Ecological water requirements of wetlands in the middle and lower reaches of the Naoli River

In the last few decades, the wetland area of the Sanjiang Plain in northeast China has shrunk severely. To provide a scientific basis for the protection and restoration of wetlands in the Sanjiang Plain, Landsat TM images of 13 typical years of four well-preserved and contiguous wetlands are interpreted by remote sensing technology in the Sanjiang Plain of the Naoli River Drainage Basin. According to the results of the interpretation, the calculation of the minimum and the optimal ecological water requirements of the four wetlands was carried out by combining ecology with remote sensing technology. At the same time, considering the rainfall and surface runoff at different guarantee rates, the artificial recharge of four wetlands was calculated according to the principle of water balance. The results indicate that the wetland area decreased significantly from 1984 to 2013, and natural inflow of water cannot meet the actual water requirements of wetlands. The calculated artificial recharge of the four reserves provides technical support for replenishment of wetlands in the Sanjiang Plain, and lays a good foundation for the restoration of wetland ecosystems in the Sanjiang Plain. At the same time, it also provides a good habitat for rare waterfowl.