The author provides stable and safe designs of coastal and river bank
using a new structural concept which stably keeps frame structure inside
of the embankments, and therefore protects the backside of lowland
areas, where more than ten millions of people live and social investment
facilities are distributed. This new proposal simplifies the design of
multi water hazards from the probabilistic collapse risks to
deterministic planning for human lives and accumulated social public
facilities around coastal mega cities. Those regions distribute in flat
low elevation areas for conveniences of foreign trade with port
facilities, industries, and traffic infrastructures including hub
airports. Mean while, those coastal regions sometimes remains in
legendary collapse risks, such as gigantic fires or pandemic infection
diseases along with the catastrophic disasters against social frameworks
to keep human cultural livelihoods in this modern era of Gaia.