Study On The Ecological Water Demand Of Typical Wetlands And Songliao River In The Northeast Of China

With the effect of natural change and human activity, the northeast of China has a series of environmental problems. In order to control the cut-off of river, keep the normal entironment functions of the river and the wetland and protect the quality and ecology balance of water environment, the ecological water demand of the typical wetland and the Songhuajiang river and the Liaohe river were studied in this paper.On the base of the study of ecological water demand in domestic and overseas, a method of calculating the ecological water demand on the base of water cycle was brought forward in this paper. The ecological water demand was regarded as a change factor in the water cycle system, so according to the character of the Sanjiang plain, a hydrological model is build on the Hongxiyuan model. And the ecological water demand is studied on the base of simulating of the water cycle by a hydrological model. The ecological water demand of the Songhuajiang river and the Liaohe river was studied by flow during curve for this method has not been applied in China. In order to validate the result of the method, the Montana method was used to compare with the flow during curve.In order to protect the function of the wetland and the diversity of biology, the appropriate ecological water demand and the least ecological water demand were defined. The result of Qixinghe national nature reserve shows that the ecological water demand accounts 26.4%-34.5% of the total water resources in the region.The river water demand of the Songhuajiang river and the Liaohe river shown that the flow during curve was better than the Montana in this study. The result of Songhuajiang river using flow during curve accounted 48.4%-61.3% of annual flow. And the result of Liaohe river using flow during curve accounted 50.8%-64.3% of annual flow.The method of calculating the ecological water demand based on water cycle was a new method and the flow during curve was first applied in this paper, so there are many problems and it needs to perfect.