Journal of Henan Agricultural Sciences ›› 2025, Vol. 54 ›› Issue (4): 144-154.DOI: 10.15933/j.cnki.1004-3268.2025.04.015

• Agricultural Information and Engineering and Agricultural Product Processing • Previous Articles     Next Articles

Identification of Rice in Southern Mountainous Area Based on Object‐Oriented and Machine Learning Methods

WANG Yingying,DUAN Liangxia,ZHAO Yining,SUN Guangrui,YANG Lihong,ZHOU Qing,XIE Hongxia   

  1. (College of Resources,Hunan Agriculture University,Changsha 410128,China)
  • Received:2024-10-22 Published:2025-04-15 Online:2025-05-20

基于面向对象与机器学习融合的南方山区水稻识别研究

王莹莹,段良霞,赵怡凝,孙广睿,杨丽红,周清,谢红霞
  

  1. (湖南农业大学 资源学院,湖南 长沙 410128)
  • 通讯作者: 谢红霞(1973-),女,湖南岳阳人,教授,博士,主要从事耕地和土壤质量、农业信息技术研究。E-mail:xiehongxia136@sina.com
  • 作者简介:王莹莹(1998-),女,河北承德人,在读硕士研究生,研究方向:农业遥感。E-mail:1574554601@qq.com
  • 基金资助:
    湖南省重点研发计划项目(2023NK2026)

Abstract: The phenology information of rice varies with terrain.In view of the cloudy and rainy conditions and complex terrain in the southern mountainous areas,it is of certain research value to find a remote sensing identification method for rice. With Yongshun County,a typical mountainous terrain in Hunan Province,as the research area,combined with Sentinel‐1 SAR and Sentinel‐2 MSI data,the time series curve was generated by the images of four key phenology periods of rice to grasp the growth trend of rice.Firstly,the object‐oriented method was used to segment the images of transplanting period and harvesting period;secondly,the feature variables optimized by the feature space optimization algorithm(FSO)were input into four models for classification such as random forest(RF);finally,the results were compared. Otherwise,according to the transplanting order,the rice samples were divided into early moving and late moving samples,the images of transplanting period and harvesting period were reclassified to explore the influence of rice transplanting time on the classification of the two images.The results showed that,compared to imagery from the transplanting stage,imagery from the harvesting stage offered better classification accuracy and was more suitable for rice mapping.The object‐oriented FSO‐RF model achieved the best classification results for imagery during the harvest period,with an overall accuracy of 93.19% and a kappa coefficient of 0. 901. The time of rice transplanting had little effect on the image classification at harvest stage,but had a great influence on the image classification at transplanting stage. The reason was that the earliest transplanted rice was easy to be similar to the spectral characteristics and texture characteristics of some dry land crops and woodlands,and there was a phenomenon of confusion and mis‐classification. In order to improve the recognition accuracy of the image during the transplanting period,it is necessary to improve the time resolution of the image,add more texture features or mask the ground objects.

Key words: Rice, Sentinel‐1/2, Object‐oriented, Multi‐feature optimization, Random forest, Transplanting period, Harvest period, Identification

摘要: 水稻的物候信息随地形的差异而不同,针对南方山区多云多雨、地形复杂的情况,寻找一种合适的水稻识别方法具有一定的研究价值。以湖南省典型山地地形的永顺县为研究区,协同Sentinel-1 SAR和Sentinel-2 MSI数据,结合水稻4个关键物候期影像生成时间序列曲线以掌握水稻生长趋势,使用面向对象方法对移栽期和收割期影像分割,将经过样本特征空间优化算法(FSO)优选的特征变量输入到随机森林(RF)等4种模型中进行分类,并对比结果;之后将水稻样本按移栽先后分为早移、晚移样本,对移栽期和收割期影像重新分类,分析水稻移栽的早晚对该两景影像分类的影响。结果表明,与移栽期影像相比,收割期影像分类精度更好,更适合水稻制图;利用面向对象的FSO-RF模型对收割期影像分类的效果最好,总体精度为93.19%,Kappa系数为0.901。水稻移栽的早晚对收割期影像的分类几乎没有影响,对移栽期影像分类的影响较大,原因是最早移栽的水稻易与部分旱地作物、林地的光谱特征和纹理特征相似,出现混淆错分现象。提高移栽期影像的识别精度,需使用其他指数、纹理特征或进行地物掩膜。

关键词: 水稻, Sentinel-1/2, 面向对象, 多特征优选, 随机森林, 移栽期, 收割期, 识别

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