Over 60% of the World's inhabitants live within a 40 miles wide area along the coastline and our largest cities spread out along the sea.

Coastlines urbanization contributes to the coastal development process which gives way to the destruction of shallow' natural habitats.
Urban density, when out of control, has a high damaging impact on the marine environment: physical destruction, pollution... in addition to the impact of sea water desalinisation stations in dryer areas.

The theme is highly transversal because the urban/rural relationship has, as we know and shall see below, a huge environmental and social value and is totally dependent on the power relations (urban-rural, northern-southern classes, articulation of the economic power groups) and on the pattern of production and consumption.
Moreover, the theme also brings into play urban planning, life styles, the relation between humankind and nature, etc.