Modeling of Urban Population Changes Background of Issue The growth of population is the issue that caused widespread concern in the world now. As the world’s top 1 populous country, China’s population problem becoming more prominent. Because of the base of large population, although China has implemented the one-child policy to practice family planning, population is still increasing greatly. This huge population pressure has brought a series of problems on China’s social, political, economic, health, employment, etc. herefore, research and solve the population problem is particularity important for China. Usually people will notice that in newspapers about population growth forecast, when it comes to the end of this century or the middle of next century, the whole world or a certain region’s population will reach XX billions. It is important to note that the number of population forecast in the each newspaper will show large difference for the same time, it’s clearly due to result of using different mathematical models in population calculation.
As the human society entered the 20th century, the rapid development in science and technology has made productivity improved strongly, meanwhile, the world’s population is growing in an unprecedented scale. Every unit time for increasing billion in population, has been shorten from one hundred years to two or three decades. The earth we live on, has been carrying its’ 6 billion people entered into the 21 century.
For quite a long time, human reproductions has been spontaneously, only because of the rapid expansion of population and dramatically worsen of environment quality, people just suddenly come to realize the truth that it is extremely urgent to research the relationship between human and nature, the variation trend of population, and how to control it. Mathematical Model in Use What I choose is the exponential growth model of China’s population, and using this model to make some predictions, then comparing with the actual population data. 5] Step 1 : raise question The following table showing the population of China during 1988 to 1998 , make the 1988 as starter year, t=0, so N[pic]=1110 millions people, N[pic] =2000 millions people.  |Year |1988 |1989 | | | | (million) | difference | |1992 | 1158. 23 | 1156. 16 | 2. 7 | |1993 | 1171. 71 | 1169. 14 | 2. 57 | |1994 | 1185. 17 | 1182. 26 | 2. 91 | |1995 | 1198. 50 | 1195. 53 | 2. 97 | |1996 | 1211. 21 | 1208. 94 | 2. 27 | |1997 | 1223. 9 | 1222. 51 | 1. 38 | |1998 | 1236. 26 | 1236. 23 | 0. 03 | Implication of the results As the natural population growth rate for these years is 0. 01116 at average, this modeling reflects the actual situation well. According to the forecast, until 2016 China’s population will exceed 1. 5 billion. We can see that although China’s population control policy is effective, but it still at a high growth period in recent years.
With the increase of population, the retardation of natural resources and environmental conditions on population continues to be more obvious. In order to survive and enhance the level of human civilization, taking effective measures to control population growth, and make the growth rate as a decreasing number, is necessary. Meanwhile, the natural resources and environment conditions for human survival are also given tougher restrictions for the maximum of population. This is not only the instruction bringing by the mathematical, but also can react on promoting the new models which are more suitable for population development.
Reference:  http://en. wikipedia. org/wiki/Demographics_of_China, “Demographics of China”  Qifan Yang, Xusheng Kang, Mathematical Modeling [M] Beijing Higher Education Press. (May, 2006)  Xuejun Yu, , Phase II of 2000. China’s population information website.  M. G. Dmitriev and A. P. Petrov , On the Possible Reasons for the Hyperexponential Growth of the Earth Population: Mathematical Modeling of Social and Economic Dynamics / Moscow: Russian State Social University, 2004. Qiyuan Jiang, Jinxing Xie, Mathematical Modeling Cases, Higher Education Press, 2006.