Asymptotic Dynamics of a Single-species Model with Resource-dependent Dispersal in One Dimension

In this paper,we study the asymptotic dynamics of a single-species model with resource-dependent dispersal in one dimension.To overcome the analytical difficulties brought by the resource-dependent dispersal,we use the idea of changing variables to transform the model into a uniform dispersal one.Then the existence and uniqueness of positive stationary solution to the model can be verified by the squeezing argument,where the solution plays a crucial role in later analyses.Moreover,the asymptotic behavior of solutions to the model is obtained by the upper-lower solutions method.The result indicates that the solutions of the model converge to the corresponding positive stationary solution locally uniformly in one dimension as time goes to infinity.

Population Shrinkage in Resource-dependent Cities in China: Processes, Patterns and Drivers

Resource-dependent cities(RCs)are a vulnerable group of urban settlements that often face population shrinkage;however,population changes in RCs in China are not well understood.This study offers new insight into this matter through a robust analysis that features a longer time scale,a larger sample of RCs,and a finer unit of analysis.It finds new evidence that problems of population shrinkage in RCs are more serious than previous literature has suggested.Approximately 30%of the studied units have experienced either long-term or short-term population shrinkage,and many more are experiencing a slowing down of population growth.Problems are especially common among three types of RCs:the resource-depleted RCs,the forestry-based RCs,and RCs in Northeast China.These results underscore transition policy inadequacies in addressing population loss,and call for a more comprehensive and diversified population policy that tackles the multifaceted factors that contribute to population shrinkage,including lack of industrial support,maladjustment to market oriented reformation,poor urban environment and natural population decline.

Identification and classification of resource-based cities in China

Resource-dependent cities are cities whose economic development depends on the exploitation and processing of natural resources. Their transformation and sustainable development are an important area of research on regional industrial development, regional economy and urban development. Since the Chinese government launched a pilot project to transform resource-dependent cities, starting with Fuxin in Liaoning Province in 2001, accurately identifying and classifying China’s resource-dependent cities has become a focus of geographical research. Based on previous studies, this paper uses the theory and methods of urban function classification to analyze indicators and threshold values for identifying and classifying resource-dependent cities. It has thus identified 262 cities as being resource-dependent. Looking at the development levels, problems, characteristics and developmental direction of such cities, this paper attempts to establish a comprehensive analytical framework using the two evaluation indicators of resource security and sustainable development. It also creates a model to classify the 262 cities identified as resource-dependent cities into four types: growing cities, mature cities, declining cities and regenerating cities. The different connotations and characteristics of the city types were then analyzed. The results of this research support the delineation of scopes and categories of resource-dependent cities set out in the National Sustainable Development Plan for Resource-Dependent Cities published by the State Council, and they serve as a foundation for formulating policies on planning, classification and guidance.