Precise chronology of hydrological changes around 4.2kyr in central China to assess the impact of flooding on Neolithic societies

A lack of quantitative rainfall reconstruction has hindered understanding of the role of hydrological disturbances at ∼4.2 kyr BP in the collapse of the Shijiahe culture, an advanced Neolithic culture in the Middle Yangtze Valley (MYV). We provide a quantitative paleo-hydrology reconstruction for the period 4.6-3.5 kyr BP using calcium-isotopes, trace-elements and δ13C, from an annually-laminated stalagmite from the MYV. Our reconstructed-rainfall shows three drier-intervals with rainfall <700 mm/yr (4.36-4.33 kyr BP, 4.23-4.10 kyr BP, 3.57-3.55 kyr BP), and two wetter-intervals with rainfall >1000 mm/yr (3.95-3.84 kyr BP, 3.70-3.59 kyr BP), with suggestions of tripole/dipole rainfall patterns. Combined with archaeological and paleo-flood evidence, this data suggests that the Shijiahe culture underwent transformation during drier periods, but abandoned the region when rainfall was >1000 mm/yr. This robust, multi-proxy record demonstrates that water-excess can be as problematic as water-shortage even for advanced civilizations, and contributes to understanding hydrological-perturbations at ∼4.2 kyr BP.