1, architectural form. Culvert is a closed underground pipeline. Open channel is built on the ground with free water surface.
2. Coverage. Culverts occupy less land. Open channels occupy a lot of land.
3. Construction difficulty. Culvert construction is difficult and consumes a lot of building materials. Open channel construction is convenient and the cost is low.
4. Scope of application. Culverts are suitable for areas with large population and small population or arid areas with insufficient water resources. Open channel is suitable for ordinary irrigation channels.