Urbanization Leading to Alteration of Soil Function of the Zhengzhou City in China.
Ke-ning WU, Department of Land Science and Technology, China University of Geoscience, 29,Xueyuan Road , Haidian Dist, Bejing, 100083, China
Abstract: The paper tries to reveal the impact of urbanization on the soil function evolution. Method of comprehensive analysis is applied. The Zhengzhou city lies in the transition between loess hill and Huang-Huai-Hai plain, so it has a variety of soil types. Because of the optional distribution of soil resource function, zoning of agricultural cropping structure adjustment and assurance of agricultural product quality, it is of great significance to study the transition among different functions of soil resources, the spatial-temporal changes of soil fertility and environmental condition, which are caused by land use changes during the urbanization. Pedodiversity decrease: According to the WRB,the soil is divided into 5 sub-unit:Calcic Luvisols, Calcaric Calcaric Cambisols,Fluvic Cambisols;Luvic-Hydragric Anthrosols, Calcaric-Arenosols,17 family and 51 series. Combining urbanization with GIS, figuring out change of the land use patterns .Compared with 1982, the extant soil area of sub-unit has reduced in various degree. Calcic Luvisols, Cambisols, has been reduced by 4160.61 hm2.Fluvic Cambisols reduced by 18195.95hm2 Calcaric-Arenosols reduced by 451.11hm2. Luvic-Hydragric Anthrosols disappear. Soil family decreased: 15,Soil species decreased: 40. Function transformation of soil resource: In the course of urbanization, the inner transition of productivity function were mainly from the field of orchard and pond, reaching 535.58 hm2. It reflected the influence of urbanization on the surrounding agricultural structure, As a result, cropping has been converted to more economically profitable forms of agricultural land use. The area of soil function as bearing got 629.20 hm2, which was converted from those function as productivity and ecological environment, while that which lost its ecological environment function got 332.84 hm2. According to the above, we can find out that soil in the suburb has been mainly convert from the productivity and ecological environmental function to the bearing function because of urbanization, which has reduced the decomposition ability to the exotic matter , increase the risk of soil contamination, and brought harms to the quality of primary products and the health of residents. Key words: urbanization; land use change; soil function evolution