基于GIMMS NDVI3g(the third generation of Global Inventory Modeling and Mapping Studies Normalized Difference Vegetation Index)数据,辅以趋势分析、Mann-Kendall检验、Hurst指数等方法,识别了1982—2013年及1982—1999、2000—...基于GIMMS NDVI3g(the third generation of Global Inventory Modeling and Mapping Studies Normalized Difference Vegetation Index)数据,辅以趋势分析、Mann-Kendall检验、Hurst指数等方法,识别了1982—2013年及1982—1999、2000—2013年黄土高原植被覆盖时空演变特征,并探讨其驱动因素。研究发现:1)1982—2013年及1982—1999、2000—2013年期间黄土高原生长季NDVI分别以0.019/10 a(P<0.01)、0.016/10 a(P<0.05)和0.057/10 a(P<0.001)的速率增加;2)除1999年以前林地外,所有植被类型的生长季NDVI均呈现显著的增加趋势,2000—2013年尤为明显;3)黄土高原生长季NDVI呈现由东南向西北递减的趋势,1982—2013年及1982—1999、2000—2013年NDVI显著上升的面积分别占74.94%、24.26%和53.34%,主要集中在黄土高原的北部和中部地区;4)研究区未来生长季NDVI呈持续性和反持续的比重分别为33.32%和66.68%,其中持续改善和由改善变为退化的面积分别占31.08%和61.88%;5)2000年以后降水增多与生长季NDVI上升相对应,大规模的生态工程建设对2000—2013年生长季NDVI增加有重要影响。展开更多
This study analyzed the spatial and temporal variations in the Normalized Difference Vegetation Index(NDVI) on the Mongolian Plateau from 1982–2013 using Global Inventory Modeling and Mapping Studies(GIMMS) NDVI3 g d...This study analyzed the spatial and temporal variations in the Normalized Difference Vegetation Index(NDVI) on the Mongolian Plateau from 1982–2013 using Global Inventory Modeling and Mapping Studies(GIMMS) NDVI3 g data and explored the effects of climate factors and human activities on vegetation. The results indicate that NDVI has slight upward trend in the Mongolian Plateau over the last 32 years. The area in which NDVI increased was much larger than that in which it decreased. Increased NDVI was primarily distributed in the southern part of the plateau, especially in the agro-pastoral ecotone of Inner Mongolia. Improvement in the vegetative cover is predicted for a larger area compared to that in which degradation is predicted based on Hurst exponent analysis. The NDVI-indicated vegetation growth in the Mongolian Plateau is a combined result of climate variations and human activities. Specifically, the precipitation has been the dominant factor and the recent human effort in protecting the ecological environments has left readily detectable imprints in the NDVI data series.展开更多
Variation in vegetation cover in Inner Mongolia has been previously studied by the remote sensing data spanning only one decade. However, spatial and temporal variations in vegetation cover based on the newly released...Variation in vegetation cover in Inner Mongolia has been previously studied by the remote sensing data spanning only one decade. However, spatial and temporal variations in vegetation cover based on the newly released GIMMS NDVI3g data spanning nearly thirty years have yet to be analyzed. In this study, we applied the methods of the maximum value composite （MVC） and Pearson＇s correlation coefficient to analyze the variations of vegetation cover in Inner Mongolia based on GIMMS NDVI3g data spanning from 1982 to 2013. Our results indicate that the normalized difference vegetation index （NDVI） increased at a rate of 0.0003/a during the growing seasons despite of the drier and hotter climate in Inner Mongolia during the past three decades. We also found that vegetation cover in the southern agro-pastoral zone significantly increased, while it significantly decreased in the central Alxa. The variations in vegetation cover were not significant in the eastern and central regions. NDVI is positively correlated with precipitation （r=0.617, P=0.000） and also with air temperature （r=0.425, P=0.015）, but the precipitation had a greater effect than the air temperature on the vegetation variations in Inner Mongolia.展开更多
