Study And Prediction On Temple And Spatial Distribution Characteristics Of Environment Factors In Heihe River Watershed

With the increase of population and rapid development of social economy,Heihe River basin was in the face of increasingly prominent eco-environmental problems.Water environment problems had serious impact on economic development in Heihe River basin.The method of principal component analysis and factor analysis were used to study the influence factors on water quality of Heihe River basin,the method of cluster analysis and principle component analysis were used to class the ten sub-watershed of Heihe River basin,the method of GM(1,1)model was used to predict the trend of the main influencing factors on the water environment of the Heihe basin in the coming years.The results would provide basic data and theoretical foundation for water environment treatment,water resources protection and sustainable utilization of Heihe River basin.The main results of the paper were as follows:(1)Based on the analysis of temporal and spatial distribution characteristics of water environmental factors of the Heihe River basin,some water environmental factors showed obviously seasonal variation.The of content Copper(Cu),nitrate nitrogen(NO3-N),nitrite nitrogen(NO2-N),total nitrogen(TN)reached the maximum in April and gradually decrease from July to December.In April and July,the content of(Na),arsenic(As),chloride ion(Cl-),sulfate ion(SO42-),carbonate ion(CO32-),dissolved oxygen(DO),conductivity(EC),total dissolved solid(TDS),transparency(SD)were relatively small but reached the highest level in December.The of content(Pb),zinc(Zn),mercury(Hg),pH,suspended matter(SS),total organic carbon(TOC),soluble organic carbon(DOC),permanganate index(CODMn)were smaller in April and December but reached the maximum in July.The variation regularity of water environment factor was not only related to seasonal change,but also related to regional environment.The Babao River belonged to the source area of Heihe river,and the variation degree of water environmental factor had litte change,which mainly varied with the season.The water environmental factors of Zhangye Wetland and Dongjuyan lake varied greatly.(2)By the method of principal component analysis,the water environment factors were divided into several main elements.The first four main components basically reflected the whole water quality information.By the method of factor analysis,the most important water environmental factors in different periods were selected.As,pH,ammonia nitrogen(NH3-N),TN,TP and CODMn were the main influence factors on the water quality of the Heihe River basin,which mainly come from industrial wastewater,domestic sewage and withdrawal water of agricultural irrigation.As content was higher in Zhangye wetland,Red river and Middle reach main stream which mainly come from industrial wastewater.TN and TP mainly come from domestic sewage and withdrawal water of agricultural irrigation.NH3-N and CODMn mainly come from domestic sewage.(3)By the method of clustering analysis and principal component analysis,ten sub-basins of Heihe River basin are classified to five category.The first category was the North River,the second category included the Middle reach main stream of the Heihe River,Babao river and Ejina River,the third category was Zhangye Wetland,the fourth category incluede the Red River,Liyuan River,Yeniugou and Shandan river,the fifth category was Dongjuyan lake.The water quality of Yeniugou,Liyuan river and Red river was better while locating in the upstream region.The water quality of Shandan river,Zhangye wetland was worse while they located in the lower part of upstream where urban industry was advanced and water quality was affected relatively serious.While located in the end of the HeiheRiver Basin.The water quality of Dongjuyan lake water quality was the worst because of nutrient and contaminant enrichment(4)By method of GM(1,1)model,the trend of water environmental factors was predicted.In 2016 and 2017 the content of As would reduce,which was lower than the standard of the first category of water.In 2016 and 2017 the content of pH would increase with small amplitude.In 2016 and 2017 the content of NH3-N would increase which would not surpass the standard of the second category.In 2016 and 2017 the content of TN would decrease which was within the scope of third and fifth category.In 2016 and 2017 the content of TP would increase which was higher than the standard of the fifth category.In 2016 and 2017 the content of CODMn would increase which was within the standards of the third and the fifth category.The content of NH3-N,TN,TP,CODMn should be controlled in the future water environmental management.The domestic sewage and industrial waste water discharge should be supervised strongly.The utilization of fertilizer should be controlled to reduce the impact of agricultural non-point source on the water of the Heihe River basin.