美国大学生数学建模大赛一等奖论文.doc

Team Control NumberFor office use onlyT1 _T2 _T3 _T4 _ 20300Problem ChosenBSummary For office use only F1 _ F2 _ F3 _ F4 _ 2013 Mathematical Contest in Modeling (MCM) Summary SheetSave water, Save money, Save China !China is a country with a serious water shortage. It is one of the poorest countries in per capita water.Whats worse, pollution and uneven distribution of water resources make the available water even less. In view of this, we set up an optimization model to obtain an optimal allocation strategy of water resources, hoping to contribute to Chinas endeavor for getting rid of water shortage.Firstly, according to geography, climate and water resource conditions, we divide the whole country into 7 regions. Next, we predict the water demand of each region in China in 2025 by the method of GM(1,1). Then we establish Model 1-Protective Exploitation of Water Recourses, finding out the maximum exploitation of water resources on condition that the environment can not be destroyed. Further, we work out the shortfall or surplus of water supply in each region.With the help of the data preparation above, we set up Model 2-Optimization of water transfer and supplement, taking storage, movement and desalination into consideration. Besides, we set a constrain-Balance Degree which reflects the balance situation of water resources distribution in all regions. We solve the model, getting an optimal strategy to meet the water demand of each region with the lowest investment: 68.7 billion yuan.We obtain two valuable consequences through detailed analysis and verification of our model. Firstly, balance degree has significant influence on the economic growth and environmental protection. The greater the balance degree is, the better the water strategy can promote to economy and environment. Secondly,we find that China should consider building desalination factories when the cost of it decreases to 1.5 yuan/m3. In this way, not only water demand are met, but also the investment cost gets smaller-dropping to 68.1 billion yuan.Finally,we discuss the feasibility of our optimal strategy, which proves that it is effictive and practicable to help China to get rid of water shortage. Team #20300 Page 1 of 28Save water, Save money, Save China ! content 1. Introduction . 22. Model Assumptions . 23. Terminology And Analysis before Modeling . 33.1 Terminology . 3Explanation of nouns: . 3Explanation of Symbols: . 33.2 The General Idea of Our Model . 44.Zoning And Data Preparation . 44.1 Zoning: . 54.2 Data Preparation: . 75. Models. 85.1 Medel 1: Protective exploitation of water recourses in each region . 85.2 Model 2: Optimization of water transfer and supplement . 105.2.1 Assumptions for Model 2 . 105.2.2 The Establishment of Model 2 . 115.2.3 Solution And Analysis of Model 2 . 165.2.4 Water Resource Allocation in West Region . 186. Sensitivity Analysis of Our Model . 196.1 Sensitivity Analysis of Model 1 . 196.2 Sensitivity Analysis of Model 2 . 207. Verification of Model . 227.1 Economic Analysis. 22 -Is it beneficial or not for Chinas economy to improve balance degree withhuge investment? . 227.2 Realistic Analysis . 237.3 Protect Bohai Sea !. 248.Non-technical Position Paper . 269. Strengths And Weakness . 2710. Conclusion . 2711. Referrences . 28 Team #20300 Page 2 of 281.IntroductionChina is a country with a serious water shortage. Although China has a total amount of fresh water resources of 2.8 trillion cubic meters, ranking fourth in the world, the amount of water per capita is only 2200 Cubic meters - 1/4 of the world average. It is one of the poorest countries in per capita water.Whats worse, pollution and uneven distribution of water resources make the available water even less.China is now begin to construct some huge projects to improve this situation, such as the South-North Water Transfer Project, and the Three Gorges Dam. However, with the development of the country, water consumption also shows a rising trend. How to further improve the distribution of the countrys water resources, and solve water problems of water-deficient area for the next ten years? Its great challenge for the Chinese government at this stage.The rapid development of China, will inevitably result in the increase of water demand. We use Grey prediction and Model 1-Protective exploitation of water resources, to forecast the water demand of each region of the country in 2025. In order to solve the problem of water shortfall in some regions， we set up Model 2-Optimization of water transfer and supplement to obtain the optimal water strategy, which contains how to transfer water among regions and how many reserviors and desalination devices should be built in each region. This strategy can meet the water demands for all the regions in China, while spending the least.Further more, we analyze the sensitivity of our model, and find that if we want the water supply more fair on a national scale, which means to improve the balance degree, the cost will increase notably. However, in the long run, this balance of water distribution will bring a wonderful benefit for both the economy and the environment. In addition, we also find that the decrease of desalination costs can influence the optimal strategy, when this cost falls below a certain value, more desalination devices should be built.At last, we demonstrate the feasibility and the optimality of our water strategy, and give some suggestion for Chinas water policy to the government.2.Model AssumptionsOverall Assumption l The geography and water conservancy information we collected is true andreliable;l In the future years, Chinas meteorological condition remains stable and severeflood or drought will not occur . Assumption for Model 1 Team #20300 Page 3 of 