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Conserving and restoring ecosystem services in urban areas is an efficient measure to deal with increasing ecological challenges for cities while enhancing urban ecological resilience. However, rising inequalities threaten to improve critical environmental justice, public health and urban ecological resilience. This study proposed a non-monetary framework for accounting for urban ecosystem services and explored the inequality of ecosystem services using the Gini coefficient. Further, a regression-based decomposition method was used to identify primary socioeconomic factors that contributed to inequality. The results showed that the total ecosystem service in the urban areas presented a trend of first growing rapidly and then fluctuating steadily from 6.78 × 1022 sej in 1985 to 1.14 × 1023 sej in 2020 the percentage of existing services in the total ecosystem services was over 50%. The Gini coefficient of 1985 was more extensive than that of other years, which is 0.461. The runoff regulation service and the temperature mitigation service were the primary contributors for the inequality. Meanwhile, such income per capita, nonfarm rate and industrial production provided over 70% contribution rate to the inequality. This study assessed the inequality of urban ecosystem services and analyzed the driving factors, emphasizing the importance of reducing inequality, and providing a specific reference basis and theoretical support for decision-makers in urban planning and development strategies. • Establishing a framework to calculate urban ecosystem services. • Analyzing the inequality of ecosystem service inequality. • Pointing out the contributions of the related ecosystem services to the inequality. • Identifying certain socioeconomic factors that are affecting the inequality and these contributions. [ABSTRACT FROM AUTHOR]

Multiple correlated risks caused by uncertain information pose great challenges to the coordinated regulation of water-energy-food nexus (WEFN). In this study, a Copula-based radial interval chance-constrained programming (CRICP) was developed. CRICP can not only quantify composite risk induced by multiple risks with nonlinear correlations, but also tackle dual uncertainty expressed as redial intervals with adjustable protection levels. CRICP was applied to an irrigated agricultural management problem constrained by water, energy, and land resource in Bayan Nur City in northern China. Results indicate that system benefit would increase with the incline of composite risk or the decline of protection level. Monte Carlo simulation verified that the different definitions of composite risk could lead to significant differences in the combination of subsystem risks. The composite risk induced by the simultaneous shortage of multiple resources would have greater impacts on system benefits compared against composite risk caused by shortage of at least one resources, with an increase of [24.65%, 25.95%] in the minimum value of system benefits. Comparisons against two alternative models further verified that CRICP outweighs previous methods by modeling the correlation structure of multiple risks and tackling dual uncertainties without distribution information. • The complex interactions and inherent uncertainty affect the security of Water-Energy-Food Nexus. • A Copula-based radial interval chance-constrained programming method was developed. • It can tackle composite risk induced by random variables with unknown correlations. • It can also address dual uncertainties without detailed distributions. • The bias in decision making process triggered different composite risks were clarified. [ABSTRACT FROM AUTHOR]

Revealing the long-term development trajectory and peak scenarios of the urban residential building sector is crucial for formulating targeted emission reduction strategies and contributing to achieving the "Dual carbon" target. Given that, significant variables affecting carbon emissions from urban residential buildings (URBCE) at both macro and end-use building levels are identified in this study. Furthermore, an innovative dynamic simulation model is developed by integrating the Monte Carlo simulation model with the Kaya identity model, taking into account the uncertainties of the variables. Subsequently, the long-term evolution trajectories, potential emission peaks, and peak time of the URBCE close to 2060 in China's hot summer and cold winter (HSCW) zone are simulated. Results indicate that URBCE is expected to reach its peak of 272.43 Mt CO 2 in 2040 under the baseline scenario. Through the dynamic simulation, the probable peak time of energy consumption in the HSCW zone is 2044 (±1.85), with a peak of 145.42 (±6.91) Mtce, and the possible peak time of carbon emissions is probably 2039 (±1.60), with a peak of 271.93 (±13.40) Mt CO 2. According to dynamic sensitivity analysis, carbon emission factor, per capita residential space, and heating energy intensity can promote the peak size and timing. These findings lay a robust foundation for the formulation of regionally specific carbon reduction targets and initiatives. Dynamic simulation results of peaking time and peak value of URBEC and URBCE. [Display omitted] [ABSTRACT FROM AUTHOR]

