Urban Expansion Assessment Based on Optimal Granularity in the Huaihe River Basin of China

Determining the optimal granularity, which has often been ignored in the analysis of urban expansion and its landscape pattern, is the core problem in landscape ecology research. Here, we calculate the optimal granularities for differently sized cities in the Huaihe River Basin of China based on scale transformation and area loss evaluation. Accordingly, we construct a landscape index and urban land density function to analyze urban expansion and landscape pattern. The results can be summarized as follows. (1) Within the first scale domain of the landscape indices, the optimal granularities of Zhengzhou, Xuzhou, Yancheng, Xinyang, and Bozhou are 60 m, 50 m, 40 m, 40 m, and 40 m, respectively, which are the optimal units in the study of urban expansion. (2) The urban land density decreases from the urban center to the outskirts, the urban core of each city is more compact than the outskirts, and the land density curve parameter α of Zhengzhou is the largest at 4.693 and its urban core the most compact. (3) There are significant spatial and temporal differences in the urban land densities of differently sized cities. The urban land density functions of different cities are similar before 2000; after that, they are similar to the standard inverse S-shaped function and the land use density curve of large cities is closer to the standard inverse S-shaped function than that of small- and medium-sized cities. (4) Large cities have faster expansion, much larger land density curve parameter c than medium- and small-cities, stronger linkage development with surrounding areas, and a higher degree of urban centralization. Urban expansion compactness was influenced by urban locations and functions except for urban sizes. This study offers a method for identifying the optimal granularities for differently sized cities and also provides information for the decision-making efforts that concern the rapid urbanization in major grain-producing areas of China

Urban Expansion Assessment Based on Optimal Granularity in the Huaihe River Basin of China

Determining the optimal granularity, which has often been ignored in the analysis of urban expansion and its landscape pattern, is the core problem in landscape ecology research. Here, we calculate the optimal granularities for differently sized cities in the Huaihe River Basin of China based on scale transformation and area loss evaluation. Accordingly, we construct a landscape index and urban land density function to analyze urban expansion and landscape pattern. The results can be summarized as follows. (1) Within the first scale domain of the landscape indices, the optimal granularities of Zhengzhou, Xuzhou, Yancheng, Xinyang, and Bozhou are 60 m, 50 m, 40 m, 40 m, and 40 m, respectively, which are the optimal units in the study of urban expansion. (2) The urban land density decreases from the urban center to the outskirts, the urban core of each city is more compact than the outskirts, and the land density curve parameter α of Zhengzhou is the largest at 4.693 and its urban core the most compact. (3) There are significant spatial and temporal differences in the urban land densities of differently sized cities. The urban land density functions of different cities are similar before 2000; after that, they are similar to the standard inverse S-shaped function and the land use density curve of large cities is closer to the standard inverse S-shaped function than that of small- and medium-sized cities. (4) Large cities have faster expansion, much larger land density curve parameter c than medium- and small-cities, stronger linkage development with surrounding areas, and a higher degree of urban centralization. Urban expansion compactness was influenced by urban locations and functions except for urban sizes. This study offers a method for identifying the optimal granularities for differently sized cities and also provides information for the decision-making efforts that concern the rapid urbanization in major grain-producing areas of China

Eco-Economic Coordination Analysis of the Yellow River Basin in China: Insights from Major Function-Oriented Zoning

The ecological-economic coordination degree model is widely used to analyze eco-economic coordination relationships, but methods for determining the relative weights of the ecological and economic systems lack a scientific basis. Examining the Yellow River Basin based on Major Function-Oriented Zoning (MFOZ) in China, the study surveyed 42 experts and used the analytic hierarchy process (AHP)to calculate the ecological and economic weights of the different main function zones. It also improved the model and evaluated the coordination degree of the ecological economic system in 642counties of eight provinces in the Yellow River Basin from 1991 to 2015. The results indicate that (1) the ecological value of the basin increased from 823 billion Yuan in 2001 to 1142 billion Yuan in 2015; (2) the GDP shows a linear growth trend: high- and medium–high-value areas of per capita GDP are clustered around nine metropolitan areas, while cold spots are distributed in ecological protection and agricultural development zones; (3) the ecological and economic coordination of the river basin first rose and then declined; and (4) the coordinated development areas are concentrated in five urban agglomerations that are highly consistent with the per capita GDP hotspots

Evolution Stages of Oasis Economy and Its Dependence on Natural Resources in Tarim River Basin

This paper examines spatio-temporal characteristics of an oasis economy and its relationship with water and mineral resources in the Tarim River Basin from 1965 to 2005. A spatial autocorrelation model, the center of gravity model, and index system of the regional central city are used to probe the evolution laws of spatial structure of oasis economy. The study finds that: 1) The economic centre of gravity, whose variation track during this period follows linear rate law, was moving from headstream to middle reaches of the Tarim River. 2) Positive spatial autocorrelation which showed a waving and ascending trend of regional economy was significant and the neighbor effect of regional economic growth was strengthened continuously. 3) The regional economic centre was located in Hotan City before 1980, moved to Aksu City during the 1980s and to Korla City after 1990. We conclude that above all, during the recent four decades the evolution of the oasis economy in this region has gone through three stages: a traditional agriculture stage (before 1980), oasis agriculture and agricultural product processing stage (1980-1990) and oasis energy industry stage (after 1990). Furthermore, the dependence degree of the oasis economy on natural resources in different stages are studied by using dominance index, regression model, and grey relation method, which shows that an oasis economy highly depends oil water resources in the oasis agriculture and agricultural product processing stage while it depends more oil mineral resources such as oil and natural gas during the oasis energy industry stage

干旱区绿洲城市发展与水资源需求预警分析——以乌鲁木齐市为例/Scenario Warning for Urban Development and Water Resource Demand in the Arid Oasis City of Urumqi[J]

基于乌鲁木齐市城市发展与水资源开发利用历史数据,采用系统动力学方法,构建干旱区绿洲城市发展与水资源需求预警系统仿真模型,并对乌鲁木齐市城市发展的水资源需求进行多情景模拟.模拟结果显示:①现有水资源条件难以满足城市发展的需要,各情景下水资源对城市发展系统均存在较强约束,采用调水与节水方案,乌鲁木齐市中、高速发展情景下到2030年将分别存在5.17亿m3、30.15亿m3的水资源缺口;②节水方案对水资源开发利用潜力提高的效果远大于调水的效果,社会经济发展越快,节水带来的效果越明显;③适度增强城市人口和产业的集聚与规模效应,降低用水定额,提高水资源利用效率,是提高水资源开发利用潜力最有效的途径;④通过跨流域调水提高区域的供水能力,有助于减弱水资源系统对城市发展系统的约束作用