[目的]研究鄂尔多斯地区生态格局以及在全球变化下的自然演变规律,揭示中国西部矿区人工扰动生态环境的时空变化。[方法]利用1982—2012年GIMMS NDVI 3g数据集和年均气温、降水量等气象数据,分别进行最大值合成、反距离加权法插值、线...[目的]研究鄂尔多斯地区生态格局以及在全球变化下的自然演变规律,揭示中国西部矿区人工扰动生态环境的时空变化。[方法]利用1982—2012年GIMMS NDVI 3g数据集和年均气温、降水量等气象数据,分别进行最大值合成、反距离加权法插值、线性回归与变化率分析、相关性分析等处理,揭示植被覆盖的时空变化趋势下蕴含的植物生理学机理,及其对气温和降水变化趋势的响应特征。[结果]鄂尔多斯地区植被返青期(start of season,SOS)始于4月下旬,枯黄期(end of season,EOS)结束于11月上旬,植被生长期(duration of season,DOS)NDVI初始阈值为0.12,平均生长期为198d;31a间鄂尔多斯地区植被绿度变化率(slope)为0.0023,植被变化趋势逐像元回归分析表明研究区80.8%的植被有轻微改善;31a间鄂尔多斯地区NDVI变化与年均气温和降水量的相关性分别为0.054和0.400。[结论]31a间鄂尔多斯地区植被返青期有提前趋势,枯黄期有滞后趋势,生长期有延长趋势;研究区大部分区域植被均有轻微改善;年均气温与降水量均呈现升高趋势,NDVI变化受温度和降水的共同作用,且NDVI最大值增高与年均降水量增加相关性较高,与年均气温升高相关性较低。展开更多
在气候变化和人类活动的综合影响下,青海省生态环境发生了明显变化。在此背景下,以GIMMS NDVI 3g.v1为数据源,采用Sen+Mann-Kendal方法研究青海省1982-2015年植被覆盖区域NDVI时空变化,将趋势分析和R/S(rescaled range analysis)分析叠...在气候变化和人类活动的综合影响下,青海省生态环境发生了明显变化。在此背景下,以GIMMS NDVI 3g.v1为数据源,采用Sen+Mann-Kendal方法研究青海省1982-2015年植被覆盖区域NDVI时空变化,将趋势分析和R/S(rescaled range analysis)分析叠加,研究植被生长季NDVI变化的持续性特征,并揭示植被对气候变化及人类活动的响应规律。结果表明:1)近34年青海省植被NDVI整体呈从西北到东南的增加趋势;且变异系数显示,波动性较大地区集中在柴达木盆地周边和青南牧区西北部等植被NDVI较低的区域,波动性较小地区集中在祁连山东部、东部农业区和青南牧区东南部等植被NDVI较高的区域。2)近34年青海省植被NDVI整体呈增加趋势,增长率为0.38%·10a^(-1);且NDVI变化具有明显的阶段性,存在1994年和2000年两个突变点。3)近34年青海省植被改善区域(75.4%)远大于退化区域(24.6%),其中显著改善面积占植被覆盖区域面积的40.9%,退化区随时间变化在空间上表现出明显的转移现象。4)Hurst指数表明,青海省植被变化反持续性较强,趋势分析与Hurst指数叠加得出,由退化转为改善的区域占植被覆盖区面积的13.7%,由改善转为退化的区域占植被覆盖区面积的44.3%,另41.5%的区域无法确定未来变化趋势。5)青海省植被生长季NDVI受气候变化和人类活动的双重影响,且不同植被类型对气候变化的响应存在较大差异。展开更多
文摘基于GIMMS NDVI3g(the third generation of Global Inventory Modeling and Mapping Studies Normalized Difference Vegetation Index)数据,辅以趋势分析、Mann-Kendall检验、Hurst指数等方法,识别了1982—2013年及1982—1999、2000—2013年黄土高原植被覆盖时空演变特征,并探讨其驱动因素。研究发现:1)1982—2013年及1982—1999、2000—2013年期间黄土高原生长季NDVI分别以0.019/10 a(P<0.01)、0.016/10 a(P<0.05)和0.057/10 a(P<0.001)的速率增加;2)除1999年以前林地外,所有植被类型的生长季NDVI均呈现显著的增加趋势,2000—2013年尤为明显;3)黄土高原生长季NDVI呈现由东南向西北递减的趋势,1982—2013年及1982—1999、2000—2013年NDVI显著上升的面积分别占74.94%、24.26%和53.34%,主要集中在黄土高原的北部和中部地区;4)研究区未来生长季NDVI呈持续性和反持续的比重分别为33.32%和66.68%,其中持续改善和由改善变为退化的面积分别占31.08%和61.88%;5)2000年以后降水增多与生长季NDVI上升相对应,大规模的生态工程建设对2000—2013年生长季NDVI增加有重要影响。
基金National Key Technology R&D Program of China,No.2013BAK05B01,No.2013BAK05B02National Natural Science Foundation of China,No.41571491,No.61631011Program of Introducing Talents of Discipline to Universities,No.B16011
文摘This study analyzed the spatial and temporal variations in the Normalized Difference Vegetation Index(NDVI) on the Mongolian Plateau from 1982–2013 using Global Inventory Modeling and Mapping Studies(GIMMS) NDVI3 g data and explored the effects of climate factors and human activities on vegetation. The results indicate that NDVI has slight upward trend in the Mongolian Plateau over the last 32 years. The area in which NDVI increased was much larger than that in which it decreased. Increased NDVI was primarily distributed in the southern part of the plateau, especially in the agro-pastoral ecotone of Inner Mongolia. Improvement in the vegetative cover is predicted for a larger area compared to that in which degradation is predicted based on Hurst exponent analysis. The NDVI-indicated vegetation growth in the Mongolian Plateau is a combined result of climate variations and human activities. Specifically, the precipitation has been the dominant factor and the recent human effort in protecting the ecological environments has left readily detectable imprints in the NDVI data series.
