基于NDVI的2017年阿根廷大豆分布及长势数据分析

Condition Analysis on NDVI-Based Soybean Spatial Distribution and Growth in Argentina 2017

采用遥感手段提取作物分布并监测其长势对动态感知粮食安全具有重要意义。基于MODIS-NDVI产品,结合阿根廷大豆物候特征,快速提取阿根廷大豆分布及长势情况,并使用农用地连片系数FCI校正由尺度效应造成的面积失真。在此基础上,使用距平分析监测大豆长势,计算DSI指数监测干旱过程。结果表明:提取的近3年阿根廷大豆种植面积与美国农业部公布数据变化趋势一致,主产区种植比例高度吻合。2017年阿根廷大豆整体长势较差,副产区长势优于主产区,各主产省种植空间分布呈现离散或聚集变化。大豆种植面积及分布、长势的变化与干旱过程在时间和空间上具有高度耦合关系。提出的"物候匹配-LUCC降尺度作物提取法"具有准确快速的特点,通过改良和修正可用于其他作物的有效提取与监测。

Timely grasp crop distribution and monitor its growth condition is of great significance to dynamic perception of food security.Based on the MODIS-NDVI product and the phonology characteristics of soybean in Argentina,we extract the distribution of soybean and monitor its growth condition,then use farmland contiguous index(FCI)to rectify the area distortion causing by scale effect.The result shows that the change trend of soybean planting area in Argentina for past three years is in line with the trend of data released by the USDA.The planting ratio in the main producing areas is also highly consistent with official data.The overall growth of soybean is poor than normal in2017,and the soybean harvest area decrease than the past two years.The sub-region is better than the main producing area,and the spatial distribution of the main producing provinces presents a discrete or aggregated change.The soybean distribution and growth condition are highly coupled with the drought degree in time and space.In this study,the method named“phonological matching-LUCC downscaling crop extraction”is comparatively accurate and rapid,it is could be used for effective extraction of soybeans in other areas or other staple crop crops.