Estimating the Impact of Urban Planning Concepts on Reducing the Urban Sprawl of Ulaanbaatar City Using Certain Spatial Indicators

The urban sprawl process of Ulaanbaatar has changed dramatically due to population growth. Ulaanbaatar city land management master plan defined the settlement zone area suitable for living as 33,698 ha. However, due to unrestricted urban sprawl caused by the exponential growth of the city’s population, the settlement zone area reached 39,235 ha, which exceeds the limit by 5537 ha. In order to tackle this issue, several urban planning concepts were developed to be implemented within Ulaanbaatar city urban planning framework. It is, in any case, problematic to choose a single planning concept due to the fact that neither measurements nor analyses are being made of the respective spatial indicators in urban planning assumptions that are taking urban form into consideration. One of the prerequisites for identifying an optimal concept in urban planning is an assessment of urban form, and measuring the impacts against its spatial data. This study uses 1990–2020 satellite image data to investigate the urban form of Ulaanbaatar with a future action plan. Using remote sensing and GIS technology, Ulaanbaatar city sprawl was analyzed for defining urban form, and consequent results were obtained by comparatively measuring the impacts of monocentric, polycentric, and compact city concepts on city sprawl by applying spatial indicators that have been used in the world’s major cities. The study results show that the compact city concept is the optimal solution to reduce uncontrolled city sprawl based on a technical point of view. This will lower Ulaanbaatar’s sprawl threefold and compress the urban settlement area down from 39,235 ha to 12,479 ha.