surface drainage ditch的意思|示意

The existing highway design criterion only takes setting pavement longitudinal grade, side ditch and drainage ditch into account in order to eliminate surface water.

现有的公路设计中，考虑较多的仅仅是通过设置道路的纵坡、边沟及排水沟等设施来排除地表水。

This paper studies the application of digital elevation model (DEM) to the design of the surface drainage ditch system.

研究数字高程模型(DEM)在滑坡地表排水辅助设计中的应用。