The development of urban transportation network has become one of the main driving forces for urban renewal by changing the accessibility of various urban functional land and promoting the reshuffling of the surrounding land use structure. Taking Wuhan, an important industrial city, as an example, this paper uses kernel density analysis, geographically weighted regression, and logarithmic decay function comparison to discuss the impact of different traffic road networks on the transformation of urban industrial land from 2014 to 2019. Research results: (1) The total amount of “industrial land to residential land” along the traffic road network of all levels is greater than the total amount of “industrial land to commercial land”. (2) The branch road network has a significant correlation and positive driving effect on “industrial land to residential land”, and secondary road network has a significant positive driving effect, and shows a weakening from south to north, and a northwest to northwest road network. The weakening situation in the southeast. (3) In terms of the attraction of the road network to “industrial land to residential land”: secondary roads > main roads > railways; in terms of the road network’s attraction to “industrial land to commercial land”: expressways>secondary roads > main roads. Based on the research results, it provides relevant suggestions for China’s urban space optimization and transportation network planning policy formulation.

New infrastructure has become an important carrier of industrial transformation and upgrading and high-quality economic development in the new era. In order to understand the spatial pattern and influencing factors of the coupling and coordinated development of China’s new infrastructure and industrial upgrading, this paper first constructs a comprehensive evaluation index of the development level of new infrastructure. Secondly, using the provincial panel data from 2013 to 2020, it uses TOPSIS entropy method and coupling coordination model to measure the coupling coordinative degree between new infrastructure and industrial upgrade. Then, it uses ArcGIS18.0 depicts its spatio-temporal evolution pattern, and reveal its influencing factors by using spatial econometric model. The results show that: (1) the development level of China’s new infrastructure and its three subsystems (information infrastructure, integrated infrastructure and innovative economy) is rising year by year. (2) There is great spatial heterogeneity in the development level of China’s new infrastructure. The East is higher than the national average level, and the West and northeast are relatively lagging behind.(3) From 2013 to 2020, the coupling coordinative degree between new infrastructure and industrial upgrade in all provinces in China has increased significantly, but its coupling coordination degree with industrial rationalization is higher than that with industrial intensify.(4) The coupling and coordination degree of new infrastructure and industrial upgrading is affected by many factors, such as economic development, urban scale, environmental pollution and so on. This paper studies and judges the coupling and coordinated evolution characteristics and influencing factors of China’s new infrastructure and industrial upgrading, hoping to provide decision-making reference for the interactive development of China’s new infrastructure and industrial upgrading.

In order to explore the spatial and temporal distribution characteristics of larvae fish resources of the four major Chinese carps in the lower Reaches of the Yangtze River, the abundance differences of larval fishes resources in different river sections were compared, and the spatial and temporal dynamics and occurrence mechanism of larval fish resources in the lower Reaches of the Yangtze River were revealed. The study conducted a monthly survey of larvae fishes in the lower Reaches of the Yangtze River from April to August 2019 by using morphological and molecual biological methods. A total of 107 990 larvae were collected, belonging to 19 species, 2 orders, 2 families, among which 972 were four major Chinese carps, Hypophthalmichthys molitrix being the main species, accounting for 67.28% of the total catch. The results showed that the average monthly abundance of larval in each section segment was 2.57,0.90 and 0.60 ind./100 m3. respectively. The results showed that under the dual effects of river and lake compound ecosystem and estuarine tidal intrusion, the resources of larvae of the four major Chinese carps decreased gradually from Anqing to Nantong section. The study showed that the abundance of larvae fish in the Anqing River section fluctuated month by month since late April, and exploded in June and July. Compared with Nanjing and Nantong, the peak value of Anqing River segment is higher. Kruskal-wallis test showed that there were differences in the lateral distribution of larvae of the four major Chinese carps, which showed that the density of larvae in the nearshore was significantly higher than that in the middle of the river. The analysis of the Pearson test showed that the four major Chinese carps of larvae and juveniles abundance was significantly positively correlated with the water temperature and daily increase rate of and water level (P<0.05). There was a significant positive correlation between the abundance of larvae and juveniles with water temperature and the daily increase rate of water flow in Nanjing section (P<0.05). There was a significant positive correlation between the daily abundance of larvae and juveniles and the daily increase rate of water level and water flow in Nantong section (P<0.05). The results revealed the spatial and temporal distribution characteristics of the early resources of the four fishes in the lower Reaches of the Yangtze River, and concluded that the connectivity system of rivers and lakes plays an important role in the replenishment of domestic fish resources, and provides data support for the regulation of the coastal waterway and the protection of fish habitat in the Yangtze River.

