ABSTRACT
Research on RSEY is to monitor the crops of the whole country and obtain the relevant growth information. Accurate estimation for the acreage of crops is very important for food security. The method used to calculate the changing rate of the crop acreage is sampling and scaling scheme combining RS image interpretation, which is economically feasible and scientifically sound. Firstly, all
of the winter-wheat-growing counties in China were stratified into 6 strata according to the statistical acreage in the past years. Then about 20 TM scenes were used for sampling. The winter wheat acreage (WWA) change between two years was drawn with TM interpretation . Secondly, 20 RS monitoring sample sites were set in grain production area according to the principle of stratifying and sampling in 2005. Each sample site was covered with 2 scene TM images within two years, which comes to 32 scene TM images. The distribution of these sample sites is, 10 sample sites in the Yellow Sea and Huai-Hai Plains, 6 sample sites in Loess Plateau, and 4 sample sites in the middle and lower Yangtze valley plains.
