Rairy Karst Wetland Eutrophication Situation And Countermeasure Research

In recent years, there is an increasing decrease of the area of Hui Xian wetland together emerging eutrophication problems and aquatic ecosystems issues, which due to the local economic development and the changing climate. Strengthen the research of and put forward countermeasures to the huixian karst wetland has practical significance in pollution control and aquatic ecosystem restoration. By studying the water quality indicators, we try to find out the current status of eutrophication and analysis the changing of water quality. Together with field investigation, we aim to find out the main sources of nutrients and pollutants that lead to huixian karst wetland eutrophication and give suggestions on further control measures.The main results as follows:(1) The wetland water quality decreased significantly from moderate nutrition status in2006to general moderate eutrophication with some parts heavy eutrophication in2013. Generally, the eutrophication status in this wetland is aggravating over time.(2) In spring, with stable temperature condition, there is a significant change of the concentration of nitrogen and phosphorus with time. The changing trend and range of nitrogen is bigger than that of phosphorus. Besides, the growth of algae and water hyacinth has a similar increase trend with nutrients. Thus, N is an important nutrient affecting the eutrophication of wetland water. Moreover, there is a match between anomaly change of nutrient and rainfall caused nitrogen and phosphorous input in terms of spatial distribution and time line. Visible exogenous nitrogen and phosphorus input are the main cause of eutrophication, which resulted from aquaculture wastewater.(3) The vertical distribution of total phosphorus, total phosphorus, total nitrogen, and other indicators in pond water show an increasing trend relation with water depth, and the concentration of dissolved oxygen (DO) decreases with water depth; Distribution of N and P are affected by hydraulic disturbance of stream water, and has a close relationship with the growth of algae and water hyacinth. (4) With the exogenous input of nitrogen in Autumn, there is the possibility of occurrence of algal blooms in some rivers due to the well supply phosphorus and suitable temperature and light. The time between Summer and Autumn is an important period to prevent water eutrophication.