Hydrological adjustment and flooding control of wetlands in the Liaohe Delta

The function of estuary wetland on hydrological adjustment and flooding control is studied in this paper. It is estimated that the evapotranspiration in the reed field during growth season(June to October) is 722.9 mm, which is 37.5 % higher than large water body(E₆₀₁ : 525.9 mm). The water replacement rate in the reed field can reach 95 % only when the rains continuously for 11 days and the precipitation reached 912 mm. For the water balance in the paddy field, the total water requirement ranges between 1920 and 1860 mm, among which, 31 % is from precipitation, and the left is provided by reservoirs. The water usage efficiency is 0.35 at present productivity. Based on the landscape characteristics and functionalities on flooding control, 5 functional zones are designed for the Liaohe Delta: key protected area: underground storage area; flooding discharge area; flood diversion area in emergency ; and flood control drainage area.