Basin Cities Research Articles

Exploring the complex relationship between industrial upgrading and energy eco-efficiency in river basin cities: A case study of the Yellow River Basin in China

The synergistic advancement of industrial upgrading and energy eco-efficiency is crucial for the attainment of the Sustainable Development Goals. This study explored the coupling coordination relationship and its spatial-temporal evolution characteristics between industrial structure advancement and energy eco-efficiency, industrial structure rationalization and energy eco-efficiency in Yellow River Basin cities from 2010 to 2020. The super-SBM model and coupling coordination degree model were used to calculate the energy eco-efficiency and coupling coordination degree. Moran's I and Tobit model were used to analyze the spatial autocorrelation and the factors of coupling coordination degree. The coupling coordination degree of industrial structure advancement and energy eco-efficiency decreased from 0.535 to 0.489, with a growth rate of −8.60 %, showing a fluctuating downward trend. The coupling coordination degree of industrial structure rationalization and energy eco-efficiency decreased from 0.296 to 0.246, with a growth rate of −16.88 %, showing an "M" -shaped downward trend. The coupling coordination degree had a significant spatial correlation, and the global Moran's I value was stable around 0.2. Additionally, public transport and degree of opening-up can significantly promote the coordination relationship between industrial upgrading and energy eco-efficiency. These consequences can supply evidence for industrial and energy structure adjustment in river basin cities.

Identification of Urban Carbon Emission Peaks through Tree-Ring 14C.

Independent identification of carbon emission peaks determined from fuel inventories is a challenging goal. Because of the complete depletion of radiocarbon (14C) in fossil fuel sources, the measurement of atmospheric 14CO2 has proven to offer a means of achieving this goal. Here, we present a study identifying peak carbon emissions from two Chinese cities using urban tree-ring Δ14C time series during 2000-2019. After subtracting background atmospheric Δ14C from urban tree-ring Δ14C to isolate local Δ14C (Δ14Clocal), we find a minimum in 2010 (-51.1 ± 4.5‰) in Beijing and in 2013 in Xi'an (-52.5 ± 0.5‰). These levels correspond to an urban carbon emission peak in 2010 and in 2013 in the two respective cities. The urban carbon emission peaks are further identified by the declines of the mean absolute interannual rate of decrease of tree-ring Δ14C during a period, with the respective values of 3.6 and 6.4 ‰/yr after and before a turning point in Beijing and 3.0 and 6.0 ‰/yr after and before a turning point in Xi'an. This study provides an observation method to identify carbon emission peaks in basin cities.

Spatial network analysis of green electricity efficiency dynamics in the Yellow River Basin cities

Improving the green electricity efficiency (GEE), is an important issue for China's high-quality economic development. This study presents a spatial correlation network of urban GEE in the Yellow River Basin from 2012 to 2021, constructed using an improved gravity model. Social network analysis and the quadratic assignment procedure method are employed to analyze the spatial correlation characteristics and influencing factors. The findings indicate that urban GEE in the Yellow River Basin exhibits complex and stable network characteristics. The spatial network analysis reveals that Jiayuguan City, Dongying City, Dingxi City, Zibo City, and Shizuishan City occupy central positions within the network. The results indicate that spatial adjacency, GDP per capita, industrial structure, and the level of science and technology expenditure are positively related to urban GEE, while environmental regulation and average temperature are negatively related. The findings of the study have led to policy recommendations aimed at enhancing urban GEE in the Yellow River Basin.

Exploring the impact of nocturnal boundary layer stability on wintertime air pollution in a highly polluted basin city using unsupervised learning classification

