Coastal dike, how it should be

A rising concern recently is whether coastal dike project is economically good? What is the benefit of the dike at the present?

I would say coastal dike is good for some areas, and not for the others. And the reason could be lighted up in these two recent projects:

Firstly, it is noticeable that the two projects attempted to minimize the length of dike by choosing reasonable position.

Secondly, both the dikes wouldn’t provide only protection value but also territory enlargement (What we concern here is increasing land for using). The benefit of land increasing could possibly be accounted in the present or future benefit of the project.

So there are at least two more reasons to doubt about the feasibility of Quang Ngai – Kien Giang sea dike project.