Environmental changes of Hemudu site

Judging from the accumulation of the site strata, there were at least two continuous floods during the Hemudu culture period. The first time happened around 6000 years, and the second time happened around 5000 years. The second flood not only flooded Hemudu people's homes, but also washed out a river with a width of 100 meters between the site and Siming Mountain in the south, changing Yaojiang in the north to the east. After the diversion of Yaojiang River, it not only set a serious natural obstacle for the ancestors to go hunting and gathering in the mountains, but more seriously, the salt tide flooded in twice a day, and the land became salinized, which made the rice they depended on decrease year by year, so they had to give up this land that had lived for nearly 2,000 years.

From the perspective of cultural relics, within 2800 square meters of the bottom of the fourth cultural layer of Hemudu site, a large number of wooden stakes and criss-crossing wooden components are exposed. Among them, the larger long logs (top beam or ground beam, keel) lie neatly on the ground on the west side of the pile. From this point of view, the flood at that time easily washed away the thatch and branches on the roof, and most of the long logs that fell into the water floated down, only a few of them were blocked by wooden stakes and preserved.

Geological data show that the silt layer of the third and second cultural layers of Hemudu site gradually thickens from west to east, which is the remains of a catastrophic flood.

Hemudu culture is an important Neolithic culture along the southeast coast of China, represented by Hemudu site in Zhejiang. Hemudu Site was discovered in 1973, located in Hemudu Town, Yuyao City, Zhejiang Province, with a total area of about 40,000 square meters and a cumulative thickness of about 4 meters, with four cultural layers overlapping, of which the fourth cultural layer is about 7000 years ago. The fourth and third floors are the period of its formation and development, and the second and first floors are the period of decline and large-scale migration.

Hemudu culture, known as the light of ancient civilization in China, lasted for about 2000 years, but suddenly migrated outward around 5000 years. There are two viewpoints in academic circles: transgression theory and flood theory.