In a recent paper (Valera, in print 2010) I presented a first attempt to organize these particular designs in four basic categories according to integral or almost integral plans of ditches:
A. Sequences of regular and aggregated lobes (1. Santa Vitória; 2. Outeiro Alto 2; 3. Xancra); B. Sequences of separated regular lobes (4. Moreiros 2; 5. Águas Frias); C. Regular wavy (6. Juromenha 1; 7. Perdigões); D. Irregular wavy (8. Águas Frias; 9. Perdigões).
This morphological diversity is certainly meaningful and the traditional association to the design of walls with bastions, if arguable for some of these categories (such as the B. or even D.), is clearly unacceptable for the A. and C.. Explanations for the particular designs like the ones in Xancra, Santa Vitória or Outeiro Alto, that so far represent a specificity of the middle Portuguese Guadiana basin, need to be searched elsewhere. In the quoted paper I argued that some answers can be found in the ideological connotation of architecture, namely in its cosmological foundation. Locations, topography, astronomic orientation, landscape connections and design, all talk about architectures that are impregnated by cosmologic senses, without which these sites cannot be comprehended.
Valera, António Carlos (in print 2010), “Fossos sinuosos na Pré-História Recente do Sul de Portugal: ensaio de análise crítica”, Actas do V Encontro de Arqueologia do SW Peninsular.