Impacts of urban stream pollution: A comparative spatial hedonic study of high-rise residential buildings in Guangzhou, south China

Urban streams are scarce natural elements in compact cities, and suffer from pollution in the course of city expansion and densification, especially in developing nations like China. They may offer the amenity of a riverscape view, but also the dis-amenity associated with water pollution. Yet whether and how polluted urban streams affect high-rise residential property values remain under-investigated. Based on a total of 315 transaction records of apartment sales in two residential precincts located near two typical urban streams in Guangzhou, south China, this study attempts to assess the impacts of urban river pollution, in terms of view and proximity, at a neighbourhood level. A novel cube contiguity, consisting of a three-dimensional spatial weighting matrix, is developed to incorporate the effect of property height in hedonic price models. Comparison of the spatial hedonic analysis of the two selected residential precincts reveals that views of heavily polluted urban streams fail to command a premium, and the impacts of proximity to urban streams vary considerably in high-rise, compact urban contexts, when micro-level landscape variations are carefully represented in hedonic modelling. This could be associated with the hydro-morphological features and riverine landscape, as well as with homebuyers' subjective perception of river pollution. Assessing the impacts of urban stream pollution could provide a basis for understanding the negative externalities of urban river pollution, establishing priorities for restoring polluted urban streams, and planning the provision of multi-functional green-blue spaces with respect to homebuyers' demand for environmental amenities in mid- and high-rise housing markets in both developed and developing nations.