Measuring and mapping the spatial distribution of the quality of life in a city: a case study in Nanjing

Population agglomeration in urban areas makes it easy to share valid urban facilities and services that make up a high Quality of Life (QoL). However, most cities in a developing stage face the problem of under-service; this means the supply of service facilities cannot catch up with the agglomeration of the population. Additionally, insufficient transport infrastructure also does not meet the swift growth of transport demand. Urban QoL inevitably decreases under the conditions of insufficient service facilities and transport infrastructure. This paper investigates an integrated methodology to evaluate QoL by measuring the aggregated values of urban services: education services, shopping services, and medical care services. All the values of urban services are evaluated in three stages: existing values, accessible values, and perceived values, in which existing values are examined by the scale of service facilities; accessible values are effected by travel costs and obtained by applying spatial analysis in GIS and using the road and subway network in the city; and perceived values are affected by people's preferences to each service and obtained by a questionnaire that was conducted in Nanjing. As a result, this paper integrates both the objective and subjective approaches of QoL calculation and illustrates that QoL distribution in Nanjing is spatially unbalanced and unequal among different population groups; which is highlighted in that QoL distribution is visualized in 1000 m × 1000 m grids in Nanjing city. Moreover, this method can aggregate for any size of space and combination of people's attributes, which allows it to provide overall information for urban planning and policy making.