基金supported by the National Key Technology R&D Program of China(2013BAK05B01,2013BAK05B02)
文摘Variation in vegetation cover in Inner Mongolia has been previously studied by the remote sensing data spanning only one decade. However, spatial and temporal variations in vegetation cover based on the newly released GIMMS NDVI3g data spanning nearly thirty years have yet to be analyzed. In this study, we applied the methods of the maximum value composite （MVC） and Pearson＇s correlation coefficient to analyze the variations of vegetation cover in Inner Mongolia based on GIMMS NDVI3g data spanning from 1982 to 2013. Our results indicate that the normalized difference vegetation index （NDVI） increased at a rate of 0.0003/a during the growing seasons despite of the drier and hotter climate in Inner Mongolia during the past three decades. We also found that vegetation cover in the southern agro-pastoral zone significantly increased, while it significantly decreased in the central Alxa. The variations in vegetation cover were not significant in the eastern and central regions. NDVI is positively correlated with precipitation （r=0.617, P=0.000） and also with air temperature （r=0.425, P=0.015）, but the precipitation had a greater effect than the air temperature on the vegetation variations in Inner Mongolia.
文摘[目的]研究鄂尔多斯地区生态格局以及在全球变化下的自然演变规律,揭示中国西部矿区人工扰动生态环境的时空变化。[方法]利用1982—2012年GIMMS NDVI 3g数据集和年均气温、降水量等气象数据,分别进行最大值合成、反距离加权法插值、线性回归与变化率分析、相关性分析等处理,揭示植被覆盖的时空变化趋势下蕴含的植物生理学机理,及其对气温和降水变化趋势的响应特征。[结果]鄂尔多斯地区植被返青期(start of season,SOS)始于4月下旬,枯黄期(end of season,EOS)结束于11月上旬,植被生长期(duration of season,DOS)NDVI初始阈值为0.12,平均生长期为198d;31a间鄂尔多斯地区植被绿度变化率(slope)为0.0023,植被变化趋势逐像元回归分析表明研究区80.8%的植被有轻微改善;31a间鄂尔多斯地区NDVI变化与年均气温和降水量的相关性分别为0.054和0.400。[结论]31a间鄂尔多斯地区植被返青期有提前趋势,枯黄期有滞后趋势,生长期有延长趋势;研究区大部分区域植被均有轻微改善;年均气温与降水量均呈现升高趋势,NDVI变化受温度和降水的共同作用,且NDVI最大值增高与年均降水量增加相关性较高,与年均气温升高相关性较低。
文摘在气候变化和人类活动的综合影响下,青海省生态环境发生了明显变化。在此背景下,以GIMMS NDVI 3g.v1为数据源,采用Sen+Mann-Kendal方法研究青海省1982-2015年植被覆盖区域NDVI时空变化,将趋势分析和R/S(rescaled range analysis)分析叠加,研究植被生长季NDVI变化的持续性特征,并揭示植被对气候变化及人类活动的响应规律。结果表明:1)近34年青海省植被NDVI整体呈从西北到东南的增加趋势;且变异系数显示,波动性较大地区集中在柴达木盆地周边和青南牧区西北部等植被NDVI较低的区域,波动性较小地区集中在祁连山东部、东部农业区和青南牧区东南部等植被NDVI较高的区域。2)近34年青海省植被NDVI整体呈增加趋势,增长率为0.38%·10a^(-1);且NDVI变化具有明显的阶段性,存在1994年和2000年两个突变点。3)近34年青海省植被改善区域(75.4%)远大于退化区域(24.6%),其中显著改善面积占植被覆盖区域面积的40.9%,退化区随时间变化在空间上表现出明显的转移现象。4)Hurst指数表明,青海省植被变化反持续性较强,趋势分析与Hurst指数叠加得出,由退化转为改善的区域占植被覆盖区面积的13.7%,由改善转为退化的区域占植被覆盖区面积的44.3%,另41.5%的区域无法确定未来变化趋势。5)青海省植被生长季NDVI受气候变化和人类活动的双重影响,且不同植被类型对气候变化的响应存在较大差异。
