基于时序MODIS-EVI监测华中地区耕地复种指数

复种指数是衡量耕地资源集约化程度的基础性指标，也是国家宏观评价耕地资源利用状况的重要技术指标，它能有效反映农业生产在时间尺度上利用农业资源的程度。时序的植被指数曲线蕴涵着植被的生长和枯萎的循环节律，可以反映农作物的出苗、拔节、抽穗、收获等过程。利用经过Savitzky Golay滤波平滑的250 m分辨率的时序MODIS EVI(enhanced vegetation index,增强型植被指数)监测华中地区2005～2008年复种指数。监测结果与根据统计数据得到的复种指数线性回归斜率为1.1097（〖WTBX〗R2=0.759,P<0.0001），样点验证总体精度为92.4%，样区验证精度为97.91%。结果表明，利用时序MODIS EVI能及时快速、低成本、高精度的监测复种指数，方法独立，提取结果比较准确、可靠。

MONITORING FOR MULTIPLE CROPPING INDEX OF CULTIVATED LAND IN CENTRAL CHINA USING TIME SERIES OF MODIS EVI

〗Multiple Cropping Index is a very important indicator in agricultural statistic in China,which represents the degree of utilizing agriculture resources at time scale and the situation of arable land effective using.The time series of EVI contain the rhythm of vegetation growth and wilting,and can accurately reflect the biophysical processes of planting,seedling,elongating, heading and harvesting of agricultural crops.The objective of this paper is monitoring Multiple Cropping Index of Central China according to the period of time series of MODIS EVI after Savitzky Golay filter processing from 2005 to 2008.The results revealed that this method could provide an effective way to monitor Multiple Cropping Index.Results are accurate and stable.The slope of linear regression of the Multiple Cropping Index between remote sensing data and statistical data was 11097（〖WTBX〗R2=0759,P〖WTBZ〗<00001).The total precision of sample validation based on visual identification was 924% and precision of sampling areas based on visual identification was 9791%,suggesting that according to the period of time series of MODIS EVI it could provide an effective way to extracting spatial information of the Multiple Cropping Index for management department of agriculture.