This study utilizes ten years of wintertime boundary layer meteorological and surface air quality observations to characterize the nocturnal boundary layer (NBL) stability and assess its relationship with air pollution in Taiyuan, a highly polluted basin city in China. An unsupervised learning feature extraction technique known as the self-organizing map (SOM) is applied to objectively classify nocturnal virtual potential temperature (VPT) profiles. The SOM-based classification scheme allows the representation of wintertime day-to-day NBL evolutions by just nine regimes. Special attention is given to four dominant regimes: weak to moderate stability regime (NBL1), cloudy moderate stability regime (NBL3), windy moderate stability regime (NBL7), and strong stability regime (NBL9). These dominant regimes have relatively higher occurrence frequencies (>10%), with the highest frequency associated with the strong stability regime (NBL9) at 25.2%. The diurnal cycles of selected pollutants (CO, NO2, SO2, and PM2.5) exhibit significant distinctions among the different NBL regimes. For instance, in the strong stability regime, CO, NO2, and PM2.5 show explosive growth in the evening due to the accumulation of primary pollutants. However, in the cloudy moderate stability regime, PM2.5 exhibits persistent slow growth throughout the day, likely due to secondary particle formation under high humidity and high SO2 conditions. These findings enhance our understanding of NBL meteorological impacts on surface air pollution in basin cities.

The spatial spillover effect of financial growth on high-quality development: Evidence from Yellow River Basin in China

River basin cities are areas with remarkable conflicts between the human activity and the ecological environment. They are also important targets for policy implementation of sustainable and high-quality development (HD) in various countries around the world. This article exploits the panel data of 99 cities located in the Yellow River Basin (YRB) from 2006 to 2019 to empirically analyze the spatial effect of financial growth on HD. Spatial weights participated econometric models are utilized to analyze this spatial effect. Empirical results reveal that: (1) the HD in the YRB shows a strong positive spatial autocorrelation. (2) Financial growth exerts an N-shaped curve effect on the HD from a long-term perspective. When this influence spills out to the surroundings, it exhibits an inverted U-shaped characteristic. (3) Green innovation can be an important intermediary factor in the influence of financial growth on HD. (4) The influence of financial growth on HD appears stronger in regions with higher economic levels, where N-shaped effects can be transmitted to the surrounding regions. However, the backward economic development in low-economy regions prevents the spatial spillover of N-shaped effects. This study can be instrumental for countries to formulate financial policies that aim to promote HD in river basin cities.

Sources, gas-particle distribution and health risks of atmospheric PAHs in two typical basin cities in China

The sources of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of various cities are highly intricate. Conducting research on the pollution characteristics of different types of PAHs in cities will help to focus on solving air pollution problems based on urban characteristics. Polycyclic aromatic hydrocarbons (PAHs) in the PM2.5-bound state and gas-phase were analyzed in the winter atmosphere of Yuncheng and Nanyang, China, to determine their pollution and spatial characteristics. The results revealed that in Yuncheng, the average concentrations of these 16 PAHs were 129.83 ± 96.63 ng m−3 in the PM2.5-bound form and 168.05 ± 88.64 ng m−3 in the gas phase, surpassing those observed in Nanyang, where the averages were 66.53 ± 32.49 ng m−3 and 112.80 ± 65.90 ng m−3 for particulate and gas phases, respectively. Gaseous samples primarily contained low molecular weight PAHs, while medium and high molecular weight PAHs were more prevalent in particulate samples. The linear relationship between the gas-particle partition coefficient (logKP) and the gas partition coefficient (PL0) and KOA value of PAHs in both cities suggested that during winter, PAHs in Yuncheng and Nanyang predominantly adsorb onto particles, failing to achieve gas-particle equilibrium. Source analysis using positive matrix factorization (PMF) identified coal combustion (26.4%–41.9%), biomass combustion (26.3%–29.6%), motor vehicle emissions (16.3%–30.4%), and evaporation sources (15.8%–26.9%) as the primary sources of atmospheric PAHs in both cities. Potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) analyses indicated that pollutants originating from the northwest direction and near-earth air masses exerted a substantial influence on both cities. According to health risk assessments, both Yuncheng City and Nanyang City exhibited a certain risk of cancer due to atmospheric PAH exposure. However, the risk of cancer was higher in Yuncheng City compared to Nanyang City. The research results uncover the pollution characteristics and primary sources of polycyclic aromatic hydrocarbons (PAHs) in different types of urban air. It emphasizes the substantial contribution of local pollution sources to atmospheric PAHs and emphasizes the necessity of prioritizing control measures.

