Number of nodes, elements

Dear all friends,

Do you have any advices in designing superelement mesh and generating Finite Element Mesh for a large region (from 10000 to 20000 km2)? Is there any relative links among the study area - number of nodes in superelement mesh (or the distance between nodes) - number of elements?

Thanks!

The required element size and node/element number highly depends on the spatial degree of accuracy you need. While for a regional study looking at the overall water balance large elements may be sufficient, for detailed applications a more dense is required. There is - and cannot be - not a general rule of thumb.