Browsing by Author "Sumari, Neema Simon"

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Characterizing urban expansion combining concentric-ring and grid-based analysis for Latin American Cities
(MDPI, 2021) Wu, Su; Sumari, Neema Simon; Dong, Ting; Xu, Gang; Liu, Yanfang
Spatio-temporal characterization of urban expansion is the first step towards understanding how cities grow in space. We summarize two approaches used in urban expansion measurement, namely, concentric-ring analysis and grid-based analysis. Concentric-ring analysis divides urban areas into a series of rings, which is used to quantify the distance decay of urban elements from city centers. Grid-based analysis partitions a city into regular grids that are used to interpret local dynamics of urban growth. We combined these two approaches to characterize the urban expansion between 2000–2014 for five large Latin American cities (São Paulo, Brazil; Mexico City, Mexico; Buenos Aires, Argentina; Bogotá, Columbia; Santiago, Chile). Results show that the urban land (built- up area) density in concentric rings decreases from city centers to urban fringe, which can be well fitted by an inverse S curve. Parameters of fitting curves reflect disparities of urban extents and urban form among these five cities over time. Grid-based analysis presents the transformation of population from central to suburban areas, where new urban land mostly expands. In the global context, urban expansion in Latin America is far less rapid than countries or regions that are experiencing fast urbanization, such as Asia and Africa. Urban form of Latin American cities is particularly compact because of their rugged topographies with natural limitations.
Urban growth dynamics and expansion forms in 11 Tanzanian cities from 1990 to 2020
(Taylor & Francis Group, 2023) Sumari, Neema Simon; Ujoh, Fanan; Swai, Calvin Samwel; Zheng, Muchen
With rapid urban expansion across Tanzania, there is a need to institute steps to address factors and forms as well as impacts and challenges associated with the observed trend. This study’s aim is to use spatial urban landscape indices to analyze the spatial changes in urban forms, patterns, and rates across 11 urban centers in Tanzania over a 30-year study period (1990–2020). During the past three decades, urban lands of 11 cities and town in Tanzania have grown by a total of 480 km 2 . Leapfrog growth was found as the most dominant form of urban expansion in Tanzania while Dodoma, the capital city of Tanzania, had the highest rate of urban expansion when compared to all other individual cities. The most robust and significant interaction of the AWMLEI and MLEI was found in Kigoma, Arusha, Mtwara, Mafinga, and Tunduma cities. In contrast, Mbeya agricultural city, Arusha the tourist city, Tabora, and Geita Lake zone areas did show their own peculiarities revealing an interesting spatial temporal variation in rate and form of expansion. The outcome of this study reveals that the influence and management of economic and socio-cultural opportunities will be an effective tool for the determination of the rapidly expanding cities and towns of Tanzania.