利用MODIS-NDVI进行草地估产研究--以内蒙古锡林郭勒草地为例

MODIS较高的空间分辨率(250 m/pixel)比AVHRR(1.1 km/pixel)在空间分析方面具有更高的精度.以内蒙古自治区锡林郭勒盟的温性荒漠草原、温性沙地典型草原、温性典型草原和温性草甸草原4种具有代表性的草地类型为例,以2002年5-9月的地面测产数据和同步MODIS遥感数据为基础,分别建立每类草地的草产量与MODIS-NDVI关系模型及4类混合的总模型.所有模型均通过0.01的极显著水平的F检验,不同模型拟合效果不同,R由0.55～0.87不等,分析得出:植被覆盖度大、空间分布均匀、NPP大的模型拟合效果好,反之则差.在此基础上初步探讨了利用MODIS-NDVI进行草地估产研究的可行性.

Estimate the yield of grassland using MODIS-NDVI--a case study of the grassland in Xilinguole in Inner Mongolia

MODIS data has higher spatial resolution(250m/pixel) than AVHRR(1.1km/pixel). In this article the author took the four representative kinds of grassland (temperate meadow, temperate steppe, temperate sand steppe and temperate desert steppe) in Xilinguole in Inner Mongolia as sample, combined the simultaneous MODIS datum with yield investigation of grassland from May to September in 2002, developed one relation model between MODIS-NDVI and yield for each type of grassland of the four types, also developed a general model for all the four types. All the models passed the F test of the significance level of 0.01. But different model has different effect of regression. R changed from 0.55 to 0.87. The analysis suggested: the models do well in the regions where the vegetation is of higher density and distributes evenly, and has higher NPP. Otherwise the effect of the models will not be very good. At last the feasibility of estimating yield of grassland using MODIS-NDVI was put forward.