Exploring the potential of SWOT for water level monitoring in the Qinghai Lake SWOT卫星对青海湖的水位监测潜力研究

Xiong，Jinghua1; Guo，Shenglian1; Jiang，Liguang2; Yin，Jiabo1; Wang，Jun1

2023-08-01

10.11834/jrs.20231628

National Remote Sensing Bulletin   Impact Factor & Quartile

1007-4619

The water level changes in the lake groups on the Qinghai‒Tibetan Plateau is crucial for understanding global climate change and melting glaciers regionally. However, in-situ measurements are still lacking due to remote locations and material requirements. The current in-orbit optical satellites as well as radar and laser altimetry satellites have a relatively coarse spatiotemporal resolution and poor retrieval accuracies, both of which can be addressed in the future Surface Water and Ocean Topography (SWOT) mission. Therefore, the main objective of our study is to assess the water level monitoring potential of SWOT for the largest lake in China, that is, the Qinghai Lake in the Qinghai‒Tibetan Plateau. This study obtained SWOT-like water level time series covering the years 2010 to 2018 for the Qinghai Lake from in-situ measurements, the optical altimetry dataset, and radar altimetry products by using the CNES SWOT Hydrology Toolbox. A systematical performance evaluation of SWOT-like lake level was then conducted by comparing this level with the reference height. SWOT-like water volume time series under different input scenarios for the Qinghai Lake were estimated based on its hypsometric curve and were subsequently validated using the results derived from the Gravity Recovery and Climate Experiment (GRACE) mission and the WaterGAP global hydrological model (WGHM). In general, the SWOT-like water level time series can capture the seasonal and annual water level variations with an r/NSE ranging from 0.9 to 1.0 and from 0.8 to 0.99, respectively. Meanwhile, the SWOT-like lake level time series accurately demonstrate the long-term trends of water level in Qinghai Lake for the years 2010 to 2018 at various scales. The SWOT-inferred water volume changes under multiple forcing scenarios show change patterns that are comparable with the GRACE and WGHM results. The SWOT-like water level for the Qinghai Lake for the years 2010 to 2018 shows satisfactory accuracy at both seasonal and annual scales as revealed in comparisons with in-situ measurements, the optical altimetry dataset, and the radar altimetry product. The patterns of the SWOT-inferred water volume changes are also similar to the GRACE and WGHM results, thereby indicating the great water level and volume monitoring potential of the future SWOT mission. In our future work, we will derive time-varying water extent maps of Qinghai Lake by using multi-source optical imageries, including Landsat, Sentinel, and Gaofen series satellites. We also plan to carry further experiments for all lakes (> 1 km) in the Qinghai‒Tibetan Plateau to assess the large-scale lake level monitoring potential of SWOT.

altimetry Qinghai Lake Qinghai-Tibetan Plateau remote sensing SWOT water level monitoring

Chinese

Others

National Natural Science Foundation of China[U20A20317];

2-s2.0-85170433315

Scopus

1.State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan,430072,China
2.School of Environmental Science & Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Xiong，Jinghua,Guo，Shenglian,Jiang，Liguang,等. Exploring the potential of SWOT for water level monitoring in the Qinghai Lake SWOT卫星对青海湖的水位监测潜力研究[J]. National Remote Sensing Bulletin,2023,27(8):1888-1898.

Xiong，Jinghua,Guo，Shenglian,Jiang，Liguang,Yin，Jiabo,&Wang，Jun.(2023).Exploring the potential of SWOT for water level monitoring in the Qinghai Lake SWOT卫星对青海湖的水位监测潜力研究.National Remote Sensing Bulletin,27(8),1888-1898.

Xiong，Jinghua,et al."Exploring the potential of SWOT for water level monitoring in the Qinghai Lake SWOT卫星对青海湖的水位监测潜力研究".National Remote Sensing Bulletin 27.8(2023):1888-1898.