利用Terra/MODIS数据提取冬小麦面积及精度分析

利用遥感技术提取作物播种面积是农情监测研究中一种实用而可行的方法。以河北省藁城市为研究区域,研究利用多时相Terra/MODIS数据提取2004年冬小麦播种面积的技术方法。在分析MODIS波谱特性与冬小麦生物学特征,并考虑了有关植被指数图像对面积提取精度的影响基础上,选择将MODIS数据的Red、Blue、NIR和ESWIR波段作为基础工作波段。利用4种方法提取了2004年藁城市各乡镇的冬小麦播种面积,并利用2004年各乡镇统计数据及土地利用数据进行了精度评价。结果表明：4种方法提取的冬小麦播种面积总体上都与参考值比较吻合,总体误差和平均误差均小于5%。可见,利用Terra/MODIS数据提取冬小麦播种面积是完全可行的。研究还发现,最佳的MODIS数据是冬小麦抽穗期的Red、Blue、NIR、ESWIR波段图像和冬小麦播种期与抽穗期EVI差值图像的组合。

Method for extracting winter wheat area using Terra/MODIS data and its accuracy analysis

Agricultural crop area extraction using remote sensing technology has been proved to be a practical and feasible method, thus numerous researches and studies have been done by many scientific institutions worldwide. This paper, a new method for extracting winter wheat area of Gaocheng County, Hebei Province, using multi-temporal Terra/MODIS images is presented. At first, based on the analysis of spectral features of MODIS data and biological characteristics of winter wheat, four bands(Red, Blue, NIR, ESWIR bands) of MODIS data were selected as the basic processing bands, and the impact of VI images on accuracy of acreage detection was also taken into considerations during this stage. Then four different methods were applied to the MODIS images for sown area extraction at a town level in 2004. The accuracy assessment results by using 2004 statistical data and land use map product indicated that the acreage derived from MODIS data using four methods coincided well with the real conditions, with both a total and average error less than 5%. Therefore, it is concluded that the coarse resolution MODIS image can be utilized in agricultural crop sown area extraction, the most appropriate MODIS temporal data for such applications are the combination of Red, Blue, NIR, ESWIR bands at tasseling stage and EVI image at emerging stages of winter wheat.