Dear Đàm Bá Giang ,

In mike zero create a dfsu file (Data Manager) and import your mesh file in order to setup the spatial information . Then it will provide you a mesh that you can define bed resistance for each element .

Regards ,

Amin

If you follow Amin advice you need to select the areas and then insert the value you want in and hit "calculate". You can then select other areas until you have your map.

Alternatively, you can create a dfs2 file from your mesh or dfsu from the bathymetry, then it is straight forward how to define you bed resistance. The flexible mesh models are able to read also dfs2 files.