Dabieshan Mountain Area in Hubei Province is an important water supply area of the middle reaches of the Yangtze River, and the middle and lower reaches of the Huai River, as well as an important ecological barrier in the central region. The evaluation of water conservation function provides an important data basis for ecological protection and ecological planning. Take the Dabieshan Mountain Area in Hubei Province as a study object, the paper evaluates the water conservation with the water balance model using high-precision and fine ecosystem types data, and analyzes the impact of spatial distribution characteristics, ecosystem types, altitude, and slope on the water conservation function. The results show that: (1) the mean water conservation depth of the study area in 2020 was 292 mm, and the total water conservation was 43.57×108m³ , which showed it was powerful in the east and weak in the west from the space． (2) the forests and shrubs contributed 70% of the total water conservation; the evergreen broad-leaved forest and evergreen broad-leaved shrub had a better water conservation capacity per unit area, namely 620.63 mm and 539.51 mm respectively． (3) the total water conservation in the middle and lower altitude areas is 100-300 m, accounting for the largest proportion of 42.86%, and the water conservation capacity per unit area in the area of high altitude, namely 1 000-1 700 m was the highest, which was 711.79 mm; the gentle slope area is 5°-15°, making the greatest contribution for the total water conservation, which was 47.80%. (4) the extremely important areas for water conservation took up 6.56% of the total area, and they were mainly in the east, such as Jiuzihe Town, Wenquan Town and Qingshi Town; while the important areas of water conservation accounted for 12.08% of the study area, mainly concentrated in the mountainous areas of Caopandi Town, Shitouzui Town, Yingshan County and Jiuzihe Town, Luotian County in in the south of the study area. The results of this study can provide important data support for ecological environmental protection, ecological restoration planning and ecological space control in the Dabieshan Mountain Area of Hubei Province, and have great significance for promoting the construction of ecological civilization in Dabieshan Mountain Area of Hubei Province.

To examine the spatial distribution patterns of nematode-trapping fungi (NTF) and driving factors in the Jinsha River Basin in North China, 54 sampling sites were set up along the river, and 5 samples of aquatic sediment and 5 samples of terrestrial soil were taken from each sampling site. The NTF strains were isolated, purified, and identified using conventional pure culture techniques along with morphological and molecular biology techniques. 540 samples were collected and a total of 567 strains, classified into 29 species and 3 genera, were isolated. The upstream stream included 79 strains, which were classified into 16 species from 2 genera; the middle stream contained 205 strains, which were classified into 18 species from 2 genera; and the downstream contained 283 strains, which were classified into 21 species from 3 genera. From upstream to lower, NTF detection rates and species richness increased. Terrestrial soil had 354 strains classified into 23 species from 3 taxa, and aquatic silt included 213 strains classified into 22 species from 2 genera. In comparison to aquatic sediment, terrestrial soil had greater detection rates and species richness of NTF. (1) Among the geographical environmental factors, both longitude, latitude and altitude had significant effects on the species richness and detection rate of NTF (P<0.05).(2) Under phenological conditions, the average annual temperature had significant effects on species richness and detection rate of NTF (P<0.05), while average annual rainfall had no significant effects on species richness and detection rate of NTF (P>0.05).（3) In terms of soil physical and chemical properties, soil pH, total potassium and total phosphorus had extremely significant effects on species richness (P<0.01), soil total phosphorus, total potassium and organic matter had significant effects on species detection rate (P<0.05), while soil total nitrogen had no significant effects on species distribution of NTF (P>0.05).Geographical factors, phenological conditions and soil physicochemical factors all jointly drive the formation of this pattern to different degrees.

