Significance of building heights for urban environmental safety

Abstract

Purpose -A natural gas pipeline accident could prove to be a dangerous fire source in city centers. Taking the explosive danger caused by natural gas leakage as an example, the purpose of this paper, based on the box model, is to examine how such an environmental hazard can be hindered by the variation of building heights in the context of urban safety design and land-use decision making. Design/methodology/approach -The box model measures the concentration of pollutants within a defined box in which a mixture of pollutants with air and their transport by wind take place. A street surrounded by tall buildings in the city center is a good example for the application of such a model, and the building heights shape the box size and the mixing height. Under the consideration of atmospheric conditions this study identifies how the constellation of physical factors shaping the citystreet box and its change affect the elapsed time to reach the lower explosive limit (LEL) and the upper explosive limit (UEL) of natural gas. Findings -Ceteris paribus higher building heights expand the time span between initial gas leakage and reaching LEL, in which appropriate safety measures should be taken before ignition, but more rapidly increases the elapsed time to reach UEL, making the time scope for potential explosive danger in the city center even larger. Originality/value -In the past, the aspect of preventing explosive dangers caused by natural gas leakage has been largely ignored in the building height regulations related to urban safety design and city center development.