Maowusu Desert

Maowusu Desert is one of the four sandy lands in China. It is located between Yulin area in Shaanxi Province and Ordos City in Inner Mongolia. Maowusu is Mongolian, which means "bad water". The place name originates from Maowusu village in haizetan Township, Jingbian County, Northern Shaanxi Province. In ancient times, it was rich in water and grass. Later, due to the climate and war, the vegetation here was destroyed. Since the Qing Dynasty, it has become a vast desert. But because Yulin people have been closing sand for decades, the greening here has achieved remarkable results. Now Yulin has become a famous city.

Maowusu Desert

This entry is compiled and applied by "popular science China" Science Encyclopedia

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The Maowusu Desert is located in the north of the Great Wall line of Yulin City in Shaanxi Province, so Yulin city is also known as camel City, which means the city of desert. The area of Maowusu Desert is about 42200 square kilometers. More precipitation (250 ∼ 400mm) is favorable for plant growth. It was originally a relatively developed area of animal husbandry, with a large area of fixed and semi fixed sand dunes.

Since 1959, great efforts have been made to build windbreak belts, divert water to pull sand, divert flood and silt the land, and carry out huge projects to transform the desert.

By the beginning of the 21st century, more than 6 million mu of sandy land has been controlled, and the sand has stopped and become green. 80% of the Mu Us desert has been controlled, and there is no longer any soil erosion. The annual sediment discharge of the Yellow River has been reduced by 400 million tons. Due to good rainfall, many sandy lands have now become woodlands, grasslands and fertile fields. In the hinterland of the desert, Yulin has built up 1.6 million mu of farmland, and Yulin, the "desert capital", has become a "desert oasis". On April 22, 2020, the forestry bureau of Shaanxi Province announced that the desertification land control rate in Yulin has reached 93.24%, which means that the Mu Us desert will "disappear" from the territory of Shaanxi.

brief introduction

The origin of the name

Mu Us Desert (or Maowusu Shamo) is also called Erdos desert. Maowusu, which means "bad water" in Mongolian, originated from Maowusu village, haizetan Township, Jingbian County, Northern Shaanxi. The continuous sand belt from mengjiashawo in Dingbian to gaojiagou in Jingbian is called xiaomaowusu sand belt, which was originally understood as Maowusu area.

Because the sand belt along the Great Wall in Northern Shaanxi and the sand in the south of Ordos (YIKEZHAO League) in Inner Mongolia are continuously distributed together, the sand in the southeast of Ordos Plateau and along the Great Wall in Northern Shaanxi are collectively referred to as "Mu Us Sand".

geographical position

Maowusu Desert is one of the four sandy lands in China. It is located between Yulin area of Shaanxi Province and Ordos City of Inner Mongolia Autonomous Region, covering an area of 42200 square kilometers.

It is located at 37 ° 27.5 ′ - 39 ° 22.5 ′ N and 107 ° 20 ′ - 111 ° 30 ′ E. It includes the south of Ordos in Inner Mongolia Autonomous Region, the north of Yulin in Shaanxi Province and the northeast of Yanchi County in Ningxia Hui Autonomous Region. The area of fixed and semi fixed sand dunes is large. The great wall passes through the southern edge of the desert from east to west.

Topography

The altitude of Maowusu sandy land is 1100-1300 meters, which is slightly higher in the northwest, reaching 1400-1500 meters, and about 1600 meters in some areas. The southeast Valley is as low as 950 meters.

Maowusu Sand Area is mainly located in the lacustrine alluvial plain depression between the Ordos Plateau and the Loess Plateau. The Liangdi outcrops in the periphery of the sand area and extends into the sand area are mainly Cretaceous red and gray sandstones. The rock strata are basically horizontal, and most of the top surface of the Liangdi is flat.

All kinds of Quaternary sediments are obviously Sandy. The loose sand layer is transported by wind to form movable quicksand. The plain high flat land (including the plain water diversion land and the high flat land beside the beam) is mainly distributed with the Holocene unified upper Pleistocene lacustrine alluvium.

Climatic characteristics

The average annual temperature is 6.0-8.5 ℃, the average temperature in January is - 9.5-12 ℃, the average temperature in July is 22-24 ℃, and the annual precipitation is 250-440mm, which is concentrated in July September, accounting for 60-75% of the annual precipitation, especially in August. The interannual variability of precipitation is large, the rainy year is 2-4 times of the less rainy year, drought and waterlogging often occur, and drought is more than waterlogging.

In summer, there are frequent rainstorms and hail disasters. The maximum daily precipitation can reach 100-200 mm. The annual precipitation in the eastern part of the sandy land is 400-440mm, which belongs to the dry grassland zone of light chestnut soil. Quicksand and Bala (semi fixed and fixed sand dunes) are widely distributed. The precipitation in the northwest part is 250-300mm, which belongs to the semi desert zone of brown calcareous soil. 　