Reservoir impoundment affects local climate. The soil microbes are a sensitive indicator for environmental changes and their response to dam development is rarely investigated. This study investigated the soil microbial in April and September in four reservoir zone: Xiluodu, Xiangjiaba, Baihetan, and Wudongde in the lower Jinsha River. The total PLFA content and soil microbial community in April and September in the reservoir areas of the dry-hot valleys were determined by the phospholipid fatty acid (PLFA) method. This study analyzed the dominant factors of soil microbial variations and quantified the effects of river interception and reservoir impoundment on the soil microbial community. The results showed that： (1) meteorological factors and soil nutrients could explain most of the variation of soil microbes, with the degree of explanation of Baihetan and Wudongde reservoirs (84.1%, 93.5%) larger than Xiangjiaba and Xiluodu reservoirs (41.1%, 77.0%). (2) soil microbes positively correlated with total nitrogen, available nitrogen, and precipitation in April, and negatively correlated with temperature and potential evapotranspiration. In September, soil microbes positively correlated with precipitation, organic matter, and available nitrogen, and negatively correlated with potential evapotranspiration.(3) the individual contribution of water impoundment to soil microbial variation in April and September was 2.2% and 6.8%, respectively, and the variation explained by both impoundment and other factors less than 22.4%. In contrast, in the Baihetan and Wudongde reservoirs, the individual contribution of the impoundment to soil microbial variation in April and September was 5.5% and 8.3%, respectively, and the joint contribution with other factors was 13% in both cases. Overall, impoundment caused by the hydropower development in the lower Jinsha River in hot-dry valleys affects soil microbial PLFA content and their community structure, but their effects are easily masked by climate change and soil properties. The impoundment in the cascade reservoirs, to some extent, moderates the adverse effects of typical hot and dry climate on soil microorganisms and improve the stability of soil microbial community structure. This study contributes to an in-depth understanding of the response of soil microorganisms to hydropower development and is important for the scientific assessment of the terrestrial ecosystem impacts of hydropower development and soil sustainability.

With the wide application of rare earth elements (REEs) in modern industry, medical field, more and more are brought into the natural water environment, has been considered as a potential emerging micro-pollutants. Taking Guiyang city as the research object, this study analyzed the contents of REEs, the Post Archean Australian Shale （PAAS） standardized distribution pattern and characteristics of anthropogenic REEs in groundwater samples. The results show that the ∑REE scontent in groundwater in Guiyang City is 6.9-155.5  ng/L, with an average of 24.7  ng/L. The overall performance is that the medium and heavy REEs are enriched relative to the light REEs and have obvious negative Ce anomalies and positive Eu anomalies. Positive Gd anomalies were found in groundwater in all regions of Guiyang. The Gd anomalies in the urban center area with dense population and strong human activities were generally higher, while the Gd anomalies in the area with relatively small population and less human disturbance factors were relatively low. The proportion of anthropogenic Gd is between 7.4%-96.0%. The high proportion of anthropogenic Gd reflects that karst groundwater is affected by more intense surface domestic wastewater and medical wastewater. This study shows that anthropogenic Gd has good application potential in karst groundwater pollution tracing.

Yangtze River Economic Belt, as the leading demonstration belt of the national ecological civilization construction, shoulders the major mission of taking the lead in realizing “carbon peak” and “carbon neutrality”. Mastering the carbon emissions of cities in the Yangtze River Economic Belt and its influencing factors is of great significance to the realization of the “dual carbon” goal of the Yangtze River Economic Belt. Based on the IPCC coefficient, the carbon emissions of 110 prefecture-level and above cities in the Yangtze River Economic Belt from 2008 to 2018 were calculated, and the spatial and temporal pattern distribution was studied by using spatial autocorrelation, and a geographically weighted regression model was constructed to explore the influencing factors of carbon emissions in cities in different locations. Spatiotemporal heterogeneity and revealing why. The results show that from 2008 to 2018, the total carbon emissions showed a slowing trend, and its center of gravity shifted to the central and western regions year by year; the carbon emissions of cities in the Yangtze River Economic Belt showed a significant positive spatial correlation and agglomeration in the past 10 years, and the correlation fluctuated There is a downward trend; there are obvious differences in the influencing factors of carbon emissions, and the impact size is: per capita electricity consumption < population < construction land < industrial structure. The spatial pattern of structure and population is basically stable. The research results show that the realization of the “dual carbon” goal of the Yangtze River Economic Belt should be further accelerated from the fields of low-carbon transformation of industrial structure, rational planning of construction land, optimization of population spatial pattern, and planning of new energy power generation.

