1982—2015年可可西里NDVI变化特征及其气候响应

Variation of NDVI and Its Response to Climate Change in Hoh Xil during the Period of 1982-2015

利用最新的GIMMS NDVI 3g＋数据,辅以MVC、趋势分析、变异系数及偏相关分析等方法,探讨了1982—2015年可可西里世界自然文化遗产保护区NDVI时空分布特征及变化趋势,并对其驱动因素进行分析。研究发现：（1）由于海拔引起的水热条件的变化,该研究区NDVI由西北向东南逐渐增大;（2） 34 a来研究区NDVI具有明显增长趋势,核心区NDVI增速为0. 69%·（10a）^-1,比缓冲区NDVI增速高出0. 41%·（10a）^-1;（3）研究区NDVI改善面积远大于退化面积,总体上呈缓慢上升趋势,其中核心区NDVI呈改善和退化趋势的面积分别占47. 92%和3. 00%,缓冲区中有65. 70%的面积基本不变;（4） 34 a间研究区NDVI相对较低波动变化和中等波动变化共占全区的75. 54%,主要分布在核心区的中部和南部以及缓冲区大部分区域;（5）相关和偏相关分析结果表明,该研究区NDVI受温度和降水共同影响,与降水相比,温度是影响该研究区NDVI变化的主要因素。

In this study,the latest data of GIMMS NDVI 3 g plus,MVC,trend analysis,coefficient of variation and partial correlation analysis were used to study the spatial and temporal distribution and change trend of NDVI in the Hoh Xil Natural and Cultural Heritage Reserve in Qinghai Province during the period of 1982-2015 and to analyze the driving factors. The results showed that：（1） The NDVI in the study area increased gradually from northwest to southeast due to the change of water and heat conditions caused by altitude;（2） During the period of 1982-2015,the NDVI in the study area was in an obvious increase trend,the increase rate of NDVI in the core was 0. 69% ·（10 a）^-1,and it was 0. 41% ·（10 a）^-1 higher than that in the buffer area;（3） The area of the regions with NDVI improvement in the study area was much larger than that with NDVI degeneration,and the NDVI was holistically in a slow increase trend. The areas of the regions with NDVI improvement and NDVI degeneration in the core accounted for 47. 92% and 3. 00% respectively,65. 70% area in the buffer area was basically maintained;（4） The area of the regions with relatively low and moderate NDVI fluctuation in the 34 years accounted for 75. 54% of the total,and these regions were mainly distributed in the central and southern parts of the core and most areas of the buffer zone;（5） The results of correlation and partial correlation analysis showed that the NDVI in the study area was affected by temperature and precipitation,especially by temperature.