The coordinated development of the Yangtze River economic belt has undertaken an important mission in building a new development pattern. Based on the traditional driving forces of regional development transformation, building the new development pattern will inject new dynamics into the coordinated development of the Yangtze River economic belt from three aspects of endogenous, exogenous, and incentive. To effectively solve the new challenges and problems such as the stark inequality of regional development and its factor flow, the synchronization of industrial upgrading with infrastructure construction and land space optimization, the collaborative governance of ecological environment and the coordinated mechanism between regional plates and urban clusters, the economic belt must put forward the promotion path including realize the cooperation of industrial development by jointly building industrial park facilities, share development opportunities by integrating the spatial layout of land, jointly undertake rights and responsibilities and then realize the coordinated protection of ecological environment, negotiate the interests of different subjects by jointly designing systems and mechanism, establish the consciousness of regional community and create a new model of regional coordinated development.

Accurately measuring the green efficiency of water resources in cities along the Yangtze River Economic Belt is of great significance to the rational utilization of water resources and green development and construction of cities along the Yangtze River Economic Belt. The SE-SBM model (Super-Efficiency Slacks-Based Model) is used to measure the green efficiency of water resources in 45 cities along the Yangtze River Economic Belt from 2010 to 2019. Combined with the decomposition of Theil index, the root causes of regional differences in green efficiency of water resources are explored, and the ML index method (Malmquist-Luenberger) is used to explore the internal causes of changes in green efficiency of water resources; Furthermore, the difference between the actual value and the optimal value of water resources input and water pollutant output is used to calculate the water-saving and emission reduction potential of 45 cities along the Yangtze River Economic Belt. The results show that: First, during the study period, 77.8% of the 45 cities along the Yangtze River Economic Belt were inefficient in the green efficiency of urban water resources, and the spatial distribution of green efficiency of water resources shows that the lower reaches of the Yangtze River Economic Belt > the upper reaches > the middle reaches; Second, from 2010 to 2019, the green efficiency of water resources in 45 cities along the Yangtze River Economic Belt was on the rise, but the green efficiency of water resources in 9 cities along the Yangtze River Economic Belt, including Zhaotong, Lijiang, Panzhihua, Guiyang, Tongling, Huzhou, Shaoxing, Zhoushan and Ezhou, was on the decline, which was affected by the changes of pure technical efficiency, scale efficiency and technological progress to varying degrees; Third, the water-saving potential, sewage emission reduction potential and industrial wastewater emission reduction potential are divided into three sections of “low, medium and high”, and 45 cities along the line are divided into five types of “three high, two high, one high, medium and three low”, of which Yueyang, Ma’anshan, Huangshi and Jingzhou belong to the “three high” type; In terms of spatial pattern, cities with “three low” types of water-saving and emission reduction potential show the agglomeration trend of “large settlement, small scattered”. Based on the above research results, this study can provide countermeasures for promoting the rational development and utilization of urban water resources along the Yangtze River Economic Belt and realizing regional high-quality green development.

Based on analysis of the coupling mechanism and its transition mode, this paper established an evaluation index system for three systems: technology innovation, economic growth and ecological environment. Using the entropy method, coupling coordination model, spatial center of gravity model and grey prediction model, this paper scientifically measured and analyzed the spatial-temporal evolution and trend prediction of coupling coordination among technology innovation, economic growth and ecological environment in Yangtze River Delta Urban Agglomerations from 2006 to 2019. According to the research: during the study period：（1) the comprehensive level of technology innovation, economic growth and ecological environment developed favorably.（2) the level of coupling coordination of the three systems was on a steady upward trend, with a state shifting from dysfunctionality to coordination. However, there was an imbalance in the spatial distribution featuring with “center-edge” and “zigzag”. (3) the Yangtze River Delta Urban Agglomerations were characterized by a significant spatial mismatch between cities with high levels of technology innovation, economic growth and ecological environment. Therein, the technology innovation and economic growth matched best spatially, but after a period of rapid integration, it was hard to continue in deepening. （4) during the prediction period, the level of coupling coordination of the three systems continued to increase, however, partial western cities would continue to be dysfunctional in development. In order to promote the Yangtze River Delta Urban Agglomerations to achieve a higher quality of integrated development, this paper proposes corresponding suggestions for coordinated development.