Yangtze River Economic Belt(YEB) has a major mission to take the lead in achieving the “Dural Carbon” target, and it is urgent to accurately identify the pressure of reducing emissions and increasing sinks in YEB and its disequilibrium characteristics. Based on the calculation of carbon emission and carbon sink data of 336 prefecture-level and above cities in China from 2000 to 2019, this paper constructs an index of “city carbon footprint pressure” to identify the pressure of reducing emissions and increasing sinks of cities in YEB in a national perspective, and study its characteristics of regional differences, distribution dynamics and spatial agglomeration using Dagum Gini coefficient, kernel density estimation and local Moran index, respectively, to explore its disequilibrium from multiple dimensions. The results show that: (1) the carbon footprint pressure of cities in YEB is lower than that of both regions outside YEB and the national average. There are obvious differences between the upper, middle and lower reaches, showing a spatial pattern with gradient increasing. (2) From the perspective of regional differences, the overall difference is large and tends to expand. The difference decomposition shows that the net difference between regions is the main source of the overall difference, and it is mainly caused by the difference between upper and lower reaches. (3) From the perspective of distribution dynamics, the absolute differences is large, while there are obvious multi-polar differentiation characteristics. (4) From the perspective of spatial agglomeration, there are four types of spatial agglomeration. The upper and middle reaches of YEB are dominated by low-low spatial agglomeration, and the lower reaches of YEB is dominated by high-high spatial agglomeration.

It is of great significance to systematically analyze the differences in carbon emissions among the three provinces and one municipality in the Yangtze River Delta (YRD) region, explore its impact mechanism and predict the trend of carbon emissions, for promoting the coordinated peaking of carbon emissions in this region and achieving green and integrated development. In this paper, the carbon emissions of energy consumption in Zhejiang, Jiangsu, Anhui and Shanghai from 2005 to 2019 were measured according to the emission coefficient method. The variation coefficient, Gini coefficient and Theil index were selected to measure the carbon emission differences in the YRD region. Based on the STIRPAT expansion model, the ridge regression was used to explore the impact mechanism of carbon emissions in the three provinces and one municipality in the YRD region. Using the scenario analysis method, combined with the policy planning and development law of each province, and referring to the historical rate of change of each variable, a baseline development scenario is set to predict the carbon emissions and carbon peak years of the provinces and cities in the Yangtze River Delta from 2020 to 2035.The results show that: (1) During the investigation period, there were significant differences in carbon emissions among the three provinces and one municipality in the YRD region, and the disparities in carbon emissions fluctuated and increased over time as a whole. (2) Population, urbanization level, GDP per capita, and energy intensity all significantly affect the carbon emissions of the three provinces and one city in the Yangtze River Delta. The energy structure only has a significant impact on the carbon emissions of Jiangsu. In term of the driving factors of carbon emissions in Shanghai, Zhejiang, and Anhui, the industrial structure has the most significant influence on them. (3) Under the baseline scenario, Shanghai, Zhejiang, Anhui and Jiangsu will achieve carbon peaks in 2026, 2027, 2028, and 2031,with peaks of 207.68, 408.55, 635.33 and 949.73 million tons.

 Based on the carbon emissions data of 48 districts and counties in the Wuhan city circle from 2008 to 2017, spatial autocorrelation and standard deviation ellipse methods are used to study the spatial-temporal evolution characteristics of carbon emissions from three scales of city circle scale, municipal scale, and county scale. Then, the Tapio decoupling model is used to analyze the relationship between economic development and carbon emissions change at different scales. The results show that: (1) At the city circle scale, the total carbon emissions of the Wuhan city circle continued to increase before 2012, and then gradually stabilized. The decoupling trend between economic growth and carbon emissions of the Wuhan city circle is also generally positive. (2) At the municipal scale, the carbon emissions levels of all cities have stabilized. The carbon emissions levels of Wuhan, Huanggang, and Xiaogan are higher than the average of 9 cities in the Wuhan city circle, and the carbon emissions level of Wuhan is much higher than those of the other 8 cities. The relationship between economic growth and carbon emissions of Tianmen, Xiantao, Xiaogan, and Huanggang has changed from weak to strong decoupling. (3) At the county scale, the carbon emissions of the Wuhan city circle shows significant spatial characteristics of circle distribution. The carbon emissions levels of close circle districts and counties are generally high, while the carbon emissions levels of the core circle and peripheral circle districts and counties are generally relatively low. The circle characteristics of the decoupling state have also appeared, the districts and counties with strong decoupling are mainly located in the core circle and peripheral circle of the Wuhan city circle, and the districts and counties with weak decoupling are mainly located in the close circle. Finally, based on the existing problems of carbon emissions decoupling effect in the Wuhan city circle, the corresponding measures are put forward from the aspects of the circle and polar nucleus, to provide decision-making reference for the high-quality development of the Wuhan city circle and the compilation of relevant planning.