The spatial-temporal evolution and driving mechanism of Urban resilience in the Yellow River Basin cities

The rapid urbanization poses the potential risk of overload and collapse for cities. Addressing the problems brought about by rapid urbanization to ensure urban safety and sustainable development has become particularly urgent and crucial, especially for regions with high ecological vulnerability and weak economic foundations. This study utilizes panel data spanning from 2013 to 2020 and applies the entropy weight-TOPSIS model to assess the urban resilience of 54 cities within the Yellow River Basin. It explores the temporal evolution, spatial distribution, and dynamics of urban resilience. Further, through the application of the Geographically and Temporally Weighted Regression model, the research investigates the drivers of urban resilience, considering temporal and spatial variations. Findings indicate a consistent increase in urban resilience across the Yellow River Basin, albeit with widening regional disparities. The spatial pattern of urban resilience exhibits a gradient decline from downstream to midstream and then upstream. The impact of various factors on urban resilience differs by region, with technological innovation emerging as the most influential. To foster a sustainable future, the Yellow River Basin should prioritize technological innovation, particularly in industrial cities, and advocate for the adoption of green technologies to diminish resource consumption and mitigate environmental pollution.

Assessing Future Precipitation Patterns, Extremes and Variability in Major Nile Basin Cities: An Ensemble Approach with CORDEX CORE Regional Climate Models

Understanding long-term variations in precipitation is crucial for identifying the effects of climate change and addressing hydrological and water management issues. This study examined the trends of the mean and four extreme precipitation indices, which are the max 1-day precipitation amount, the max 5-day precipitation amount, the consecutive wet days, and the consecutive dry days, for historical observations (1971–2000) and two future periods (2041–2060/2081–2100) under RCP2.6 and RCP8.5 emission scenarios over the Nile River Basin (NRB) at 11 major stations. Firstly, the empirical quantile mapping procedure significantly improved the performance of all RCMs, particularly those with lower performance, decreasing inter-model variability and enhanced seasonal precipitation variability. The Mann–Kendall test was used to detect the trends in climate extreme indices. This study reveals that precipitation changes vary across stations, scenarios, and time periods. Addis Ababa and Kigali anticipated a significant increase in precipitation across all periods and scenarios, ranging between 8–15% and 13–27%, respectively, while Cairo and Kinshasa exhibited a significant decrease in precipitation at around 90% and 38%, respectively. Wet (dry) spells were expected to significantly decrease (increase) over most parts of the NRB, especially during the second period (2081–2100). Thereby, the increase (decrease) in dry (wet) spells could have a direct impact on water resource availability in the NRB. This study also highlights that increased greenhouse gas emissions have a greater impact on precipitation patterns. This study’s findings might be useful to decision makers as they create NRB-wide mitigation and adaptation strategies to deal with the effects of climate change.

Cultivated Land Green Use Efficiency and Its Influencing Factors: A Case Study of 39 Cities in the Yangtze River Basin of China

In recent years, the Chinese government has been paying more and more attention to agricultural development and ecological protection. Improving cultivated land green use efficiency (CLGUE) is becoming a crucial issue in promoting the sustainable development of agriculture. This study aims to study the current situation and influencing factors of agricultural production from the perspective of green utilization efficiency of cultivated land. It takes 39 cities in the upper, middle and lower reaches of the Yangtze River basin in China as an example. The CLGUE values in those 39 cities from 2011 to 2020 were specifically measured, using the Super-SBM model, kernel density estimation and geographic detector method. Their temporal and spatial heterogeneity was described, and the influencing factors were detected at both single and interactive levels. The results showed that (1) from 2011 to 2020, the green utilization efficiency value of cultivated land in the Yangtze River basin showed an upward trend on the whole; (2) there is clear spatial heterogeneity between CLGUE values in the Yangtze River basin cities, and the distribution is as follows: downstream region > midstream region > upstream region; (3) cultivated land resource endowment, socioeconomic development and agricultural production technology are important factors affecting the variability in CLGUE values. However, there are some differences in the degree and direction of influence of different influencing factors on different sample subgroups.

