开都—孔雀河流域NDVI动态变化及其与气温和降水的联系

Change Trend of NDVI and Its Response to Temperature and Precipitation in Long Time Series in Kaidu——Kongqi River Basin

基于2000—2014年开都—孔雀河流域的MODIS NDVI数据,采用最大合成法、偏相关分析法,结合气象站同期降水与气温数据,研究流域近15年NDVI时空动态,并分析了其与气温和降水的关系。结果表明:(1)研究区NDVI多年平均呈北部和中部高,南部和东部低的空间分布态势;(2)近15年开都—孔雀河流域植被退化区域大于植被改善区域,退化区域面积占研究区总面积的9.1%,主要集中在和静县山区;改善区域面积占总面积的6.33%,主要集中于博湖绿洲和库尔勒市及周边;84.57%的区域NDVI基本保持不变,主要集中于尉犁县;(3)植被覆盖2002年与2010年有明显改善,2001年、2004年有明显退化,其他年份退化和改善程度不一;(4)研究区NDVI对降水和气温变化均具滞后性且滞后水平存在显著的空间差异;(5)气温对NDVI的影响明显高于降水对NDVI的影响。

The MODIS NDVI data were selected from 2000 to 2014 in Kaidu-Kongqi River Basin.We used MVC,partial correlation analysis,precipitation and temperature data of meteorological stations in the same period to analyze the annual and inter-annual change trend of NDVI in recent 15 years in the region and the response to precipitation and temperature changes.The results showed that:(1)NDVI presented a high trend in the north and middle in the study area,the lower levels in the parts of the south and the east from the point of view of space distribution;(2)during the last 15 years,the vegetation degradation area was larger than that of the vegetation improvement area in Kaidu-Kongqi River Basin with respect to inter-annual change trend,the degradation area accounted for 9.1%of the study area,mainly concentrated in the mountains of Hejing County;the improved area percentage was 6.33%of the total area,mainly concentrated in the Bohu Oasis and the Korla City and the surrounding areas;and 84.57%of the region where NDVI was basically unchanged mainly concentrated in Yuli County;(3)NDVI improved significantly in 2002 and 2010 in terms of the annual change trend,but NDVI showed different degrees of degradation in the other years;(4)NDVI in the study area had hysteresis to precipitation and temperature,and the lag levels had obvious spatial differences;(5)the influence of temperature on NDVI was significantly higher than that of precipitation.