Study On The Water Use And Water Demand Of Beijing City

Beijing is suffering from a lack of water resources. In order to solve the water resources problem of Beijing in future, the costly South-to-North Water Diversion Project is in expedite progress. But the actual data of Beijing water use in past years indicated that Beijing's water consumption has not presented the anticipated rapid increase, instead, it has been keeping stable. This has brought different opinions of the existing and planned water diversion projects. In addition, it caused many scholars to consider the water demand forecast in the past programmings. This thesis is mainly about what trend Beijing's water demand will take in future and what changes the water use took in the past.This thesis firstly analyzed the reasons for the historical changes of water use in Beijing by qualitative analysis. And then it used quantitative analysis to study the rules of water use in Beijing. Because of a large number of statistical data collected from the yearbooks, the thesis adopted data mining notion to find the driving factors of Beijing water consumption. This thesis gathered 56 climatic, social and economic variables from the Beijing Statistical Yearbook covering from 1986 to 2008, which had the same time range of water use data. This thesis applied statistical analysis method. It used principal component analysis to combine the variables which had similar meanings and high correlativities to an integrated factor, then carried stepwise regression analysis by SPSS software. Through removing the variables which are selected earlier, the thesis finally obtained the satisfied fitting formula of the historical water use process and the driving factors as well. Since the presence of a large amount of data, this thesis used GP, one of the data mining technologies, to improve the fitting equation. By using GP, the study found some factors which have not been noticed in the past, such as air temperature. Finally, this thesis used multiple regression formula got from the former analysis, Grey Model and per capita water use method to forecast the water demand of Beijing from 2009 to 2020.The thesis concluded that industry water use had a great relation of the secondary, tertiary industry and economic integrated factor, construction added value index, proportion of primary industry in GDP, etc. Domestic water use has a great relation of domestic integrated factor and gross output value of farming. Agricultural water use is mostly affected by agricultural integrated factor and proportion of primary industry in GDP. Total water use is driven by agricultural integrated factor, CPI and the number of employed persons, etc. The forecast result calculated by the fitting formula is the water demand peak of Beijing from 2009 to 2020 will be about 3.9 billion m~3. Grey Model is a monotonic model, which predicts the water demand of 2020 will be less than 3.8 billion m~3. The largest number of predicting results analyzed by the per capita water use method is 4.06 billion m~3. As a result, the maximum year water demand of Beijing in the next 10 years will be about 4.0 billion m~3.