The one-child policy, which is also named as family planning, is the one-child limitation in the population control policy of the People’s Republic of China (PRC). The policy is enforced at the provincial level through fines that are imposed based on the income of the family and other factors. This policy was introduced in 1978, after over 30 years, it still remains a basic state policy for China Mainland. During the period, the policy had a great impact on the population. In this project, our aim is to find out the positive effects as well as the negative effects on the population. By comparing the birth rate in 1990 and 2000, we can find out whether the policy is efficient to control population. On the contrary, by looking into the sex ratio and the percentage of people over 65 years old, we can know if there would be some problems such as the gender imbalance or aging problems.

All the population data we used were collected by the statistical bureau of China, which were recorded in the official statistical yearbook of China. The census of population is taken every ten years in China Mainland, there was a population census in 1990 and 2010 separately so the data of the 2 years are more accurate. There is a point to mention that Chongqing Municipality used to be part of Sichuan province and was independent as a municipality in the year 1997. So the data of Chongqing before 1997 was regarded as the same as Sichuan province. The yearbooks of the two years are all available on the Internet as PDF file.

A base shapefile of China was used in all the maps and was obtained from the Internet. Because the one- child policy is just carried out on China Mainland, so we didn’t consider about Hong Kong, Macau and Taiwan province.
As for the coordinate system, the original map didn’t use any coordinate, so China Geodetic Coordinate System 2000, which is the newest national geodetic reference system, was projected to the shapefile. This gives China Mainland a better and advanced look.

All the five maps we created use choropleth colors as the background, with indicates the population density of China Mainland. Natural break classification was used because the values of population density are not continuous, and some values are really distinct from the others, Shanghai, for example. In order to well present the distribution of the population density, it will be better to minimize the variance for all the classes to make the map more accurate. Although the variances among the classes can be very large, it is not what the project really cares.