Abstract: To ensure the safety of Qingcaosha reservoir dam during operation, dynamic monitoring of underwater terrain on the outer side of the dam is carried out. On the large amount of terrain and fixed cross section data, different from traditional data processing method, this paper uses 3D software and CAD secondary development software for data processing, which visually shows the local and whole underwater terrain changes, providing data support for safety operation of the dam, worthy of reference.

Key words: underwater topographic, dynamic monitoring, CAD secondary development, Microstation

摘要： 为确保上海市青草沙水库运营期大堤安全，在大堤外侧滩面实施了水下地形动态监测，针对长期监测获得的大量地形数据及固定断面数据，区别于传统水下地形测量数据处理方式，采用三维软件及CAD二次开发软件进行数据处理，直观地表现出大堤外侧水下地形整体及局部的变化情况，为水库大堤的安全运营提供数据支持，对同类工程水下地形动态监测具有借鉴意义。

关键词: 水下地形, 动态监测, CAD二次开发, 三维软件