Acta Geodaetica et Cartographica Sinica ›› 2024, Vol. 53 ›› Issue (5): 823-834.doi: 10.11947/j.AGCS.2024.20230211

• Significant changes in the Qinghai-Tibet Plateau cryosphere • Previous Articles     Next Articles

Accuracy assessment of lake level and area measurement in the Qinghai-Tibet Plateau using simulated SWOT satellite data

Xiaoran HAN1,2(), Yinghai KE3,4,5, Jinyuan YU6, Mengjie ZHAO1,2, Guoqing ZHANG1()   

  1. 1.State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
    2.University of Chinese Academy of Sciences, Beijing 100049, China
    3.State Key Laboratory Cultivation Base of Urban Environment Process and Simulation, Capital Normal University, Beijing 100048, China
    4.Beijing Laboratory of Water Resources Security, Capital Normal University, Beijing 100048, China
    5.College of Resource of Environment and Tourism, Capital Normal University, Beijing 100048, China
    6.Remote Sensing and Country Monitoring Laboratory, Department of Urban and Resource, School of Ecology and Environment, Tibet University, Lhasa 850000, China
  • Received:2023-06-08 Revised:2024-01-04 Published:2024-06-19
  • Contact: Guoqing ZHANG E-mail:xrhan@itpcas.ac.cn;guoqing.zhang@itpcas.ac.cn
  • About author:HAN Xiaoran (2000—), male, postgraduate, majors in remote sensing of lakes. E-mail: xrhan@itpcas.ac.cn
  • Supported by:
    The National Natural Science Foundation of China(41988101-03);The Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0201)

Abstract:

As the “water tower of Asia”, the Qinghai-Tibet Plateau is densely covered with alpine lakes, accounting for about half of China 's lakes in both number and area. These lakes serve as critical indicators of climate and environmental conditions, highlighting the significance of monitoring their temporal variations in water level and volume. Launched in December 2022, the Surface Water and Ocean Topography (SWOT) mission will revolutionize our ability to observe global surface water dynamics, providing unprecedented temporal resolution and areal altimetry patterns. However, prior to the official release of SWOT satellite data to the scientific community, it is important to assess its performance and measurement accuracy. To achieve this goal, this study uses the SWOT simulator to facilitate simulated observations of water levels and areas of selected lakes on the Qinghai-Tibet Plateau. These simulated results are then combined with in-situ data to assess the SWOT satellite 's measurement accuracy in terms of temporal aliasing, altimetry errors, and area errors. The results show that the mean average percentage error of the temporal aliasing of the subsampled data is less than 4.1%, the average height measurement error is less than 3 cm, and the area error is less than 7% among these lakes. The development of this study has laid the foundation for the application of SWOT satellites on the lakes of the Qinghai-Tibet Plateau to better understand the response of future lake changes to climate change.

Key words: SWOT satellite, lake level, lake area, Qinghai-Tibet Plateau

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