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• The paper constructed a RECC calculation method based on the EWM-CPM. • The spatiotemporal characteristics of RECC in resource-based cities. • The relationship between RECC and NEES is deconstructed by the path analysis method. The development of resource-based cities faces with stagnation due to the exhaustion of resources. Scientific and rational characterization of the temporal and spatial characteristics of resource environmental carrying capacity (RECC) is conducive to the sustainable development of these cities. In the present study, 8 resource-based cities in Sichuan Province were used as the research objects. A RECC research framework was constructed based on natural resources, environmental resources, economic resources and social resources dimensions (NEES), and a RECC assessment system was then extracted. This paper constructed a RECC calculation method based on the EWM-CPM (EWM: entropy weight method, CPM: catastrophe progression method). Mean and standard deviation were used for statistical analysis of RECC. The temporal trends of the NEES and RECC of resource-based cities in Sichuan Province were analyzed from the perspective of time, and the dynamic characteristics were analyzed combined with the dynamic evaluation measure model. The spatial pattern of RECC in the resource-based cities in Sichuan Province was analyzed from a spatial perspective. The relationship between NEES and RECC was evaluated through a path analysis method. The research results were as follows: (1) In terms of time, the average value of RECC in the resource-based cities in Sichuan Province was 0.628, and the standard deviation was 0.200, indicating that the stability of RECC in the entire region was poor. Natural resources are the main subsystem of RECC impacts in NEES. From the calculation results of the dynamic evaluation measure model, the level of RECC in PZH (Panzhihua) was stable, and the level of RECC in GA (Guang'an) increased with time, whereas the level of RECC in NC (Nanchong) was poor. (2) In terms of space, the eight resource-based cities showed uneven development in regard to RECC from 2010 to 2019, and the urban advantageous industries were related to the types of resources in the NEES. (3) The path analysis method results indicated that the directional impact of natural resources on RECC was the highest (0.658), followed by the effect of social resources, environmental resources and economic resources. The findings of the present study provide a basis for the establishment of methods for the sustainable development of urban areas, effective information extraction and the integrated assessment of factors that affect the development of resource-based cities. [ABSTRACT FROM AUTHOR]

[Display omitted] • Apply a more realistic approach to independent black/odor evaluation. • Hilsenhoff biotic index is most suitable as an indicator of the degree of black odor. • The number of the genus Chironomidae is indicative of the black and odor. Macroinvertebrate community structure parameters can reflect the water quality and water ecosystem health status of rivers. In this paper, using the results of macroinvertebrates in 16 urban rivers in Sichuan Province from November 2020 to March 2021, we independently evaluated the level of black odor in urban rivers based on the mathematical model. On this basis, we examined the community structure, fouling tolerance, diversity, and feeding functional groups of macrobenthos in rivers with different degrees of black odor. During the study, a total of 39 species of macroinvertebrates were collected and identified to 3 phyla, 7 classes, 16 orders, 26 families and 30 genera. Urban rivers changed from non-black and non-odorous to black and odorous: (1) the dominant species, Chironomus flaviplumus , Physa fontinalis and Barbronia weberi , changed to Chironomus flaviplumus , a fouling-tolerant species with wide adaptability; (2) According to the tolerance values (TVs), the pollution resistance categories gradually increased as the level of black odor increased, which indicated the level of black odor in water bodies; (3) The calculation of the Hilsenhoff biotic indices (HBI) indicated that 83.3% of the sampled sites were moderately to heavily polluted. In general, the severity of water quality pollution in the black and odorous type of river was significantly higher than that in the non-black and odorous type of river, and with the deepening of the degree of blackness and odor the quality of the water deteriorated; (4) The community structure had an unstable community structure and a low diversity index of macroinvertebrate species; (5) The taxa of feeding functional groups shifted from the presence of all five types of feeding functional groups to the dominance of fouling-resistant species represented by scrapers. The results summarize the characteristics and change patterns of various indicators under different black-odorous degrees, indicating that the HBI can be used as an alternative indicator for the evaluation of black odorous water, and the number of species of Chironomidae can indicate the degree of black odor in water bodies. [ABSTRACT FROM AUTHOR]

