Why did the ancient city of Loulan disappear?

Loulan was an oasis city-state in western China during the Han and Wei Dynasties, located at 98 22 ′ 22 ″ east longitude and 40 29 ′ 35 ″ north latitude. That is, Tarim Basin in Xinjiang, east of Taklimakan Desert and southwest of Lop Nur? In the desert of Qiang county. When was this city built? The exact age has not yet been determined. Most scholars believe that it was built in the Qin and Han Dynasties and disappeared in the middle of the 4th century, while others think it was lost in the 5th century. After a century of exploration, Chinese and foreign archaeologists and explorers initially found out that this ancient city covers an area of about 65,438+10,000 square meters, with a length of 300 meters from north to south and a width of 300 meters from east to west. There are streets, yamen, temples and houses in the city, which is the military, political, economic and cultural center on the Silk Road connecting the Han Dynasty and the Western Regions. Han Jindun stationed troops here to station wasteland and set up officers. Why did such an oasis city suddenly disappear into the vast desert in less than half a century? 1900, Swedish explorers discovered the Loulan site, which caused a sensation in the world. They were amazed at the sudden disappearance of this splendid civilization, which had been sleeping for 15 centuries and communicated cultural and economic exchanges between China and foreign countries, and attracted many archaeologists and humanities scholars to explore the reasons for the disappearance of the ancient city. A century has passed, and opinions vary. Generally speaking, there are views of Theory of Three Represents Theory: First, the "theory of natural environment change" was put forward for the first time; Main arguments: the retreat of icebergs leads to the decrease of river flow, desertification of land and abandonment of Loulan. Second, "the theory of political and economic center transfer"; Main argument: The Silk Road was diverted, Loulan lost its advantage and declined, and was finally abandoned. Third, "the theory that human activities destroy natural harmony"; Main argument: while creating a high degree of civilization, human beings are also creating desertification at an alarming rate. The disappearance of Loulan, like the tragedy of the disappearance of ancient civilizations in the world, abandoned the city because of the expansion of desertification. The third view was popular in the late 20th century. Media publications published articles regarding Loulan phenomenon as a typical example of human destruction of the environment and ancient civilization, and discussed that population growth, over-exploitation, vegetation destruction, drought, water shortage, desertification and human survival are the direct reasons for the rapid disappearance of ancient oasis cities. ?

Academic discussion is in line with the direction of advanced culture. As far as * * * is concerned, the imbalance and imbalance of human utilization of water resources will inevitably lead to floods or droughts. Overexploitation and deforestation of oasis ecological environment will inevitably lead to the intensification of drought, the expansion of desert and the disappearance of oasis. However, as Loulan's rapidly disappearing personality problem, we need to analyze specific problems and explore scientific conclusions that are in line with reality. Based on the frequent sandstorms in China in recent years and the new achievements of international natural disasters research, this paper puts forward a new theory that "the ancient city of Oasis Loulan was destroyed by sandstorms", which needs to be taught by experts and scholars and archaeological proof. In order to clarify this point, the following three issues will be discussed:

First, the general process of the rise and disappearance of the ancient city of Loulan; ?

Second, is the disappearance of Loulan gradual or abrupt?

Thirdly, it is proved that the rapid disappearance of Loulan is the basis of extremely special sudden climate-sandstorm. ?

( 1)?

The rise and death of Loulan ancient city can be roughly divided into four stages, namely, the initial stage, the rising stage, the heyday and the death stage. ?

Start time of the first phase: 1997 Six ancient tombs of Gugugou dating back to 3800 years were discovered in Loulan area. The funerary objects are extremely simple, only a bag of jute and a straw basket containing more than 10 wheat. The tomb owners are all men, wrapped in linen, wearing pointed felt hats with feathers on them, and there are no funerary objects and tools such as pottery and metal. Archaeologist Wang Binghua said: "Life is primitive, poor and inefficient." . ( 1)? 1980 In the spring, a well-preserved female corpse was unearthed at the iron gate at the tail of Peacock River, and no other funerary objects were found, indicating that time has advanced for about 500 years, and Loulan's social productivity and social civilization have not improved. 200 1 1 Archaeologists have rediscovered Xiaohekou cemetery, which has been restored for 60 years and has extremely rich connotations. This tomb spans from about 1600 to 4000 years ago. Both the tombs in Gugugou and the tombs in Xiaohekou reflect that the residents in Loulan area started around 4000 years ago and developed very slowly. ?

