Extraction of rape planting distribution information in Jianghan Plain based on MODIS EVI time series data

Rape is the major oil crop in China, and timely and accurately obtaining the information about rape planting spatial pattern has great significance for growth monitoring, yield estimation and disaster assessment. In this paper,the distribution of rape growing in the Jianghan Plain from 2014 to 2015 was extracted utilizing the MODIS EVI time series data with 250 m spatial resolution. The field survey data were used to extract crop training samples for MODIS EVI data indirectly by using TM data as the transition data between the field survey data and MODIS EVI image. According to the spectra and phenological calendar of winter wheat and rape in Jianghan Plain, the authors established the extraction model for the area of rape growing by multiple threshold comparative method. With the Agricultural Bureau Statistics data as the verification, the overall accuracy of the extraction results of MODIS data were up to 95.22% and 91.29% respectively in 2014 and 2015. In addition,the extraction result was quite consistent with TM-based result with a precision of 88.61%,in 2014. The results show that,based on the time series MODIS-EVI data sets,combined with the EVI spectral characteristics and phenological information of crop and using the study method presented in this paper, the rape planting distribution information could be extracted effectively in Jianghan Plain.