摘要
在对1982-1999年NOAA/AVHRR NDVI数据集进行缺失处理、平滑处理以及残存误差订正的基础上,利用基于NDVI累积频率曲线的Logistic拟合模型计算生成了各年份全国植被绿度始期数据,统计了所有气候植被类型和生物气候区的平均绿度始期,并对不同空间类型植被绿度始期的年际变化趋势与显著性程度、时空变化特征等做了统计分析。结果表明:①全国大部分地区植被绿度始期呈提前趋势,其中华北平原、贵州东北部、湖南中南部山地丘陵区、广东西部地区以及内蒙古高原东部典型草原区等明显提前。②植被绿度始期年际波动程度高于10天的地区主要分布在农业植被区、常绿植被区和草原区,其中河套平原、关中盆地、河南中东部、川西盆地、广东、藏东南边缘地带以及台湾部分地区超过15天。③除温带荒漠以外,其它所有植被类型绿度始期均为提前趋势。④从各生物气候区空间变化来看,随着年积温降低和干旱指数增大,植被绿度始期大致呈推迟趋势;从年际变化来看,华南、华东、华中、华北、内蒙、东北和青藏区植被绿度始期提前,陕晋和西北区植被绿度始期推迟。⑤受1982～1983年厄尔尼诺事件影响,各空间类型植被绿度始期分别表现为推迟和提前趋势。
Beginning date of greenness period of vegetation （BGP） is closely related to seasonal dynamics of the lower atmosphere and is therefore an important variable in influences and feed- back mechanisms of global climate variation to terrestrial ecosystem. Detecting BGP using remote- ly sensed data at regional or global scales has become an advanced topic in geography and ecolo- gy. Based on the processed NOAA/AVHRR NDVI data, the study is to use Logistic fitting model on cumulative frequency of NDVI to compute BGP of China by pixels from 1982 to 1999, count the annual average BGP of every vegetation type and bio-elimate district, and analyze the inter- annual change trends, spatio-temporal dynamic change feature of BGP of various spatial types. The results indicate that： （1） BGP have an advance trend in most regions and obviously advance in North China Plain, northeast Guizhou, the middle and south Hunan, west Guangxi and typical grassland area of east Inner Mongolia. （2） The regions in which inter-annual fluctuation of BGP are over 10 days are mainly distributed in the area covered with agricultural vegetation types, the areas covered with evergreen vegetation types and the areas covered with steppe vegetation types. Thereinto, the fluctuation of BGP in Hetao plain, Guanzhong basin, east Henan, west Sichuan basin, Guangdong, Taiwan and so on, are over 15 days. （3） BGPs of the other vegetation types except temperate desert show an advance trends. （4） With the reduction of annual accumulative temperature and increase of drought indices, BGP of various bio-elimate areas delay. An advance of BGP is found in South China, East China, Central China, North China, Inner Mongolia, Northeast China and Tibet, whereas a delay occurred in Shaanxi, Shanxi and Northwest China. （5） BGP of all vegetation types evidently delay in 1982, 1983 or 1984, which may be associated with the strong EI-Nino effect in the 1982-1983 period.
出处
《地理科学进展》
CSCD
北大核心
2008年第6期32-40,共9页
Progress in Geography
基金
国家科技支撑计划课题(2006BAD04B07)
关键词
NDVI
植被绿度始期
植被类型
生物气候区
中国
NDVI
beginning date of vegetation greenness period
vegetation type
bio-climatearea
China
