若尔盖盆地古湖泊消亡-黄河贯通-黄河源现代水系形成，是青藏高原东部环境变化的转折点。关于这个标志性事件的发生年代问题，众说纷纭，尚无定论。本项目发挥我们在黄河流域古洪水研究的优势，在若尔盖盆地进行黄河古洪水沉积学、年代学和水文学研究。以河岸天然剖面为主、关键地段浅层钻孔为辅，排除各种复杂地表过程影响，准确鉴别黄河古洪水沉积层。在若尔盖盆地内建立完整的黄河古洪水事件序列。以最初的黄河古洪水沉积层与下伏古湖相沉积层之间的不整合面为标志，确认最早发生的黄河古洪水事件，获得古湖泊消亡与黄河贯通若尔盖盆地的直接证据。采用AMS-14C和OSL测年技术，准确界定这个重要事件的发生年代。结合黄河源河流地貌与气候水文演变过程，深入分析论证，揭示若尔盖盆地古湖泊消亡-黄河贯通-黄河源区现代水系形成机制。该研究对于深刻理解黄河水系形成发展，完善青藏高原环境演变理论具有重要的科学意义。

The lake environment in the Zoige Basin persisted for a long time. It represents a turning point of environmental change over the eastern Tibetan Plateau when the basin was dissected, the lake was disappeared and the Yellow River course was formed. The ages of these important events are still questions, disputable and unresolved. On the basis of our knowledge accumulation of the palaeoflood deposits, chronology and hydrology in the Yellow River drainage basin, We will carry out investigations on palaeoflood deposits, chronology and hydrology of the Yellow River within the Zoige Basin. By accurate identification of the palaeoflood deposits and eliminating the influences of many other surface processes, a complete sequence of the Yellow River palaeoflood events will be established along the Yellow River banks, and in the auxiliary shallow-drilling sediment cores. Based on the unconformity between the earliest palaeoflood deposit and the lake deposit, identifying the earliest Yellow River palaeoflood event, the direct evidence of Yellow River dissecting and flowing across the Zoige Basin will be obtained. The age of these remarkable events will be resolved by using AMS-14C and OSL dating methods. In combination with the environmental change, especially the evolution of geomorphology and hydro-climatology, the mechanisms of the dissection and the formation of the Yellow River course, and the disappearance of the palaeo-lake will be revealed in-depth. These results are of great significance in understanding the formation of the Yellow River course, completing the theory of environmental evolution over the Tibetan Plateau.