CHARACTERIZATION OF PERI-URBAN TERRITORIES: PATTERNS AND DYNAMICS. The case of the Metropolitan District of Quito, Ecuador

In contexts of globalization, economic restructuring and information and communication revolution, the relocation of services in peripheries and new urban expansion patterns have dramatically altered periurban landscapes. Particularly, Latin American contemporary cities are facing a rapid urban dispersion which is mainly occurring in these zones. These interstitial territories are characterized for being highly heterogeneous, with hybrid and complex dynamics and -due to their landscape ambiguity and rapid transformation- frequently lack of clear regulations. Since these transitional spaces remain geographically and conceptually unclear, having a greater understanding of its landscape composition has become a key issue for territorial planning purposes.
Firstly, this contribution aims at establishing new precisions about the most recurrent terms used in the scientific literature to describe the urban-rural gradient in a Latin- American context. As methodology, in order to identify and systematize the most outstanding attributes for each term, a Citation Frequency Index has been calculated. Also a Sorensen Similarity Index has been developed to identify distinctions and synergies among terms, obtaining a wider understanding of these territories and its interactions. In this section we highlight the importance of specific studies that distinguish the conceptual nuances of terminology in each region and the realities and imaginaries they represent.
Then, as our case of study, the Metropolitan District of Quito (MDQ) urban-rural gradient, its landscape structure and its spatiotemporal transformations, were analyzed. Focusing in 1 square kilometer 64 samples based on high resolution satellite images, this research tested a novel and accurate method to identify urbanization patterns and its dynamic in the last decade. Here, various research methods were applied: landscape metrics calculation to undestand the landscape structure, a multivariate cluster analysis to recognize samples’ similarities/differences, a transition matrix along with a stability index to analyze landscape composition change intensity, the Markov chains modelling technique as a land change tendency analysis, among others.
Results suggest that the MDQ presents patterns of urban diffusion and coalescence. The diffusion starts at the urban core and expands to rural parishes where some emerging traditional settlements merge, constituting a complex pattern of urbanization. Results also demonstrate that peri-urban areas show the highest landscape instability within the urban-rural gradient, although through a great diversity of land occupation typologies. Parsing LULCs independently, vegetation showed the greatest instability, which significantly alters ecosystems and their services, threatening the territory's environmental sustainability. Particularly, significant levels of fragmentation were identified in this LULC within the periurban areasSimilarly, the analyses identify significant changes in agricultural coverages which highly are related to rural lots subdivision, evidencing the environmental fragility of these territories in transformation. On the other hand, the mega-road infrastructure that connects the city with the airport (located in the city outskirts), appears to be one of the most dramatic drivers of peri-urban transformation, evidencing the main role that these infrastructures have had in urban expansion. However, results show that there are other drivers such old historical settlements in the city outskirts or land price that are also strongly influencing periurbanization dynamics.
Finally, this research thesis proposes and tests an analytical approach which could be applied to other Latin-American cities, where urban expansion patterns remain unknown and where micro-scale policymaking should be a priority in scenarios of complex and highly heterogeneous peri-urbanization. This methodology is particularly useful for land-use planning policies since it provides precise knowledge about urbanization patterns and its main tendencies.