Carbon emission regulation should not only focus on its own emission reduction, but also examine the inter-provincial carbon emission linkage. To clarify the network characteristics and influencing factors of spatial correlation of carbon emission at the national level is the basic premise of overall carbon emission control and sustainable development. Based on the panel data of China's provinces from 2015 to 2019, social network analysis (SNA) was used to conduct empirical analysis on the spatial correlation of carbon emissions, and the influencing factors were explored by QAP method. The results show that China's carbon emissions show typical spatial network characteristics, and the inter-provincial carbon emissions are increasingly correlated, and the stability and complexity of the network are gradually improved. Shanghai, Jiangsu, Beijing and other places live in the network center, and play the role of "bridge"; The economically developed eastern coastal region plays the role of "two-way spillover" and "net benefit" in the network, while the central and western inland regions with rich energy reserves belong to the "broker" and "net spillover" plate. Differences in geographical proximity, industrial structure, income, technological innovation and population density have a significant positive impact on the spatial correlation of carbon emissions. The more similar the energy consumption is, the stronger the correlation of carbon emissions is. Therefore, in carbon emission governance, it is necessary to base on the concept of regional collaborative governance, to establish a "leader-follow" carbon emission reduction mechanism, to give full play to the strategic advantage of "a national chess game", to formulate differentiated carbon emission reduction policies, and to promote the formation of a balanced carbon emission reduction pattern at the national level.

Under carbon peak and carbon neutrality constraints, improving the tourism carbon emission efficiency is of great significance to realize the low-carbon development of tourism. Based on the panel data of provinces in China from 2003-2019, the improved entropy method and SBM model based on the undesired output are used to measure the level of new-type urbanization and tourism carbon emission efficiency of 30 provinces in China in the research. On the basis, a spatial Durbin model is further constructed to explore the spatial spillover effect of new-type urbanization on tourism carbon emission efficiency. The results show that: (1) During the research period, the average level of new-type urbanization increases from 0.251 to 0.481, with an annual growth rate of 5.4%; the average of tourism carbon emission efficiency increases from 0.598 to 0.719, with an average annual growth rate of 1.2%. At the same time, both of them present an obvious spatial pattern where the higher provinces are in the eastern region while the lower provinces are in the western region. (2) Bivariate Moran′s I shows that there is a positive spatial correlation of the new-type urbanization and tourism carbon emission efficiency, and the positive spatial correlation is gradually increasing. Meanwhile, the number of regions which are in H-H type and L-L type decreases while the number of regions which are in H-L type and L-H type increases. (3) New-type urbanization has a significant positive spillover effect on tourism carbon emission efficiency. At the same time, there is an obvious positive spatial spillover effect on tourism carbon emission efficiency in China, and the improvement of tourism carbon emission efficiency in each province will have a significant improvement effect on the tourism carbon emission efficiency in the neighboring provinces.

Modelling and evaluation of stormwater overflow and flood inundation characteristics is the basis for scientific assessment of flooding risks and formulation of drainage optimization measures. Taking eight plain polder areas in Dian Shanhu Town, Kunshan City as an example, this study applied topography, meteorology and rainwater pipe network data to analyzes the overflow characteristics of rainwater pipe network under extreme rainfall scenarios by using one-dimensional SWMM model, and quantitatively depicts the surface flood inundation area due to overflow runoff by two-dimensional CADDIES mode. Moreover, the the main influencing factors between rainfall events and flood inundation were explored, and two optimization strategies, i.e., enhancing the pumping station drainage capacity and increasing the water surface, were evaluated to identify flood regulation effect. The results show that: (1) the number of overflow points is affected by the surface properties and rainfall characteristics in the polder area. The extent of flood inundation area is significantly related to the rainfall characteristics. When the rainfall return period is greater than 0.63 a, the inundation area also increases significantly; (2) The flow volume of pipe network in Dian Shanhu town is overloaded under heavy rainfall, and the pipe network in the polder area cannot effectively deal with heavy rainfall events exceeding 50 a; (3) Increasing the drainage capacity of the pump station cannot reduce the number of overflow channels and overflow points of the rainwater pipe network, but can effectively reduce the submerged area; (4) Increasing the water area ratio can significantly improve the storage capacity of stormwater and floodwater. When the water area ratio of Xinxing polder, Yongsheng polder and Hongqi polder reaches 6.03%, 10.87% and 8.83%, they can effectively resist the river overflow caused by 100 a rainfall events. The results can support decision-making for flood disaster risk assessment and stormwater management in the study area and other plain polder areas.