• A new research framework for identifying the key Ecological nodes was proposed. • Achieved dynamic analysis on ecological networks and their components. • Weighted complex networks have been used to obtain ecological network topology information with higher credibility. • Rethinking landscape function from the perspective of animal movement. Regional ecological security is a pressing issue in the context of escalating human-environment conflicts. Ecological networks(ENs), the fundamental tool for characterizing ecosystems, have enabled further quantitative analysis at the micro level by integrating with complex networks in recent years. However, most studies neglect the unreliability of unweighted complex networks and the dynamic characteristics of ENs. This paper takes the Sichuan Basin as the research area and adopts the following methods. Firstly, it integrates landscape ecology and ecosystem services to construct the ENs using Linkage Mapper. Secondly, it introduces the cost-weighted distance as the weight to build complex networks and identifies potential pivot ecological sources and key ecological corridors based on the topological features of the weighted complex networks in 2000, 2010, and 2020. Thirdly, it applies circuit theory to detect ecological pinchpoints and ecological barrier points within the corridors as priority areas for ecological conservation and restoration. The results show that the ENs in the study area are denser on the northern and southern sides, and some ecological corridors change direction due to variations of resistance surfaces and landscape morphology. Through dynamic analysis of the weighted complex networks, 27 potential pivot ecological sources and 25 key ecological corridors are identified; then, 28 priority conservation areas and 10 priority restoration areas within these ecological corridors are extracted based on circuit theory. The study reveals a certain correlation between the distribution of ecological nodes and water bodies. Furthermore, comparing the weighted and unweighted complex network, we find that the weighted complex network is more reasonable, with 64.2% of ecological sources showing lower betweenness centrality than that in the unweighted network, reflecting the obstacles that urbanization poses to ecological networks. This study explores the impact of constantly changing resistance surfaces on the overall ENs and their components through dynamic analysis. The evolving topological features reflect the feedback of the ENs to external environmental changes, as well as the dynamic characteristics of the real ENs. Therefore, the findings of this study provide valuable references for ecological conservation and governance efforts in Sichuan Basin, promoting regional ecological security and the advancement of ecological civilization. [ABSTRACT FROM AUTHOR]

• Geological disasters in hilly areas are related to Land-Use and Land-Cover Changes. • The number of geological disasters in the cultivated land area is the largest. • The point density of geological disasters and vegetation coverage is limited. • Geological disasters are more likely to occur in the period of heavy rainfall. • The closer geological disaster to river, the greater probability/scale of occurrence. Sichuan hilly area is located in southwest China, which have many hilly area, is a densely populated, economically active, frequent geological disasters area. In this paper, Neijiang City in the region is taken as the test sample. This article, which analyzes Land-Use and Land-Cover Changes (LUCC), meteorological and hydrological data from 2015 to 2020, takes Neijiang City in this region as the research object. We explored the relationship between geological disasters such as collapse and landslides that often occur in the natural ecological environment with LUCC and meteorological and hydrological factors, using GIS spatial analysis and statistical analysis methods. The research results indicate that geological disasters mainly occur in farmland areas. The density of geological disaster points is highest within urban areas, making them the most prone to geological disasters. Geological disasters are more densely distributed in the area within 600 to 800 m from the river. There is a strong correlation between the average rainfall amount and the probability of geological disasters occurring. This study provides a scientific basis for the geological disaster risk assessment, prevention and control in this region. It has certain reference significance for the ecological environment governance, land resources planning and management in other similar regions. [ABSTRACT FROM AUTHOR]

