| Abstract: | Water quality deterioration as a consequence of nonpoint source (NPS) pollution or diffuse pollution has been documented
around the world (Davis and Koop 2006; Ma et al. 2011; Novotny 1999; Smith 2003). This deterioration not only damages
the social and ecological functions of water bodies as water supply, fisheries, ecosystem maintenance, and recreation
(Pretty et al. 2003), but also largely raises water treatment and policy response costs (Novotny 1999; Pretty et al. 2003). Understanding and evaluating the processes of pollution generation, transport, and transformation are continuous challenges for scientists and engineers. Modeling as a way to simplify the complex natural processes has been widely used in NPS pollution research (Zhuang et al. 2012). There are various NPS pollution models available now, which were summarized and compared in different previous studies (Alexander et al. 2002; Borah and Bera 2003; Shen et al. 2012). These reviews of available models are meaningful, though they hardly provide a direct overview of worldwide research efforts and the general trends in NPS pollution modeling. Since researchers have conducted research in this field for several decades, a comprehensive and quantitative review of past efforts, including influencing researchers and their performance, participating regions and their activity, and general shift of key issues, will provide an informed perspective on future research. Bibliometrics, which utilizes visual and quantitative analysis to summarize trends in
selected research fields (Pritchard 1969), can reveal research patterns of certain field, such as publication output, author performance, geographical distribution of publications, scientific cooperation, and temporal variation of hot issues (Liu et al. 2011; Zhuang et al. 2012). The quantitative and visual characteristics of bibliometric analysis are
important supplements to traditional literature reviews. This paper presents worldwide performance and trends in NPS pollution modeling from 1994 to 2013 based on bibliometric methods. |