Suspended solids concentration is one of the important parameters to evaluate water quality and regional ecological environment. Based on the measured suspended sediment concentration and synchronous spectral data of the Three Gorges Reservoir area and Changshou Lake in May 2020, and compared with the landsat-8, sentinel-2 and GF-1 satellite remote sensing image data, this paper analyzes the correlation between the water leaving spectral reflectance and the concentration of suspended solids in the water body under different satellite simulation bands and different band combinations, selects the sensitive bands of suspended solids in the Three Gorges Reservoir area, and attempts to calibrate its effective parameter range. Using linear, exponential, polynomial and other mathematical statistical regression methods, the inversion models corresponding to three types of satellites are established respectively. The optimal models that different satellites can be used for remote sensing inversion and monitoring of suspended sediment concentration in the Three Gorges Reservoir area are compared, and an optimal model is selected for remote sensing monitoring of suspended sediment concentration in the Three Gorges Reservoir area of the Yangtze River. The results show that: (1) among the three types of satellite data, the band combination of near-infrared / green light has the most significant correlation with suspended sediment concentration, in which the correlation coefficient of landsat-8 is 0.771 3 (p<0.001), sentnel-2 is 0.773 4 (p<0.001), GF-1 is 0.730 0 (p<0.001); (2) The best regression models of the three types of satellites are linear models, and the model R2 is more than 0.60. The equation F test passes the 99% confidence interval, indicating that the commonly used three types of satellites can be effectively applied to the monitoring of suspended solids in the Three Gorges water body. However, combined with the characteristics of the water body in the Three Gorges of the Yangtze River, the accuracy of model verification, the spatiotemporal resolution and the difficulty of data acquisition, sentinel-2 satellite data is considered to be the most suitable for the operational application monitoring of suspended solids in the Three Gorges area; (3) The concentration of suspended sediment in the Three Gorges of the Yangtze River is higher than that in the center of the river and higher in the downstream than that in the upstream. The concentration in summer is significantly higher than that in spring. The concentration of suspended sediment increases significantly in July and August when the water volume increases and floods occur frequently; In May, the concentration of suspended sediment in the main stream of the Yangtze River was basically about 40-80 mg/L, and the concentration along the river bank reached about 100 mg/L. In July and August, the concentration of suspended sediment remained about 80-120 mg/L, and even reached more than 160 mg/L in the downstream area. As for Changshou Lake, which is an inland lake in the tributary, the suspended sediment concentration shows the distribution characteristics that the suspended sediment concentration is higher on the bank than in the center of the lake. The fluctuation of suspended sediment content in different periods is small, and the flood in the main stream of the Yangtze River has little impact on it. The concentration in the lake is basically about 40-80 mg/L in May, July and August, and the concentration on the Bank of the lake reaches 110 mgmg / L.

Ecological risk assessment on urban agglomeration scale is one of the problems urgently needed to be studied.Chengdu-Chongqing urban agglomeration is taken as the research area. Based on the GlobeLand30 data set of 2000, 2010 and 2020, landscape ecological risk index is introduced. From the perspective of landscape ecology, geostatistics and GIS software are used to carry out spatial analysis, combined with semi-variational function and spatial autocorrelation analysis method.The change of landscape pattern in Chengdu-Chongqing urban agglomeration was analyzed and its ecological risk was evaluated.The results showed that: (1) construction land increased year by year in chengdu-chongqing urban agglomeration, while the total area of cultivated land and grassland decreased, and cultivated land reclamation existed; (2) The spatial distribution of landscape types in chengdu-Chongqing urban agglomeration becomes complicated and fragmented; (3) The overall ecological risk index of Chengdu-Chongqing urban agglomeration showed an increasing trend, and the area of high ecological risk area and high ecological risk area gradually expanded.The results of this study provide reference for land use allocation and ecological security pattern construction in this region.

