Effects of urban forms on energy consumption of water supply in China

Abstract

More than half of the energy consumed for urban water utilities is for the water supply system (including water distribution and secondary water supply systems). Urban form (defined as city shapes and population distribution) is found to have significant impacts on energy used by the water supply system. This study aimed to explore the integrated impacts of urban forms on energy consumption for water supply by employing empirical analysis methods and virtual city modeling. In total, three types of city shapes (i.e. radial, grid and satellite) and three types of population distributions (i.e. uniform, monocentric and polycentric) were identified. The results reveal that population distribution has more significant impacts on the energy for water distribution and secondary water supply than city shapes. Energy consumed by secondary water supply accounts for more than 80% of total energy consumption. It is found that radial-uniform cities consume the least energy for water supply (up to 89% lower). The findings of this study shed light on enhancing overall sustainability in the urban water supply system. For future urban planning and governance, radial/monocentric urban form is encouraged when secondary water supply is not widely applied or needed, radial/uniform urban form is recommended when secondary water supply is required, and the entirely pressurized pumping system is suggested for secondary water supply in order to reduce energy use.