A Study Of The Effect Of City Development On Yellow River Water Quality In Lanzhou Reach

The Lanzhou part of Yellow river through the city zone,it's the most importance surface water source for city development.But city development of produce amount of pollutants discharged into the Lanzhou reach of Yellow river,cause that the Yellow River water quality continues to deteriorate.Therefore,it has important practical significance and theoretical value that engage on the research of the affects of city development on the Yellow river water quality.In this paper makes a systematic research on the affects of city development on the water quality,main contents this article are as following:(1)The waste water,which was pure into Yellow river form Lanzhou,can be partition to industry wastewater and domestic sewage.As a whole,the capacity of industry wastewater is gradually decrease with time,the capacity of sewage have a slight upward trend.The most of industry wastewater come form the chemical industry,petroleum industry,the textiles industry,black metal smelting industry,building materials non-metallic mineral products industry,steam and heat by electricity industries,especially form the leading of these industries,such as fertilizer plant,organic compound plant,petrochemicals plant,synthetic rubber plant,oil refining petrochemicals plant,New Western Vinylon plant,carbon plant.(2)In study by evaluate the water quality of Yellow river during 1996 to 2005,we found that as following:(一)The water quality has been improving,pollution have downward trend,"Ninth Five-Year Plan" period not attain ClassⅢstandards,and "tenth Five-Year Plan" period reached ClassⅢstandards.(二)The basic characteristics of the pollution of Lanzhou reach of Yellow River:Biologic and organic is the mainly pollution,followed by metal and mineral pollution;the trait of distribution of the pollution:almost of entire reach had pollution by biological and organic,and the pollution aggravate along the river,and the pollution outstanding in plentiful period;organic and inorganic pollution centralize on the four sections of the lower reaches,and outstanding in the Bao-Lan Bridge section,the main pollution of the Huangshui bridge section is TP and hexad chromium.(3)Analysis the relation between Lanzhou city development and the changes of water quality by the single factor,found that with the improvement of water quality, City have some changes in the social and economic as following:population increase year by year;total annual water supply,the number of waster water continue to decline,the gross domestic product,per the gross domestic product,industrial production value are all growing;Constantly raise the rate of urbanization;invest of water pollution control increasing.(4)By the grey system of relation analysis method,analysis the affects of the Lanzhou social,economic factors on the water quality of Yellow River,and found the order of influence degree is:The total annual water supply＞the number of waster water＞the daily waste water handling capacity＞the industrial production value＞gross domestic product＞the rate of urbanization＞population.(5)In brief sum up the conclusion,and pointed out the lack of research and further research directions.