Abstract
The lake ice phenology variations are vital for the land–surface–water cycle. Qinghai Lake is experiencing amplified warming under climate change. Based on the MODIS imagery, the spatio-temporal dynamics of the ice phenology of Qinghai Lake were analyzed using machine learning during the 2000/2001 to 2019/2020 ice season, and cloud gap-filling procedures were applied to reconstruct the result. The results showed that the overall accuracy of the water–ice classification by random forest and cloud gap-filling procedures was 98.36% and 92.56%, respectively. The annual spatial distribution of the freeze-up and break-up dates ranged primarily from DOY 330 to 397 and from DOY 70 to 116. Meanwhile, the decrease rates of freeze-up duration (DFU), full ice cover duration (DFI), and ice cover duration (DI) were 0.37, 0.34, and 0.13 days/yr., respectively, and the duration was shortened by 7.4, 6.8, and 2.6 days over the past 20 years. The increased rate of break-up duration (DBU) was 0.58 days/yr. and the duration was lengthened by 11.6 days. Furthermore, the increase in temperature resulted in an increase in precipitation after two years; the increase in precipitation resulted in the increase in DBU and decrease in DFU in corresponding years, and decreased DI and DFI after one year.
Highlights
Explicit knowledge of lake ice is crucial for understanding a wide variety of earth system processes and interactions with the environment, including hydrological budgets, sediment trapping; heat fluxes and coupled weather and climate effects; lake productivity; species richness; food chain dynamics; and inland fishery yields [1,2]
The lake surface water–ice state is controlled by the local geolocation and climate conditions, especially the freeze-up dates and the break-up dates
The Qinghai Lake locates in the Yellow River sub-basin, which is an area of approximately 2.5 × 105 km2 ; the distinctive climatic conditions and geophysical environment make it a highly attractive research region [5]
Summary
Explicit knowledge of lake ice is crucial for understanding a wide variety of earth system processes and interactions with the environment, including hydrological budgets, sediment trapping; heat fluxes and coupled weather and climate effects; lake productivity; species richness; food chain dynamics; and inland fishery yields [1,2]. The lake surface water–ice state is controlled by the local geolocation and climate conditions, especially the freeze-up dates and the break-up dates. The lake surface water’s physical properties changed due to the transition of the lake surface water–ice state processes [3]. With an overall surface water area of 47,000 km , which makes up beyond 50% of the overall surface water area of Chinese lakes, including the largest lake: Qinghai Lake (4254.90 km2 ) [4]. The Qinghai Lake locates in the Yellow River sub-basin, which is an area of approximately 2.5 × 105 km ; the distinctive climatic conditions and geophysical environment make it a highly attractive research region [5]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
