基于文献计量的寒区流域地下水研究态势分析

Research status and development trends of groundwater in cold regions:a bibliometric review

气候变化是贯穿整个寒区地下水研究领域中重要的影响因素,对寒区流域水文过程、生态环境、工程地质和水文地质条件的影响已引起诸多学者的关注,截至2022年底该研究领域已呈现出纷繁复杂的现象。为了厘清该领域的研究态势,基于中文库(中国知网)和外文库(Web of Science和Science Direct)的文献数据,分别利用文献计量软件CiteSpace和VOSviewer、网络分析工具SCImago Graphica和Pajek,以及数据分析软件OriginPro对该领域的作者文龄、发文量、科研机构、国家地区以及关键词进行统计分析,在此基础上筛选出60篇具有代表性论文,结合ArcGIS软件所投影的研究区位置,进一步归纳与总结其研究趋势。研究表明作者文龄结构均为增长型,年发文量均呈上升趋势,而后者的作者、各个科研机构和欧美国家之间合作关系更为紧密,且美国、中国和加拿大主导该领域的研究。前者的研究热点相对局限,近年来多致力于多年冻土区冻融循环作用影响下的地下水动态对气候变化的响应研究;后者的研究热点分别从地下水、气候变化、多年冻土三个主题展开:(1)采用数值模拟、同位素和水化学示踪手段研究地下水的年龄、水均衡、水分来源和流动路径;(2)水文输入变化对地下水的补给、径流和排泄过程的影响;(3)研究高纬度寒区多年冻土消融与退化、溶解性有机碳释放与迁移、冻土地貌形成与地下水之间的联系。未来应从不同含水层地下水动态特征及其对气候变化的响应机制、冻土退化影响下含水层系统与地下水的相互作用、冻土区有机碳释放与迁移机制,以及非连续冻土区地下水与地表水的交互作用四个方向继续展开研究,并建议在高海拔山区含水层类型与水力特征,以及高纬度低海拔寒区工程地质和生态环境方面的薄弱环节上加强和完善。

Climate change is essential throughout the groundwater research field in cold regions,significantly impacting hydrological processes,ecological environment,and engineering geological and hydrogeological con⁃ditions in cold regions.This research field has attracted extensive attention from experts and scholars in different research fields.Until December 31,2022,the research field has led to many research efforts in different direc⁃tions.In order to understand the research status and development trends in this field,this paper was based on the literature data of CNKI,Web of Science(WOS),and Science Direct(SD),employing the following three methods:(1)CiteSpace,Originpro,and SCImago Graphica were used to conduct statistical and co-occurrence analyses of publications,authors’writing age structures,institutions,and countries or regions to understand the research situation and status.(2)VOSviewer and Pajek were used to identify research topics and hot spots by keywords’co-occurrence,clusters,and co-citation analysis.(3)Sixty representative papers were selected by VOSviewer and manual search and summarized to clarify this field’s leading research directions and develop⁃ment trends,combined with the locations of these papers’study areas projected by ArcGIS.The results based on CNKI showed that the authors’writing age structure was positively triangular,and the annual number of pub⁃lications was on the rise,with 86 papers published in the past four years.There needed to be more cooperation among Chinese scholars and research institutions.Research hot spots based on CNKI focused on groundwater under the influence of the freeze-thaw cycle in permafrost areas in the following two aspects:(1)Engineering geological problems such as tunnel excavation,roadbed laying,and frost damage prevention and treatment,as well as ecological environment problems of alpine meadows and wetlands;(2)Response of groundwater regime to climate change in high-altitude mountainous areas.The results based on WOS and SD showed that authors’writing age structure was trapezoidal,and the annual number of publications increased yearly,with 1057 papers published in the past four years.Cooperation significantly existed among foreign scholars,scientific research in⁃stitutions,and European and American countries.Besides,the Chinese Academy of Sciences and the United States Geological Survey contributed the most to the research field.Moreover,the United States,China,and Canada played a leading role in this field.Research hot spots based on WOS and SD focused on three core themes of groundwater,climate change,and permafrost,corresponding to the following three hot spots:(1)The groundwater age,water balance,water source,and groundwater flow path were studied using isotopes,hy⁃drochemistry,and numerical simulation;(2)Hydrological input changes caused by climate warming affected the formation process of groundwater runoff and its interaction with surface water;(3)The mechanism of perma⁃frost degradation,the release and migration of dissolved organic carbon,and the formation mechanism of perma⁃frost landforms were primarily studied in cold regions of high latitudes.The development trend of this field should be studied closely around climate change,such as characteristics of groundwater regime in different aqui⁃fers and their response mechanism to climate change,the interaction between aquifer systems and groundwater under the influence of permafrost degradation,the mechanism of organic carbon release and migration in perma⁃frost areas,and the interaction between groundwater and surface water in discontinuous permafrost areas.Re⁃cent advances suggest we continue studying aquifers’types and hydraulic characteristics in high-altitude moun⁃tainous areas and engineering geology and ecological environments in high-latitude and low-altitude cold re⁃gions.Furthermore,we recommend continuing field investigations,improving hydrogeological data,strength⁃ening numerical simulation research,and combining marginal or interdisciplinary research content boldly.This study can provide a reference for the sustainable utilization of water resources,ecological environment protec⁃tion,and geological engineering problems in cold regions.