ABSTRACT
Quantifying and interpreting the water-energy-food (WEF) nexus is critical to achieve the sustainable development of urban resources. The mismatch between urban water, energy and food allocations is a prominent problem that is particularly acute in the Yellow River Basin (YRB) of China. In this study, models for the WEF coupling degree and coupling efficiency were constructed. The WEF coupling efficiencies of the 94 cities in the YRB from 2011 to 2020 were quantified using a data envelopment analysis (DEA) model. On this basis, the spatial distribution characteristics and evolutionary trends of different urban WEF coupling efficiencies were analysed and explored using an exploratory spatial data analysis (ESDA) model and a parametric kernel density estimation model. The results show that the energy subsystem constrain the development of the WEF nexus, and the food subsystem, in turn, regulates the development of the WEF nexus. In some years, the phenomenon of 'resource curse' occurred, in which the WEF coupling degree increased while the coupling efficiency decreased. Overall, the values of the urban WEF coupling efficiency were low, ranging from 0.5300 to 0.6300, which is not effective. Spatial clustering was detected in the urban WEF coupling efficiency. The clustering types were 'high-high' clustering areas in less developed regions and 'low-low' clustering areas in developed regions. The two clusters and the median contiguous group had different evolutionary trends. Both efficiency and polarisation increased in the high-clustering group, efficiency improved in the low-clustering group, and a new efficiency pole was formed in the median contiguous group. Among the three grouped cities, we discuss the potential of policies such as cross-city cooperation, intra-city multi-sectoral cooperation and cultivating new central growth cities to improve the WEF coupling efficiency in the YRB.
ABSTRACT
To achieve China's "Double Carbon" target, overall carbon emissions should be effectively controlled, and carbon emission quota (CEQ) allocation is an important tool. This study develops carbon emission prediction, CEQ allocation, and scheme feasibility evaluation models based on the principles of fairness, efficiency, and economy. The purpose is to propose a suitable CEQ allocation scheme for the Industrial Sector in Henan Province (ISHP). The results show that (1) the allocation model combining the technique for order preference by similarity to ideal solution (TOPSIS) and the zero-sum gains DEA (ZSG-DEA) can trade off the fairness and efficiency principles. (2) The reallocation scheme has an environmental Gini coefficient of 0.393 (< 0.4), which maximizes efficiency while lowering the abatement costs by 126.268 billion yuan, making it an ideal scheme that considers multiple principles. (3) CEQ should be reduced in 7 subsectors of ISHP while increasing in 33 others. Carbon emissions from these 7 subsectors are high, and CEQ should be reduced in accordance with the fairness principle. Even if their abatement costs are high and CEQ rises according to the efficiency principle, the increase is much smaller than the decrease. The findings are useful for optimizing the CEQ allocation under the "Double Carbon" target.
ABSTRACT
The urban development in the Yellow River basin (YRB) varies widely. Therefore, it is necessary to choose a development path that fits the characteristics of each city to achieve high-quality development. The purpose of this paper is to address the problem of how to choose a characteristic path for high-quality development and clarify its suitability for YRB cities. Firstly, based on data from 50 YRB cities from 2011 to 2020, the suitability evaluation was carried out from the perspective of an ecological niche, followed by the measurement of sub-dimensional niche breadth and overlap. The results confirmed the great diversity of development between cities and the intense competition for resources. Then, based on the classification approach using the k-means method, this study proposes a method for selecting a suitable path for high-quality development. It classifies the suitable paths into 3 major types with 7 minor types and recommends policies for the suitable paths for YRB cities. The systematic thinking and specific path selection method for the high-quality development of YRB cities is not only of practical significance for implementing city classification strategies but also provides a reference for the sustainable development of basin cities in other countries.