The second stage is the rising period: the earliest place name "Loulan" appeared in the fourth year of Emperor Wendi in the Western Han Dynasty (BC 176). Attila modu chanyu said in a letter to Wendi that the Xiongnu army "gathered Loulan, Wusun, Hu Jie and the next 26 countries ...". (2)? Although Loulan is a country here, it is not clear whether it is a big country or a small country, whether it is a "country of residence" or a "country of travel", and what is its military and political status. Half a century later, in the second year of Jianyuan (BC 139), Han made Zhang Qian go to the Western Regions, and in the third year of Yuanshuo (BC 126), he returned to Chang 'an. In his report to Emperor Wu, he said: "Loulan and Gushi have battlements and salt marshes." (3)? Loulan is an oasis city near the water. Although the soldiers are weak and vulnerable, their status is very important, which affects the development of the western regions by the dynasty. "Loulan and Gu are in power, and they are miserable." (4)? To develop the western region, we must first open the main passage to the western region-Loulan. In the third year of Liang Wudi's reign (BC 108), he "captured the king of Loulan, and then broke his aunt's teacher". Loulan was a small country at that time, between the Han Dynasty and Attila. By the fourth year of Zhao Yuanfeng (77 BC), the forces of the Han Dynasty had taken control of Loulan and became a "Shanshan country". (5)? At the request of King Tu Jian of Shanshan, he sent a captain to guard the volunteer training not far from the city, and sent troops to settle the field to protect the Shanshan regime. Loulan has entered a period of rising from wasteland, but its development is not fast. In Yuan Di (48-33 BC), Loulan was still a small country among dozens of countries in the Western Region: hukou 1.570, population 1.4 1.000, and 29 1.2 people won the battle. Official position is to assist the country and food. (6)? Among the seven countries in front of Kunlun Mountain, the registered permanent residence and population rank fourth, and the number of soldiers won ranks third. It may not be outrageous to set the rise time of Loulan in the middle of the first century BC. ?

The third stage reached its peak: with the communication between the western regions and Central Asia in the Eastern Han Dynasty and the Wei and Jin Dynasties, the Silk Road was unimpeded, and the cultural and trade exchanges between China and the West were frequent, and the ancient city of Loulan gradually reached its peak. 199965438+In February, a colorful coffin was found in a Wei-Jin tomb 48km away from Loulan. Colorful coffins reflect the cultural characteristics of the East and the West. It is painted with "Suzaku" and "Xuanwu" representing the sun and the moon in the east, and covered with silk velvet blanket representing the Roman style of western culture. The deceased was an elderly man wearing a cotton silk robe. Colored coffins were also found in Xiaohe ancient tombs, with yellow, orange and green patterns, painted with copper coins and flowers, and divided by diagonal lines. The Han bamboo slips unearthed from Loulan site, the missing Luwen bamboo slips, architectural remains, and documents such as Hanshu, Jin Shu and Zitongzhi Bamboo Slips all prove that the culture and economy of the ancient city gradually reached its peak from the middle of A.D. 1 century to the 1930s, with a time span of more than 300 years. ? The fourth stage of disappearance: there are only three bases to decipher the exact time of Loulan's disappearance: ① An ancient short film written by Lu Wen found in Loulan site is for sale: The book reads "His Majesty Jia Wasemona, the son of my king, was in office for eleven years in July, and he was far away from the country". (7)? The reign of King Vasomona was 32 1-334. According to this, 1 1 should be in 332, that is, the seventh year of the Eastern Jin Dynasty. From the middle of the second century to the second half of the fourth century, Quluwen was popular in Khotan and Shanshan areas, obviously influenced by Loulan and Yilan languages, and now it is occasionally found in ancient Buddhist scriptures. (2) The age of Lu Wenjian bamboo slips and Han bamboo slips found in Loulan site only ended in 1930s, and no remains were found after the middle of 4th century. (3) In 399 AD, that is, in the third year of Emperor Longan of the Eastern Jin Dynasty, the eminent monk Faxian went to India to seek dharma, taking Loulan as the route. Here, it is already "there is no bird in the sky, there is no beast in the sky, I look everywhere, and if I don't get what I want, I just take the dead eye as the standard ear." (8)? The above three points can be considered that Loulan disappeared between 332 and 339 AD, with a short time span and the characteristics of mutation.