Coupling coordination degree analysis and spatiotemporal heterogeneity between water ecosystem service value and water system in Yellow River Basin cities

Accelerated urbanization has caused encroachment on urban water ecological land in China's Yellow River basin, resulting in a strong disturbance of water ecosystem service functions and increasingly serious water ecological environmental problems. In this study, two entities—water ecosystem service value (WESV) and the urban water system—are identified, to investigate the interactions between WESV and the urban water systems and their subsystems in six Yellow River basin cities (Lanzhou, Yinchuan, Hohhot, Xi'an, Zhengzhou, and Jinan) from 2005 to 2020. First, the integrated level of the WESV and the water system in each city is calculated using the modified and developed method of equivalence factor per unit area and the entropy method, respectively. Then, the coupling coordination relationship and interactions between WESV and the water system in each city are revealed by using the coupling coordination degree model (CCDM) and the Geographically and Temporally Weighted Regression (GTWR). The results show that: 1) The level of both WESV and the water system in each city basically shows an increasing trend, the hydrological regulation function dominates the water ecosystem service functions, and the comprehensive evaluation level of the water environment is generally higher than that of the other urban water system's subsystems. 2) The degree of coupling coordination between WESV and the water system in each city gradually rose from extreme incoordination to basically coordination, and the coupling coordination degree (CCD) between WESV and the water environment and the water resources also shows an obvious upward trend, but the CCD between WESV and water safety is developing more slowly. 3) The area where the WESV and the water system have greater positive impacts are primarily focused in Lanzhou and Xi'an, while the negative impacts are mainly located in Yinchuan and Zhengzhou. In summary, in the planning and decision-making of cities in the Yellow River basin or other basin cities, it is critical to promote the protection of water ecology and high-quality development in cities by clearly understanding the interaction between water ecosystem services and the water system, and coordinating and balancing development between the two systems.

Spatial–temporal characteristics and obstacle factors analysis of urban resources and environment carrying capacity in the Yellow River Basin cities

Spatial–temporal characteristics and obstacle factors analysis of urban resources and environment carrying capacity in the Yellow River Basin cities

Study on the spatial–temporal evolution and driving mechanism of urban land green use efficiency in the Yellow River Basin cities

Under the current social background of green, sustainable, and high-quality development, countries and regions have increasingly begun to regard green development as a major goal of their economic and social development plans. If the evaluation of urban land use efficiency continues to be based only on economic and social outputs, such research will not conform to the current social development situation. Therefore, this paper introduces negative impacts, such as environmental pollution, into the evaluation system, using the Super-EBM model to measure the urban land green use efficiency (ULGUE) of the Yellow River Basin (YRB) based on panel data from 2011 to 2019. Exploratory spatial data analysis, kernel density estimation, and trend surface analysis were used to study the spatial–temporal evolution characteristics of ULGUE, and the GTWR model was used to explore potential driving mechanisms. The overall ULGUE remained relatively flat from 2011 to 2015, before showing a climbing growth in the post-2015 period; at the sub-basin level, the ULGUE in the midstream area was significantly higher than that in the downstream area, and slightly higher than that in the upstream area, but the rate of ULGUE increase in the upstream area was significantly higher than that in other areas. The spatial aggregation degree of ULGUE showed an increasing trend followed by a decreasing trend, but at the end of the study period, it was still slightly higher than its initial level. The overall ULGUE showed a “polarization–non-differentiation–polarization” trajectory, with the highest efficiency area gradually shifting from the northwest to the central region. Although the driving factors vary between different cities, in general, the roles of technology input and pollution emission factors have gradually increased. This research provides a scientific reference for high-quality development of the YRB and supports the optimal allocation of land resources and regional coordinated development.

Collaborative optimal allocation of water resources and sewage discharge rights in watershed cities: considering equity among water sectors.

