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干旱区地理 ›› 2020, Vol. 43 ›› Issue (5): 1242-1252.doi: 10.12118/j.issn.1000-6060.2020.05.09

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基于 MODIS 数据的吐鲁番盆地 2001—2017 年 植被变化及水热组合影响分析

庞 冉, 王 文   

  1. 河海大学水文水资源与水利工程国家重点实验室,江苏 南京 210098
  • 出版日期:2020-09-25 发布日期:2020-09-25
  • 作者简介:庞冉(1996-),女,安徽省霍山县人,硕士,主要从事气候变化的水文响应方面的研究.E-mail:pangran_hhu@163.com
  • 基金资助:
    国家重点研发计划课题(2017YFC0406101)

Analysis of vegetation index changes and the influence of hydrothermal combination in the Turpan Basin from 2001 to 2017 based on MODIS Data

PANG Ran, WANG Wen   

  1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University; Nanjing, Jiangsu, China, 210098
  • Online:2020-09-25 Published:2020-09-25

摘要: 中国西北干旱地区的气候变化及其对植被的影响一直备受关注。以地形特殊的吐鲁番盆 地为研究对象,利用实测气象站点数据、再分析气象格点数据以及 MODIS 卫星遥感植被指数,采用 趋势检验、线性回归、偏相关分析等方法,探究了该地区 2001—2017 年间的植被变化及其与水热组 合特征之间的关系。结果表明:(1)吐鲁番盆地降水量整体没有显著变化,但北部山区降水增长较 多,气温总体呈显著上升趋势,尤其是盆地底部中心区域增温较大。(2)全区域植被指数(NDVI)总 体呈极显著上升趋势,山区及中心区域 NDVI 增长率较大。(3)受水汽来源和日照时长的影响,吐鲁 番盆地周边山区高程 3 000 m 左右 NDVI 值最高,山区植被最好的坡向是西北坡。(4)吐鲁番盆地水 热组合复杂,水分条件是大部分地区植被生长的主要限制因素,降水与 NDVI 有较好的正相关,在 山区和荒漠区热量增加不利于植被生长,但中心区域受地下水和人类活动影响,水分的供给相对 稳定,热量增加利于植被生长。

关键词: 水热组合, 植被变化, 气候变化, NDVI, 地形, MODIS

Abstract: Climate change and its effects on vegetation in the arid areas of northwest China have been a major con? cern in the geosciences community. The case study area, the Turpan Basin, is an area of approximately 5.85 × 104 km2 in the eastern part of Xinjiang Province in northwest China. The Turpan Basin’s topography consists of a low flat area in the center with high mountains surrounding it, yielding a large elevation difference in a small distance. Water vapor brought by prevailing westerly winds is the main source of moisture in this area. The basin’s climate is very dry and hot and the hydrothermal combination is complicated. In this paper, ground-based meteorological ob? servation data, GLDAS-2.1 reanalysis meteorological data, and satellite-based MODIS normalized difference vege? tation index (NDVI) data are used to investigate the impacts of climate change, terrain, and human activities on spa? tiotemporal changes of vegetation in the Turpan Basin from 2001 to 2017. The analysis uses the methods of trend test, linear regression, and partial correlation analysis. The results of this analysis indicate that the following. (1) There was no significant change in precipitation in the Turpan Basin overall; however, the rate of increase in the northern mountains is large. Additionally, the temperature increased significantly over the whole region, especially in the central area at the bottom of Turpan Basin, with a remarkable growth rate. (2) The NDVI of the whole region exhibited a very significant upward trend, and the NDVI growth rates in the mountains and the central region were relatively large. (3) Affected by the availability of water vapor and sunlight duration, the NDVI value is the highest in the mountains around the Turpan Basin at an elevation of approximately 3,000 m. In the northern Tianshan Moun? tains, which extend from east to west, and the combination of water and heat conditions is the best in the northwest- facing slopes, which is beneficial to vegetation growth. In contrast, the north-facing and south-facing slopes have ei? ther too little or too much solar radiation. In the western Tianshan Mountains, which generally extend generally south to north, the northwest-facing slopes also have the best combination of water and heat, whereas the southeast- facing slopes have the smallest NDVI. (4) Because of the special terrain, the hydrothermal combination in the Tur? pan Basin is complex. Although water is the major limiting factor for vegetation growth in most regions, as indicated by the positive correlation between precipitation and NDVI, the effects of temperature change on NDVI are compli? cated. In the mountains and desert areas, temperature is generally negatively related to NDVI, but in the central ar? ea at the bottom of the Turpan Basin, the relationship is positive because of the accumulation of groundwater from the surrounding mountains which provides a comparatively stable water supply.

Key words: Hydrothermal Combination, Vegetation Change, Climate Change, NDVI, Terrain, MODIS