Visualization of the dynamic changes of Zhaling Lake in the past 45 years

Zhaling Lake is the first lake at the source of the Yellow River. The morphology of Zhaling Lake has changed frequently in recent decades. We conducted a visual analysis of Landsat remote sensing images and weather station observations in Maduo County from 1976-2021. We derived the space-time evolution of Zhaling Lake shoreline and area change trends. This paper obtained the basic characteristics such as the area and shoreline of Zhaling Lake by using water index and visual interpretation. Based on these basic characteristics, we calculated other shoreline characteristics. We analyze the morphological, meteorological, and other data characteristics of Zhaling Lake by visualization method. Research results show that the area of Zhaling Lake is highly variable. Its overall change shows a cyclic trend of recession-expansion-recession. A significant shrinkage of Zhaling Lake occurred from 1976 to 1986, from 544.177 km2 to 537.32 km2. Between 1986 and 1993, Zhaling Lake gradually expanded, adding 9.541 km2. During 1993-2019, the area of Zhaling Lake showed a continuous trend of increase. In 2019, Zhaling Lake reached the largest area of 555.368 km2 in nearly 45 years. During 2019-2021, Zhaling Lake begins to shrink slightly again. In 2021, Zhaling Lake's area shrinks to 549.41km2.