摘要
利用1998—2012年SPOT NDVI数据和气象站点的温度和降水数据,采用趋势分析和相关分析法,研究了我国西南岩溶区NDVI时空变化特征,并分析了NDVI与气候因子的关系。结果表明:(1)近15年来,西南岩溶区NDVI变化整体呈显著增加趋势,增速为0.052/10a,9月份NDVI达到最大值,2月份降到最小值;NDVI增加的区域占97.13%,其中显著增加(p<0.05)的区域占17.60%,减少区域占2.87%,显著减少(p<0.05)占0.35%。(2)从年际变化来看,NDVI与温度和降水量的相关系数各异,其中42.75%的地区NDVI与温度呈正相关,57.25%区域呈负相关;20.15%的地区NDVI与降水量呈正相关,而79.85%区域呈负相关,说明温度对研究区植被生长的影响大于降水量。(3)从年内变化来看,NDVI与当月温度和降水量的相关系数高于年际,91.62%的NDVI与当月温度呈正相关性,其中显著正相关(p<0.05)约占75.94%;94.29%的NDVI与当月降水量呈正相关,其中显著正相关(p<0.05)约占51.05%;表明水热因子的季节变化对植被生长影响更大。NDVI受前1个月温度和前2个月降水量的影响最显著,表现出明显的滞后效应。
The spatial and temporal variation of NDVI and its relationship with climate factors in the southwest karst area of China during the period from 1998 to 2012have been examined based on SPOT NDVI data and temperature/precipitation data from meteorological stations by using linear regression and correlation analysis.The results showed that：（1）during the past 15 years,NDVI overall increased significantly and with the growth rate of 0.052 per decade,maximum NDVI appeared in September and minimum in February,areas with NDVI increase accounted for97.13%and about 17.60% of area increased significantly（p〈0.05）,the degraded areas accounted for 2.87% and with 0.35% passing p0.05 significance test;（2）at the annual scale,correlations between NDVI and temperature/precipitation had the distinct spatial difference in the southwest karst area of China,the correlation of NDVI with temperature was positive in 42.75% of the total area,and negative in the rest area,while its correlation with precipitation was positive in 20.15% of the study area,and negative for the rest area,above analysis indicated that temperature affected growth more significantly than precipitation;（3）the correlations between NDVI and temperature/precipitation at the monthly scale were higher than the annual scale,the area with positive correlation between NDVI and temperature accounted for 91.62% of the total area,and area with significant positive correlation（p〈0.05）accounted for 75.94% of the total area;94.29% of NDVI was positively related with month precipitation,and significantly positive correlation（p〈0.05）accounted for about 51.05%.The statistics reflected that the vegetation growth was mainly affected by the seasonal variation of hydro-thermal factors.NDVI was significantly affected by the preceding one month′s temperature and the preceding two months′precipitation,and there was obvious lag-effect.
出处
《水土保持研究》
CSCD
北大核心
2016年第5期169-174,共6页
Research of Soil and Water Conservation
基金
国家自然科学基金(41261088
41461085)
广西"八桂学者"岗位专项经费
广西空间信息与测绘重点实验室项目(1305114-11)
关键词
西南岩溶区
NDVI
气候因子
相关分析
southwest karst area
NDVI
climate factor
correlation analysis
