Study On Water Quality Analysis And Pollution Control In Songhua River Harbin Section After Dadingzishan Project Completed

Dadingzi Dam Project (DDP) is the first water conservancy project in mainstreamof Songhua River. The main purposes of the DDP are improving the waterenvironment of Harbin City, generating electricity, transportation, aquaculture andtravelling. Some negative phenomenons of water happened after the DDPcompleted, so the research of the water quality in Songhua River Harbin Sectionafter the DDP completed has the important meaning.This study is focus on the water quality situation after the Dadingzi DamProject (DDP) completed, and tries to find the pollution control strategy based onthe water environmental capacity. To begin with, the data matrix, collected from sixmonitoring sites of the Songhua River-Harbin Region, was analyzed for dividedthem into three groups. Group A represents low polluted area including Zhushuntunand HulanInner sections; group B represents moderately polluted area includingAshenDown and HulanDown and Dadingzishan sections; group C has onlyAshenInner section. Then typical sections (Zhunshuntun S1, Dadingzishan S2andHulanInner S3) of each group were selected for the future research.Water quality data of three sections were analyzed before and after the DDPcompleted, the results show that DO is increasing and CODMn, ammonia, TN andTP is desearsing in all three Sections after DDP completed. Meanwhile, the Singlefactor method was applied for evalution of year2005and2011which are the mostfar away from the DDP completed point. The result shows that the pollution level of2011is lower than2005, but the pollution of S3need to control seriously in bothyear.Secondly, water quality rank assessment model was established based on fuzzyneural network (FZZ). The water quality of three sections in year2005and2011were evaluated by using FZZ. The results are reasonable and show that the waterquality of2011is better than2005and the water quality of study area is improvedafter DDP completed, but the water quality rank of S3is till class V in manymonths, which need to control pollution in the future. Afterwards, BP neural netwokmodels were trained and validated for forecasting the five water quality indexincluding ammonia, DO, CODMn, TN and TP. Then the assess result of October2011shows that water qualiy of study area is becoming better except S3and the accuary of the predicted model can meet the needs of the application inenvirontment field.Thirdly, the2-D water quality model and End section approach were used todynamically calculate the water environmental capacity of COD and ammonia inSonghua River Harbin Region. The results show that the ideal water environmentalcapacity of COD and ammonia were46305t/a and4299t/a in Zhunshuntun-Dongjiangqiao functional area, but were136112t/a and6717t/a in Dongjiangqiao-Dadingzishan functional area.Finally, the actual water environmental capacity were recaluated throuthconsidering the upstream water quality and the influence of tributaries. The resultsshow that the upstream water quality should be controlled seriously if it is want toassure that the downstream water environmental capacity can meet the need ofpeople healthy. The actual water environmental capacity of ammonia is below0andit is smaller than the ideal one in icebound months. Then the dynamical waterpollution control strategies of2009yr were obtained by considering the acturalpollution situation of each outlet. The ammonia still should be controlled seriouslyin study area in the winter after DDP completed.