In order to carry on the comprehensive evaluation research to the construction of resettlement areas for the poverty-alleviation relocation, this paper takes 12 cities (prefectures) of Hubei province as an example to construct a comprehensive evaluation index system,including community governance, grass-roots party building, basic public services, training and employment services, cultural services,uses entropy method to objectively assign weights to indicators, gets the overall score for each district, then carries on the comprehensive Evaluation of construction of resettlement areas for the poverty-alleviation relocation in Hubei province, and identifies the following characteristics:(1) From the comprehensive score, there is a large gap in the construction level between different regions. (2) From the perspective of the “five systems”, the construction of all aspects of the relocation of poverty-alleviation relocation in different regions shows the characteristics of imbalance and great difference. (3) From the perspective of index weights, there is a small gap in infrastructure and a large gap in software facilities of resettlement communities. Based on this, this paper proposes corresponding follow-up help measures: promoting community governance of fine comprehensive transformation, promoting basic party leading, promoting basic public service quality upgrading, promoting employment income levels increase, promoting the development of cultural services diversification.The “five push” corresponds to the “five systems”, comprehensively helping the follow-up work, so that the relocated people can not only “move out”, but also “stay stable” and “ get rich”.

Taking the lakeside zone in the north of Chaohu Lake as the research area, the 0~20cm surface soil of the intertidal zone, plant wetland, forest land and field were collected. The soil dissolved organic matter (DOM) was analyzed by UV absorption spectrum and three-dimensional fluorescence spectrum combined with parallel factors to explore the spectral characteristics of DOM in different land types. The results showed that the dissolved organic carbon (DOC) of the four land types in the northern lakeside zone of Chaohu Lake had a significantly positive correlation with the colored dissolved organic matter (CDOM) and the fluorescent dissolved organic matter (FDOM) (p<0.05), and the CDOM and FDOM also had a significantly positive correlation (p<0.05). Compared with the other three types of soil, the contents of DOC, CDOM and FDOM in plant wetland soil were the highest. The UV absorption spectrum parameters showed that the relative molecular weight, hydrophobic components and aromatization degree of DOM in field and forest soil were higher. The spectral slope ratio (SR) of the four types of soil was less than 0.70, and the fluorescence index (FI) was between 1.40 and 1.90, indicating that the degree of soil humus in the lakeside zone was better. DOM had dual characteristics of endogenous and exogenous, and the exogenous ones were the main sources. The biotic index (BIX) and Fn(280) of plant wetland soil were higher than those of the other three land types, and the humification index (HIX) was the lowest, indicating that the biogenic and protein-like components were higher than the other three land types, and the humification degree was the lowest. The four types of soil DOM were composed of three fluorescent components:fulvic-like acid(Ex/Em=245,320/420 nm),tryptophan-like(Ex/Em=280/340 nm),humic-like acid (Ex/Em=275,375/455 nm).The contribution rate of fulvic-like acid components up to DOM was 46~62%, and the proportion of tryptophan-like in DOM of plant wetland soil was higher than that of other soil types. The results provide basic data for revealing the composition, structure and source of soil DOM of different land types in Chaohu lakeside, and provide scientific basis for the protection of aquatic environment in Chaohu Lake.

