Greenbelt development: Correlation between greenbelt patterns and metropolitan areas

Abstract

Greenbelts, which were first implemented in London in the 1930s, are now popular throughout the world and are an effective land-control and land-use planning idea. However, to accommodate increasing urban sprawl existing greenbelts have been reduced. It is therefore necessary to explore factors in the spatial patterns of current greenbelts so that improved greenbelts can be constructed. For this study we chose 11 cities: Paris, Los Angeles, Tokyo, Moscow, Mexico City, Sao Paulo, Delhi, Beijing, Shanghai(each with a population greater than ten million), and London and Hong Kong. Cities in developed or BRIC(Brazil, Russia, India and China) countries were chosen. Urban remote sensing data and greenbelt planning data were analyzed using ArcGIS 10.0 software. We studied three spatial levels(city, urban and metropolitan) and results showed that: 1) The minimum distance from city center to greenbelt had a high correlation with the maximum urban radius(r=0.83, P=0.01), middle correlation with the maximum metropolitan radius(r=0.69, P=0.05), and complete correlation with the minimum city center to hill distance(r=1.00, P=0.01). 2) The maximum distance from city center to greenbelt had a high correlation with the maximum urban radius(r=0.86, P=0.01), middle correlation with the maximum city and metropolitan radii(r=0.65 and 0.72 respectively, P=0.05), and complete correlation with the maximum city center to mountain distance(r=1.00, P=0.01). Developed metropolises with established greenbelts have larger greenbelt radii than developing metropolises that are currently constructing greenbelts and need to reserve space for future urban development. Surrounding mountains are a strong geographic priority factor of greenbelt planning. We propose the following four concepts in greenbelt planning: staged and hierarchical planning models, satellite forest ideas, geographic priority principles and spatial change from mosaic distribution to anti-mosaic distribution. These concepts enrich the theoretical system of urban planning and provide a guide for scientific planning, effective implementation and protection of greenbelts.