(2)?

The disappearance of the ancient city of Loulan is a mutation, not a gradual change. In the early years of the Western Han Dynasty, when Zhang Qian went to the Western Regions, he saw the Loulan economy of "few fields, sending fields to countries near the valley" and "people chasing water plants with grazing". (9)? At that time, the agricultural economy was very underdeveloped and food depended on neighboring countries. In 77 BC, the garrison settled the field and began to plant drought-tolerant crops such as millet, barley and wheat. After more than two centuries of development and operation to the early Jin Dynasty, it was already "fertile land, postal services were placed in a crucial place, postal savings emerged one after another, and merchants sold customers' money every day." ( 10)? Although these records were written by the ancients, they may be suspected of beautification. Modern people's description of the face of the ancient city through textual research is: lush forests, rich aquatic plants, seven miles of 100 thousand homes, camel bells, an endless stream of merchants, a scene of prosperity. ( 1 1)? Loulan agriculture is prosperous and the traffic is busy. Politicians have seen the importance of protecting ecology and forests. A "Forest Protection Law" was found in the ruins of Loulan, stipulating that if a tree is cut off by roots while alive, a horse will be fined; A cow will be fined if the branches are cut off. ( 12)? The above points show three points: ① Contemporary studies show that there are more than 10,000 troops stationed in Loulan, with a maximum of 15,000. ( 13)? Based on this, it is impossible to calculate that the cultivated area is 6.5438+0.5 million square kilometers, which is one third larger than the total area of Lop Nur, and the Lop Nur area has not been completely cultivated. ② The overall climate of Loulan has not developed in a direction that is seriously unfavorable to human survival and production, or there are unfavorable natural factors that restrict economic prosperity. (3) The rulers of Loulan country, including the envoys sent by Han and Jin dynasties, all noticed the role of trees in protecting ecology and consciously protected trees, which reflected from one aspect that Loulan area did not cut down all vegetation because of over-exploitation of agriculture. ?

As far as the general theory of the causes of desertification expansion is concerned, if it is caused by human activities, over-exploitation of agriculture, serious destruction of vegetation, soil erosion, etc., there will inevitably be a relatively long gradual process, or it will be staged. Xiaohekou cemetery spans over 2000 years, including mummies dating back 4000 years and colored coffins in Wei and Jin Dynasties, indicating that the surrounding desert is basically stable. At least, when the last group of the dead entered the cemetery, the desert didn't change much. If the desert advances to the cemetery, the noble members of Loulan Kingdom will never be buried here, nor will they paint huge wooden columns, build exquisite wooden fences and enjoy the hall conspicuously. If it is caused by an extremely unusual natural disaster, the situation will be completely different, and all civilizations may be destroyed in a short time. In the history of the world, paleontology experienced five extinctions, each of which was caused by a sudden natural disaster. ?

In the 1930s, the ancient city of Loulan did not reflect the signs that people could not survive because of over-cultivation and ecological deterioration. They abandoned the city and moved to other places in batches. On the contrary, there are many unearthed remains and historical documents in this period, which record the struggle of minority nationalities in the Central Plains and the Western Regions to control Loulan. What's the point of arguing if Enemy at the Gates's desert enemies are about to be abandoned? According to Yu Taishan's A General History of the Western Regions, after about 270 AD, the Jin forces seemed to have withdrawn from Loulan, and Shanshan Wang An (reigned in the 1950s and 1990s) and important officials visited Loulan, and set up states, counties, 100 households and 10 households in Loulan. An Jiagui also accepted the positions of "Daizhong" and "Big Dewey" awarded by the Jin Dynasty. ?

