Ecological Restoration Pilot Engineering Technology Of Jialu River

Jialu River is one of the main tributaries of the Huaihe River, flows through the city of Zhengzhou, due to economic growth, industrialization and urbanization process accelerated; river basin water were polluted seriously, leading to eutrophication, biodiversity loss, the fracture of the food chain and ecological function decline. In order to enhance the Jialu River ecological function, the restoration of the self-purification capacity of the river. Basin of biological diversity and ecosystem function of the river was investigated. Based on the investigation results, ecological function planning Jialu River was proposed. After the restoration of river according to the planning, water quality and biodiversity, ecological function of the restored river was investigated. The results of the investigation are as follows:(1) The biodiversity of Jialu River was investigated. The results shows that biological diversity was very low. In the construction section of the river, the alien invasive species such as Alternanthera philoxeroides was dominated in the river. The total number of species were less than 20, of which the number of aquatic plants was only 6, riparian vegetation coverage rate was less than 20%.(2) After the preliminary investigation, based on the principles of ecology, considered to restore the river biodiversity, ecosystem structure and ecological function, In the section of Jialu River Ecological restoration design was conducted, aiming to recover the diversity, functional group and the structure of the ecosystem. And the construction of demonstration project was carried out from 2014 to 2015. After the construction of the Jialu River section, the river structure has been improved, habitat restoration, biodiversity has been increased significantly, ecological function group recovered, the ecological structure has been improved, ecosystem function have been very running well. Vegetation coverage rate reached more than 80%, the number of plant species was from the initial 29 to 39. With overall transparency of the river increased by 60%, aquatic animal activities increased, species increased 7, increasingly stable microbial community structure, the relatively entire food chain of producers consumers-decomposers in the river ecosystem has been established. The ecological restoration project to restore the biological diversity of Jialu River reached obvious effect. Meanwhile, the riparian landscape become beautiful.(3) Through the project implementation comprehensive managed, the total nitrogen, total phosphorus, ammonia nitrogen, COD and other indicators of water body decreased significantly, DO content was improved. In the construction section, the average total phosphorus, ammonia nitrogen, COD value decreased from 7.125mg/L, 2.41 mg/L,3.917mg/L and 21mg/L down to 2.65mg/L,0.325mg/L,1.2mg/L,16.7mg/L, respectively, while, dissolved oxygen (DO) was increased from 2.7mg/L to 6.14mg/L, and water quality from the inferior V class gradually was restored to class III.Through ecological restoration techniques research and ecological engineering demonstration on Jialu River, the water pollution have improved significantly, the ecosystem stability and function increased obviously. These results provide technical support for ecosystem restoration and ecological restoration of water pollution in the whole watershed. They also give a good reference for the ecological management of polluted rivers in china.