Environmental Changes in the Yangtze Delta since 7000 aBP
长江三角洲7000年来的环境变迁

C dating, geochemical analysis, pollen analysis and environmental magnetism analysis are performed on samples from the Maqiao site, Shanghai. Comparitive study was conducted on the large amount of the collections from the archaeological sites and natural sedimentary stratum in the Yangtze Delta. The research results indicate that ocean degression happened 7200 aBP-5300 aBP, which made large area of land exposed, and offered good space for human activities during the Liangzhu Culture epoch. In the Liangzhu Culture epoch, suitable climatic conditions accelerated human activities, leading to the developed culture and unprecedented jade-article culture. At the late Liangzhu Culture, climatic transition from warm/wet climate to cold/dry climate occurred. This climatic transition resulted in large scale flooding periods, leading to the collapse of the Liangzhu Culture, followed by the relatively backward Maqiao Culture. Single archaeological section is not enough in reconstruction of paleo-climatic change and therefore, natural sections and archaeological sections are widely collected for further research. Comparitive research results between natural deposition sections, archaeological sections and climatic curves reconstructed from pollen analysis on samples taken from Qingfeng section, Jianhu Lake, Jiangsu Province indicate that the flooding periods in the Yangtze Delta matched well the climatic transition periods, which are also corresponding well to the strong changing fluctuations of the climatic conditions. Comprehensive research on the archaeological sections and natural sedimentary sections suggests that the cultural interruptions at the archaeological sites are the results of the flood events in the Yangtze Delta. Climatic changes, flood events and water changes play the important parts in influencing the development of human civilization in the Yangtze Delta. The research results are meaningful in further research on the climatic changes in the Yangtze Delta, esp. in research methodology.