Under the background of climate change and regional economic integration, flood disasters occurred in a certain place will have serious ripple effects on external regions through industrial correlation, although these regions are far apart in space. Accurate estimation of the ripple effect is helpful for policy-makers to formulate industrial layout plan and improve the efficiency of flood management. The purpose of this research is to construct an integrated framework for estimating the direct and ripple losses at the same time. The specific steps to build the framework are as follows. First, using functional fragility curves to estimate the direct losses of various sectors in the stricken area under simulate scenarios of different massive inundation. Then, based on the mixed multiregional input-output model, this study uses the direct losses data as exogenous variables to evaluate the ripple losses outside the stricken area under different inundation depths. Vulnerable regions and industrial sectors in Hubei Province can be identified by aggregating data from simulations across different regions. The main findings are as follows: (1）The ripple losses caused by Wuhan City under the moderate inundation scenario is 36.61% of the direct losses. （2)From the perspective of regional correlation, Jingmen City and Jingzhou City are more vulnerable, which are closely linked with other regions in Hubei Province. Because these two cities have always suffered huge losses in the numerical simulation of massive flood disaster. The average ripple loss of these two cities is about 4.8 times and 4.2 times that of Tianmen and Shennongjia area, which has the smallest ripple loss. (3）From the perspective of industrial sectors correlation, the ripple economic impact of flood disasters is mainly concentrated in agriculture, livelihood-related manufacturing, residential services, as well as transport, storage and postal services. Among them,the livelihood-related manufacturing with the largest loss is even a hundred times more than the scientific research and technical service. The results can provide reference for the government to formulate disaster prevention and mitigation policies and make post-disaster reconstruction decisions.

 In this study, the spatial heterogeneity of soil organic carbon content in citrus orchards was studied. The relationship between organic carbon content and other soil physicochemical properties, topographic characteristics and climate variables was discussed. This will provide a scientific basis for improving economic forest ecosystem services. Field soil sampling was carried out in the citrus distribution area of Zigui County. The main influencing factors of soil organic carbon were simulated and the spatial distribution of soil organic carbon content was predicted based on the random forest algorithm and geographically weighted regression model in combination with eight topographic variables, two climate variables and thirteen soil variables. The results show that the average contents of soil organic carbon in 0-20 cm (topsoil) and 20-40 cm (subsoil) in the study area were 11.95 and 9.01 g·kg^-1, respectively. The soil organic carbon content on the northern bank of the Yangtze River (9.24 and 7.56 g·kg^-1) was lower than that on the southern bank of the Yangtze River (14.48 and 10.36 g·kg-1), while the coefficient of variation on the northern bank (0.53 and 0.66) was higher than that on the southern bank (0.45 and 0.58). The relative contribution of influencing factors to the spatial distribution of soil organic carbon content was different among soil layers. The relative contributions were in descending order: total nitrogen (53.0%) > total potassium (11.9%) > available nitrogen (11.4%) > mean annual precipitation (7.6%) > soil moisture content (7.3%) > mean annual temperature (5.1%) > elevation (3.7%) in topsoil; total nitrogen (69.7%) > available nitrogen (14.2%) > bulk density (7.5%) > plane curvature (4.3%) > total potassium (3.8%) > fine sand (0.6%) in subsoil. Based on the geographically weighted regression model, the predicted values of soil organic carbon content in topsoil and subsoil were obtained, i.e., 6.92-16.85 and 5.76-13.75 g·kg^-1, respectively. The local coefficients of determination of soil organic carbon content were 0.662-0.692 and 0.596-0.642, respectively. The soil organic carbon content also exhibited the characteristic of “high in the north and low in the south in topsoil, and high in the east and low in the west in subsoil”. The measured and predicted soil organic carbon contents of citrus orchards in Zigui County showed obvious spatial differentiation characteristics: the southern bank > the northern bank and the topsoil > the subsoil. The influence of soil physicochemical properties on the spatial distribution of regional organic carbon content was higher than that of topographic and climate factors. Particularly, total nitrogen had the largest relative contribution. Therefore, regulating soil physicochemical properties such as soil nitrogen in economic forests is beneficial to increasing soil organic carbon storage.

