甘肃省草原产草量动态监测模型

利用MODIS数据和地面实测资料,研究了甘肃省不同草原区的最适草原生物量遥感估算模型,并反演了甘肃省2005-2009年的草原产草量,分析了其空间分布特征。结果表明,不同草原区适合的植被指数和反演模型类型存异,其中河西走廊高平原荒漠草原区适合的植被指数是RVI、模型类型为对数模型,甘南高原草甸草原区适合的植被指数是EVI、模型类型为指数模型,而黄土高原温性草原区适合的植被指数是NDVI、模型类型为二次多项式模型。甘肃省2009年草原总产鲜草3 718.30万t,整体呈现东北低、西南高的空间变化过程,形成3个高产中心,分别是甘南高原、祁连山北麓中东段和陇南南部。与1985年相比,2005年草原明显减产(相对变化率V=19.34%),但2005-2009年间甘肃省草原产草量有总体上升的趋势。

Monitoring models of the grass yield for grassland in Gansu Province

Based on MODIS data and field data, the optimal prediction models of remote sensing were established for different grassland distribution regions, and these established models were also used to estimate the grass yields during the period of 2005 to 2009 in Gansu, and discuss the feature spatial distribution of grass yield. The results showed that optimal vegetation index and inversion model was different for different grassland distribution regions. The vegetation index RVI with logarithm model was suitable for the desert grassland areas of high plain in Hexi Corridor, and vegetation index EVI with exponent model was suitable for meadow grassland areas in Gannan High-land, and vegetation index NDVI with quadratic polynomial model was suitable for temperate steppe grassland areas in the Loess Plateau. The total grass yield of grassland in Gansu was 3.718 30×107 t in 2009, with an increasing trend from northeast regions to southwest regions. There were 3 high yield regions which were in Gannan High-land, the middle-east part of North Slope of Qilan Mountains and south region of Longnan. Compared with that of year 1985, the grass yield of grassland in Ganau province obviously decreased with percent of 19.34%.