울란바토르시 20분 도시 개념에 따른 주거유형별 보행 접근성 연구 : 울란바토르시 2040 도시기본계획 및 바양골구 공립 통합학교 중심으로

울란바토르 20분 도시 구상에 따른 주거유형별 보행 접근성을 연구했다.

The "N-Minute City" paradigm has emerged as a core strategy in modern urban planning to enhance the overall quality of life through proximity and walkability. In alignment with this global trend, Ulaanbaatar City adopted the "20-Minute City" vision in its statutory "Ulaanbaatar 2040 Master Plan" to overcome the severe limitations of its historically monocentric spatial structure. Currently accommodating over 1.65 million people, which represents 48.3% of the national population, Ulaanbaatar faces profound spatial polarization. The unplanned, low-density urban sprawl in Ger areas heavily contrasts with planned, high-density apartment districts, thereby exacerbating infrastructure inequality.

However, the 20-minute city vision currently remains a rhetorical and normative slogan, lacking empirical spatial validation and concrete implementation strategies. To address this fundamental gap, this study aims to empirically evaluate the spatial alignment of this policy vision within the actual urban environment. Bayangol District was selected as the optimal case study area due to its distinct hybrid topography of both apartments and Ger settlements, making it ideal for analyzing spatial disparities. The primary analytical indicator utilized is the public general education school (grades 1 12), an essential public good that starkly reveals supply-demand imbalances in urban space.

To holistically assess the divergence between normative policy goals and physical reality, this research employed a robust mixed-methods approach combining qualitative content analysis and quantitative spatial analysis. Qualitatively, a text-mining-based frequency and in-depth content analysis were conducted on 16 key statutory policy documents, including "Vision-2050" and the 2040 Master Plan, to critically review the presence of micro-level implementation indicators and housing-specific infrastructure guidelines.

Quantitatively, to overcome the Modifiable Areal Unit Problem (MAUP) inherent in macro-level administrative boundary analysis, high-resolution micro-spatial data was constructed at the building level. A total of 16,138 residential building polygons were extracted and classified into five typologies ranging from Ger to high-rise apartments. The school-age population (ages 6 18) was spatially allocated based on the Gross Floor Area (GFA) weighting of individual buildings, ensuring zero allocation error. Spatial network analysis was subsequently conducted using a conservative walking speed of 3.5 km/h to reflect the region's harsh winter conditions.

Accessibility was rigorously measured using Closest Facility Analysis alongside the Gaussian Two-Step Floating Catchment Area (G2SFCA) method, which mathematically models capacity-demand imbalances and distance decay to capture realistic, experienced accessibility. The empirical results revealed a profound structural discrepancy between the aspirational policy vision and the physical urban reality. Qualitatively, the 2040 Master Plan lacks robust micro-level guidelines; macro-scale terminology regarding land-use zoning and housing supply dominated 79% of the policy discourse, while crucial micro-indicators like "school accessibility" and "pedestrian environment" were severely marginalized.

Furthermore, a regulatory discrepancy was identified wherein administrative practices arbitrarily apply a 750-meter Euclidean buffer despite the statutory service radius for schools being legally defined as 500 meters. Quantitatively, the distribution of public schools fundamentally mismatches potential demand. Notably, 13 out of 31 administrative units (khoroos) lack a public school entirely, and the 26th khoroo, despite possessing the highest school-age population of 5,803, has zero educational facilities, indicating a severe state of "educational infrastructure desertification".

Spatial stratification is equally stark, as only 10.1% of all residential buildings are located within a 20-minute walk to a school. Ger residents experience an average minimum walking time of 60.8 minutes, and the G2SFCA index revealed a 4.7-fold disparity in practical accessibility between apartment areas and Ger areas, with 95.4% of Ger buildings classified as having "insufficient" accessibility. Crucially, the study identified an "accessibility illusion caused by overcrowding". Among the buildings physically located within a 20-minute walk, 17.6% failed the G2SFCA threshold because the nearby schools were already operating beyond their maximum capacity.

Consequently, an overwhelming 89.9% of all residential buildings exist in a state of "complete accessibility vulnerability," failing both physical distance and capacity-adjusted metrics. These findings quantitatively prove that Ulaanbaatar's 20-minute city vision is entirely unattainable under the current density-centric and skewed infrastructure supply paradigm. To rectify this, the study proposes urgent and targeted policy shifts. Planners must suspend convenience-driven facility expansion in established apartment districts and prioritize precise, pinpointed new school developments in marginalized Ger areas where potential demand vastly exceeds current zero supply.

Furthermore, policymakers must abolish regressive, static Euclidean buffer metrics that ignore demographic dynamics, and institutionalize dynamic accessibility indices like G2SFCA as the new statutory standard. Finally, institutionalizing a data-driven "Supply-Demand Imbalance Spatial Monitoring System" on the municipal network is essential to mandate practical pedestrian accessibility as the paramount criterion for all future public facility feasibility studies.

By applying the advanced G2SFCA model to micro-level building data within Ulaanbaatar's unique hybrid topography, this research exposes the critical gap between normative rhetoric and spatial reality, providing a definitive empirical foundation for transitioning toward a time-based urban planning paradigm. 현대 도시계획 개념의 주요 자리 잡은 'N분