Global urbanization research from 1991 to 2009: A systematic research review

We performed a bibliometric analysis of published urbanization research from 1991 to 2009, based on SCI and SSCI database. Our analysis reveals scientific outputs, subject categories and major journals, international collaboration and geographic distribution, and temporal trends in keywords usage in urbanization studies and discusses the relationships between urbanization papers and urbanization rate and offer a substitute demonstration of research advancements, which may be considered as a potential guide for future research. The growth of article outputs has exploded since 1991, along with an increasing collaboration index, references and citations. Environmental sciences, ecology, environmental studies, geography and urban studies were most frequently used subject categories and Landscape and Urban Planning was the most productive journal in urbanization studies. The United States was the largest contributor in global urbanization research, as the USA produced the most independent and collaborative papers. The geographic distribution of urbanization articles overlapped quite well with regions with high economic growth in North America, Europe, and Pacific-Asia. A keywords analysis found the USA and China were "hotspots", confirmed land-use's significant position and revealed keen interest in ecological and environmental issues in urbanization studies. In general, urbanization research was strongly correlated with the urbanization rate although there were different patterns and underlying processes across different countries. This is the first study to quantify global research trends in urbanization. Our study reveals patterns in scientific outputs and academic collaborations and serves as an alternative way of revealing global research trends in urbanization. (C) 2011 Elsevier B.V. All rights reserved.