Loulan site found that Li Bo, the long history of the Western Regions in the third year of Xianhe in the Western Jin Dynasty (AD 328), sent a letter to the king of Yanqi on May 7 in order to fight against the United front between Gaochang and Yanqi, saying in the letter that "cordial greetings show great concern and respect to show his invincible meaning". ( 14)? At this time, it was slightly earlier than the eleventh year of Vassemona, king of Loulan. The crux of Loulan's disappearance lies in "suddenness", and what we need to find out is the reason for this "suddenness". ?

Only half a century later, 90 years later, Fa Xian, a monk, took the route of Loulan to India, and the Loulan he saw was desolate. However, the vast Loulan area, including Shanshan and other countries, has not been swallowed up by the desert and the Silk Road has not been completely closed. In the 8th century, Cen Can, a military poet in the Tang Dynasty, left a poem about Loulan: "The official car has arrived at Xiloulan, and the camp is near the Moon Cave." Pu Shuang tied his ponytail, and the snow rustled in the green hills. Contemporary archaeology also proves that Lop Nur did not dry up due to desert erosion in the 4th century, but disappeared in the gradual change of 10 for more than a century. 193 1 year, it is measured that Lop Nur is170km long from north to south and 40-90km wide from east to west, and it is still rich in water and plants. 1942 declaration map describes the area of lop Nur as 3006 square kilometers. ( 15)? The disappearance of Lop Nur and Loulan ancient city is the result of two different reasons and cannot be simplified. We can use a theory to explain the two different phenomena of "mutation" and "gradual change". ?

(3)?

We believe that the direct cause of Loulan's disappearance is extremely frequent sandstorms. The drought ecology, sandstorm and high temperature and cold in Loulan are all natural phenomena formed by crustal movement in essence, and there is no trace of human activities, which did not start from the agricultural development in this area in Han Dynasty. Therefore, the rapid disappearance of Loulan is essentially attributed to nature, but it never denies the unscientific development activities of human beings. On March 2 1 2002, Academician Ye Duzheng of Chinese Academy of Sciences told the media: "We should re-recognize the sandstorm". Sandstorm is essentially a natural phenomenon. Although humans can do something to reduce its harm, they can't completely eradicate it. " On April 24th, 2002, the media reported that the Han bamboo slips of the Western Han Dynasty in Dunhuang area were first discovered in China. There are also records of sandstorm climate in China's history books: The Book of Songs has a saying that "the wind will eventually blow the haze", and The Biography of Langqi Pages in the Later Han Dynasty has a saying that "the weather is wrong, and the haze will cover the sun". "Smog" and "Cihai" are interpreted as "a weather phenomenon of atmospheric turbidity". That is, a sandstorm with flying dust. In ancient books, sandstorms are written as "yellow fog", "flying sand and stones", "black gas" and "black fog", which is considered as an ominous sign. Tian Wenzhi in the Book of Jin said: "If it rains in the four corners of heaven and earth, it will cover the earth with rain for ten days and five days, or for a while, so it is said that heaven and earth are hazy and good." The Book of Jin records: since 249 AD, that is, the first year of Cao Fangjiaping, king of Wei and Qi in the Three Kingdoms; By AD 402, the first year of Anyuanxing in the Eastern Jin Dynasty, 153 recorded 15 severe sandstorms, including twice a year. The record is as follows:

In the first year of Jiaping, Qi Weiwang (AD 249), there was a strong wind in the northwest, and houses were demolished, covering the sky. ?

In November of the first year of Sun Xiu's Yong 'an (AD 258), the Sino-Japanese War broke out, and it was foggy for days. /kloc-in October/February, there was a big sandstorm at night in Dingmao. ?

In the Western Jin Dynasty, Emperor Huaidi Yongjia lived for five years (AD 3 1 1), and the atmosphere was gloomy. ?

In the second year of Emperor Yan's founding in the Western Jin Dynasty (AD 3 15), the first month was dark and foggy, and people were like ink for five days a night. ?

In August of the fourth year of Daxing in the Eastern Jin Dynasty (AD 32 1), fog covered the sun. ?

