Why did the ancient country of Loulan disappear?

Sima Qian recorded in his "Historical Records": "Loulan, Gushi, the city has a wall, near the salt flats." It can be seen that during the period of Emperor Wu of the Han Dynasty, people have been to Loulan and seen the ancient city of Loulan. In the 4th century BC, the ancient country of Loulan suddenly disappeared in the long river of history, and there were no more words about Loulan in the history books. Then, why did the ancient country of Loulan suddenly disappear? Where the hell did Loulan go?

It was not until 1895 that the Swedish explorer Harding became the first person to break into Lop Nur in the past thousand years, but his exploration failed due to insufficient preparation.

1899, He Ding never gave up and led the team to Lop Nur Desert again. Walking in the vast desert, they suddenly met with a sandstorm. They squinted into the wind, but got lost. When the storm stopped, the scene in front of him stunned Harding and his team:

The stone base of an ancient city is half buried in the sand, and the broken giant wooden strips are inserted in it in disorder, exposing the sand from time to time? What happened to your milk? What happened? The tomb is shallow? /p & gt；

He Ding was very surprised to see this scene. This great discovery is the greatest reward for an explorer. What is the capital of this kingdom on the desert oasis?

The following year, He Ding led a team to return to the mysterious ancient city of Lop Nur, and unearthed a large number of wooden slips and pieces of paper in Wei and Jin Dynasties, ancient coins in Han and Tang Dynasties and many sculptures. On the sculpture, He Ding saw the word "Kroraina", thus confirming that this city is an ancient country of Loulan that has disappeared for thousands of years.

Later, the Xinjiang archaeological team conducted a comprehensive archaeological excavation of the ancient country of Loulan and found a "female corpse of Loulan" that did not rot for thousands of years. This female corpse has a claw face, a high nose, big eyes, long eyes and thick brown hair. These characteristics conform to the appearance of Europeans. Because of the dry weather in the desert, this female corpse of Loulan will not rot for thousands of years. According to the determination of carbon 14, this female corpse is more than 4000 years old.

So, are Loulan people local aborigines or European "immigrants"? This problem has been puzzling archaeologists. Loulan ancient ruins are located in the northwest of Lop Nur. The ancient city existed from the early Western Han Dynasty to the Wei and Jin Dynasties, and was later abandoned.

For the reason why the ancient city of Loulan was abandoned, many people think that the natural environment is deteriorating, the water source is getting less and less, and the food produced can't meet the needs of the growing population, so Loulan people have to move to a more suitable place for survival. So, where did Loulan people migrate? Archaeologists need to find more evidence.