Investigation on Water Pollution of Four Rivers in Coastal Wetland of Yellow River Estuary

[Objective] The study aimed at analysing water pollution of four rivers in coastal wetland of Yellow River estuary.[Method] Taking four seriously polluted rivers(namely Guangli River,Shenxiangou River,Tiao River and Chao River) in coastal wetland of Yellow River estuary as study objects,water samples were collected from the four rivers in May(dry period),August(wet period) and November(normal period) in 2009 and 2010 respectively,then pollution indices like nutritive salts,COD,chlorophyll,petroleum,etc.were measured.Afterwards,the status quo of water pollution was assessed based on Nemero index and comprehensive trophic level index(TLI),so as to find out the integral status quo of water quality of rivers in the wetland and the damages to aquatic ecological environment.[Result] On the whole,water pollution of four rivers in coastal wetland of Yellow River estuary was serious,being in the eutrophication state,and the main pollutants were TN,TP,NH+4-N and petroleum.In addition,excessive N and P in the four rivers resulted in water eutrophication of Bohai Bay,so leading to ride tide,which destroyed the coastal ecological environment of Bohai Sea.Moreover,compared with historical data,water pollution by nitrogen and phosphorus became more serious,while there was no obvious aggravation in the water pollution by petroleum.In a word,water pollution wasn't optimistic on the whole.[Conclusion] The research could provide theoretical bases for the protection and utilization of river water in coastal wetland of Yellow River estuary and coastal sea area.