The Yellow River, the fifth longest river in the world, is a 5464-kilometer-long river winding in the north of China. From the air, it looks like a huge word "Ji" and is also a unique totem of our nation.

Second, the characterization of the Yellow River

Not just a big river. Yellow River, Yellow Land, Emperor and Yellow Peel, all these yellow appearances sublimate this turbid stream flowing through the heart of China into a holy river. Han Shu Gou Ji regards the Yellow River as the head of thousands of waters: "China has the source of all rivers, not in the four capitals, but in the river."

Third, the theory of loess weathering.

In a long geological time, in the desert Gobi in the interior of Asia, the sand everywhere is decomposed and crushed in the harsh environment of rapid cooling and rapid heating until it forms powder. The northwest airflow prevailing in the inland has blown them to the east for many years, and the coarse sand has fallen on the Mongolian plateau, and the most delicate powder has fallen to today's six provinces of Gansu, Shaanxi, Shanxi, Qinghai, Ningxia and Henan. After millions of years of transportation and accumulation, a loess plateau has finally formed, starting from the Great Wall in the north, reaching Qinling Mountain in the south, Sun Moon Mountain in the west and Taihang Mountain in the east.

Fourth, the deep and vast loess layer.

This is an unparalleled loess, with an area of 4 1 1,000 square kilometers, and the thickness of loess coverage is generally above 1 1,000 meters. The loess in Longdong, Shaanxi, Shanxi and other places is as deep as 100 to 200 meters, and the thickness in Lanzhou is more than 300 meters.

The Garden of Eden five or six thousand years ago.

Botanists have found that although the rainfall in the Loess Plateau is not as abundant as that in the south, there is less nutrient leaching, which is very suitable for the growth of poplar, birch, oak, Chinese pine, spruce, jujube and Vitex negundo. At that time, lush vegetation gave birth to a warm and rainy Garden of Eden. Today, Shanxi, Shaanxi, Gansu, Ningxia and other provinces have large areas of virgin forests. Henan Province, located in the Central Plains, is referred to as "Yu" for short. It can be seen that in the era of word-making in Cangjie, it was still a place where elephants haunted.

Six, the foundation of historical prosperity

Geologists have found that loess has excellent understanding and is suitable for digging caves to live in; Agronomists have found that various minerals in loess are rich in nutrition and high in natural fertility. The ancestors gradually dug caves in this yellow land to live in and made a living by planting grain. More than 5,000 years ago, Emperor Yan and his tribe flourished, and the footprints of Chinese ancestors traveled all over the yellow land. In the days that followed, the first dynasty of China flourished here, the 800-year founding week started here, and the Qin Empire, which swept Liuhe and unified the whole country, flourished here.

Seven, the enlightenment of ancient civilization

Charred animal fossils and antler fossils were found in Houdu human activity site in Ruicheng, Shanxi, more than 6.5438+0.6 million years ago, and many carbon deposits were found in Lantian human site in Shanxi, 6.5438+0.6 million years ago.

Since then, Lantian people, Dali people, Dingcun people and Hetao people have all thrived in the embrace of the Yellow River. Until 6000 years ago, matriarchal clan culture represented by Banpo civilization appeared on the yellow land.

Our ancestors hunted and gathered in such a green field and spent the golden childhood of Chinese civilization.

VIII. Historical account of achievements in transforming nature

It is indeed the first place to bathe in the light of civilization, and it must be the first place to be touched by the fire of civilization. According to ancient legends, Shennong once taught people to grow crops. What is intriguing is that Shennong is Emperor Yan, that is, Vulcan, and what he teaches is actually burning forests for farming.

Mencius recorded the "merits" of the three emperors and five emperors burning the forest: "When Yao was in power ... vegetation was flourishing, animals were breeding, crops were not growing, animals were threatening ... Yao was the only one who was worried, and he handled it well. Use fire well. " When the mountain burned down, the animals all ran away. "

In the Book of Songs, we heard the ancestors chanting when they cut down trees: "Kan Kan cut sandalwood, the river is dry, the river is clear, and the blue waves are rippling." "Logging jingles and birds sing."

