摘要
Desertification research plays a key role in the survival and development of all mankind.The Normalized Comprehensive Hotspots Index(NCH)is a comprehensive index that reveals the spatial distribution of research hotspots in a given research field based on the number of relevant scientific papers.This study uses Web Crawler technology to retrieve the full text of all Chinese journal articles spanning the 1980s-2018 in the Chinese Academic Journal full-text database(CAJ)from CNKI.Based on the 253,055 articles on desertification that were retrieved,we have constructed a research hotspot extraction model for desertification in China by means of the NCH Index.This model can reveal the spatial distribution and dynamic changes of research hotspots for desertification in China.This analysis shows the following:1)The spatial distribution of research hotspots on desertification in China can be effectively described by the NCH Index,although its application in other fields still needs to be verified and optimized.2)According to the NCH Index,the research hotspots for desertification are mainly distributed in the Agro-Pastoral Ecotone and grassland in Inner Mongolia,the desertification areas of Qaidam Basin in the Western Alpine Zone and the Oasis-Desert Ecotone in Xinjiang(including the extension of the central Tarim Basin to the foothills of the Kunlun Mountains,the sporadic areas around the Tianshan Mountains and the former hilly belt of the southern foothills of the Altai Mountains).Among these three,the Agro-Pastoral Ecotone in the middle and eastern part of Inner Mongolia includes the most prominent hotspots in the study of desertification.3)Since the 1980s,the research hotspots for desertification in China have shown a general downward trend,with a significant decline in 219 counties(10.37%of the study area).This trend is dominated by the projects carried out since 2002.The governance of desertification in the eastern part of the Inner Mongolia-Greater Khingan Range still needs to be strengthened.The distribution of desertification climate types reflects the distribution of desertification in a given region to some extent.The Normalized Comprehensive Hotspots Index provides a new approach for researchers in different fields to analyze research progress.
荒漠化研究关乎全人类生存与发展,“归一化综合热度指数”(Normalized Comprehensive Hot spots Index,NCH)是通过学术论文数量揭示某一科研领域研究热点空间分布的一个综合性指数。本文采用网络爬虫(Web Crawler)技术从CNKI中检索中国学术期刊全文数据库(CAJ)1980S-2018年全部中文期刊论文全文,针对检索到的253055篇有关荒漠化的文章,构建了基于NCH指数的中国荒漠化研究热点提取模型,揭示了中国荒漠化研究热点的空间分布和动态变化。研究表明:(1)归一化综合热度指数可较好地刻画中国荒漠化研究热点空间分布格局,该指数在其它领域的应用仍待验证和修正。(2)根据归一化综合热度指数可知:中国荒漠化研究热点主要分布在内蒙古农牧交错区及草原区、西部高寒地带的柴达木盆地沙漠化区和新疆的绿洲-荒漠交错带(包括塔里木盆地中部向昆仑山山麓延伸区,天山山脉周边零星分布区和阿尔泰山南麓前山丘陵带),其中以内蒙古中东部农牧交错区的荒漠化研究热度最高。(3)1980年代以来,中国荒漠化研究热度总体呈下降趋势,219个区县研究热度显著下降(占研究区面积的10.37%),该趋势由2002年以来开展的各项工程所主导,内蒙古-大兴安岭东部仍需加强治理。荒漠化气候类型分布在一定程度上反映了一个地区的荒漠化分布,归一化综合热度指数为各领域获取研究进展提供了新途径.
基金
The National Key Research and Development Program of China(2016YFC0503701,2016YFB0501502)
The Strategic Priority Research Program of Chinese Academy of Sciences(XDA19040301,XDA20010202,XDA23100201)
The Key Project of the High Resolution Earth Observation System in China(00-Y30B14-9001-14/16)
