translate English to French: As a large part of this population has limited means, their situation is sometimes very difficult, as is the case when they settle on rented or purchased sites in locations where planning permission cannot be obtained, or sites where their presence is unauthorised.
Compte tenu de la faiblesse des ressources d’une grande partie de cette population, on observe parfois des situations très difficiles, telles que l’installation sur des terrains loués ou achetés dont la localisation ne permet pas d’obtenir un permis de construire, ou l’installation sur des terrains sans autorisation.