In October of the first year of Yongchang in the Eastern Jin Dynasty (AD 322), the capital was foggy, the sky was covered with black gas, and the sun and the moon were dull. ?

In the first year of Taining in East Jin Mingdi (A.D. 323), the last month passed and there were four yellow fogs. It's yellow fog again in February. ?

In March of the seventh year of Yonghe in the Eastern Jin Dynasty (AD 35 1 year), there was a strong wind and trees were uprooted in Liangzhou, with dust flying and yellow fog. ? In the third year of Kangning, Emperor Xiaowu of the Eastern Jin Dynasty (AD 376), in March, a storm broke out, flying sand and stones.

In the fourth year of Taiyuan (AD 379), Emperor Xiaowu of the Eastern Jin Dynasty, there was a storm in August. ?

In the eighth year of Taiyuan (AD 383), Emperor Xiaowu of the Eastern Jin Dynasty, there were four yellow fogs. ?

In the first year of Yuan Xing in the Eastern Jin Dynasty (AD 402), it was applied in October, and the yellow fog was cloudy without rain. ?

The above incomplete statistics: 3 times in the 3rd century; 9 times in the 4th century, including 3 1 1-3 15 2 times, 321-323 times and 351-383 times; 5th century AD 1 time; Total 13 years 15 times. It is very clear that the 4th century belongs to the "sandstorm-prone period in a hundred years", and there are two frequent peaks in a century. The first peak appeared in the 1920s and 1930s, and the second peak appeared in the 1950s and 1980s. This is completely consistent with the written record that "people are far from the border" and "there are no birds and no animals under the world". Therefore, it is believed that the direct cause of the destruction of the ancient city of Loulan Oasis is the severe sandstorms that occurred many times in the 4th century, and the disasters were caused by the deserts of Mongolia and western China. We might as well use the sandstorm weather in China in 2000, 200 1 year and 2002 as historical evidence.

In 1950s and 1960s, the frequency of sandstorms in China showed a decreasing trend, but reversed in 1990s, with an increase in 2 1 century, and more frequent in 200 1 and1-May, with the scale and frequency unprecedented since 1990s. * * * Sandstorm and sand blowing 18. Experts said, "In recent years, the sharp increase of severe sandstorms in China is due to the peak of El Ni? o events". Put forward the warning that "China has entered the sandstorm-prone period with once-in-a-century return period". On March 20th, 2002, Xinjiang, Gansu, Beijing and Tianjin reached 18 provinces and cities south of the Yangtze River, and the biggest sandstorm weather occurred in 10 years. Visibility is generally less than 500 meters, and street lamps in some cities turn on automatically. There is a particularly strong sandstorm in Longdong-black storm, which is invisible, and the visibility of Huichang County is invisible. In recent years, due to the dusty weather, sand dunes in China have moved to villages, towns and even counties. ?

The content discussed in this paper is not the cause of desertification and its expansion, but the direct reason why Loulan Oasis disappeared rapidly in less than half a century. It helps to understand natural disasters and respect the laws of nature. ?

In March 2002, China Radio International reported that Bao Kuba, director of the Russian Far East Coastal Marine Culture Center, said: "The extremely serious sandstorm weather in the coastal areas is unprecedented in the Russian Far East for more than 100 years." Compared with western China, the rainfall and evaporation in Russian Far East are quite different, and sandstorms have also appeared. Liu Jiyuan, a scientist in China, said: "The sandstorm of such intensity and scale on March 20th, 2002 was the result of global change on a scale of one million years". Therefore, to explore the reasons for the rapid disappearance of Loulan Oasis, we should not stop at summing up the "mistakes" of our ancestors in "excessively" developing agriculture, but broaden our horizons. ?

Human society is always advancing and developing. It is impossible to stay in the virgin forest forever, hunting to satisfy hunger and not eating food. Developing agriculture is an eternal theme and will develop in the future. The problem is that the development plan is not comprehensive and practical, which violates the laws of nature and sacrifices long-term interests. We hope to actively strengthen the research on the prediction, prevention and reduction of natural disasters.