【摘要】 利用三角洲平原河网水系丰富的历史遗存,重建过去人类水利活动面貌与水文环境变迁,有利于揭示人类社会对自然环境演变的响应或改造,是长江三角洲人地关系研究的重要内容之一。本文利用上海市志丹苑元代水闸遗址区所获钻孔进行全新世古环境演变过程分析,并基于254个工程地质钻孔资料恢复了遗址附近约25 km2的全新世晚期水系图,以揭示水闸遗址所在河道及周边水网特征。研究结果显示:气候海平面控制下的三角洲进积是志丹苑水闸废弃的根本原因。志丹苑水闸遗址所在古河道是潮滩地貌基础上形成的三角洲平原感潮河流,属古吴淞江支流;水闸所在位置河床明显束窄,且上、下游存在显著坡降,推测水闸下游有过人工疏浚。古水系图还显示了长江三角洲平原典型的"横塘纵浦"水网格局,其中横塘深度普遍大于纵浦,这种特征与其各自的成因密切相关,即横塘多源自潮沟、纵浦则是滩涂淤涨速度快慢更替形成的微地貌。更多还原

【Abstract】 The ancient water conservancy project is useful as it reveals the societal response to the evolution of the hydrological environment in the delta plain, which is important for the study of the human-nature relationship. In this study,we used a sediment core obtained from the historical site to investigate the impact of the Holocene environmental change on the site. We also collected data from 254 engineering geological cores to reconstruct the palaeo-waterway system in an area of ～25 km2 around the Zhidanyuan sluice. The results indicated that the abandonment of the Zhidanyuan sluice was induced by delta progradation in response to the sea level rise. The palaeo-channel on which the Zhidanyuan sluice was built developed from a tidal flat environment to a tidal channel. The river is a tributary to the Palaeo-Wusong River. The riverbed at the sluice was characterized by a narrow channel and a steep gradient to the downstream of the sluice, which might suggest that artificial dredging accompanied the water conservancy project. The reconstructed local waterway system demonstrated a typical network pattern, i.e., rivers ran transverse and longitudinal to the palaeo-shoreline in the Changjiang delta plain. The depth of the transverse rivers was generally greater than that of the longitudinal rivers, which we attribute to their origin. The former originated from tidal creeks, while the latter were formed due to the change in the rate of shoreline advance.更多还原