Land type and utilization

Maowusu sandy area is located in the junction of several natural zones, and the vegetation and soil reflect the transitional characteristics. In addition to the semi desert zone of brown calcareous soil to the northwest, the semi desert zone of gray calcareous soil to the southwest to Yanchi, and the forest steppe zone of gray cinnamon soil in warm temperate zone of Loess Plateau to the southeast.

The types of land use in sandy area are complex, and different land use patterns are often staggered together. The staggered distribution of agricultural, forestry and animal husbandry land shows obvious regional differences from southeast to northwest. The natural conditions in southeast are superior, the man-made damage is serious, and the ratio of quicksand is significant; besides quicksand distribution in northwest, there are also patches of semi fixed and fixed sand distribution.

In the eastern and southern regions, the farmland is highly concentrated in the river valley terraces and beaches, while in the northwest, the farmland decreases and the grassland distribution increases. The existing land for agriculture, animal husbandry and forestry is not fully utilized and the management is extensive.

The area of quicksand in the whole region is 13800 square kilometers. After the founding of the people's Republic of China, the work of sand fixation, water diversion and sand pulling, development of irrigation, afforestation, soil improvement and desert transformation have achieved remarkable results. The southeast of Maowusu sandy area has changed through various transformation measures.

Origin and evolution history

Desert origin

Studying the causes of the Maowusu Desert has long been a relatively professional knowledge, because we know how it became like this, and then we know how to improve it. There are several theories about geological origin and historical origin, but it is generally accepted that most of the Maowusu Desert was once rich in water and grass in ancient times. In the 5th century, the southern Maowusu (now baichengzi in the north of Jingbian County) was the political and economic center of the Huns. At that time, grassland was vast and rivers were clear. According to textual research, in ancient times, this area had beautiful water and grass, pleasant scenery and was a good pasture. Later, due to unreasonable reclamation, climate change and war, the vegetation on the ground was lost, and sand was formed on the spot, forming the later desert (sand). The Maowusu Desert was gradually expanded in a period of one to two thousand years. From the Tang Dynasty, there was sand accumulation, until the Ming and Qing Dynasties, the vast desert was formed.

Evolution process

The researcher's point of view is that there was a small piece of primitive desert between e Qi, Etuokeqian Qi and Wushen Qi. According to the research, the most primitive desert in Maowusu Desert is just a small area in the west of modern sandy land.

However, because the shallow surface of the whole Ordos Plateau is composed of gravel materials formed during the geological period, once the turf is destroyed, it becomes a desert. Therefore, after excessive nomadism in history, the desert finally spreads around like an infectious psoriasis.

Maowusu area in the pre Qin and Qin and Han Dynasties once developed agriculture, and then it was a nomadic area until the early Tang Dynasty.

After unreasonable reclamation, the vegetation was destroyed and the quicksand continued to expand. According to a researcher in Shaanxi, the destruction of Maowusu forest and grassland originated from the overgrazing of the nine surnames of Zhaowu in the "Liuhu state" in the early Tang Dynasty. In the Song Dynasty, the desertification of Maowusu expanded to the southeast, and the speed was faster from the late Ming Dynasty to the early Qing Dynasty.

The Great Wall traversed Maowusu. In the middle and late Ming Dynasty, it was a national event to "strip sand" for the wall of the Great Wall. The huge cost of sand raking made civil and military officials scratching their ears. The consequence of not picking up the sand is "to take the horses in and out like walking on the ground; to plunder my belongings and prostitute my women".

By the middle of the 17th century, there was no need to pick up the sand, because the Ming Dynasty was dead. The Great Wall was no longer used in the Qing Dynasty.

By 1949, the moving sand dunes along the great wall were concentrated in Jingbian, Yulin and Shenmu, but most of them were fixed and semi fixed in the northwest.

In the whole process of Maowusu Desert formation, thousands of square kilometers of sandy land between Shenmu Yulin Wushenqi should be "xuansun" level. In fact, until the early Qing Dynasty, there were forests and grasslands here; to the present age, there are natural juniper forests and Pinus tabulaeformis trees in the northwest of Fugu County and yangshita township of Zhungeer banner, which are witnesses of the disappearance of lush forests in the eastern part of the border between Shaanxi and Inner Mongolia, and also the last defenders of the desert invasion to the south.

The story of "three migrations in Yulin" once spread here. Now Yulin is a famous city.

government

Governance achievements

Since 1959, great efforts have been made to build windbreak belts, divert water to pull sand, divert flood to silt up the land, and carry out huge projects to transform the desert.

There are two kinds of power of government and people in contemporary Maowusu governance. There are many cases of private spontaneous desertification control and enterprises' investment in desertification control; on the government side, Ningxia, Shaanxi and Inner Mongolia have their own plans, which are approved and guided by the three North Bureau of the Ministry of forestry of the people's Republic of China. From the last generation

Chinese PinYin : Mao Wu Su Sha Mo