中文摘要：

通过深入的考察，在渭河宝鸡峡河段发现典型的全新世古洪水滞流沉积地层剖面，并进行了古洪水沉积学和水文学研究。对于采集的序列样品，进行粒度成分、磁化率、烧失量、CaCO3含量等分析，从沉积学角度证明了剖面上覆盖在古土壤S0顶部的沉积物为典型的古洪水滞流沉积层。根据其地层结构及其与流域内其他剖面的对比，结合其所含古文化层考古学年代和OSL断代数据等，确定渭河上游在3200～3000aB．P．发生了3次特大洪水事件。利用古水文学原理恢复其水位，并且利用水位一流量关系模型，计算出古洪水洪峰流量为22560～25960m^3／s。这个结果大大延长了洪水水文数据序列，从而能够建立渭河万年尺度洪水流量一频率关系，对于防洪减灾、水能源和水资源开发具有重要的应用价值。该成果揭示出万年尺度大暴雨洪水与气候变化的关系，丰富了全球变化的区域响应理论。

英文摘要：

Palaeo-hydrology is a newly developed field in the last twenty years. The Weihe River is a major tributary in the middle reach of the Yellow River, which is well-known in the world because of its great hydrological variation, heavy sediment load and flood disasters in history. This paper did a palaeo-hydrological investigation in the Baojixia Gorges of the upper reach of the Weihe River. Except routine field work,the methods used are mainly to analyze grain size,magnetic susceptibility, CaCO3 content and luminescence dating（OSL）for samples collected from the WH-GCZ profile. There were three extreme flood events to be recognized in this profile. They occurred in 3200 - 3000aB. P. of Holocene. By calculating on the basis of a water level-discharge model, the peak discharges of these three floods were between 22560m^3/s and 25960m^3/s. These results will provide references for establishing a 10000-year scale peak flood discharge-flood frequency relationship of the Weihe River.