基于环境减灾卫星遥感信息估测呼伦贝尔草原叶面积指数(英文)

国产环境减灾小卫星星座的HJ-1A和HJ-1B星于2008年发射升空,其具有的高时间分辨率和中高空间分辨率的特点,使它们可在资源环境监测中发挥巨大作用.文章探讨了利用环境减灾卫星遥感影像数据估测中国重要牧草基地呼伦贝尔草原叶面积指数的可行性.为实现此目的,2009年夏季获得呼伦贝尔草原区遥感影像三景和对应地面采样点草地叶面积指数信息,利用8个常用光谱指数分别建立了叶面指数的反演模型.结果表明:各光谱指数均与叶面积指数具有较好的定量关系.其中,增强光谱指数(Enhanced Vegetation Index,EVI)的结果最好,模型的交叉检验决定系数为0.50,均方根误差为0.34.环境减灾卫星可为草原监测和管理提供重要数据支撑.

HJ Microsatellite to Estimate Hulunbeier Grassland Leaf Area Index

HJ-1A and HJ-1B microsatellites were launched in 2008 as environmental and disaster monitoring constellations with high time and medium spatial resolutions.These microsatellites have shown utility in natural resource monitoring.The Hulunbeier grassland is one of the richest natural resources in China.The feasibility of using HJ microsatellite data to estimate Hulunbeier grassland leaf area index(LAI) was examined in this study.LAI was measured at selected sampling sites in the Hulunbeier grassland during 2009.Three microsatellite images were taken nearest the sampling times.Eight commonly used spectral indices were selected and calculated from the images.Relationships between spectral indices and corresponding LAI were investigated.Results indicated that all tested indices had statistically significant relationships with LAI,and the Enhanced Vegetation Index(EVI) was the best predictive index.The LAI cross-validation prediction using EVI showed an R2 value of 0.50 and a root-mean-square-error(RMSE) value of 0.34.Our results indicated that HJ microsatellite is an important data resource for grassland monitoring and management.