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草业学报 ›› 2016, Vol. 25 ›› Issue (1): 1-12.DOI: 10.11686/cyxb2015111

• 研究论文 •    下一篇

三江源区近30年植被生长动态变化特征分析

杜加强1, 2, 贾尔恒·阿哈提3, 赵晨曦3, 房世峰4, 刘伟玲1, 2, 阴俊齐3, 袁新杰3, 徐延达1, 2, 舒俭民1, 2, 何萍1, 2*   

  1. 1.中国环境科学研究院,北京 100012;
    2.中国环境科学研究院环境基准与风险评估国家重点实验室,北京 100012;
    3.新疆环境保护科学研究院,新疆乌鲁木齐 830011;
    4.中国科学院地理科学与资源研究所资源与环境信息系统国家重点实验室,北京 100101
  • 收稿日期:2015-03-03 出版日期:2016-01-20 发布日期:2016-01-20
  • 通讯作者: *通信作者Corresponding author. E-mail: heping@craes.org.cn
  • 作者简介:杜加强(1980-),男,山东临沂人,副研究员,博士。E-mail: dujq@craes.org.cn
  • 基金资助:

    国家自然科学基金资助项目(41001055),国家环保公益性行业科研专项经费项目(201209027-5),中央级公益性科研院所基本科研业务专项(2012-YSKY-13)资助

Analysis of vegetation dynamics using GIMMS NDVI3g in the Three-Rivers Headwater Region from1982 to 2012

DU Jia-Qiang1, 2, JIAERHENG Ahati3, ZHAO Chen-Xi3, FANG Shi-Feng4, LIU Wei-Ling1, 2, YIN Jun-Qi3, YUAN Xin-Jie3, XU Yan-Da1, 2, SHU Jian-Min1, 2, HE Ping1, 2, *   

  1. 1.Chinese Research Academy of Environmental Sciences,Beijing 100012,China;
    2.State Key Laboratory of Environmental Criteria and RiskAssessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;
    3.Xinjiang Academy of Environmental Protection Science,Urumqi 830011,China;
    4.The State Key Laboratory of Resources and Environmental In formation System,Institute of Geographic Sciences and Natural Resources Research,ChineseAcademyofSciences,Beijing 100101,China
  • Received:2015-03-03 Online:2016-01-20 Published:2016-01-20

摘要:

三江源区为长江、黄河、澜沧江提供了丰富的水资源,其地表植被状况与我国水安全和生态安全密切相关。由于所使用的数据时间序列长度有限,以往研究缺乏近30年整体视角的连续时间序列研究,也很少分析多时段变化趋势的持续性。为此,本文利用最新发布的1982-2012年的GIMMS NDVI3g数据集,采用多个嵌套时间序列的分析方法,在多个空间尺度上,研究了近30年来三江源区各季节植被活动的变化趋势和过程。研究表明,1)三江源区生长季和各季节NDVI在近30年均呈增强趋势,春季植被变化具有明显的阶段性,1998年前后NDVI分别呈显著增加、减少趋势。2)生长季、春季和夏季NDVI的增加随时段延长而趋缓,尤其是春季减缓迅速甚至停滞,而秋季植被活动持续增强。3)尽管区域尺度生长季、春季和夏季NDVI变化趋缓,但在像元尺度显著变化的区域范围却多呈增加趋势。4)不同植被类型显著变化的季节、时段存在差异。针叶林和灌丛NDVI主要在春季前几个时段增加显著,荒漠、草甸的增加主要集中在春季、夏季前几个时段。5)各季节NDVI在14个时段增加趋势持续性的差异,引起各季节对生长季植被活动变化贡献的变化。总的趋势是,前几个时段,春季NDVI变化较为剧烈,夏季NDVI的贡献最大,而随时段延长,逐渐过渡到秋季NDVI变化幅度、变化量最大,夏季次之。

Abstract:

The Three-Rivers Headwater Region (TRHR) refers to the source area of the Yangtze River, Yellow River and Lancang River, an important water resource. Vegetation activities in this region are closely related to water and ecological security in China. As a critical component of terrestrial ecosystems, vegetation has become one of the important issues in global climate change. Numerous case studies have been conducted on vegetation dynamic trends over relatively short study periods however, few long-term studies from the 1980s to recent years have been completed because the normalized difference vegetation index (NDVI) datasets limited. Additionally there are few quantitative analyses of the consistency of vegetation trends over time. In this study, the latest GIMMS NDVI3g datasets from 1982 to 2012 were used to identify any spatiotemporal patterns in vegetation changes over the growing season and seasonal NDVI at regional, biome and pixel scales in the TRHR. To explore the change process linear regression over progressively longer periods from the initial year of the study was applied to detect vegetation growth changes in TRHR. At the regional scale, although a positive trend of growing season and seasonal NDVI were found during past three decades, there were two distinct periods with opposite trends in spring NDVI, a significant increase and a significant decrease before and after 1998, respectively. As the study period increases, the rates of NDVI increase in the spring and summer growing season markedly reduced, but in autumn the NDVI increased. However, significant NDVI increases were found in most seasons. The season and period with significant trend in NDVI differed among vegetation types. Significant increases in NDVI were observed in spring during the first few periods for coniferous forest and shrub and in spring and summer during the first few periods for desert and meadow areas. The difference in persistence of NDVI trends caused variation in the contribution of seasonal vegetation activity to plant growth. During the first few periods, the largest NDVI increase and the largest contribution were generally found in spring and in summer, respectively. During the last few periods, both the largest NDVI increase and contribution were found in autumn. It can be inferred that increases in NDVI during the growing season was mainly due to both the earlier start of vegetation growth and accelerated vegetation activity during previous periods and from both the accelerated vegetation growth and a delay in the end of the growing season during latter periods.