Soybean planting area extraction based on Sentinel data and multi feature learning
[Purpose]Soybean is an important dual-use crop for grain and oil in China and a major source of high-quality protein.Timely and accurate access to the planting area of soybean is of great significance in assessing the implementation effect of the Soybean Revitalisation Plan and the formulation of subsequent policies.[Method]In this study,Heihe City in Heilongjiang Province was taken as the study area,and based on the Google Earth Engine platform,multi-feature datasets such as spectral features,vegetation index features,texture features and topographic features after feature screening were constructed using data such as multi-fertility Sentinel-2A,SRTM(Shuttle Radar Topography Mission).Also,the algorithms such as Random Forest(RF),Classification and Regression Tree(CART)and Support Vector Machine(SVM)were compared and analyzed.The best algorithm was selected to extract and analyze the soybean planting area in Heihe City from 2019 to 2021,and to realize the regional mapping of soybean planting area.[Result]The results showed that nine features have good differentiation for soybean,rice and corn.Comparing the results of area extraction from remote sensing images of different fertility periods,the best results were obtained in the bulging grain period.Comparing different feature learning methods,the random forest algorithm has the best area extraction results in the soybean bulging stage.Taking the county township division as the smallest statistical unit,the soybean planting area in Heihe City from 2019 to 2021 was 936 700 hm2,1 596 200 hm2 and 1 335 400 hm2 respectively.[Conclusion]Soybean planting area increases and then decreases,the spatial distribution of planting shifts from decentralized field planting to concentration.The method based on Sentinel data with multi-feature learning can quickly and accurately extract the planting area of soybean,which helps to accurately grasp the planting situation of soybean and provides a basis for the planting and management of soybean.
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万方数据
