Do local factors or teleconnections control urbanization? The shifting balance in a Chinese megaregion

Numerous studies have investigated the local driving forces of expansion of developed land in a single city, or in comparisons of several cities. Few studies, however, have examined both the local and distant or “tele” drivers. We take the Beijing-Tianjin-Hebei (BTH) urban megaregion as a case study to investigate the local and tele driving forces of expansion of developed land from 1984 to 2010. We pose two research questions at an urban megaregion scale: (1) What are the effects of local and tele driving factors on expansion of developed land; (2) Does the relative importance of these two kinds of factors change through time? We examined the expansion of developed land, and classified the potential driving factors into local and tele variables, and detected their effects on expansion of developed land for three periods, 1984-1990, 1990-2000, and 2000-2010. The results showed that the BTH megaregion experienced a rapid and significant expansion of developed land during 1984-2010, with an increase of 9970.60 km2, or an annual rate of 276.96 km2. The local and tele driving factors both affected the expansion of developed land. Overall, local drivers were dominant in the process of urbanization for BTH. However, over that time period, the effect of local driving factors deceased, while that of tele driving factors increased. This study extends the understanding of expansion of developed land in a holistic view by including both local and tele drivers, and provides quantitative insights into the issue of urban planning and management in urban megaregion.