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
The purpose of this paper is to develop Advanced Very High Resolution Radiometer(AVHRR)Global Inventory Modelling and Mapping Studies(GIMMS)Normalised Difference Vegetation Index(NDVI;AVHRR GIMMS NDVI for short)based ...The purpose of this paper is to develop Advanced Very High Resolution Radiometer(AVHRR)Global Inventory Modelling and Mapping Studies(GIMMS)Normalised Difference Vegetation Index(NDVI;AVHRR GIMMS NDVI for short)based fraction of absorbed photosynthetically active radiation(FPAR)from 1982 to 2006 and focus on their seasonal and spatial patterns analysis.The available relationship between FPAR and NDVI was used to calculate FPAR values from 1982 to 2006 and validated by Moderate-resolution Imaging Spectroradiometer(MODIS)FPAR product.Then,the seasonal dynamic patterns were analysed,as well as the driving force of climatic factors.Results showed that there was an agreement between FPAR values from this study and those of the MODIS product in seasonal dynamic,and the spatial patterns of FPARvary with vegetation type distribution and seasonal cycles.The time series of average FPAR revealed a strong seasonal variation,regular periodic variations from January 1982 to December 2006,and opposite patterns between the Northern and Southern Hemispheres.Evergreen vegetation FPARvalues were close to 0.7.A clear single-peak curve was observed between 308N and 808N?an area covered by deciduous vegetation.In the Southern Hemisphere,the time series fluctuations of FPAR averaged by 0.78 latitude zones were not clear compared to those in the Northern Hemisphere.A significant positive correlation(PB0.01)was observed between the seasonal variation of temperature and precipitation and FPAR over most other global meteorological sites.展开更多
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
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.
基金funded by the National Basic Research Program of China(contract:2009CB723902),Key Project of Digital Earth Science Platform CEODE(contract:Y01002101A),National Natural Science Foundation of China(contract:41001205/D0106).The authors acknowledge the following data support:the AVHRR GIMMS NDVI from Global Land Cover Facility(GLCF)Globcover products from European Space Agency(ESA)and the ESA Globcover Project led by Medium Resolution Imaging Spectrometer Instrument(MERIS)France+1 种基金temperature,precipitation from National Climatic Data Center(NCDC)MODIS FPAR product from the Warehouse Inventory Search Tool provides access to a complete data record of all MODIS and ASTER products available from the LP DAAC,respectively.
文摘The purpose of this paper is to develop Advanced Very High Resolution Radiometer(AVHRR)Global Inventory Modelling and Mapping Studies(GIMMS)Normalised Difference Vegetation Index(NDVI;AVHRR GIMMS NDVI for short)based fraction of absorbed photosynthetically active radiation(FPAR)from 1982 to 2006 and focus on their seasonal and spatial patterns analysis.The available relationship between FPAR and NDVI was used to calculate FPAR values from 1982 to 2006 and validated by Moderate-resolution Imaging Spectroradiometer(MODIS)FPAR product.Then,the seasonal dynamic patterns were analysed,as well as the driving force of climatic factors.Results showed that there was an agreement between FPAR values from this study and those of the MODIS product in seasonal dynamic,and the spatial patterns of FPARvary with vegetation type distribution and seasonal cycles.The time series of average FPAR revealed a strong seasonal variation,regular periodic variations from January 1982 to December 2006,and opposite patterns between the Northern and Southern Hemispheres.Evergreen vegetation FPARvalues were close to 0.7.A clear single-peak curve was observed between 308N and 808N?an area covered by deciduous vegetation.In the Southern Hemisphere,the time series fluctuations of FPAR averaged by 0.78 latitude zones were not clear compared to those in the Northern Hemisphere.A significant positive correlation(PB0.01)was observed between the seasonal variation of temperature and precipitation and FPAR over most other global meteorological sites.
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。
