城市职住空间错位的研究通常以测度就业可达性为基础,但传统测度方法在应用到国内城市时具有明显的缺陷.本文提出一种改进的就业可达性测度方法,通过引入就业机会权重系数,量化了城市就业机会分布不均的特征,并以此为指标分析了职住空间错位对于居民通勤行为的影响程度.研究显示,南京市主城区就业可达性差异性明显,呈现从中心向外围逐步递减的趋势,且递减程度愈发明显.同时就业可达性对于低收入者的通勤时间影响显著,可达性的提高有利于降低通勤时间,但是由于低收入群体在出行方式选择上的局限性,可达性的提高无法拓展他们的就业范围,必须从优化公共资源配置的角度来消减弱势群体的就业障碍.
Studies on spatial mismatch between residence and employment locations are often based on measurement of job accessibility. But traditional measuring methods show obvious defects. This paper proposed an optimized job accessibility measuring method. Then, the influence of spatial mismatch on commuting behavior was analyzed with job accessibility as a quantitative indicator. According to the analysis results,job accessibility shows great variation across urban area of Nanjing: the inner urban area is more accessible to employment than the outer urban area. In addition, regression analysis shows job accessibility has significant impact on commuting time in general, and the impact is more obvious in low-income group. Higher job accessibility index may encourage shorter commuting time of low-income residents, but have no effect on expanding commuting range of low-income residents. They prefer to search job opportunities near to dwelling places, which restricted their commuting modes. The only way to reduce employment hurdle for low-income group is to optimize configuration of public traffic facilities and employment locations.