Rising waters: New geoarchaeological evidence of inundation and early agriculture from former settlement sites on the southern Yangtze Delta, China

New pollen, phytolith, charcoal and diatom data from ¹⁴C AMS-dated sediments from three clusters of former occupation sites on the southern Yangtze Delta - Liangzhu, Majiabang and Chuodun - reveal that hydrological conditions were a key factor influencing early food production on the southern Yangtze Delta. At least two episodes of inundation are recognized, the first occurring at c. 7200-5700 cal. yr BP and a second from c. 4700 cal. yr BP. The first involved increasing salinity of surface waters, likely associated with marine intrusion linked to post-glacial sea-level change (meltwater pulse (MWP) 2). The second appears to have been freshwater in nature and driven at least in part by extreme meteorological events of high levels of precipitation in combination with impeded drainage. These two episodes had profound impacts on Neolithic settlement and farming. Further hydrological changes, presumably linked to changes in sedimentary regime, geomorphology and drainage of the Taihu depression, recorded at the Chuodun site after c. 3000 cal. yr BP, appear to have had a major effect on technologically relatively advanced food production systems. While environmental pressures appear to have played an important role in shaping human activities and settlement on the southern Yangtze Delta, people responded by adopting strategies that included an increased reliance on food production, migration to more clement locations and implementation of new technologies, which possibly included the construction of flood defence works.