@article{oai:ir.soken.ac.jp:00003941,
 author = {那須, 浩郎 and YASUDA, Yoshinori and FUJIKI, Toshiyuki and NASU, Hiroo and et, al.},
 journal = {Quaternary International, Quaternary International},
 month = {},
 note = {Fortified settlements had emerged as early as 6400-6100 cal yr BP in the middle reaches of the Yangtze River during the early Daxi culture, particularly at the Chengtoushan site in Hunan Province, China. There were four major stages for the development of the Yangtze River civilization in the middle reaches of the Yangtze at ca. 6400-6100 cal yr BP (beginning of early Daxi culture); ca. 5800 cal yr BP (beginning of middle Daxi culture); ca. 5300 cal yr BP (beginning of Qujialing culture) and ca. 4500 cal yr BP (beginning of Shijiahe culture). These periods correspond to times of climate deterioration, especially of weakened summer monsoon. The decreased rainfall in summertime resulting from the weakened summer monsoon would have necessitated a system for securing water supply by irrigation, and this, in turn, may have lead to the rise and development of urban settlements and monarchs to govern the irrigation and new social systems. The Yangtze River civilization began to decline at 4200-4000 cal yr BP and the great settlements were abandoned. This event was also considered to be the consequence of a severe climate deterioration that swept through Eurasia ca. 4200-4000 cal yr BP.},
 pages = {149--158},
 title = {Environmental archaeology at the Chengtoushan site, Hunan Province, China, and implications for environmental change and the rise and fall of the Yangtze River civilization},
 volume = {123-125},
 year = {2004}
}