上海地区属长江三角洲冲积平原,六千年前,在形成第一条海岸线(古冈身)以后,总的趋势是东部陆地继续外涨,逐步由海变陆;西南部则随着杭州湾的形成,自东晋以后不断坍陷后退,逐步由陆变海,直至清代初期海岸才基本稳定。对历史时期海陆变迁的研究。除了考古发掘以外,古海塘的兴废成为海岸演变的重要标志。历代地方志对海塘虽有较多的记载,但大多“语焉不详,”且多系后志抄前志之作,常有抄错或牵强附会之说。由于史料不足和人们的理解不同,对同一条海塘往往也有众多不同的说法。作为新一代修志工作者,我们决不能盲目迷信, Shanghai is an alluvial plain in the Yangtze River Delta. After the formation of the first coastline (the ancient Gagang body) six thousand years ago, the general trend was that land in the east continued to rise and gradually changed from sea to land. In the southwestern part of the country, Since the Eastern Jin Dynasty, it continued to collapse and retreat gradually and gradually changed from land to sea. It was not until the early Qing Dynasty that the coast was basically stable. Study on the Change of Sea and Land in Historical Period. In addition to archeological excavations, the revival of the ancient sea pond became an important symbol of the evolution of the coast. Although there are many records about the seashore in ancient dynasties, most of them do not know the details of the seabed. Due to the lack of historical data and people’s understanding, there are often many different opinions about the same seawall. As a new generation of volunteer workers, we must never blindly believe in superstition,