Water production, utilization and recycle in urban system associated with a large amount of energy consumption and carbon emission that has increasingly international attention under sustainable development goals. In this study, a comprehensive urban water resources system management model is proposed under water-energy-carbon nexus and multiple uncertainties. The water-energy-carbon nexus was reflected in the processes of water extraction, water production and sewage treatment, and two objectives of maximizing the system benefit and minimizing carbon emission is transformed into two linear programming problem through the dual-objective interval fractional programming. Considering the interaction among water supply/demand, pollutants discharge control, energy consumption and self-energy utilization, indirect carbon emission as the main constraints, the developed model is applied to a typical water and energy sources shortage area of Qingdao city in north China. Multiple scenarios related to energy consumption and carbon emission control are designed to search the relationship among energy consumption, carbon emission and water resources allocation schemes. The results indicated that water demand as the main driving factor of energy consumption and carbon emission in urban water system cannot be directly limited through water supply structure adjustment. Through introducing self-energy supply (sludge utilization) and energy consumption control, water resources allocation schemes and water supply structure would be changed to improve energy saving potential with an obvious decrease trend of carbon emission intensity from 0.7921 tCO 2 /MWh to 0.5544 tCO 2 /MWh. The model could effectively provide reasonable urban water system management strategies under different water allocation demands and carbon emission challenges scenarios and deal with multiple uncertainties in decision-making process. [Display omitted] • Urban water resources system brings ecological environment issues. • A comprehensive urban water resources system management model is proposed. • Maximizing the economic benefits of per carbon emission to obtain the scheme. • Sludge utilization and energy consumption control can reduce carbon emission. • The model provides experiences for water-scarce regions around the world. [ABSTRACT FROM AUTHOR]

Freshwater ecosystems face serious degeneration risks from anthropogenic activities, among which land use heterogeneity transformation is one of the main threats on aquatic biodiversity. However, the mechanisms by which land use heterogeneity affects fish community structure in aquatic ecosystems are still difficult to determine. The results of this study showed that we detected a total of 164 fish species during two seasons, with 97 fish species belonging to 15 orders, 31 families and 74 genera in dry season and 138 fish species belonging to 14 orders, 40 families and 98 genera in wet season. The intergroup differences between the upstream, midstream and downstream of the basin in dry season were smaller than those in wet season, and the species richness in wet season were higher than this in dry season. The values of β-diversity between the upstream and midstream regions was greater than downstream in dry season. The value of β-diversity between upstream and downstream regions was larger than in the midstream in wet season. It concluded that the β-diversity values were generally smaller in wet season than in dry season. Land use types on both sides of the Han River basin are mostly cropland, forest land and man-made surfaces. The results of calculating LUI and fish life history characteristics showed a greater correlation between K and M values in the dry water period and a greater correlation between PD50 and longevity in the rich water period. Moreover, we calculated the correlation between the land use index (LUI) and β-diversity NMDS values, respectively, showed a significant positive correlationship (0.712 in dry season; 0.742 in wet season). This research (a) obtained the spatial and temporal distribution of α-diversity and β-diversity data of fish in the whole basin using eDNA technology; (b) analyzed the relationship of land use heterogeneity on fish life history characteristics; and (c) revealed the correlation between land use index and β-diversity communities. Overall, this study can provide data support and theoretical basis for integrated watershed ecosystem management, and provide suggestions for environmental protection and management around the watershed. • obtained the spatial and temporal distribution of fish diversity data based on eDNA technology for the whole basin. • analyzed the relationship of land use heterogeneity on fish life history characteristics. • revealed the correlation between land use index and diversity communities. [ABSTRACT FROM AUTHOR]