28 l Each region is supposed to exploit its own water resources in the principle ofsustainable development;l Weather condition changes little so that we can estimate the rainfall in 2025 withthe data in 2012. Assumption for Model 2 l If one region transfers water to another, the transfer distance is centroid distancebetween two regions;l The altitude difference between two regions is the difference of the averagealtitude of two regions;l Cost of water transfer between two regions consists of water conservancyconstruction and transporting costs. This cost can be represented with quantity of water transfer. Obviously, higher altitude and further distance make larger amount of cost ;l Storage in a reservoir mainly comes from rainwater and its cost of building canbe roughly estimated by its capacity;l Desalination project is available for coastal regions only.3.Terminology And Analysis before Modeling3.1 TerminologyExplanation of nouns:Storage: Water storing. In this paper, it refers to water storing of reservoirs. Movement: Transfer of water via canal or large pipe from one region to another. Explanation of Symbols:x: Exploitation quantity of a certain kind of water resources c: Capacity of reservoirtij: Quantity of transfer water from region i to region j .dij: Distance between region i and region j .hij：Altitude difference between region i and region j. Team #20300 Page 4 of 28 raink：Annual amount of precipitation of region k.coastk：Coastline length of region k.pk：Quantity of water after desalination of region k.oi：Surplus of water of region i.sj：Shortfall of water of region j.B：Balance degree of water of the whole country.W：Total cost of allocation strategy of water resources3.2 The General Idea of Our ModelIn order to make a good strategy, we find three ways of water exploitation, and they are storage of reservoirs, surface runoff and desalination of seawater. With reasonable use of these three ways,we can solve water crisis of China. The following flow chart shows our general idea of modeling. Figure 1: Flow chart of modeling Team #20300 Page 5 of 284.Zoning And Data Preparation4.1 Zoning:China is a big country with vast area, complex terrain and various climate. As a result, situation of each region is different .So we divide China into several regions. Within a region, geography and climate conditions is similar, so we can discuss several regions instead of 34 provinces. According to “Water resources distribution of China” and “Possession of water resources per capita of every province” as follows, Figure 2: Water resources distribution of China1 Figure 3: Possession of water resources per capita of every province2 Team #20300 Page 6 of 28 We divide China into seven regions and they are: Ø Inner Mongolia (IM):There is vast territory but less population, and one could hardly find a river in IM.Ø The Northeast region (NE):This region has dense population, moderate rainfall and flat terrain. There are Songhuajiang River and Heilongjiang River in this region.Ø The Central region (CR):There is little rain in this high-terrain region. The Yellow River flows across it, but soil erosion often occurs at the same time.Ø The North region (NR):There is very dense population and developed economy,thus NR has a great demand of water, but it has less rain that concentrats in the summer .Ø The South region (SR):SR has large population ,developed economy. Rainfall and rivers provide enough water for this region.Ø The Southeast region (SE):There is dense population, rich precipitation ,large number of rivers and lakes. Ø The west region (WR):Though there is a large amount of river and rain, rugged and complex terrain and high altitude makes it hard to build water conservancy facilities. The following figure shows partition results: Figure 4 : Partition results Team #20300 Page 7 of 284.2 Data Preparation:-Prediction of water demand of each region in 2025 According to China Statistical Yearbook, we can find water demand of each province from 2003 to 2011 3, combined with partition result we get, we obtain water demand of each region in these past years . Using Grey prediction GM（1,1）4,we predict their water demand in 2025.Grey prediction makes predictions by setting up model with little incomplete information. Here ,we choose Xinjiang as an example and build Grey prediction model:bì(A-)iïïF=+bv íia×(i-1)aeïïîGi=Fi-Fi-1Where:F1=A1 ，i=1,2,3×××,22,23.Employing Matlab, we get that: a =-0.0105，b =493.8847 and water demand after 2011 as the following figure shows: Figure 5: Water demand of Xinjiang after 2011 In the same way, we can obtain water demand of each region. In addition, we also get surface runoff, storage of reservoir and compensation amount of groundwater from China Statistical Yearbook 3 and spread out these four items in the following table : Team #20300 Page 8 of 28 unit:billion m3Table 1: Four items of water of different regionsRegion NE NR IM CR WR SR SEW.D 88.45 85.73 20.30 28.34 70.01 173.32 275.99SUR.R 98.63 20.56 15.75 16.66 397.09 695.09 488.36STO.R 41.44 33.48 0.75 4.94 40.60 76.71 82.79CA.G 29.60 20.79 9.96 17.50 167.24 232.65 138.40 W.D: Water Demand; SUR.R: Surface runoff;STO.R: Storage of reservoir; CA.G: Compensation amount of groundwater5. Models5.1 Medel 1: Protective exploitation of water recourses in each regionIn model 1,we are going to optimize the way of water supply of Regional internal. Supposed that water resources of every region can satisfy its own water demand in 2012 and water resources will not reduce by reasonable exploitation. As time goes by,water demand of each region increases as we find in the data preparation process. But considering the protection of water resources, taking the principles of sustainable development as constraints, we are supposed to limit