Small lakes on Tibetan Plateau act as a climate change indicator

As still-water bodies, the change of lakes reflects the effect of climate change and human activities and play as sentinels of the earth. It has been witnessed that the detailed area change of lakes on Tibetan Plateau (TP) are more sensitive to global warming than the many other places of the world. Among them, small lakes are especially abundant in number, having disproportionately high hydrology and nutrient processing rates, and playing an irreplaceable role in regional and global carbon and nitrogen cycle meanwhile. It has been proved that the change small lakes and ponds, like emerging and disappearing, show strong correlation with that of precipitation, permafrost, and ecological systems in Arctic. However, as the third pole on earth with extremely complex terrain and physical surface properties, the small lakes are also a unique part while has not been investigated thoroughly. Based on the cloud computing platform Google Earth Engine (GEE), this study focused on the 11,400 small lakes on TP (lakes with max area between 0.1 and 1 km²) to answer the question that how the emergence and vanishing of small lakes responses to the climate change from 1972 to 2019. The lakes with area shrinking below 0.01 km are regarded as vanished, while area increasing above the value are regarded as emerged. Comparing with Ocean Nino Index (ONI) and and in-situ precipitation data, preliminary results show that: 1. the severe El-Nino events have been well captured by the emergence and vanishing of small lakes; 2. the emergence and vanishing of small lakes have a negative relationship in each year and the emergence peaks have about one-year time lag after those vanishing peaks; 3. the net emergence rate of small lakes has strong positive relationship with precipitation. This work could support further studies on the relationship among climate change, carbon cycle, and water cycles on Tibetan Plateau.