Due to soil erosion, the surface area of Dongting Lake in
China is decreasing. Its surface area was about 2626,5 square kilometers
in 1995. From 1950 to 1995, the average rate of change in surface area was
about -38.3 square kilometers per year. From 1825 to 1950, the average
rate of change was about -13.2 square kilometers per year. Approximate
the surface area in 1825.​