• The spatial competitions contribute to the evolution of rural residential land (RRL). • RRL in study area is characterized with "dense in the west and sparse in the east". • Evolution of RRL is impacted by macro factors and micro housing selection. • Spatial distribution pattern of RRL will remain nearly unchanged in the long run. Spatial systematic competition definitely contributes to rural residential evolution. Rural residential land of mountainous economic circle is generally hard to govern due to the disturbances from natural factors and economic activities. This study established a framework and adopted Kernel Density Estimation (KDE), Exploratory Spatial Data Analysis (ESDA), Geographical detector (Geo-detector) and Patch-generating Land Use Simulation (PLUS) to examine the evolution characteristics, drivers and trends of rural residential land of Chengdu-Chongqing Economic Circle(CCEC). Our research uncovered that: 1) The competitions between rural living space (RLS), rural production space (RPS) and rural ecological space(RES) substantially contribute to the evolution of rural residential land according to the conceptual framework, and the evolution in mountainous economic zone is greatly impacted by the close coupling interaction of macro driving factors and micro farmers' housing selection. 2)The characteristics of rural residential evolution of Chengdu-Chongqing area presents "dense in the west and sparse in the east", and the majority of which are concentrated in Sichuan Basin and Chengdu plain area. 3) Although the size of rural residential land in Chengdu-Chongqing area presents a fluctuant downward trend according to the simulation results, the spatial distribution pattern will remain nearly unchanged in the long run. 4) Rural residential evolution reflects the interactional process of muti-factors, as well as the matching result between man-land relationship and regional development goals under the land use policies. Overall, The theoretical and empirical research form the perspective of spatial competition in this paper provides a new idea for future studies on the evolution of rural residential land. [ABSTRACT FROM AUTHOR]

• A zoning method based on ecological indicators and economic indicators is applied. • Ecological and economic situations are highly correlated with topographic conditions. • The coupling coordination degree(CCD) between ecology and economy is calculated. • Economic development is highly positively correlated with CCD. • Targeted regional sustainable development strategies are put forward. The coordinated development of ecology and economy is one of the key issues of sustainable development. A full understanding of the relationship between ecology and economy is necessary for the coordinated development of the two. This paper takes Sichuan Province as the research area and county-level administrative districts as the research unit. Based on the medium value of the ecological quality index and economic growth index of each unit, Sichuan Province is divided into dual pressure zones (DPZ), economic backward zones (EBZ), ecological crisis zones (ECZ), and coordinated development zones (CDZ) and the coupling coordination degree (CCD) of each unit is studied. The results show that: (1) On the whole, the eastern part of Sichuan Province has a better level of economic development, and the southern part of the western region has a higher ecological quality. The ecological quality and economic growth pattern are highly correlated with topographical conditions. (2) The distribution characteristics of the four types of partitions are significantly different. The EBZ are more distributed in the western and southern of Sichuan Province, the ECZ are more distributed in the eastern, the DPZ and CDZ are relatively more sporadic. More than 90% of the partition changed zones are distributed in the eastern area. (3) The CCD of more than 95% units belongs to moderate coordination and high coordination. The overall CCD of the four types of zones has shown an upward trend from 2010 to 2015. Based on the results, Sichuan Province should follow the path of clear waters and green mountains are as good as mountains of gold and silver, and targeted sustainable development suggestions for DPZ, EBZ, ECZ, and CDZ are put forward. This paper provides guidance for formulating regional sustainable development strategies, especially in areas with unbalanced development due to congenital topographical conditions. [ABSTRACT FROM AUTHOR]

• An optimization of eco-industrial structure considering economy-society-ecology. • A multi-objective optimization model meeting three dimensional objectives is built. • The hybrid ACO-PSO algorithm is applied to solve the model. • Optimized scenarios realize overall development of economic-social-ecological benefits. • The optimized scenarios with different tendencies promote different benefits. The establishment of ecological economic system has become the key to realize the transformation of China's economy from high-speed development to high-quality development. This paper considers the multiple goals of economic, social, and ecological benefits to achieve sustainable development. Firstly, it establishes an indicator system affecting economic, social, and ecological benefits to guide the construction of the subsequent model. Secondly, this study constructs a multi-objective optimization model for ecological industrial structure. According to the different emphasis of objectives, a hybrid approach based on ant colony optimization and particle swarm optimization (ACO-PSO) is implemented to solve the optimal solution set of feasible schemes. Finally, Sichuan Province is selected as the case study area, and three scenarios including economic oriented scenario, employment protection scenario and environment-friendly scenario are screened and analyzed. The results show that: (1) After reasonable optimization and adjustment of the industrial structure, it realizes the overall development of economic benefits, social benefits, and ecological benefits. The comprehensive benefits of sustainable development have been significantly improved. (2) The optimized scenarios with different tendencies promote different benefits. Decision makers can make better choices based on the diverse needs of the different development stage. [ABSTRACT FROM AUTHOR]