| The ecological river construction is one of most important measures to restore the damaged river, and the focus on river ecological restoration in and abroad. The study on the construction theory and application of ecological river can provide theory bases and technology support to the ecological river construction, possessing most important practice meaning.Studying on the theory of the ecological river, this paper defined the conception, connotation and function of the ecological river, analyzing the key damaging factors to the river, and established the assessment index system. According to the application examples in and abroad, this paper summarized the ecological engineering technology in the ecological river construction, described the ecological riverbed and ecological revetment classified according to their application conditions and function characteristics.Relying on the national high tech project "863", Iinzhuanggang ecological river was constructed, and it's ecosystem characteristic and law of water quality variety were studied. The results show that:(1) The ecological river construction had meliorative effects on the Iinzhuanggang river. The water quality index such as DO, CODMn, NH3-N, NO2+NO3"-N, TN, TP were improved to 1-4 rank. The BI (biotic index) shows that the water quality was changed from "moderately polluted" to "clean". The B-IBI (index of biotic integrity) shows that the river ecosystem health condition was changed from "worse" to "sub-healthy".(2) During the experiment period, water transparency, water temperature, water depth and velocity of flow, pH, DO and nutrition salt were in the healthy condition feasible to water biology. The water plant density and coverage were in favorable condition. The superior species, diversity, sensitive species of Microzoobenthos in ecological reaches were excelled to natural reaches.(3) The retention ability to pollutants of ecological reaches was better than natural reaches, with retention rate of 15%, 30% and 25% to CODMn, NH3-N and TP respectively, especially in Reach HI and reach V, showing the strong self-purification in ecological rivers. |
