Hydrological changes and its impacts on prehistoric human welfare in the western Tibetan Plateau since the last deglaciation

In recent decades, the rapidly changing climate environment in the Tibetan Plateau (TP) poses significant challenges to human survival and future sustainable development. The suitability and stability of the climate in the TP undoubtedly affected the living conditions and welfare of prehistoric humans. However, few studies have attempted to link climate stability and the survival of ancient humans, especially considering their lesser adaptability in responding to rapid environmental changes. The Xiada Co is a Neolithic period archaeological site in the western TP. In this study, we reconstructed the hydrological changes in the basin over the past 15,000 years using X-ray fluorescence (XRF) elemental analysis on the Xiada Co cores. The XRF results revealed three main paleoenvironmental units during the entire study interval. The late Pleistocene prior to ~10,000 cal year BP was characterized by more rapidly fluctuating hydrologic conditions. The early and middle Holocene (~10,000–4000 cal year BP) by stable hydrologic conditions, and the late Holocene to present by a return to more variable conditions. Using the calculation method of Square Chord Distance (SCD), a quantitative dissimilarity comparison was made regarding the climate variations in the western TP for 15 time periods. The results showed that the climate and hydrology were relatively stable during the period of occupation of the region (8500–7500 years BP), which provided a stable and suitable living environment for the hunter-gatherers at the site. This study illustrates how the paleoenvironment influenced the survival of hunter-gatherers in the extremely harsh western TP.