Study Of Water Environmental Carrying Capacity In Qingdao Reach Of Dagu River

Dagu River is the important waterhead of Qingdao and is praised the mother river. In recent years, the booming economic development of the city has aroused the daily serious pollution risk of the river, and the protection of her hereby has caused wide public concern.There has been a lot of scholars researching into the river, such as using QUAL2E model to study the water environment capacity of Dagu River and doing research on the amount of the pollutant gathered in the river valley to reflect the water environmental carrying capacity of the river etc., but none of these researches has combined with the water function subarea of the river. According to the inquisition of Dagu River, data manipulation and combine with the water function subarea in Qingdao City, this paper divides the river into 6 water function subarea reaches. And according to the characteristics of the pollutant and the status of development, this paper analyzes the amount of the pollutant gathered in the river valley in reference year (2007). During the account, the pollutant is separated into two major types, the point pollutant and the plane pollutant. After analyzing the amount of the pollutant in 2007, the author gives the forecast of the pollutant amount in 2015 and 2025.The research shows that, in reference year, the COD and ammonia nitrogen pollutants of Chanzhi reservoir exit～Shabu reach, Shabu～Zaozhao reach and Jiangjiazhuang～Mawan reach in Laixi City are mainly caused by agricultural field runoff pollutions; the COD and ammonia nitrogen pollutants of Zaozhao～Jiangjiazhuang reach are mainly caused by the pollutants carried by Zhu River; the COD pollutant of Jiangjiazhuang～Mawan reach in Pingdu City is mainly caused by the pollutants carried by Xiaogu River, and the ammonia nitrogen pollutant of this reach is mainly caused by agricultural field runoff pollutions; the COD pollutant of Jiangjiazhuang～Mawan reach in Jimo City is mainly caused by the pollutants carried by Wugu River, and the ammonia nitrogen pollutant of this reach is mainly caused by agricultural field runoff pollutions; the COD and ammonia nitrogen pollutants of Jiangjiazhuang～Mawan reach in Jiaozhou City are mainly caused by the pollutants carried by Nanjiaolai River; the COD pollutant of Mawan～Nanzhuang strobe reach is mainly caused by industrial pollutants, and the ammonia nitrogen pollutant of this reach is mainly caused by agricultural field runoff pollutions; the COD and ammonia nitrogen pollutants of Nanzhuang strobe～estuario reach in Jiaozhou City are mainly caused by domestic pollutants of cities and towns; the COD and ammonia nitrogen pollutants of Nanzhuang strobe～estuario reach in Chengyang District are mainly caused by the pollutants carried by Taoyuan River. The pollutants carried by branches have significant impact on the drainage basin. Accordingly, the branch pollution abatement has concernful meaning to Dagu River.Compare the pollutant of each reach with the water environment capacity, we can find that concentration control can not guarantee the water environment quality of Dagu River in Qingdao. In low water period, the river can not accept the pollutants or reach the human requests; the river faces serious pollution risk. And thereby we need the riverfront Laixi City, Pingdu City, Jimo City, Jiaozhou City and Chengyang District to control the pollutants go into the river, specially the pollutants carried by branches. With these works, we can protect Dagu River effectively.