Image: Poyang Lake viewed by Sentinel-1

Southern China's Poyang Lake is the largest freshwater lake in the country. Located in Jiangxi province, this lake is an important habitat for migrating Siberian cranes, many of which spend the winter there.

The lake is also home to the endangered finless porpoise, a freshwater mammal known for its high level of intelligence. Amid fears that it would soon become extinct, the porpoise made headlines last year when the Chinese government moved eight of them from Poyang Lake to two secure habitats in an effort to increase the population over the coming years.

One study found that, without action, the current rate of population decrease would likely mean extinction by 2025.

For the human population, Poyang is one of China's most important rice-producing regions, although local inhabitants must contend with massive seasonal changes in water level.

Local scientists collaborating with ESA through the Dragon programme have identified an overall drop in water level in the lake over the last decade, but the El Niño weather phenomenon earlier this year caused precipitation levels to increase and water levels of the lake to rise.

Radar images from the Copernicus Sentinel-1 mission have been used to monitor the evolution of the lake, including this image which combines two radar scans from 7 and 19 March.