Scientific research into isotope hydrograph separation (IHS) has rapidly increased in recent years. However, there is a lack of systematic and quantitative research to explore how this field has evolved over time. In this study, the methods of text mining and bibliometric analysis were combined to address this shortcoming. The results showed that there were clear periodical characteristics in IHS studies between 1986 and 2019. High-frequency words, e.g., catchment, stable isotope, runoff, groundwater, precipitation, runoff generation, and soil, were the basic topics in IHS studies. Forest and glacier/snow were the main landscapes in this research field. ‘Variation’, ‘spatial’, and ‘uncertainty’ are hot issues for future research. Today, studies involving the geographical source, flow path, and transit/residence time of streamflow components have enhanced our understanding of the hydrological processes by using hydrometeorological measurements, water chemistry, and stable isotope approaches. In the future, new methods, such as path analysis and ensemble hydrograph separation, should be verified and used in more regions, especially in remote and mountainous areas. Additionally, the understanding of the role of surface water in streamflow components remains limited and should be deeply studied in the future.

中文翻译：

---

全球同位素水文分离研究历史和趋势：文本挖掘和文献计量分析研究

近年来，对同位素水文过程图分离 (IHS) 的科学研究迅速增加。然而，缺乏系统和定量的研究来探索该领域如何随着时间的推移而演变。在本研究中，结合文本挖掘和文献计量分析的方法来解决这个缺点。结果表明，1986-2019年IHS研究具有明显的周期性特征，流域、稳定同位素、径流、地下水、降水、径流生成、土壤等高频词是IHS研究的基本主题。森林和冰川/雪是该研究领域的主要景观。“变异”、“空间”和“不确定性”是未来研究的热点问题。今天，研究涉及地理来源、流动路径、通过使用水文气象测量、水化学和稳定同位素方法，水流分量的过境/停留时间增强了我们对水文过程的理解。未来，路径分析、集合水位图分离等新方法应在更多地区尤其是偏远山区得到验证和应用。此外，对地表水在水流成分中的作用的理解仍然有限，应在未来深入研究。