Study of long-term preferred landfill after use development for nearby dense urban communities

Abstract

Fast urbanization and rapid population growth in dense cities within highly constrained territories in the past several decades have resulted in a dramatic increase in the number of people living close to operating landfills in the world. This has raised serious concerns of the public on operation nuisances, environmental impacts and health risks to the communities near to landfills. Previously, due to lack of modern technology and environmental awareness, the landfill after use development was taken as an afterthought restoration process, and empirical ecological restoration was primarily focused. Along with technology improvement, the after uses can be designed at an early stage of a landfill project. However, rational understanding of the features of after uses, specifically related to terrestrial constraints, has not been available yet; exploration of the nearby resident’s attitudes towards landfill operation in association with prediction of long-term preferred after use development has not been implemented before. To this end, this thesis conducted a comprehensive study to enhance the knowledge of after use development for sustaining our urban environment. First, in the thesis, 82 available after uses were categorized and the related terrestrial constraints of those after uses were analysed. The suitable after use development is constrained by the tolerance of settlement, minimum area requirement, and maximum slope angle of a closed landfill cover. The understanding of the constraints of after uses will be valuable for designing landfill covers at the beginning of landfill projects, and then it would be doable to develop long-term preferred after uses effectively and efficiently. Second, through questionnaire surveys, this thesis explored the nearby resident’s acceptance of the impacts of landfill operation with predicting preferred after uses. Face-to-face surveys were conducted in two dense urban communities, Lohas Park (LP) and Ocean Shores (OS), in Hong Kong. The distances of LP and OS to the Southeast New Territories (SENT) operating landfill are about 1 km and 3 km, respectively. A total 390 residents in LP and OS above 18 years old were surveyed (121 residents in LP in May 2016, 127 residents in LP and 142 residents in OS in June and July 2017). The impacts of two different long-term after use scenarios, namely green cover only (scenario 1) and green cover plus recreation use (scenario 2), on alleviation of resident’s opposition to the operating landfill were evaluated. The results revealed that it is possible to gain more support by incorporating the green cover plus recreation after use for converting the operating landfill site for future use instead of just green cover transformation. Moreover, the analysis results from survey data indicated that the level of community acceptance is largely driven by less negative impacts and expectations of after use benefits. The resident’s attitudes towards a rational process of cost-benefit calculations are based not only on how they perceive the health affection, safety, environmental nuisance but also on potential benefits of the after use development. The results suggested that the after use would moderate acceptance attitude towards possible landfill operating impacts, which works with the communities with different distances to landfill sites. This study would also shed light on the factors of the willingness-to-pay with the prediction of long-term preferred after uses, which acknowledges after use as considerable value for nearby communities. This study will not only be a benchmark for further landfill developments in Hong Kong but also have potentials to be a driver for the high-density cities other regions of the world. Moreover, it would serve as a stepping-stone for further landfill acceptance investigations.