摘要
叶面积指数(LAI)是生态系统物质和能量循环过程的重要结构参数。研究植被LAI对监测估算生态环境极其脆弱的内陆干旱区具有理论和实践价值。使用LAI-2000植物冠层分析仪观测焉耆盆地植被LAI,并结合Landsat OLI的NDVI、SAVI、NDMI、NBR、NBR2、MSAVI和EVI等植被指数数据建立了LAI的反演模型,探求焉耆盆地LAI的空间分布特征及规律。结果表明:(1)各植被指数与观测的LAI均有明显的相关性。其中,SAVI与LAI的对数函数模型更好地模拟出研究区的LAI(R2=0.84);通过LAI-SAVI模型反演研究区LAI的空间分布,估算精度可达89%(R2=0.82,RMSE=0.23);(2)博斯腾湖小湖湿地、博斯腾湖大湖西北端的黄水沟入湖沼泽区以及焉耆盆地北部冲洪积扇平原绿洲区的LAI值较高,达3.85;焉耆盆地山区和平原区之间的过渡带和博斯腾湖南部的沙漠区LAI较低;(3)焉耆盆地LAI以博斯腾湖为中心环状分布,LAI随着研究区域与湖、河流距离的增加而逐渐降低的趋势。
Leaf area index（LAI）is a primary parameter for the energy flows and matter cycles in ecosystems.Since the ecological system in the arid area is extremely fragile,studying the LAI has great theoretical and practical contributions to monitoring and estimating the changes of ecological environment in arid lands.In this paper,we use the Vegetation Indexes（including NDVI,SAVI,NDMI,NBR,NBR2,MSAVI and EVI）-LAI method to estimate the spatial distribution characteristics of LAI value in the Yanqi Basin,Xinjiang,China.The modeling data is comprised of LAI and Vegetation Indexes,which were acquired by field measurements by LAI-2000 and indoor processing work of Landsat OLI remotely sensed image respectively.Then the LAI distribution map was acquired by using validated SAVI-LAI model.The spatial distribution characteristics of LAI in the study area were analyzed.The results show that：（1）All vegetation indices have good relevance with LAI,and among them the logarithmic function model of SAVI and LAI has the highest goodness of fit（R2=0.82）.The estimation accuracy of LAI is about 89%,R2=0.86,RMSE=0.23;（2）There are three relatively high value areas in the distribution map of LAI,Bosten Lake Wetland area,the reeds area in the Huangshuigou River in northwest part of Bosten Lake and Oasis area in northern part of Yanqi Basin,and the highest LAI value reaches about 3.85.The LAI has the lower values in the transitional zone between the mountains and the plain area,and the desert area in the south,due to relative low water content for vegetation;（3）The characteristics of the LAI＇s spatial distribution are：an annular distribution of LAI centered the Bosten lake as a center;The LAI values decreased gradually along with the increase of the distance to the Lake and river.
出处
《中国沙漠》
CSCD
北大核心
2016年第5期1340-1347,共8页
Journal of Desert Research
基金
新疆维吾尔自治区青年科技创新人才培养工程项目(QN2015YX009)
新疆师范大学博士启动基金项目(XJNUBS1528)
国家自然科学基金项目(41161007
41461006
41361002)
新疆维吾尔自治区重点实验室专项资金项目(2014KL016)