Water supply systems in watershed cities face challenges due to increasing water demand and arbitrary sewage discharge allocations. Previous studies have primarily focused on water resource allocation and sewage discharge rights, neglecting the intricate interactions between the two. This study introduces a novel approach by integrating sewage discharge rights into the watershed's water resource allocation mechanism. A multi-objective optimization model was developed, employing the Gini coefficient to balance the equitable and economic aspects across various water sectors. This model takes into account the distinct water demands and sewage discharge requirements of different sectors. The findings of this study are as follows: (a) the Gini coefficients for water demand allocation and sewage discharge rights allocation exhibit simultaneous optimization and display consistent trends; (b) when the importance of sewage discharge relative to other water users increases, the return on investment for domestic and industrial water use decreases, but the fairness of water distribution improves; (c) proper allocation of sewage discharge rights can effectively enhance the economic value of agricultural water use. Overall, this strategy has the potential to enhance both the equality and economic benefits of the water supply system while ensuring the sustainable utilization of water and sewage rights in the basin cities.

Study on the evolution of green innovation city network and its carbon emission effect in Yellow River Basin cities.

Against the background of increasing urbanization rate and intensifying global warming, conflicts between humans and the natural environment continue to arise, and regionalized forms of spatial organization have become an important research direction. This paper constructs a green innovation city network. It empirically tests the evolution process of the green innovation city network and its carbon emission effect by combining the social network approach and the spatial Durbin model. The conclusions are as follows: (1) the strong ties among green innovation city networks are mainly distributed in and around the provincial capital cities and the middle and lower reaches of the Yellow River Basin; the density of green innovation city networks has been strengthened, and the degree centrality and closeness centrality have been improved. (2) The carbon emissions of cities in the Yellow River Basin are generally increasing. Still, the rate of increase is slowing down. The carbon emissions from liquefied petroleum gas show a decreasing trend yearly, and the energy structure tends to improve. (3) The impact of the green innovation city network on carbon emissions mainly comes from its externality's direct and indirect effects; the increase of degree centrality will reduce the total carbon emissions in the region and the network-associated regions.

Niche Suitability Evaluation and Path Selection for the High-Quality Development of Cities in the Yellow River Basin.

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.

The dynamic change trends and internal driving factors of green development efficiency: robust evidence from resource-based Yellow River Basin cities.

Promoting the green development of resource-based cities is an essential way to achieve sustainable regional economic development. Based on 2009-2019 panel data of the Yellow River Basin cities, this study adopts the super-directional distance function model to measure the green development efficiency of these selected cities. Furthermore, based on the Malmquist-Luenberger index, this paper focuses on the dynamic change trend of green development efficiency and internal driving factors. Furthermore, the Tobit model is used to specifically explore the influencing factors affecting the green development of cities. The findings suggested that the green development efficiency of selected cities falls in the middle to high range and that the efficiency varies among all cities in the Yellow River Basin. Likewise, technical efficiency improvements and technological progress drive development efficiency, and the former contributes more to green development. However, financial development, energy structure adjustments, and environmental regulation can strongly contribute to the green development of cities, and each influencing factor has obvious temporal and regional differences. This paper proposes appropriate policy suggestions to promote the coordinated development of the economic development and environmental protection of the Yellow River Basin.

Analysis on process of temporal and spatial evolution of urban built-up area expansion in the Yellow River Basin.

Urban spatial expansion is known as an important indicator of urbanization. In order to provide a reference for urban spatial expansion in the future high-quality development strategy of the Yellow River Basin (YB) cities in China, it is necessary to identify and calculate urban spatial expansion patterns. For this reason, we provide a "Spatiotemporal pattern-Center of gravity migrationt-Expansion pattern" solution to identify and calculate urban spatial expansion patterns in the YB. More specifically, 78 prefecture-level cities in the YB were selected as the subjects of the study, using the Defense Meteorological Satellite Program/Operational Line Scan System (DMSP/OLS) and the National Polarimetric Partnership/Visible Infrared Imaging Radiometer Suite (NPP/VIIRS) nighttime light data (NTL), together with the center of gravity shift and common edge detection models, to identify the YB urban expansion patterns from 2000–2018. The results suggest that: (1) on the spatial pattern, there is a obvious difference in the expansion intensity and growth rate of the urban built-up (UB) areas of cities in the upper and middle reaches of YB. In addition, there are also certain differences between the expansion patterns of provincial capital cities and non-capital cities; (2) The UB areas of YB has steadily expand from 3,500 km2 in 2000 to 10,600 km2 in 2018, amongst which the expansion of provincial capital cities is the most obvious 1919 km2; (3) Interestingly it is also discovered that urban expansion in Qinghai Province, the sourceland of the YB, takes place in a diffuse way, with the shifting of the centre of gravity for four types of total area, net increase in area, rate of growth and intensity of expansion followed a "northwest to southeast" tendency of development.

