Remote sensing monitoring of dusty weather after Zonag Lake outburst based on GEE

Monitoring sand and dust is essential for addressing ecological protection and assessing climate change. This study utilized Landsat TM/ETM+/OLI, Sentinel-2 MSI, and MODIS remote sensing images, and ERA5 data, along with data from the Wudaoliang meteorological station, to analyze the watershed area of the Zonag Lake from 2001 to 2021. We employed the Normalized Difference Water Index (NDWI) and three sand and dust indices: Brightness Temperature Difference (BTD), Normalized Difference Dust Index (NDDI), and Global Dust Detection Index (GDDI) to investigate the sand and dust events resulting from the lake's overflow. The findings revealed that (1) the area of the Zonag Lake increased steadily from 2001 to 2011, but after the lake overflowed in September 2011, its area began to decline until 2021, with expectations of an increase by the end of 2021. (2) Following the lake's collapse, the exposed lakebed became a source of sand, leading to frequent sand and dust occurrences. (3) Among the three indices, the BTD index proved to be the most effective for detecting sand and dust in the Zonag Lake region, identifying the maximum impact area of the sand and dust phenomenon to be approximately 1.2×10 4 km 2 , with the farthest reach extending about 300 km. Utilizing the BTD index to extract sand and dust information can provide crucial data for climate change studies, management of sand and dust source areas, and disaster prevention and control efforts.