全新世以来黄河冲积扇扇顶区发育过程研究

Development process of alluvial fan is an important part of Geomorphology. However, the development process of the Yellow River Alluvial Fan is poorly understood. The Yellow River Alluvial Fan is the largest alluvial fan that built up by heavy sediment-laden rivers. It is an important geomorphic component in the lower reaches of the Yellow River Plain. This project take the Yellow River Fan apex as the study area. Based on systematic data collection and field investigation, several typical sections are selected. By geological drilling, geophysical prospecting, historical geography analyzing, geological dating and sedimentary facies analyzing, it firstly extracts high resolution of environmental information for the selected sections; and then by using GIS technique and digital elevation model, it discusses the geomorphic evolution of the alluvial fan apex and the drainage system evolution; finally, it explores the formation mechanisms of the Yellow River Fan and recover its development process. This project aims to help understand the human-land responses in the lower reaches of the Yellow River Plain, to help understand the role of palae-geographical environment for the Chinese civilization origination, and provides theoretical base to formulate strategy of environmental protection for the Yellow River Fan.

黄河冲积扇发育过程是地貌研究重要内容，但目前关于黄河冲积扇的研究程度很低。黄河冲积扇我国多沙河流中面积最大的冲积扇，是黄河下游平原重要的组成地貌类型之一。本项目以黄河冲积扇扇顶区为研究区，在系统资料收集和野外调查的基础上，采用地质钻探与物探、历史地理、年代测定、沉积相分析等方法，对研究区典型剖面提取高分辨率的环境信息，结合地理信息系统、数字高程模型等技术，开展黄河冲积扇扇顶区地貌演化特征与水系演变研究，探讨其形成机制，进而恢复黄河冲积扇扇顶区的发育过程。以期为全面理解黄河下游地区人地之间的响应关系，弄清华夏文明产生的古地理环境背景，并为制定未来黄河下游冲积扇环境保护战略提重要供理论依据。

黄河冲积扇发育过过程是地貌研究的重要内容。本研究以黄河冲积扇扇顶区为研究区，采用地质钻探与物探、历史地理、年代测定、沉积相分析等方法，对扇顶的荥阳——广武地区开展了地貌、气候环境的演化研究。研究发现：大约距今1~3万年古黄河南支从广武山西部的豁口处进入，流经荥阳槽状洼地内；研究区自全新世以来发生了4次的气候变化，其中9820~8250aBP 和6820~4470aBP时期，环境相对来说较其他两期温湿。晚更新世晚期郑州南发育了较多湖沼相地层，郑州西部中全新世早期的湖沼较为集中，郑州东部中全新世晚期湖泊发育较好。郑州地区先民们聚落的选址位置与湖泊消亡变迁十分微妙。全新世以来，裴李岗的聚落只能居住在老湖积高地上，到了仰韶时代，遗址开始向湖沼边岸地带扩散，从龙山时期到商代，随着西部湖泊的萎缩消亡而向东发育，人类逐渐向低处转移，直至占据湖积平原，聚落的分布密度和范围逐渐从郑州西部扩迁到东部，尤以商代的遗址分布特征最为明显。