Effects of Precipitation Intensity and Temperature on NDVI-Based Grass Change over Northern China during the Period from 1982 to 2011
Effects of Precipitation Intensity and Temperature on NDVI-Based Grass Change over Northern China during the Period from 1982 to 2011
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DOI：
10.3390/rs70810164
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发表时间：
2015-08
期刊：
影响因子：
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通讯作者：
Xiuliang Yuan;Longhui Li;X. Chen;Hao Shi
中科院分区：
文献类型：
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作者：
Xiuliang Yuan;Longhui Li;X. Chen;Hao Shi
了解降水状况变化对陆地生态系统的影响对于提高我们对全球环境变化的认识至关重要，特别是在政府间气候变化专门委员会（IPCC）第五次评估预计强降水将增加的背景下。利用1982-2011年气候观测资料，结合AVHRR全球清查模型与制图研究（GIMMS）卫星反演的归一化植被指数（NDVI），分析了中国北方1.64 × 106 km 2草地植被指数的时空变化及其与降水和气温变化的关系。我们发现，平均生长季（4月至10月）草地植被指数是更敏感的强降水比中等或轻降水在相对干旱地区（RAA）和相对湿润地区（RHA），而草地植被指数对温度的敏感性与总降水量在RHA。强降水对中国北方一半以上地区（56%）影响最大，而弱降水对草地植被指数影响最大的地区（21%）主要分布在西北地区，是典型的干旱半干旱地区。我们的研究结果表明，草原的响应是不同的降水强度的变化。
The knowledge about impacts of changes in precipitation regimes on terrestrial ecosystems is fundamental to improve our understanding of global environment change, particularly in the context that heavy precipitation is expected to increase according to the 5th Intergovernmental Panel on Climate Change (IPCC) assessment. Based on observed climate data and the Advanced Very High Resolution Radiometer (AVHRR) Global Inventory Modeling and Mapping Studies (GIMMS) satellite-derived normalized difference vegetation index (NDVI), here we analyzed the spatio-temporal changes in grassland NDVI, covering 1.64 × 106 km2, in northern China and their linkages to changes in precipitation and temperature during the period 1982–2011. We found that mean growing season (April–October) grass NDVI is more sensitive to heavy precipitation than to moderate or light precipitation in both relatively arid areas (RAA) and relatively humid areas (RHA), whereas the sensitivities of grass NDVI to temperature are comparable to total precipitation in RHA. Heavy precipitation showed the strongest impacts in more than half of northern China (56%), whereas impacts of light precipitation on grass NDVI were stronger in some areas (21%), mainly distributed in northwestern China, a typical arid and semi-arid area. Our findings suggest that responses of grasslands are divergent with respect to changes in precipitation intensities.