基于MODIS的青藏高原牧草生长季草地生物量动态  

Changes of forage biomass of grasslands during the growing season in the Qinghai-Tibetan Plateau based on MODIS data

作　　者：杜玉娥[1] 刘宝康[1] 郭正刚[1] 

机构地区：[1]兰州大学草地农业科技学院农业部草地农业生态系统学重点开放实验室,甘肃兰州730020

出　　处：《草业科学》2011年第6期1117-1123,共7页Pratacultural Science

基　　金：国家科技支撑计划项目(2009BAC53B04);国家行业公益项目(200903060);兰州大学中央高校基本科研业务费专项资金(lzujbky-2009-3)

摘　　要：草地生物量是评价青藏高原生态脆弱性和敏感性的重要指标,也是度量草地退化的重要指标。本研究利用MODIS植被指数NDVI和EVI资料及青藏高原三江源地区326个样方实测数据,构建并优化了研究区不同类型草地生物量的预测模型,估算了2002-2009年期间草地生物量年际和月际变化特征。结果表明,高寒草甸地上生物量适宜植被指数为NDVI,反演模型为,y=6.202 5x2-574.89x+14 586,高寒草原地上生物量适宜植被指数为EVI,反演模型为,y=0.165 5x1.773 2。高寒草甸和高寒草原生物量在2002-2009年表现为波动状态,但高寒草甸比高寒草原波动幅度大。高寒草甸和高寒草原生物量在6-8月间均持续增加,9月开始下降,但7月高寒草原生物量波动大于高寒草甸,8月高寒草原生物量波动小于高寒草甸,6月和9月两种草地类型生物量波动不明显。Grassland biomass is an important indicator to evaluate the ecological vulnerability and sensitivity,and is also an important indicator to assess the grassland degradation.In this study,the NDVI index and EVI index from MODIS data and the field data from 326 plots in the grassland were used to establish and optimize the prediction models of grassland biomass for different grassland types,and then established model was applied to estimate the annual and monthly grassland biomass during the period from 2002 to 2009.This study showed that the alpine meadow biomass retrieval model was y=6.202 5x2-574.89x＋14 586,here,x was NDVI;alpine steppe biomass retrieval model was y=0.1 665 5x17 732,here,x was EVI.The biomass of alpine steppe and meadow showed a fluctuant trend during the period 2002-2009,and the fluctuation range of alpine meadow was bigger than that of alpine steppe.The biomass of alpine steppe and meadow increased from June to August,and decreased from August to September,the fluctuation range of alpine steppe was bigger in July and smaller in August than that of alpine meadow,however,the fluctuation range in June and September was not obvious between alpine meadow and alpine steppe.

关 键 词：植被指数 生物量 年际动态 月际动态 三江源地区 

分 类 号：S812[农业科学—草业科学]