Challenges and strategies for greening the compact city of Hong Kong

Abstract

A compact city is a special urban form with inherent physical, social, and institutional constraints on greenery that obstruct the achievement of sustainability. In this study, Hong Kong is used as a case to assess the constraints and challenges related to urban green spaces (UGS) development in compact cities. Strategies to overcome these obstacles and improve the UGS conditions are developed. Opportunities to implement the strategies are then evaluated. Because compact cities have extremely limited space allocated for UGS on the ground level, strategies to optimize the layouts of green spaces and seek additional spaces above or below the ground level, such as vertical green surfaces or structures, green roofs, and podiums, are possible solutions. Measures to implement the strategies are summarized as (1) reorganizing the departments and offices related to UGS and clarifying their individual responsibilities to increase their efficiency; (2) encouraging citizen participation; (3) establishing proper legal basis; (4) forming a comparatively connected comprehensive green network of green sources and green sinks with ground-level green spaces, skyscraper farms, and sky gardens, all with optimal layouts; (5) maintaining and repairing UGS after construction; and (6) selecting species of plants that will thrive in specific green spaces. The compact form of Hong Kong provides many chances to implement these strategies. The study increases understanding of the critical factors behind the success or failure of UGS development in one of the most compact cities in the world and provides suggestions for strategic and policy-related measures for the provision and management of UGS in other congested areas. © 2012 American Society of Civil Engineers.