Search

Hong Kong is an international metropolis with a highly dense population. As a result, it faces enormous challenges in terms of land supply. As part of the Hong Kong Government's initiative to increase land supply, the Civil Engineering and Development Department (CEDD) proposed minor relaxation of the maximum plot ratio/building height restrictions for 21 target sites in Kai Tak Development Area (KTDA). Although CEDD has explored the feasibility of increasing development intensity by assessing environmental impacts, infrastructure capacity and public consultation, these reviews and assessments were conducted based on the 2D GIS. Since the spatial distribution of land unit in the real world is three-dimensional, 3D GIS can help us look into the world in true perspective and make informed decisions. This study aims to investigate the viability of minor relaxation of maximum plot ratio/building height restrictions of 21 sites in KTDA through 3D modeling and 3D spatial analyses, including skyline, visual impact, shadow and solar exposure. Regarding to the 21 target sites, four scenarios with different plot ratios and building heights were built and compared. The results indicate that minor relaxation of maximum plot ratio and building height leads to (i) minor effect on skyline (ii) minor effect on visual impact and (iii) slight changes in shadow and solar exposure both in winter and summer. Therefore, in light of the findings from this study, scenario 4 is the recommended reasonable scale to relax the maximum plot ratio/building height restriction for the target sites in KTDA. Besides, this study can also be applied in the urban renewal studies and other new development areas in Hong Kong, or even in other densely populated cities. [ABSTRACT FROM AUTHOR]

With the development of global urbanization, high-density cities faces enormous challenges on land supply. Hong Kong is a megacity with a long-term lack of land and housing supply. To increase the development intensity of built-up areas in Hong Kong, a minor relaxation of plot ratio/building height restrictions for twenty-one sites in the three target study areas of Kai Tak Development Area has been approved by the Town Planning Board in 2015. This study aims at providing scientific evidence on the impact of this relaxation and possible further relaxations using 3D spatial analyses and simulation technologies. After a 3D model of Kai Tak and surrounding areas being generated, effects of increased PR/BH on skyline, visibility, shadow and insolation, air temperature, and wind ventilation were successfully analysed based on five scenarios. Research findings indicated that, except the extreme case of Scenario 5, no significant changes were found in Scenario 2, Scenario 3 and Scenario 4 when compared with the original plan of Scenario 1. As a pilot study focusing in Hong Kong, this research may also serve to provide new methodological and theoretical insights to facilitate rational discussion and debate on changing land development density in other similar hyper-dense cities. • We measure impacts of minor relaxation of maximum plot ratio/building height restrictions. • 3D models of Kai Tak and surrounding areas are established in GIS virtual environment. • We simulate changes of visual and microenvironment using 3D spatial analyses under five scenarios. • The most recommended scenario and implications are discussed based on the analysis results. • The proposed approach can be applied to other cities in the similar context. [ABSTRACT FROM AUTHOR]