甘南草地地上部生物量遥感监测模型

Mointoring Model of Aboveground Biomass in Gannan Grassland Based on Remote Sensing

利用2007年和2008年16d合成的250mMODIS植被指数产品和地面调查资料,分析了甘南草地地上部生物量同光谱信息之间的相关关系,并建立了甘南草地地上部生物量遥感监测模型,继而估算了2007年和2008年甘南州及各县草地地上部生物量。结果表明:在牧草生长的主要时间里,草地地上部生物量同植被指数存在极显著相关关系,尤其与地面调查同期(8月中下旬)的增强型植被指数EVI相关性最高,相关系数达到0.782。利用EVI建立的三次多项式模型模拟结果明显优于其它植被指数,能较好地模拟草地地上部生物量。2007年甘南草地地上部生物量平均为5610kg/hm2,2008年为5605kg/hm2。与2007年相比,临潭、卓尼和迭部县地上部生物量略有增加,而合作、玛曲、碌曲、夏河和舟曲县则有所下降,以舟曲县下降最为明显。

Using 16 days 250 m MODIS vegetation index dataset,the relativity of eight vegetation indexes with aboveground biomass in Gannan grassland was analyzed. And then based on this correlation,monitoring models of aboveground biomass were constructed and aboveground biomass of Gannan grassland and each county were estimated. The results showed that in most growth period,there were significant relativity between vegetation index and aboveground biomass,but it was most obviously with synchronous EVI （r=0.782）. And the cubic polynomial model using EVI fitting aboveground biomass better than other vegetation indexes. Aboveground biomass in 2007 and 2008 are 5 610 kg/hm2 and 5 605 kg/hm2,respectively. Compared with that in 2007,aboveground biomass in Lintan,Zhuoni and Diebu county increased,while Hezuo,Maqu,Luqu,Xiahe and Zhouqu decreased in 2008.