自然资源学报 ›› 2014, Vol. 29 ›› Issue (3): 398-409.doi: 10.11849/zrzyxb.2014.03.004

• 资源生态 • 上一篇    下一篇

柴达木盆地植被生长时空变化特征及其对气候要素的响应

徐浩杰, 杨太保   

  1. 兰州大学资源环境学院冰川与生态地理研究所, 兰州730000
  • 收稿日期:2013-01-06 修回日期:2013-03-16 出版日期:2014-03-20 发布日期:2014-03-20
  • 作者简介:徐浩杰(1988-),男,江苏无锡人,硕士研究生,主要从事全球植被生态学研究。E-mail:xuhj2011@lzu.edu.cn
  • 基金资助:

    国家自然科学基金资助项目(41271024)。

Spatial-temporal variations of Vegetation Activities and Its Responses to Climatic Factors in the Qaidam Basin

XU Hao-jie, YANG Tai-bao   

  1. Institute of Glaciology and Ecogeography, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
  • Received:2013-01-06 Revised:2013-03-16 Online:2014-03-20 Published:2014-03-20

摘要:

以2001—2010 年MODIS NDVI 植被数据为基础,并结合该区同期气温和降水量数据,采用线性趋势分析、偏相关分析、Hurst 指数等数理分析方法,研究了近10 a 来柴达木盆地植被时空变化特征、影响因素及未来可能的变化趋势。结果表明:①2001—2010 年柴达木盆地植被生长季NDVI平均值(NDVI)呈显著增加趋势,线性增长率为0.041/10 a。柴达木盆地主要植被类型灌丛、草原、荒漠NDVI 的线性增长率分别为0.043/10 a、0.034/10 a、0.028/10 a;②柴达木盆地植被变化具有阶段性特征,整体呈“S”型增长,具有两次明显的植被快速增长期;③柴达木盆地植被改善面积占研究区总面积的12.43%,并主要分布在布尔汉布达山、祁漫塔格山、鄂拉山、柴达木山、宗务隆山的高山区,冬给措纳湖周边和绿洲核心区。植被退化面积仅占研究区总面积的0.35%,并主要分布在绿洲边缘区,特别是柴达木河绿洲和那陵格勒河绿洲的中下游地区;④植被NDVI 与1—5 月平均气温以及5—8 月可利用降水量呈显著正相关关系,植被生长与温度呈显著正相关的区域主要分布在绿洲核心区及高山区,占植被区面积的8.36%,植被生长与可利用降水量呈显著正相关的区域主要分布在低山区及山地河谷地带,占植被区面积的30.95%;⑤植被生长季延长和生长加速是柴达木盆地植被NDVI 增加的主要原因,气候的暖湿化是促使柴达木盆地植被改善的主要驱动力;⑥柴达木盆地植被改善具有强持续性,未来大部分区域植被将持续改善。

关键词: 温度, 柴达木盆地, 植被变化, 可利用降水量

Abstract:

Global climate change has led to significant vegetation changes in recent decades. The Qaidam Basin, most of which was located in hyper-arid areas, is undergoing a process of prominent warming. It is necessary to investigate the response of vegetation to the climatic variations for a better understanding of the accumulated consequence of climate change. Vegetation NDVI is an important indicator for evaluating terrestrial eco-system change. Based on MODIS NDVI and climate data during the period 2001-2010, we analyzed spatial and temporal variation of vegetation change and its reasons for that by using methods of linear regression, partial correlation, the Hurst index and other methods. Results were shown as follows: 1) During 2001-2010, the growing season NDVI (NDVI) of the study area was improved progressively, with a linear tendency of 0.041/10 a. Trends in NDVI of shrubs, grasslands and shrub-deserts were +0.043/10 a, +0.034/10 a and +0.028/10 a respectively. The shrubs improved most significantly. 2) Vegetation restoration was characterized by two fast-growing periods, with an "S-shaped" increasing curve. 3) Vegetation restoration and degradation area accounted for about 12.43% and 0.35% of the whole study area. The restoration area was mainly distributed in high altitudes of the Burhan Budai Mt., Qimantag Mt., Ela Mt., Qaidam Mt. and Zongwulong Mt. surrounding areas of the Donggi Conga Lake and core areas of oasis. The degradation area was mainly distributed in margins of oasis, especially in the middle and lower reaches of the Qaidam and Leningrad rivers. 4) Vegetation NDVI was most positively related with average temperature (January to May) and available precipitation (May to August). The significant positive region between vegetation growth and temperature occupied about 8.36% of the vegetated lands and was mainly distributed in core areas of oasis and high latitude mountains. The significant positive region between vegetation growth and available precipitation made up about 30.95% of the vegetated lands and was mainly distributed in low latitude mountains and mountain valleys. Vegetation growth was more sensitive to hydrological conditions than to thermal conditions. 5) Vegetation growing season extension and growth acceleration were the main reasons for vegetation restoration in the Qaidam Basin. Warmer and wetter climate was the main driving force to promote vegetation growth in the Qaidam Basin. 6) The Hurst index of NDVI time series showed vegetation restoration was persistent. It is expected that promotion in vegetation growth will expand to the most parts of the region. This finding not only underlines the importance of temperature for vegetation growth in high latitudes, but also verifies the effects of precipitation on vegetation growth in low attitudes.

Key words: available precipitation, vegetation change, the Qaidam Basin, temperature

中图分类号: 

  • Q948.1