草原生物量及碳密度遥感估算——以内蒙古正蓝旗为例

为了寻求从宏观上用于草原生物量遥感估算的有效方法,提高生物量遥感估算精度,以内蒙古正蓝旗为研究区,利用2010年Landsat 5TM遥感数据与同期调查样地数据,分析了TM各波段、影像变换(主成分变换,缨帽变换)、植被指数、地形因子、气候因子与草原生物量之间的相关关系,并采用多元逐步回归法建立了生物量与各指标的回归模型。结果表明:生物量与EVI(增强型植被指数)、主成分、缨帽变换等具有较高的显著相关,在草原沙化地区应选择具有剔除土壤背景信息的指标估算生物量;正蓝旗草原生物量为1196412.9t,碳贮量约为0.54TgC,其中温性草原类的平均碳密度为517.49kgC/hm2,低地草甸类的平均碳密度为683.30kgC/hm2。

Remote Sensing Estimation of Grassland Biomass and Carbon Density: Case of Zhenglan Banner

In order to seek effective method for estimation of grassland biomass in macroscopic view and improve the estimation precision, Landsat5 TM imagery acquired in 2010 was applied for grassland biomass based on field survey data in Zhenglan Banner of Inner Mongolia, China. The author analyzed the relationship of biomass with image bands, principal component analysis (PCA), tasseled cap transformation (TC), vegetation indices, topographical data and meteorological data. And then the regression model between the biomass and all the variables in each category of data was established by mult-stepwise regression. It was shown as follows: the relationships of biomass with EVI, PCA, TC had higher significant correlation. It should choose index of elimination soil background information to estimate grassland biomass. Grassland biomass was 1196412.9 t and carbon storage was about 0.54 TgC in Zhenglan Banner. Carbon density of temperate steppe was 517.49 kg C/hm2, and carbon density of the lowland meadow was 683.30 kg C/hm2.