Arid Zone Research ›› 2025, Vol. 42 ›› Issue (6): 1032-1042.doi: 10.13866/j.azr.2025.06.07

• Land and Water Resources • Previous Articles     Next Articles

Object-based glacier boundary extraction utilizing multi-feature fusion

LIN Zhouyan1(), WANG Xiaying1,2,3,4, XIA Yuanping1,2,3,4()   

  1. 1. School of Geomatics and Spatial Information Engineering, East China University of Technology, Nanchang 330013, Jiangxi, China
    2. Key Laboratory of Mine Environmental Monitoring and Improving Around Poyang Lake, Ministry of Natural Resources, East China University of Technology, Nanchang 330013, Jiangxi, China
    3. Jiangxi Key Laboratory of Watershed Ecological Process and Information, East China University of Technology, Nanchang, 330013, Jiangxi, China
    4. Nanchang Key Laboratory of Landscape Process and Territorial Spatial Ecological Restoration, East China University of Technology, Nanchang 330013, Jiangxi, China
  • Received:2024-12-19 Revised:2025-02-13 Online:2025-06-15 Published:2025-06-11
  • Contact: XIA Yuanping E-mail:2023110417@ecut.edu.cn;ypxia@ecut.edu.cn

Abstract:

Pixel-based classification struggles with the accurate identification of glacier changes in areas with similar spectral characteristics, particularly in debris-covered areas where spectral features closely resemble the surrounding mountains and rocks, thereby resulting in low extraction accuracy. This study investigates the Yinsugaiti and Yalong Glaciers using Google Earth Engine to integrate spectral indices, microwave texture features, and topographic data. An object-based (OB) machine learning algorithm is applied for automated glacier extraction and compared to pixel-based (PB) classification methods. The results show the following. (1) The OB classification approach, integrating multi-feature fusion, significantly improved the glacier extraction accuracy. The OB_RF classifier achieved an overall accuracy of 98.1%, a Kappa coefficient of 0.97, and an F1-score of 98.67%, outperforming the OB_CART and OB_GTB classifiers. When compared to PB_RF, the overall accuracy, Kappa coefficient, and F1-score increased by 1.7%, 0.024, and 5.57%, respectively. (2) Between 2001-2022, the Yinsugaiti and Yalong Glaciers retreated at average annual rates of 0.08% and 0.13%, respectively. (3) Supraglacial debris was primarily distributed below 5000 and 4800 m on the Yinsugaiti and Yalong Glacier, respectively. Over the same period, debris-covered areas on both glaciers expanded upward.

Key words: glacier boundary extraction, object-based, pixel-based, machine learning, multi-feature fusion