In order to explore the distribution pattern and its environmental driving mechanism of Sphagnum palustre L. community in Sphagnum Wetland of Qizimei Mountain, and further to provide scientific theoretical basis for the protection, restoration and utilization of Sphagnum wetland in subtropical mountain regions, field investigation and sampling for vegetation and environmental factors were conducted on June 2021 using standard sample method, followed by measurement and analysis of these samples. Subsequently, systematic clustering was used in quantitative classification of S. palustre communities; one-way ANOVA, multiple regression analysis and Pearson correlation analysis were used to test the differences in each of the environmental indicators, each of the physiological and growth indicators of S. palustre among the four clusters, as well as to test their pairwise correlation, which ultimately to elucidate the main environmental factors affecting S. palustre growth and its underlying mechanism. Results showed that: (1) A total of 37 field samples were divided into four associations: Ⅰ. Ass. Pteridium aquilinum-Sphagnum palustre; Ⅱ. Ass. Carex rubrobrunnea var. taliensis-Sphagnum palustre;Ⅲ. Ass. Juncus setchuensis+Cnidium monnieri -Sphagnum palustre; Ⅳ. Ass. Hosta ventricose+Lycopus cavaleriei-Sphagnum palustre. (2) Each of the four growth indicators (height, number of capitula, coverage, and biomass) of S. palustre showed gradual decreasing trend from Ass. I to Ass. Ⅳ. Each of the nine physiological indicators (TN, TP, TK, TC, C/N, C/P, N/P, N/K, and water content) in S. palustre tissue showed significant differences among the four associations; among which, tissue water content and N/K in S. palustre exhibited increasing trend from Ass. I to Ass. Ⅳ, with highest values occurred in Ass. Ⅳ.（3）Multiple linear regression analysis showed that water table and soil N/K were principal environmental factors affecting growth and distribution of S. palustre populations in Qizimei Mountain. In this study, excessive water content in S. palustre tissue caused by prolonged flooding stress inhibited its photosynthesis, which further impede the growth. On the other hand, high N load led to S. palustre growth was limited by K, resulting in unbalanced nutrient absorption and thereby inhibiting its growth and development. Nitrogen input from nearby farmland may be an important factor caused excessive N/K ratio in both soil and S. palustre in association Ⅳ.

Clarifying runoff change and its driving forces is important for the sustainable utilization of water resources in the basin. Taking the Baihe River basin as the study area, this paper analyzed the trends of multi-factors including hydrometeorological, vegetation and socio-economic factors in the study area from 1982 to 2018 based on the TFPW-MK trend test method. In addition, a Budyko framework considering the time-varying characteristics of multi-factors was constructed to quantify the contribution of various factors to runoff change. The results showed that: (1) The runoff of the Baihe River basin decreased at the rate of -2.83 mm/a in the past 37 years; the hydrothermal coupling parameter n in the Budyko framework fluctuated and increased at the rate of 0.041/10 a overall. (2) The parameter n had a high correlation with precipitation, industrial and agricultural water consumption, with the coefficient of determination (R2) of 0.97. The introduction of the time-varying parameter n can improve the runoff simulation effect. (3) Runoff in the Baihe River basin was most sensitive to precipitation and least sensitive to industrial water consumption; the contribution of precipitation to runoff reduction gradually decreased from 78.7% to 20.8% during 1991-2018, while the contribution of potential evapotranspiration and agricultural water consumption to runoff reduction gradually increased, from 7.6% and 4.1% to 17.4% and 37.5%, respectively. (4) The impact of climate change on runoff gradually decreased during the study period, with its contribution decreasing from 86.3% to 38.3%.

