Two geographic information system-linked bibliometric indices to quantify the knowledge flow: A case of Qinghai-Tibet plateau research

• Two new bibliometric indices measure both knowledge inflow and outflow at the same time.
• The indices can represent the flow amount and direction of the net knowledge flow.
• Knowledge flow can be quantitatively measured and spatially displayed using a GIS tool.

Cited information is an important pathway of scientific influence. It can reflect the knowledge flows among research units. This study develops two new bibliometric indices—the Citation Flow Index (CFI) and the Normalized Citation Flow Index (NCFI)—to measure knowledge flows based on scientific literature citations. The CFI measures the interactions of knowledge flows among different research units. The NCFI measures the number of papers that a research unit cited and the number of papers by a research unit that are cited. The newly developed indices were tested on a country-wide scale using the literature on the Qinghai-Tibet Plateau (QTP) as an example. The results indicate that the worldwide flow of knowledge on the QTP can be quantitatively measured and spatially displayed. Additionally, the annual NCFI change trend is analyzed for each research unit.