Nine, the loess plateau vegetation suffered heavy losses for the first time.

When the first emperor unified the six countries, a large number of people entered Guanzhong, and the reclamation area increased greatly. At the same time, large-scale construction, the construction of the palace mausoleum, wantonly cut down the Guanzhong mountain forest. In the thirty-third year of the First Emperor (2 14 BC), Meng Tian defeated the Xiongnu and gained a large area of land in Hetao. Later, he settled in other places to defend the border and immigrated to the Ordos Plateau many times, with hundreds of thousands of people each time. The originally endless grassland has become a farming area.

Ten, the loess plateau forest suffered heavy losses for the second time.

During the Western Han Dynasty, the population of China surged to 60 million. Developing northwest immigrants has become the main means to solve the pressure of population expansion. During the period of Emperor Wu of the Han Dynasty alone, more than 700,000 people moved to the northwest frontier fortress. The Western Han Dynasty drove the Huns to the distant Mobei, and turned large areas of forests and pastoral areas into agricultural areas. The irrigation project of diverting water from the Yellow River developed in Hetao during the Western Han Dynasty was at the cost of great damage to the forests of Helan Mountain in Ningxia, Inner Mongolia and northern Shaanxi.

Eleven, the loess plateau forest was hit hard for the third time.

At the beginning of the founding of the Tang Dynasty, the economy recovered rapidly. Because the center of its economy, trade and foreign affairs is biased towards the northwest, the farmland reclamation in the northwest is very vivid. The forest and pastoral areas in the Loess Plateau have reclaimed large areas of farmland and cultivated hundreds of thousands of mu. There are 200-300 mu of cultivated land, which is extensively planted and the harvest is not good, causing extensive damage to vegetation.

Chang 'an, the central city of the Yellow Land in Tang Dynasty. During the prosperous Tang Dynasty, the national strength reached its peak, and the scale of the capital was of course unprecedented, consuming countless Woods. As far as Chang 'an is concerned, in the Tang Dynasty, in addition to logging in nearby mountainous areas such as Baoji, Meixian, Zhouzhi and Huxian, it also went as far away as Qishan and Longshan, and then went to Lanzhou (now Lanxian) and Shengzhou (now Ordos Plateau in Inner Mongolia) to purchase.

Twelve, the loess plateau forest suffered heavy losses for the fourth time.

Kaifeng, the capital of the Song Dynasty, had to go to Luliang Mountain for logging because the mountains in the north and south of the Yellow River near Luoyang had long been cut down. At that time, the forest area in the upper reaches of Weihe River was also robbed. According to historical records, just after the founding of the People's Republic of China in the Northern Song Dynasty, the Qin and the Dragon were heavily divided. Forests in Qinling, Ziwuling and Luoshan in Shaanxi, Helan and Pan Da in Ningxia, Zhao He and Longnan in Gansu have been destroyed one after another. In the Song Dynasty, officials and merchants collected more than 10,000 big trees from the Longshan Mountain between Shaanxi and Gansu every year, which made the good trees in Kaifeng city pile up at that time, and the wood collected and sold by folk merchants was countless.

Thirteen. The forest on the Loess Plateau was hit hard for the fifth time.

The Ming dynasty attached great importance to the northwest, paying attention to farming, raising the army and mobilizing the people with the army. At that time, "the fields are all over the world" and "the northwest is the most". When I was stationed near Yanmen and Pianguan Great Wall in the early Ming Dynasty, the mountains were steep and the trees were lush, "people couldn't ride in". By the middle of the Ming Dynasty, high officials and dignitaries, border guards and local residents in Beijing began to cut down trees. "Hundreds of households are in groups, and thousands of people are neighbors. They cannot be rushed, but they cannot be banned." More than one million trees are trafficked to Beijing every year alone.