Fishway is an important channel for migration and gene exchange of fish populations between upstream and downstream of dam. In this study, we sequenced 220 Cyt b gene sequences of Schizothorax waltoni, and analyzed the genetic diversity and genetic structure from five populations, including upstream of Zangmu Hydropower Station (ZMBS), Zangmu fishway (ZMYD), downstream of Zangmu Hydropower Station (ZMBX), Jiacha fishway (JCYD) and downstream of Jiacha Hydropower Station (JCBX). Our aims were to study the need for assisted gene flow to prevent further loss of genetic diversity and boost adaptive potential and genetic selectivity of fishways on S. waltoni. The results show that: (1) The level of genetic diversity for S. waltoni populations between upstream and downstream of Zangmu Hydropower Station and Jiacha hydropower station (ZMBS, ZMBX and JCBX) were similar (Hd (ZMBS)=0.868, Pi (ZMBS)= 0.004 16; Hd (ZMBX)=0.825, Pi (ZMBX)=0.003 88; Hd (JCBX)=0.833, Pi (JCBX)=0.003 70), gene flow was not blocked (25.23＜|Nm|＜81.33), genetic divergence was not detected (-0.020 2＜FST＜0.006 1；P>0.05), indicated low risk of outbreeding depression. Five geographic populations were defined as one genetic management unit. There exists the demand of gene flow to pass through Zangmu fishway and Jiacha fishway for S. waltoni to avoid inbreeding depression. S. waltoni should be a target fish for Zangmu fishway and Jiacha fishway; (2) The results of network and neighbor-joining phylogenetic tree showed three Clades of S. waltoni, indicated sympatric divergence but not cryptic species, which may be formed by the secondary contact after the Kunlun-Yellow River Movement or the Pleistocene glacial refugia. (3) Genetic selection pressure was detected on S. waltoni from Zangmu fishway and Jiacha fishway. The results could provide data support and theoretical implications for rechecking the rationality of target fish setting and promoting the refinement operation management of fishway.

As an important spatial carrier of the national ecological security strategy of “two screens and three belts”, the key ecological function area in the upper reaches of Yangtze River is intertwined with ecological sensitivity and socio-economic lagging, clarifying the influence of ecosystem services on multi dimensions and hierarchies of human wellbeing is conducive to the construction of ecological civilization in China and regional sustainable development of human-land system. Taking the key ecological function areas in Sichuan Province as case research object, this study identified changes of human wellbeing since 2000, subsequently, influence of varied ecosystem service types on human wellbeing were observed by utilizing correlation analysis and the panel quantile regression model. Results revealed that: (1) Human wellbeing index increased by 79.99% from 2000 to 2018 and internal structure of the index tended to be more balanced, low income level was an important cause to restrain the overall improvement of human wellbeing, vast majority of counties were still in the middle and poor wellbeing hierarchy, with significant difference between the east and west. (2) Ecosystem service value per capita (PESV) was negatively associated with human wellbeing, especially in the educational dimension. (3) Influence of ecosystem services showed hierarchical heterogeneity, the adverse effect of PESV tended to slow down with the increasing of human wellbeing hierarchy, arable and forestland were found to be the key ecosystems, which imposed larger marginal returns on the high wellbeing hierarchy, arable ecosystem was positive influential factors while forestland was opposite. (4) In terms of control variables, the proportion of secondary and tertiary industries, urbanization rate as well as investment in fixed assets per capita exhibited significant positive influence on each human wellbeing hierarchy, and the marginal contributions to the poor wellbeing hierarchy was greater.

Climate change has had a significant impact on human society and economic development, which means that carbon emission reduction are imminent. As an important area of economic and social development, it is of great significance to achieve the goal of carbon neutrality in agriculture. Hunan Province, a major rice-growing province, is selected as the research object to explore the spatial differences and dynamic evolution characteristics of rice ecosystem carbon neutrality used the methods of Theil index and Markov chain. The research conclusions are as follows: (1) the rice ecosystem in Hunan Province has achieved carbon neutrality and is in a carbon surplus state. But Spatial differences of carbon neutrality are evident and regional differences dominate in Spatial differences. (2) Time evolution of carbon neutralization is strong stability, and there is a phenomenon of "path dependence". At the same time, carbon neutrality has typical spatial dependence characteristics. In the low-to-medium-high spatial lag state, it has a positive radiation-driven effect on the neighborhood environment, and the radiation-driven effect is proportional to the spatial gap. (3) In the future, the rice ecosystem needs to make further efforts in the four aspects of carbon reduction and carbon control, ecological sink increase, regional cooperation, and transaction income generation, and fully coordinate the relationship between the agricultural carbon peaking and carbon neutrality goals, food security and farmers′ income increase. It can help the process of carbon peaking and carbon neutrality to some extent.

