Retrospecting the researches and efforts on Lancang-Mekong water issues: a bibliometric perspective

We adopted a spectral clustering algorithm to divide the document co-citation network of 1,776 papers in the field of Lancang-Mekong water, and 14 clusters were identified. For each cluster, the top-cited references construct the knowledge base, and the most-coverage cities are taken as the research frontier. Three indicators, namely betweenness centrality, citation burstness strength, and Sigma, were used to identify the research outputs with pioneering and transformative value. The changes in the research topics and hotspots are closely related to the planning, construction, and operation progress of hydropower engineering, that affected by the gaming results of all parties. The 2009-2010 is an important time boundary, with the original research hotspots including the impact of upstream reservoirs on the hydrological regime and sediment (Clu#3) and arsenic contamination of groundwater in the Lower Mekong (Clu#4) that obtained periodical achievements and reached consensus to some extent around 2008, and the new research boom turns to the Tonle Sap Lake and flood pulse (Clu#2) in short-term characterized literatures with the highest burstness strength mainly concentrated around 2012. HIGHLIGHTS The intellectual bases and research frontiers of 14 identified topics were analyzed based on Document Co-citation Network analysis. Vietnamese Mekong Delta is the topic with the largest size and arsenic contamination is the cluster with the longest time span. Evolution of research hotspots is related to the widespread controversy over the planned dams in the Lower Mekong mainstream and the progress of the multi-party games.