中国农业科学 ›› 2023, Vol. 56 ›› Issue (13): 2474-2490.doi: 10.3864/j.issn.0578-1752.2023.13.004

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

协同多源国产高分影像和面向对象方法的南方农作物遥感识别

王佳玥1(), 蔡志文2, 王文静1, 魏浩东3, 王聪1(), 李泽萱1, 李秀妮1, 胡琼1()   

  1. 1 华中师范大学城市与环境科学学院,武汉 430079
    2 华中农业大学资源与环境学院/华中农业大学宏观农业研究院,武汉 430070
    3 华中农业大学植物科学技术学院/华中农业大学宏观农业研究院,武汉 430070
  • 收稿日期:2022-12-04 接受日期:2022-02-06 出版日期:2023-07-01 发布日期:2023-07-06
  • 通信作者:
    王聪,E-mail:
    王聪,E-mail:
    胡琼,E-mail:
  • 联系方式: 王佳玥,E-mail:wangjiayue@mails.ccnu.edu.cn。
  • 基金资助:
    湖北省自然科学基金面上项目(2022CFB377); 国家自然科学基金面上项目(42271399); 中国科协青年人才托举工程项目(2020QNRC001); 中央高校基本科研业务费资助(CCNU22QN018); 中央高校基本科研业务费资助(CCNU22JC013)

Integrating Multi-Source Gaofen Images and Object-Based Methods for Crop Type Identification in South China

WANG JiaYue1(), CAI ZhiWen2, WANG WenJing1, WEI HaoDong3, WANG Cong1(), LI ZeXuan1, LI XiuNi1, HU Qiong1()   

  1. 1 College of Urban and Environmental Sciences, Central China Normal University, Wuhan 430079
    2 College of Resources and Environment/Macro Agriculture Research Institute, Huazhong Agricultural University, Wuhan 430070
    3 College of Plant Science and Technology/Macro Agriculture Research Institute, Huazhong Agricultural University, Wuhan 430070
  • Received:2022-12-04 Accepted:2022-02-06 Published:2023-07-01 Online:2023-07-06

摘要:

【目的】中国南方地区云雨频繁且农业景观破碎,是我国农作物遥感监测最具挑战的区域之一。我国自主研发的高分系列卫星具有高时空分辨率和高质量成像的特点。本研究挖掘多源高分系列卫星的时间和空间双重优势,实现多云雨及景观异质区作物精细化识别。【方法】基于国产高空间分辨率高分二号(GF-2)影像表征农田空间几何特征,协同中空间分辨率高分一号(GF-1)和高分六号(GF-6)加密影像观测时间序列,充分表征农作物光谱季相节律。通过构建光谱-时相-空间三维分类特征,基于随机森林进行农作物分类并计算不同特征的重要性。同时,设置不同影像组合和不同分类单元下的多种分类场景,进一步分析不同高分数据协同利用在农作物识别上的表现差异。【结果】基于GF-1、GF-2和GF-6影像和面向对象的农作物分类在湖北省潜江市研究区的总体精度为95.49%,Kappa系数为0.94;在枣阳市的总体精度为93.78%,Kappa系数为0.92。协同GF-2和GF-6进行农作物分类精度优于协同GF-2和GF-1。此外,基于GF-2进行面向对象的农作物分类效果优于面向像元,其中潜江总体精度提升了1.4%,枣阳提升了1.32%。相比GF-1和GF-2对应的光谱和空间特征,GF-6光谱波段对农作物遥感识别的贡献度最大,累计重要性得分占全部光谱波段的82%(潜江)、77%(枣阳)。其中GF-6新增的红边Ⅰ波段(B5)、红边Ⅱ波段(B6)、紫波段(B7)和黄波段(B8)4个光谱波段对作物识别的贡献度分别为47%(潜江)和33%(枣阳)。【结论】协同发挥不同国产高分数据各自光谱-时间-空间优势,不仅缓解了农业景观破碎导致的“混合像元”问题,同时一定程度上降低了多云多雨气候对农作物识别影响的不确定性,为我国南方地区农作物精准识别提供了巨大潜能。

关键词: 国产高分数据, 面向对象, 随机森林, 遥感识别, 作物分类

Abstract:

【Objective】 Due to frequent cloudy and rainy weather, it is challenging to map crop types over South China with fragmented agricultural landscapes. The Gaofen (GF) series satellites developed by China have high spatial-temporal resolution and good image quality. This study exploited the spatial and temporal advantages of multi-source GF images for fine crop classification in heterogeneous agricultural areas with frequent clouds and rain. 【Method】This study characterized the spatial geometry of agricultural fields based on GF-2 data with high spatial resolution, and cooperated with the encrypted observations from GF-1 and GF-6 time series to fully characterize the spectral seasonal variations of crops. By constructing three-dimensional classification features of spectrum-time-space, the crop classification based on random forest classifier were conducted, and the importance scores of different features were calculated. Furthermore, several classification scenarios were set based on different satellite combinations and different classification units, for further analyzing the performances of integrating different GF datasets on crop type mapping. 【Result】The overall accuracy of synergistic GF-1, GF-2 and GF-6 by object-oriented crop classification was 95.49% with Kappa of 0.94 in Qianjiang city; the overall accuracy in Zaoyang city was 93.78% with Kappa of 0.92. The accuracy of crop classification by integrating GF-2 and GF-6 was higher than that by GF-2 and GF-1. In addition, the object-oriented crop classification based on GF-2 outperformed the pixel-oriented one, in which the overall accuracy improved by 1.4% and 1.32% in Qianjiang and Zaoyang, respectively. Compared with the spectral and spatial features of GF-1 and GF-2, the GF-6 spectral bands had the largest contribution to crop type identification, and the cumulative importance score accounted for 82% (Qianjiang) and 77% (Zaoyang) of all spectral bands. Among them, the four new spectral bands of GF-6, namely, red-edge I band (B5), red-edge Ⅱ band (B6), purple band (B7) and yellow band (B8), accounted for 47% (Qianjiang) and 33% (Zaoyang) of all spectral bands for crop type identification. 【Conclusion】Integrating multi-source GF images by taking advantages of their spectral, spatial and temporal features could not only alleviate the "mixed pixel" problem caused by the fragmented agricultural landscape, but also reduce the uncertainty of crop type identification in cloudy and rainy areas, providing great potential for accurate crop mapping in South China.

Key words: GF data, object-oriented, random forest, remote sensing identification, crop classification