Drylands, hyper arid to subhumid areas where rainfall is limited, are expected to expand due to climate change. Natural resources, such as water and food, are scarcer in these areas. Population growth and urbanization are putting even more pressure on communities living there, as well as on the urban fabric and ecosystems. How can nature based ecocities be created in these environments?

A pattern language, which is able to translate practical knowledge into substantiated spatial configurations that work in arid areas is missing in current theory and practice. The ´Urban Arid Green research by design project´ addresses a sustainable population growth and urbanization in arid regions via the case study in Tamansourt. Tamansourt is one of the 19 Moroccan new towns developed under the national Villes Nouvelles (New Towns) strategy. The city is still under construction, as the spatial analysis, site visit, and conducted interviews have revealed. The city has not reached its target population nor its desired level of urban activity yet. However, fundamental issues already manifest themselves.

The vision ‘Regreen to Rewild’ aims to counteract the pressures mentioned before, by developing a transformative framework towards an ecocity, taking the natural system as the basis (nature-driven urbanism). Tamansourt Ecocity gives purpose to the local community and a new identity to the city.

The transition described in this vision requires a systemic change, including environmental, policy and behavioral change. To support this shift, a common language amongst all future stakeholders has been created: the Urban Arid Green pattern language. This spatial language includes four pathways, of which each includes a group of development guidelines. One of the four pathways captures the original design guidelines for Moroccan new towns, as formulated by Al Omrane in 2010. The other guidelines focus on the biosphere, the urban fabric, and immaterial values.

The Urban Arid Green project shows how these generic patterns can be translated into a site-specific design which stakeholders can use in the city’s transition. This sets a precedent for other arid cities that aim to sustainably develop while under the pressure of scarce resources, climate change and population growth. Every landscape needs to adapt its own site-specific pathway based on the generic language, allowing unique dialects for different landscapes.@en