계획도시의 도시활력 진단과 도시활력을 위한 공간계획 방향

계획도시의 활력을 진단하고 공간계획 방향을 제시했다.

The first-generation new towns in the Seoul metropolitan area were originally planned to address housing shortages and population overcrowding in Seoul. Developed on the outskirts of Seoul in the late 1980s to mitigate soaring housing prices and overpopulation, these new towns initially achieved their goals of stabilizing housing supply and dispersing the population, in response to rapid economic growth and the increasing demand for middle-class housing. However, after three decades, issues related to physical deterioration and declining urban vitality have emerged. Consequently, there is a growing need to assess urban vitality and explore spatial planning strategies to enhance it.

Urban vitality refers to the diverse range of human activities that take place in urban spaces and is a key factor in sustainable urban development and design. Previous studies have defined urban vitality as the interaction of the physical environment, social activities, and spatial characteristics, proposing land-use mix, development density, and street environment as critical planning factors. However, traditional analytical methods fall short of fully capturing the complex nonlinear relationships between planning factors and urban vitality. In addition, conventional approaches to measuring urban vitality often require substantial time and cost, and face limitations in data accessibility.

To overcome these challenges, this study employs nighttime satellite data to quantitatively measure the urban vitality of new towns, investigates nonlinear relationships, and proposes optimal spatial types for maximizing urban vitality. In this context, the study addresses three main research questions: First, how has urban vitality in new towns changed over time? Second, what planning characteristics do highly vital areas possess? Third, which spatial types can enhance urban vitality?

To answer these, the study begins by examining the spatiotemporal changes in urban vitality over the past decade, then analyzes the relationship between urban vitality and planning elements to provide empirical insights for the refurbishment of new towns and the formulation of future plans. Lastly, a genetic algorithm is employed to derive spatial typologies aimed at maximizing urban vitality. The scope of this study includes the five major first-generation new towns-Bundang, Ilsan, Pyeongchon, Sanbon, and Jungdong-and their surrounding areas within a 5 km radius.

Planning elements examined comprise urban form, land use, street environment, points of interest (POI), public transportation, and population characteristics. Generalized Additive Models (GAM) and CatBoost were used as the primary analysis methods. GAM was employed to elucidate nonlinear relationships between urban vitality and planning factors, while CatBoost was used to evaluate variable importance and visualize partial dependence plots (PDP). Finally, a genetic algorithm was applied to determine optimal spatial configurations for maximizing urban vitality. The results revealed that overall urban vitality in the first-generation new towns remained relatively stable over the past decade.

Planning factors exerted a significant influence on urban vitality, and these relationships proved to be nonlinear. Among the factors, distance to subway stations and land-use mix had the greatest impact on urban vitality in the new towns as a whole. In commercial areas, floor area ratio (FAR), building coverage ratio (BCR), and transportation service facilities emerged as the most influential factors, whereas in residential areas, distance to subway stations and land-use mix were found to be critical. These factors displayed threshold effects at specific values, with urban vitality either remaining high or showing declines beyond certain points.

For instance, FAR in commercial areas positively influenced urban vitality up to around 290%, after which the effect turned negative due to congestion and overcrowding. In addition, a higher number of intersections and greater road density initially bolstered connectivity and accessibility, thus enhancing urban vitality, but excessive levels led to a plateau effect. The results of the genetic algorithm optimization identified various spatial types optimized for different density levels to maximize urban vitality. In low-density areas, the selected optimal types featured high land-use mix, a high ratio of green spaces, and an abundant number of public facilities.

In medium-density areas, certain types combined high ratios of green space with good street accessibility, while others showed high population density coupled with a wealth of neighborhood amenities. In high-density areas, optimal types were characterized by a higher number of transportation service facilities and relatively short distances to subway stations. These findings offer practical design directions that reflect diverse urban characteristics and aim to enhance urban vitality.

This study makes two key contributions: it empirically analyzes the relationship between urban vitality and planning factors and introduces a novel methodology for measuring urban vitality using nighttime satellite data. Furthermore, it provides concrete, actionable planning benchmarks for the refurbishment and sustainable development of new towns, making a policy-level contribution. While the focus is on first-generation new towns, the results are potentially applicable to other urban areas, offering valuable insights for urban vitality enhancement strategies. 수도권 1기 신도시는 서울의 인구 과밀과 주택 문제를 해결하기 위해 계획되었다. 1980년대 후반, 서울의 주택 가격 급등과 인구 과밀 문제를 해결하기 위해 서울 외곽에 1기 신도시가 조성되었다.

이들 신도시는 급속한 경제 성장과 중산층 주택 수요 증가에 대응하기 위해 설계되어 주거 안정과 인구 분산이라는 초기 목표를 달성했으나, 30년이 지난 현재 물리적 노후화와 도시활력 저하 문제가 대두되고 있다. 이에 따라 도시활력을 진단하고, 이를 증진하기 위한 공간계획 방안을 모색하는 연구가 필요하다. 도시활력은 도시공간에서 발생하는 다양한 사람들의 활동으로, 지속 가능한 도시 개발과 설계를 위한 핵심 요소이다. 기존 연구는 도시활력을 물리적 환경, 사회적 활동, 공간적 특성의 상호작용으로 정의하며, 이를 촉진하기 위한 계획 요소로 토지이용혼합도, 개발밀도, 가로환경 등을 제안하였다. 그러나 기존의 분석 방법은 계획 요소와 도시