贵州省2001—2015年植被覆盖NDVI时空演变及其对SPEI的响应

引起植被覆盖变化的气候因子占据主导地位。研究探讨了贵州省近15年来植被指数长时间序列的变化特征、基于标准化降水蒸散指数（SPEI）的干旱时空变化特征及两者之间的相关关系，可为区域植被覆盖保护与恢复提供一定的理论依据。选择2001—2015年MODIS NDVI（1 km）及19个气象站点气温、降水数据，采用一元线性回归的方法探究贵州省近15年来植被覆盖NDVI在年、月尺度下时空演变特征，及其与气温、降水和标准化降水蒸散指数（SPEI）的相关关系。结果表明:贵州西北至东南地区多年平均NDVI呈低中高分布格局，p<0.01上的生长速率为0.051/（10 a），呈显著增加的趋势；多年平均气温、降水量的空间分布从西北到南方向呈现出低-中-高的特征，其易发生干旱的地区主要集中在贵州的西北地区，干旱在区域内的空间差异较大，黔西北、黔西南地区为易旱集中区；年均NDVI与年均SPEI、年均气温和年均降雨量的相关系数均为正值，表示NDVI与其响应因子具有一定的相关性，但与SPEI的相关性不显著，与气温和降水的相关性在p<0.01上呈显著性的正相关，且相关系数均大于0.5以上，相关程度较高；1—6月大致（p<0.01显著）呈现不显著的负相关，7—9月和11月表现为除9月（p<0.01显著）外均呈现不显著的正相关。 

Spatiotemporal Evolution of Vegetation Cover NDVI and Its Response to SPEI in Guizhou Province in 2001—2015

Climatic factors causing vegetation cover change are dominant.Variation characteristics of long time series of vegetation index in Guizhou province in recent 15 years，characteristics of drought-temporal variation based on standardized rainfall evapotranspiration index （SPEI） and correlation between them were explored，which could provide a theoretical basis for vegetation cover protection and restoration in Guizhou Area.Temperature and precipitation data of MODIS NDVI（1 km）and 19 meteorological stations in 2001—2015 were selected，and a linear regression method was used to explore temporal and spatial evolution characteristics of vegetation cover NDVI in Guizhou province in the past 15 years，and its temperature，precipitation and standardized precipitation evapotranspiration index（SPEI）.Results showed that，annual average NDVI from northwest to southeast showed a low-medium-high distribution in Guizhou province，showed a significant increase in growth rate of 0.051/（10a）at p<0.01.Spatial distribution of average temperature and precipitation from northwest to south showed characteristics of low-medium-high，and its prone to arid areas were mainly concentrated in the northwest of Guizhou.There were obvious differences in drought areas，and the most prone areas were concentrated in northwest and southwest of Guizhou.The correlation coefficients of average annual NDVI and average annual SPEI，average annual temperature and average annual rainfall were positive，indicated that NDVI had a certain correlation with its response factor，but correlation with SPEI was not significant，and correlation with temperature and precipitation was significantly positive at p<0.01，and correlation coefficients were all more than 0.5，degree of correlation was higher.There was no significant negative correlation from January to June（p<0.01），and there was no significant positive correlation from July to September and November except September（p<0.01）.