The Accelerated Urbanization Process: A Threat to Soil Resources in Eastern China

The eastern coastal region of China has been experiencing rapid urbanization which has imposed great challenges on soil resources, characterized by soil sealing and fragmented soil landscapes. Taking Zhejiang Province—a fairly economically-developed and highly-urbanized region in eastern China—as a case study, a practical framework that integrates remote sensing, GIS, soil quality assessment and landscape analysis was employed to track and analyze the rapid urbanization process and spatiotemporal dynamics of soil sealing and landscape change from 1990 to 2010. Meanwhile, this paper qualitatively explored the regional inequality and characteristics in soil sealing intensity among cities of different geo-zones in Zhejiang Province. Results showed that total area of 6420 km2 had been sealed during the past two decades for the entire study area, which represents 6.2% of the provincial area. Among these sealed soils, 68.6% are fertile soils located in flat plains, such as Paddy soils. Soil landscapes became more fragmented and dispersed in distribution, more irregular and complex in shape, and less dominant and diverse in soil type, as evidenced by the constant change of various spatial landscape metrics. What is more, different geo-zones exhibited significant differences in dynamics of soil sealing intensity, soil composition and soil landscape patterns. The permanent loss of valuable soil resource and increasing fragmented soil landscape patterns concomitant with rapid urbanization processes may inevitably bring about potential threats to regional soil resources and food security.