【摘要】 基于1999—2010年SPOT—VEGETATION旬值NDVI数据,并结合谐波分析、线性趋势和Kendall’sτ趋势等方法对中国各年植被生长季起止时刻进行了确定,并得到中国生长季植被覆盖的单调性趋势。结果表明:(1)1999—2010年中国植被覆盖呈明显增加趋势。中国植被覆盖变化存在4a的稳定增长期与1a的突然下降期。(2)中国生长季植被覆盖Kendall’sτ趋势平均值为0.287 3,总体上呈持续改善趋势,持续性较高的改善区主要分布在105°E以东,30°—40°N之间的区域。(3)中国植被覆盖受纬度地带性影响较为明显。纬度低,生物多样性程度较高的地区,则植被覆盖改善趋势明显,持续性强,反之改善趋势及持续性较低。黄三角和风沙区等生态脆弱区,长三角、珠三角与兰州市周边地区等经济快速发展区,植被覆盖退化严重。更多还原

【Abstract】 Using harmonic analysis,linear regression and Kendall’sτtrend,based on the 10day SPOT-VEGETATION NDVI from 1999to 2010,we determined the beginning and end times of vegetation growth of each year,found the monotonic trend of vegetation coverage in growing season and interpolated the trend difference and growing season change of vegetation coverage for different vegetation types.Results are as follows:(1)From 1999to 2010,the vegetation cover in China showed a progressively increasing trend as a whole.The annual variation of vegetation cover displayed the periodicity of 4years steady growth and 1year sudden decline.(2)On average,Kendall’sτtrend for vegetation cover in growing season in China presented a continuous improvement,being 0.2873.The improved area with high persistence was mainly distributed in the region between 30°—40°N,and to the east of 105°E.(3)The vegetation cover was controlled by the change of latitude.The trend showing improvement was more significant and persistent at low latitude with high degree of biological diversity.The vegetation cover showed serious degradation in the ecological fragile zones like the Yellow River Delta and windy-sandy region,as well as in the rapid economic development areas like the Yangtze River Delta,Pearl River Delta and surrounding area of Lanzhou City.更多还原