Based on the carbon emissions and social-economic data of 62 counties in Zhejiang Province from 2014 to 2020, the spatial dependence and agglomeration of county-level carbon emissions are analyzed through the spatial auto-correlation test and local spatial auto-correlation test respectively. According to the spatial-temporal characteristics of county-level carbon emissions revealed by the index of Moran′s I and Local Moran’s I, the spatial error STIRPAT model is used to study the influencing factors of county-level carbon emissions in Zhejiang Province, China. The main results are as follows: (1) The total amount of county-level carbon emissions in Zhejiang Province fluctuates and shows a growth trend. (2) County-level carbon emissions have a significant spatial correlation, and the spatial agglomeration trend is relatively stable, which is consistent with the hypothesis of the geographical polarization effect. (3) High-high agglomeration counties are concentrated in the northeast of Zhejiang Province, while low-low agglomeration counties are mainly in the southwest. (4) The relationship between county per capital GDP and carbon emissions has not been "decoupled"; the low-carbon effect brought by large-scale industrial development as well as scientific and technological innovation has not yet appeared. (5) The carbon emissions of a single county is positively affected by the carbon emissions of the neighboring counties, and other social-economic factors affecting carbon emissions among counties also have a spatial correlation. Therefore, the policy of realizing regional coordinated development and the carbon peaking and carbon neutrality goals should not only focus on industrial layout, but also pay attention to dynamic and comprehensive consideration from a spatial perspective.

The purpose of this study was to explore the change of flow characteristics of sloping farmland under heavy rainfall conditions in arid valley. In this study, Hanyuan County as the research area, using artificial simulation precipitation experiment. Three different precipitations (1.0, 1.5 and 2.0 mm/min) and three different slopes (10°, 15° and 20°) were set in the experiment.The effects of different precipitation on hydraulic properties on cross-ridge slope and flat slope were investigated.The results showed that with the increase of rainfall duration, the erosion sediment yield of all slopes increased firstly and then decreased. The resistance coefficient gradually decreases and then tends to be stable. The runoff shear force and unit runoff power increase gradually with time and then maintain a relatively stable state.With the increase of rainfall, sediment yield, runoff shear force and unit runoff power of cross-ridge slope increased by 4.43～38.96 times, 0.49～3.40 times and 0.64～1.50 times respectively. On the flat slope, the sediment yield increased by 1.46～1.81 times, the runoff shear force increased by 0.94～1.30 times, and the unit runoff power increased by 0.11～0.52 times.Under different experimental conditions, the erosion sediment yield rate and runoff shear force of cross- ridge slope were significantly lower than those of flat slope, and the resistance coefficient and unit runoff power of cross- ridge slope and flat slope were different, but there was no obvious regularity. As precipitation increased from 1.0 mm/min to 2.0 mm/min, the runoff pattern on all slopes changed from "laminar slow-flow zone" (Re< 500, Fr< 1) to "turbulent slow-flow zone" (Re> 500, Fr< 1). In summary, under the condition of heavy precipitation, hilly croplands with different slopes can effectively control the process of water and sediment by cross ridge measures, thus achieving good sediment reduction benefits.

Providing effective treatment for rural domestic sewage is a significant challenge in supplying public goods to rural areas. In recent years, funding shortages have made it difficult to sustain operations for rural domestic sewage treatment facilities. To promote the development of a beautiful and livable countryside and support rural revitalization, it is essential to determine whether farmers are willing to pay for these services. This study focuses on the Lashihai watershed in Yunnan Province as a case study and uses the contingent valuation method to estimate farmers’ willingness to pay for rural domestic wastewater treatment. The study also identifies the factors that influence farmers’ willingness to pay by employing a multivariate ordered logistic model. Finally, the study evaluates the cost-effectiveness of farmers’ willingness to pay based on operating costs. The findings reveal that most farmers have the willingness and ability to pay for rural domestic wastewater treatment, and their willingness to pay can cover the operating costs of appropriate treatment processes with low, medium, and high treatment effects. Additionally, the study shows the significant positive effects of farmer’s subject consciousness and income related to environmental improvement on their willingness to pay. Therefore, charging for rural domestic sewage treatment is justifiable both socially and economically, and the government should establish a farmer payment system to increase the funding source.

