Evolution of Patterns in the Ratio of Gender at Birth in Henan province, China

The imbalance in the ratio of males to females at birth is one of the major challenges facing modern China. It is a problem that cannot be overlooked, especially in the context of the socioeconomic development being experienced in China. Based on data of the sex ratio at birth in 2000 and 2010, and using exploratory spatial data analysis and geographical detector methods, this paper systematically explores spatial patterns, evolutionary characteristics and the mechanisms for the analysis of this ratio in Henan province. The results show that: (1) the degree of imbalance between the sexes is exhibiting a downward trend, while significant differences in the levels exist in internal county units and these variations are increasingly expanding; (2) areas exhibiting extreme levels of imbalance are located in the north, east and south of Henan. The remaining  areas had a mixed distribution and were widely spread in the central and western regions of the province; (3) according to the spatial correlation characteristics, there exists an obvious aggregation phenomenon in sex structure at birth which has moved northwest in the decade under review; and (4) there are many factors affecting the distribution of the ratio between the sexes at birth, including natural environmental conditions, levels of education, population stress, economic development and population migration. In addition to these factors, urbanization, living conditions, social development, traffic conditions, income level, reproductive potential and health factors have also influenced the proportion of males to females to different degrees.