地理学报 ›› 2015, Vol. 70 ›› Issue (5): 705-716.doi: 10.11821/dlxb201505003

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2000-2014年秦巴山区植被覆盖时空变化特征及其归因

刘宪锋1,2(), 潘耀忠1,2(), 朱秀芳1,2, 李双双1,3   

  1. 1. 北京师范大学地表过程与资源生态国家重点实验室,北京 100875
    2. 北京师范大学资源学院,北京 100875
    3. 北京师范大学减灾与应急管理研究院,北京 100875
  • 收稿日期:2014-12-21 修回日期:2015-02-11 出版日期:2015-05-20 发布日期:2015-06-11
  • 作者简介:

    作者简介:刘宪锋(1986-), 男, 黑龙江鹤岗人, 博士研究生, 主要从事资源环境遥感、灾害遥感研究。E-mail: liuxianfeng7987@163.com

  • 基金资助:
    国家国家“高分辨率对地观测系统”重大专项资助

Spatiotemporal variation of vegetation coverage in Qinling-Daba Mountains in relation to environmental factors

Xianfeng LIU1,2(), Yaozhong PAN1,2(), Xiufang ZHU1,2, Shuangshuang LI1,3   

  1. 1. State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China
    2. College of Resources Science & Technology, Beijing Normal University, Beijing 100875, China
    3. Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875, China
  • Received:2014-12-21 Revised:2015-02-11 Online:2015-05-20 Published:2015-06-11
  • Supported by:
    Major Project of High-resolution Earth Observation System

摘要:

利用MODIS-NDVI数据,辅以趋势分析、Hurst指数及偏相关分析等方法,本文探讨了2000-2014年秦巴山区植被覆盖时空变化特征及未来趋势,并对其驱动因素进行分析。研究发现:① 近15年秦巴山区植被覆盖呈显著增加趋势,增速为2.8%/10a,其中2010年之前植被覆盖呈持续增加趋势,增速为4.32%/10a,而2010年之后呈连续下降态势,降速为-6.59%/10a;② 空间上,植被覆盖格局呈现“中间高、四周低”的分布特征,高值区主要分布在陕西境内的秦岭山地和大巴山山地;③ 秦巴山区植被覆盖呈增加和减少趋势的面积分别占81.32%和18.68%;然而,分段结果表明,2010-2014年有71.61%的区域植被覆盖呈下降趋势;④ 秦巴山区植被覆盖变化的反向特征强于同向特征,其中46.89%的区域将由改善转为退化,而持续改善地区仅占34.44%;⑤ 植被覆盖变化主要归因于降水的减少,同时拉尼娜年的植被覆盖整体好于厄尔尼诺年;⑥ 人类活动对植被覆盖造成双重影响,是植被覆盖变化的另一重要影响因素。

关键词: 植被覆盖, 时空变化, 归因分析, ENSO, 秦巴山区

Abstract:

The Qinling-Daba (Qinba) Mountains, a key ecological zone of terrestrial ecosystem, has experienced a significant change of vegetation coverage in recent years, which is characterized by rapid climate change. Using MODIS-NDVI dataset, the current study investigated the patterns of spatiotemporal variation of vegetation coverage in the Qinba Mountains during the period 2000-2014. In addition, possible environmental factors affecting this variation were identified. Sen+Mann-Kendall model and partial correlation analysis were used to analyze the data, followed by the calculation of Hurst index in order to analyze future trends of vegetation coverage. The results of the study showed that (1) the Normalized Difference Vegetation Index (NDVI) of the study area revealed a significant increase during 2000-2014 (linear tendency 2.8%/10a). During this period, a stable increase was detected before 2010 (linear tendency 4.32%/10a), followed by a sharp decline after 2010 (linear tendency -6.59%/10a). (2) In terms of spatiotemporal variation, vegetation cover showed a "high in the middle and low in surroundings" pattern. High values of vegetation coverage were mainly found in the Qinba Mountains of Shaanxi Province, while low values of vegetation coverage were mainly observed in Longnan, Tianshui, and Gannan prefectures occupied by arable land. (3) The area covered with vegetation was larger than the degraded area, accounting for 81.32% and 18.68% of the total area, respectively. Piecewise analysis revealed that 71.61% of the total study area showed a decreasing trend in vegetation coverage during 2010-2014, of which, the extremely significant and significant decrease accounted for 6.38% and 3.45%, respectively. (4) The reverse characteristics of vegetation coverage change were stronger than the same characteristic in the Qinba Mountains. Some 46.89% of the entire study area is predicted to decrease in future, while 34.44% of the total area will follow a continuous increasing trend. (5) The change of vegetation coverage was mainly attributed to the deficit of precipitation. At the same time, vegetation coverage during La Nina years was larger than that during El Nino years. Statistical analysis showed that positive and negative anomaly pixels accounted for 28.37% and 71.63%, respectively during El Nino years and 80.48% and 19.52%, respectively during La Nina years. (6) Human activities can induce ambiguous effects on vegetation coverage: both positive effect (through the implementation of the ecological restoration project) and negative effect (through urbanization) were observed.

Key words: vegetation coverage, spatiotemporal variation, attribution analysis, ENSO, Qinling-Daba (Qinba) Mountains