Resumen
As a new theme in agricultural water resources evaluation, the crop water footprint (CWF) has attracted much attention, and the number of published studies has shown rapid growth. In order to explore the research prospects of the CWF, this paper conducted a visual bibliometric analysis of its development context, hot topics and knowledge base, by using CiteSpace (version 5.6. R5, Chaomei Chen, Philadelphia, PA, USA). Up to the retrieval time, there were, in total, 838 articles based on the Web of Science core collection database. In terms of contribution, China, the Netherlands and the United States were the three most representative countries, and the University of Twente and Arjen Y. Hoekstra were the most productive institution and author, respectively. In terms of the discipline background, Environmental Sciences & Ecology, Environmental Sciences and Water Resources were the three most relevant categories. Based on the co-occurrence analysis of the keywords, the hot topics of the three periods has been illustrated, and assessing the climate change impact on the water-use efficiency of crop production is the focus of the current research. The knowledge background of the CWF was elaborated by the co-citation and cluster analysis of references, which consists of four parts: concept, quantification, evaluation and reduction. Reducing the water requirement to improve crop water productivity through rainwater harvesting and formulating reasonable hydro-policies is the main responsive strategy to improve agricultural water-use efficiency. In particular, the accurate differentiation of the blue, green and gray water footprint calculation, considering multiple pollutants, the exploration of mitigation policies for the climate change impact and the combination of the CWF and traditional indicators, will be the focuses of future research in the CWF.