A reliable GIS-based FAHP-FTOPSIS model to prioritize urban water supply management scenarios: A case study in semi-arid climate

• Developed a GIS-based-MCDM method to select optimum urban water management scenario. • The paper considers triangular fuzzy sets to reduce uncertainty in decision-making. • The developed model is robust and flexible to manage required urban water demands. • A hydrologic model utilizing WEAP is designed to assess the developed model scenarios. The growing problem of urban water shortage and its sustainable management methods is one of today's critical research needs globally. This paper applies an integration of the Geographic Information System (GIS) and Multi-Criteria Decision-Making (MCDM) with the help of triangular fuzzy sets to manage urban water supply priorities in a semi-arid region. Hence, a group decision-making approach was proposed by combining the Fuzzy AHP (FAHP) and the Fuzzy TOPSIS (FTOPSIS) models based on quantitative and qualitative criteria. Therefore, a hierarchical model-based GIS and AHP was developed to classify the effective criteria and determine the Importance Weights (IWs) of criteria according to the experts’ opinions and using data layers based on spatial criteria. The priority ranking of scenarios was obtained using the FTOPSIS method. Different criteria such as environmental, geographical, geological, economic, climatic, and social conditions were considered in this study. Furthermore, to assess the water supply scenarios under the essential water demands of the basin cities and suburbs, a hydrologic model utilizing WEAP software was designed. Among the considered criteria, total expense, climatic conditions, and geographic conditions with the IWs values of 0.9, 0.85, and 0.83 were determined as the most effective criteria for evaluating the scenarios' ranking, respectively.

Evaluating the Sustainable Land Use in Ecologically Fragile Regions: A Case Study of the Yellow River Basin in China.

How to realize the sustainable use of land resources is extremely important for environmental protection and sustainable development in ecologically fragile regions. Nevertheless, the logic of achieving sustainable land use (SLU) in ecologically fragile regions and the corrective mechanisms for the implementation of land use efficiency systems are not fully revealed in theory. The Yellow River Basin is an important ecological barrier in China, and it holds an important position in China’s economic and social development, as well as for ecological safety. However, the basin is also ecologically vulnerable. Therefore, investigating eight central cities in the Yellow River Basin of China and using municipal-level panel data from 2009 to 2018, this paper constructs a multidimensional index system and is dedicated to carrying out a comprehensive evaluation of SLU and the diagnosis of obstacle factors in ecologically fragile regions. The study found the following: (1) From 2009 to 2018, the SLU level in the central cities of the Yellow River Basin evolved from the “Unsustainable Level” to the “Initial Sustainable Level” and then to the “Basic Sustainable Level”. The overall development trend was positive, and the level of SLU also rose. (2) From 2009 to 2018, there was significant geographical variation in spatial disparities in SLU in the central cities of the Yellow River Basin. In 2018, the average comprehensive score of SLU showed a pattern of downstream > upstream > midstream. (3) The obstacle factors of SLU in the Yellow River Basin of these cities in 2009 were concentrated on resource and environmental sustainability, while those in 2018 were concentrated on social acceptability. (4) In terms of the transfer process of land use types in these Yellow River Basin cities, the transfer from cultivated land to other types of land use played a major role, while construction land showed a significant expansion over the past ten years.

Comparative study of spatiotemporal variation in the urban heat island core in coastal and inland basin cities

Comparative study of spatiotemporal variation in the urban heat island core in coastal and inland basin cities