毛乌素沙地属于我国北方农牧交错区,生态环境脆弱,植被生长受气候环境影响较大。基于1982—1999年GIMMS NDVI3g.v1数据、2000—2020年MOD13Q1数据,以及相关气象站点的气温降水数据,运用趋势分析、变异系数、偏相关分析及Hurst指数等方法,探讨1982—2020年毛乌素沙地植被生长时空特征及其对气候变化的响应。研究结果表明:1)毛乌素沙地植被生长状况呈现持续向好趋势,每10 a的增速为1.3%,以2005年为拐点,2005年以前植被长势缓慢,之后长势迅猛。2)毛乌素沙地NDVI均值介于0.10~0.41之间,空间分布呈“西低东高”的特征,沙地植被变化以增加为主,约占总面积的94.07%,其中显著增加占57.43%,极显著增加占30.14%;植被的空间变化稳定性地区差异明显,高波动变化区域占比最大,为35.95%,带状分布于沙地东南部边缘植被生长旺盛区域。3)4,6,8月,毛乌素沙地NDVI与气温正向相关系数较高;6—9月,NDVI与降水正相关性较强,降水对沙地植被生长发育的影响更大,植被变化的同向特征强于反向特征。4)毛乌素沙地未来变化趋势将以持续改善和持续退化为主,持续改善占总面积的51.49%,持续退化占46.49%。

Mu Us Sandy Land belongs to the agro-pastoral staggered area in northern China,the ecological environment is fragile,and the vegetation growth is greatly affected by the climatic environment.Based on GIMMS NDVI3g.v1 from 1982 to 1999 and MOD13Q1 from 2000 to 2020,combined with the temperature and precipitation data of relevant meteorological stations,this paper discussed the spatiotemporal characteristics of vegetation growth and its response to climate change in Mu Us Sandy Land from 1982 to 2020 by using trend analysis,coefficient of variation,partial correlation analysis and Hurst index.The research results showed:1) The vegetation growth of Mu Us Sandy Land showed a continuous upward trend,with an increase rate of 1.3% per 10 a,with 2005 being the inflection point,and the vegetation growth being slow before 2005 and rapidly thereafter.2) The NDVI_average range of Mu Us Sandy Land was between 0.10~<0.41,and spatial distribution characterized by "low west and high east ",and the change trend was mainly increased,accounting for about 94.07% of the total area,of which a significant increase accounted for 57.43% and a very significant increase accounted for 30.14%;The spatial variation and stability of vegetation varied significantly,and the proportion of high fluctuation change area was 35.95%,and the bands were distributed in areas with strong vegetation growth at the southeast edge of sandy land.3) The positive correlation coefficient between NDVI and temperature in April,June and August was high,and the positive correlation coefficient between NDVI and precipitation from June to September was strong,and precipitation had a greater impact on the growth and development of sandy vegetation,and the co-directional characteristics of vegetation change were stronger than the reverse characteristics.4) The future change trend of Mu Us Sandy Land would be mainly continuous improvement and continuous degradation,with continuous improvement accounting for 51.49% of the total area and continuous degradation accounting for 46.49%.