, and a large amount of soil erosion reached the Yellow River. Then, in modern history, it has become the geomorphological characteristics of the Loess Plateau with vertical and horizontal ravines and bald mountains and barren mountains.
Due to the terrain in the natural and man-made environmental disadvantages, the average annual temperature is 3.6 degrees to 14.3 degrees, the average annual rainfall can reach 250 mm to 600 mm, the rainfall is generally concentrated in July and September, and the average annual evaporation is 1400 to 2000 mm, far exceeding the average annual rainfall.
Why is soil erosion serious? Due to the irresistible and continuous influence of natural or man-made factors, it is common for water and soil to be lost at the same time.
The main reason for the rapid desertification of the Loess Plateau is that the ground vegetation has been destroyed due to the large slope of the ground, the low level of education of the people, and the improper use of land. It is also caused by overgrazing and other problems.
Serious soil erosion will lead to a decrease in cultivated land, soil fertility, and crop yields. The ecological environment continues to deteriorate, so it restricts the local economic development and exacerbates the poverty situation and poor environment.
The water level has risen dramatically due to the loss of sediment into the Yellow River, resulting in frequent floods and droughts, and tens of thousands of people have been put in danger of their lives, seriously affecting industrial and agricultural production and posing a serious threat to downstream rivers.
70 years of perseverance have finally paid off
In the 50s of the last century, some experts proposed slope management, wanting to slow down the rate of soil erosion by means of managing other areas, as well as by stabilizing the soil through covering.
However, the speed of change in the development of the harsh environment has not only failed to effectively control the slope treatment, but has made the terraces more rapid, that is to say, the way of slope management needs to be improved.
By the end of the 70s, some experts proposed ditch management, hoping to build "silt dams" to intercept sediment loss, and at the same time use the silt to continue farming. And the 50s, it really works well, the Yellow River sediment
Maybe God just can't see us turning the loess into an oasis, and there has been a catastrophic flood disaster in northern Shaanxi, but we just have a persistent belief that we must turn the loess into an oasis!
By the end of the 20th century, the local government adopted a method according to local conditions, and finally figured out the appropriate method for soil erosion control on the Loess Plateau. In general, it is to subdivide the natural environment in different places and combine different governance methods to carry out governance work, and the results are remarkable.
According to the idea of "", after decades of experience accumulation, to sum up the results of practice, it is necessary to build terraces on the gentle slope of the mountain, dam the dam in the ditch, build an orchard on the sunny slope of the mountain with high mountains and distant mountains, plant pasture on abandoned slopes, and plant caragana on barren slopes and dangerous depressions.
At the same time, comprehensive treatment of mountains, waters, fields, forests, roads, beams, ridges, ditches, slopes and depressions was carried out, and an effective comprehensive prevention and control system was finally formed.
In 2008, the green coverage rate of the Loess Plateau has reached 19.55%, that is to say, the Loess Plateau does not grow trees, is not suitable for human habitation, and has become history.
During the period from 2000 to 2015, a total of 5,811,200 hectares of the Loess Plateau completed the construction tasks of returning farmland to forests, including 2,150,700 hectares of farmland returned to forests, 3,286,500 hectares of barren mountains for afforestation, and 375,000 hectares of mountains closed for afforestation.
The current Loess Plateau has basically achieved a situation. It is only now that there is a large-scale terraced construction, vegetation and forest cover, which has formed a guarantee of food and ecological security in this area, and at the same time, let the people live a good life, and it has also become an important asset reserve on the mainland.
What do you think of 70 years of perseverance?