摘要
选取长江上游地区生态环境相对脆弱的宜宾市为典型案例,分析其16年来NDVI所表征的植被生长动态变化。以MODIS MOD 13Q1为数据源,采用Sen+Manna-Kendall非参数检验方法和Hurst指数模型,分析NDVI时间变化特征、变化趋势与未来可持续特征,并应用空间转移矩阵和重心迁移模型分析其空间变化特征,最后应用地理探测器模型探测影响NDVI空间分布的主导因素,进一步揭示NDVI分异特征及其驱动力。结果表明:(1)2000—2015年宜宾市植被覆盖整体状况良好,自北向南逐渐优化,多年平均NDVI大于0.6的区域占52.06%。年际NDVI以极显著趋势波动增长,平均年际变化率达到0.007/a,极显著增长区域面积达70.18%。与此同时,NDVI增长整体持续性不强,未来可能出现波动的区域占53.65%。(2)2000—2015年间宜宾市植被生长以正向演进为主,演进过程和已有生态建设工程成效研究结论相符,生态环境不断优化。(3)宜宾市NDVI主要受一系列地表差异,包括海拔、年均温、土地利用类型、人口密度所决定,其因子解释力均超过25%,自然环境因素与人类活动共同作用对NDVI影响更加显著。
In this paper,we chose Yibin City as a typical case,which is the district of relatively fragile eco⁃environment in the upper reaches of the Yangtze River,to study the dynamic changes of vegetation growth characterized by Normalized Difference Vegetation Index(NDVI)in past 16 years.Based on MODIS MOD 13Q1 data,we analyzed the variation characteristics in time,variation tendency,and future sustainable characteristics of NDVI by using the Sen+Manna⁃Kendall nonparametric test and the Hurst index.The spatial variation characteristics were analyzed by the transition matrix and gravity migration model.Furthermore,we explored the dominant factors,and analyzed distribution characteristics and driving forces of the NDVI with application of Geodetector model.The results showed as follows.(1)During 2000 to 2015,the fractional vegetation cover in Yibin City was in a good growth state,with the tendency of gradually optimized from north to south.The area with average annual NDVI more than 0.6 accounted for 52.06%.With the average annual variation rate of 0.007/a,the annual NDVI increased significantly in fluctuation,which accounted for 70.18%.With the Hurst index,the variation of NDVI was not wide.The potential fluctuation area accounted for 53.65%in the future.(2)During 2000 to 2015,vegetation growth in Yibin City was dominated by positive evolution.The evolution process was consistent with the results of previous studies on the effect of eco⁃construction projects.And the ecological environment was constantly optimized.(3)The NDVI in Yibin City was determined by a series of surface differences,including altitude,average annual temperature,land⁃use type,and population density.The explanatory power of these factors exceeded 25%.The combination of natural factors and human activities had a more significant impact on NDVI.
作者
陶帅
邝婷婷
彭文甫
王广杰
TAO Shuai;KUANG Tingting;PENG Wenfu;WANG Guangjie(The Institute of Geography and Resources Science,Sichuan Normal University,Chengdu 610068,China;Key Laboraotry of Land Resources Evaluation and Monitoring in Southwest,Ministry of Education,Sichuan Normal University,Chengdu 610068,China)
出处
《生态学报》
CAS
CSCD
北大核心
2020年第14期5029-5043,共15页
Acta Ecologica Sinica
基金
国家自然科学基金项目(41371125)
教育部人文社科基金项目(17YJA850007)。
关键词
NDVI
长江上游
时空变化
空间转移矩阵
地理探测器
宜宾市
NDVI
the upper reaches of the Yangtze River
spatio⁃temporal variation
transition matrix
Geodetector⁃model
Yibin City
