黄河下游2300年以来沉积速率的变化

Sedimentation Rate Change in the Lower Yellow River in the Past 2300 Years

采用沉积学方法提取沉积速率的记录,利用历史文献研究的方法提取气候与人类活动变化的信息,对黄河下游2300年以来的沉积速率的变化及其与气候、植被及人类活动的关系进行了研究,揭示黄河流域地貌系统对气候变化及人类活动所导致的土地覆被、土地利用方式变化的响应过程。研究表明,黄河流域地貌系统中的下游沉积带对于中游侵蚀带的响应是灵敏的,流域植被和土地利用方式的变化,是导致下游河道沉积加速的主导因素;这种变化主要取决于人类活动,同时与气候的变化也有一定关系。在沉积加速的过程中,公元7世纪至10世纪以及18世纪中叶以来,表现为两个突变时期。

Sedimentary method has been used to determine the historical sedimentation rate in this study, and historical literature has been studied to obtain information on climate change and human activities. Based on the data obtained in this way, the temporal variation in the sedimentation rate of the lower Yellow River in the past 2300 years has been studied in relation with climate change and human activities. The results indicate that the response of the sedimentation zone of the Yellow River system to the change in the erosion zone is sensible. The changes in vegetation and land use, both related to climate change and human activities, are two major controls for the acceleration of sedimentation rate. In addition, changes in strategies for the harnessing of the lower Yellow River are also responsible for such acceleration. During the process of accelerated sedimentation in the past 2300 years, the period of the 7th-10th centuries and the period since the mid-19th century have been identified as two periods with abrupt changes.