Investigation And Analysis On Water Quality Of Dasha River And Study On Ecological Control Scheme

Water is an important source of life on the earth and an important driving force and factor for productive activities.At present,China is facing problems such as uneven distribution of water resources and serious river pollution.Therefore,it is practical significance to fully understand the pollution situation of rivers in China and put forward for corresponding solutions.In this article,the water quality of Dasha River was investigated through field visits,sampling and experiments.The pollution status of Dasha River was analyzed by data analysis,and the corresponding ecological control measures were planned to improve its water quality.Firstly,in the initial stage of water quality survey,consult relevant information to understand the pollution status of Dasha River Basin and the water quality of each section of the Dasha River Basin.Through map software,we can get familiar with the towns and traffic conditions around the Dasha River Basin,and plan sampling points and sampling routes.Secondly,the sampling points of Dasha River Basin are sampled on the spot,the water samples collected from the sampling points are determined,and the experimental data are collated and analyzed.Through the analysis of physical indexes such as water temperature,PH,dissolved oxygen,BOD,COD,total nitrogen,total phosphorus and other biochemical indicators,it is concluded that the water quality pollution in Dasha River Basin is mainly caused by nitrogen pollutants seriously exceeding the standard.The water quality of Dasha River basin is evaluated by Nemerow index method,organic pollution comprehensive evaluation method and fuzzy evaluation method.From the evaluation results,the water quality of Dasha River is generally poor,and the water quality of middle and upper reaches is more serious than that of other river sections.At the same time,through on-the-spot inquiry and investigation,we can understand the pollution sources of Dasha River.Finally,the planning and design of constructed wetlands are carried out according to the water quality situation obtained from the investigation and analysis and the geographical location of the polluted reach of the Dasha River Basin.The site of constructed wetland is selected in Qiaotouqiao section,and the type and combination of wetlands are selected.The wetland area,water quality index of import and export,length and width of wetlands aredesigned according to the specifications and actual needs.The plants and substrates of wetlands are selected to make the wetlands have reasonable pollutant removal efficiency.In a word,through on-the-spot investigation and planning and design,the paper puts forward the method to solve the water quality problem of Dasha River to the maximum extent,and provides technical support for Dalian's strategy of realizing economic development while taking into account environmental development.