Water Balance of the Reclaimed Wetland in the Sanjiang Plain

The Sanjiang ecological test station of mire and wetland served as the research base.Water balance of wetland was discussed by observing various elements,such as rainfall,evaporation,runoff.The result shows that during rainless summer evaporation of wetland is higher than that of farmland,but during rainy autumn is lower than that of farmland.Wetland can increase the interannual variation and average intra-annual distribution of river runoff,and wetland vegetation can decrease the velocity of flood flow.So it can store floodwater and control flood.But after reclaimation,the function of flood control and wetland benefit will be weakened.