Chongqing City Population Projections And Control

China has the largest number of population in the world,which consists of one fifth of the world population.The number of population in Chongqing is one of the largest cities in China.The large number of population is a big problem to the development of economy and society of Chongqing.The number of population greatly affects the development level of economy and social advancement.To exactly forecast the number of population and its developmental trend of an area is important for the economic plan and tactics of social development. Through the population evolution equation,the number of population and the distribution by age in Chongqing are forecasted and analyzed,which supplies a foundation for the economic plan and tactics of social development of Chongqing.Based on the demographic data of the 5^thcensus,the author simulate the mortality mode function,fertility mode function in Chongqing,then predicts the population growth in the next years by the population evolution equation.The results show the number of population in Chongqing will increase gradually in this period,approaching 33.90 millions in 2025,whereas it was 30.90 million in 2000.The net immigration will pay a main contribution to the population growth.The number of population over the age of 65 will be 5.35 million in 2025.The trend of age distribution shows that the elder population will slimly increase.The dependence number will increase to 20.95%in 2025 as it was 11.33%in 2001.Further,if it is completely depends on reducing the total fertility rate to control the number of population in Chongqing,it will lead to the age distribution unbalanced.A strategy is to increase the number of immigration,alleviating the stress of the society.The results show that the model will maintain high predicting accuracy in mid-and long-range predictions.It is flexible in model operation with small calculations. Consequently,the model is a useful tool for population prediction.