The evaluation of fish index of biotic integrity (F-IBI) is an important basis for ecosystem health assessment, and it is also a prerequisite for ecological restoration. In order to explore the impact on fish resources and habitats in the projectaffected area by the human disturbance, the study constructed a evaluation system ofF-IBI based on the 2020-2021 fish resources survey and historical data, and then evaluated the status of F-IBI and the degree of coercion.In general, the F-IBI has not change muchin the projectaffected area before and after the operation of Datengxia Project, and the evaluation grades were all at the "general" level.However, compared with historical data, the number of rare and endemic fish species has decreased significantly and the number of alien species has increased of the current survey; and then, the F-IBI in the reaches of the reservoir and typical tributarywere better than that of the reservoir area and the lower reaches of the dam. So, it’s necessary to Long-term evaluate the changes of F-IBI, for identify the ecological impact caused by Datangxia Project and the effect of ecological protection measures. Meanwhile, we should implement some measures such as habitat restoration, ecological scheduling and alien species prevention and control, to improve the level of ecological health.

Green development of agriculture is the inherent requirement of rural revitalization strategy, and the digitalization of rural development is the strategic direction of rural revitalization. Exploring the synergistic and interactive relationship between the two is an important issue that needs to be solved urgently for the achievement of rural revitalization in the current new era. According to the research, a comprehensive evaluation system is constructed based on the connotation and coupling mechanism of the two, the development level of digitalization and greening of Chinese agriculture from 2010-2019 is quantitatively calculated based on the coupled and coordinated relative development degree model, and the coupled and coordinated characteristics of spatio-temporal pattern evolution is analyzed. Research shows that (1) during 2010-2019, the digitalization level of Chinese agriculture has been steadily increasing, showing an overall spatial distribution pattern of “highly digitalization in the southeast, lowly digitalization in the northwest”, and the digitalization gap between the east and west is gradually narrowing. The greening level of Chinese agriculture shows a robust upward trend, and the difference in greening level of agriculture between regions is gradually narrowing. (2) The coupling and coordination degree of digitalization and greening of Chinese agriculture is on an upward trend, and the area with high value of coupling and coordination degree is mainly distributed in the area east of Hu Huanyong line. Digitalization is the key direction for future optimization in the area west of Hu Huanyong Line, and greening is the key direction for development in the area east of Hu Huanyong Line. (3) The spatial differentiation of the coupling and coordination degree of digitalization and greening of Chinese agriculture is the result of a combination of multiple factors, among which the innovation level and economic level are the core influential factors. Based on this, the government should speed up the construction of rural digital infrastructure, improve the efficiency of utilization of agricultural resources, introduce targeted regional policies for the synergistic development of digitalization and greening of agriculture according to local conditions, and promote the digitalization to empower the development of modernization of agriculture.

Agricultural ecological efficiency is an important index to measure agricultural sustainability, which is one of the important issues affecting agricultural sustainable development in China. Based on the data of 9 provinces and 2 cities in the Yangtze River Economic Belt from 2008 to 2019, the undesirable two-stage network Super- NSBM model was used to measure the agricultural ecological efficiency and its stage efficiency, and the spatial and temporal characteristics and influence mechanism of regional agricultural ecological efficiency were investigated by using the kernel density analysis method and Tobit model. The results show that: (1) During the study period, the average agricultural ecological efficiency is less than 1, below the effective value, 0.932,0.845 and 1.117 7 in the upper, middle and down-stream, respectively, showing a trend of down-stream > upper stream > middle stream, with significant differences among provinces and cities. (2) From the regional perspective, only Jiangsu Province achieved DEA efficiency in two stages.Jiangxi, Guizhou, Shanghai and Sichuan are weak DEA efficient provinces. (3) Agricultural ecological efficiency and its stage efficiency are positively affected by agricultural mechanization level, agricultural planting structure adjustment, and negatively affected by the agricultural disaster rate. The degree of agricultural marketization and the level of financial support for agriculture have a positive impact on the efficiency value of the agricultural ecological governance stage.