Rural population shrinkage is an inevitable process of human social development, and is a key issue in alleviating the rural man-land relationship, as well as achieving high-quality development of rural territorial systems. By defining the concept and identification method of rural population shrinkage, the paper analyze the spatial and temporal evolution patterns of China's rural population shrinkage from 1950 to 2020 and its spatial effects on the utilization of water and soil resources by using a series of statistical and spatial analysis methods, taking 31 provinces as spatial units and based on two calibers of permanent residence and registered residence. It is found as follows. (1) At the national scale, rural permanent population and registered population shrinkage enter the full-blown period in 1996 and 2011, respectively, with the former entering the stable period of the full-blown period in 2011. (2) At the provincial scale, the evolution of rural permanent population shrinkage present a expansion from the "along the border-along the Yangtze river-along the coast" areas to the whole region, while the shrinkage evolution of rural registered population show an expansion path from north to south. (3) The grade of rural permanent and registered population shrinkage in provinces gradually change from mainly mild to mainly moderate, and the elevated evolution all present an extension from the eastern coast to the central and western inland. (4) From 2010 to 2020, there are differences in the spatial heterogeneity of the impact of the shrinking of the rural permanent population and registered population on the utilization of water and land resources in provinces. Among them, the change of rural per capita farmland is most strongly influenced by the rural permanent population shrinkage and have the most significant spatial heterogeneity. (5) In the spatial effects on the utilization of water and land resources, the inhibition of the growth of rural domestic water and the promotion of the decline of agricultural water by the rural permanent population shrinkage in provinces exist a spatial and temporal lag, and the significant effect areas are southern China and northern China respectively. The shrinkage of rural permanent population and registered population has led to the growth of rural per capita construction land, with significant effects concentrated in the northwest China and southwest China respectively.

It is of great significance to promote the unity of economic benefits and green production behavior of large-scale farmers for the high quality of agriculture in China. Based on the survey data of scale farmers in Jiangsu Province, PSM model is used to test the impact of socialized service supply on economic benefits and green production of large-scale farmers from the perspective of service supply, and compared the impact of different service supply contents and different types of large-scale farmers. Results show that: (1) Service supply has positive impact on economic benefits and green production of large-scale farmers, which can not only increase the per capita income of households and enhance income stability, but also promote the use of two types of green production technologies: organic fertilizer and soil testing and formula fertilization. (2) There are differences in the impact of different service contents. Providing transplanting service, field management service and drying service can improve economic benefits; in terms of green production, only field management service play a significant role. (3) There are obvious group differences in the impact of service supply. After joining cooperatives, without credit constraints and using the Internet to provide services, the economic benefits and green production have improved more significantly. Therefore, it is suggested to encourage scale farmers to transform from single land scale operation type to "land + service" integration type; support the services development that are in short supply in market; Improve the development environment of scale farmers by improving the level of organization, informatization and alleviating financing constraints.

The development of a household’s livelihood in rural areas is challenged by multiple risks. In order to stabilize the achievement of poverty alleviation and to promote rural revitalization, it is of great practical importance for rural households to build livelihood resilience to internal and external risks. Based on the resilience assessment framework proposed by Food and Agriculture Organization (FAO), this study developed an evaluation index system for measuring livelihood resilience of rural households from five dimensions, including livelihood assets, agricultural exchange and learning, adaptive capacity, social safety nets and access to basic services. Using household surveydata collected from 302 rural households in Qiliping Township, Dabie Mountain area, Hubei Province, this study examines the factors influencing livelihood resilience of rural household and evaluatesits environmental effects usingstatistical analysis and econometric models. The results show that: (1) the livelihood resilience of rural households in the study area is at a medium to high level in general. There is a clear symbiotic relationship between the livelihood resilience of rural households andthe five dimensions measuring it, presenting a gradient and gradual growth trend, among which the adaptive capacity is the weakest aspect of maintaining livelihood resilience. (2) There are a number of factors affecting the livelihood resilience of rural households, including health status, number of labour force, information access channels, involvement in local organizations or associations, the relationship between villagers and farmers, participation in collective affairs, satisfaction with village cadres and the operation of the rules and regulations in a village. (3) Rural households face a variety of negative environmental externalities attributable to their livelihood activities, and this amount increases as their livelihood resilience increases. Consequently, in order to effectively promote the sustainable development of rural livelihoods as well as the local ecological environment, it is necessary to enhance the adaptability of rural households, enhance their livelihood resilience, and minimize the negative impacts of their livelihood activities on the environment.