As science and technology innovation resources gradually shift from a technology-driven and demand-driven linear model to a cooperative spatial network model,it is of great significance for regional science and technology innovation to explore the characteristics of its spatial pattern and network structure,and analyze the reasons for its formation.This paper uses the Arcgis visualization and social network analysis method to analyze the spatial pattern and network structure character of science and technology innovation resources in the Yangtze River economic belt from 2004 to 2017.The results show that: (1)the sci-tech innovation resources aggregation ability of the Yangtze River Economic Belt is gradually increasing, the polarization is serious, the gradient from east to west becomes weaker,and it have the characteristic of “leading-pursuing-following type” obviously;(2) the spatial network of Science and Technology Innovation Resources gathering ability is becoming more and more intensive,the network density presents the downward trend,the network grade,and the network efficiency present the upward trend;(3) the ability of sci-tech innovation resource aggregation of the top ten cities is more connected with other urban spatial networks, and plays a central and dominant role in the networks;(4)plate 1(33 cities including Shanghai and Nanjing) belongs to the “net spillover” plate,plate 2(26 cities including Chongqing and Chengdu) belongs to the “broker” plate,and plate 3(41 cities including Wuhan and Changsha) belongs to the “bidirectional spillover” plate Plate 4(Guiyang, Kunming and 29 other cities) is a “net beneficial” plate.According to the above conclusions,this paper puts forward some policy suggestions from the following aspects:vigorously develop new types of infrastructure,promoting scientific and technological innovation in core cities and promoting the construction of sci-tech innovation resources cooperation platform.

This paper constructs a “cost-capacity-energy efficiency” evaluation model for urban resilience, comprehensively using entropy method, principal component analysis method, SBM model, ESDA,K-means clustering method and GWR evaluate the resilience of 126 cities in the Yangtze River Economic Zone. The results show that: (1) Core cities show the “double high” of resilience cost and resilience capacity, while resilience efficiency is led by non-core cities. From the perspective of equilibrium, resilience cost and resilience efficiency have obvious horizontal hierarchy, while resilience capacity is relatively small among cities. (2) Based on the resilience cost, capacity, and efficiency index of each city, the resilience model can be classified into five categories and exhibit the following clustering characteristics: In terms of resilience level, cost and capacity gradually increase with the expansion of city size, but the efficiency gradually declines. The resilience model has obvious interregional differences between upstream, middle, and downstream. The upstream area is characterized by “low consumption, low capacity and high efficiency”, the middle reaches are “low consumption, low capacity, and medium efficiency”, and the downstream area is “high consumption, high capacity, and low efficiency”. In terms of resilience correlation, it has the dual interaction of vertical polarization in core cities and flat cohesion in general cities. (3) From the perspective of mechanism, the power consumption of the whole society, the area of built-up areas, and the expenditure on science and technology are the main cost factors that affect the resilience of cities. Cities with different resilience modes have different main control factors. The research has important practical significance for improving the urban resilience evaluation system, enriching the perspective of urban resilience evaluation, and promoting urban resilience construction.

Leading industries have a significant impact on the direction of regional industrial development, the composition of industrial structures, and the status and role of regional industrial division of labor in the country. Taking the national and provincial development zones along the Changjiang River bank as the survey object, with the methods of buffer analysis, text mining to analyze the type conversion and spatial pattern evolution of leading industries in the upper, middle and lower reaches along the bank within 0-5 km, 5-15 km and 15-30 km in 2006 and 2018. The results show that: (1) The manufacturing industry has always occupied the core position along the bank and high-polluting industries have gradually withdrawn from the near bank of the Changjiang River. The phenomenon of “Changjiang River surrounded by chemical industries” has improved, and the industrial upgrading trend is obvious. (2) The distribution of dominant leading industries is more stable which have the potential to build world-class industrial clusters, meanwhile the types of industries are becoming more diversified, and strategic emerging industries are growing rapidly. (3) The overall industrial distribution presents a gradual decline pattern from the near bank of Changjiang River to the outside, from the downstream to the upstream, but it shows a certain degree of regional balance. (4) The distribution of the types of leading industries in the upper, middle and lower reaches shows a gradient evolution, and it has the condition for industrial transfer, but there are certain risks of industrial competition at the same time.

The water front resources of the Yangtze River are important to support the socio-economic development along the Yangtze River. At the same time, they are at the border between water and land with irreplaceable ecological value. The purpose of this paper is to estimate the scale of the water front utilization of container ports in the mainstream of the Yangtze River and analyze the water front organizational structure and change characteristics of container ports by analyzing remote sensing images and related data. Based on this, various types of environmental protection areas are used as representative items to explore the impact of container port shipping on water front resources and the environment. Also, how to coordinate the rational organization of productive water fronts to achieve the unity of development and protection under the pressure of the Yangtze River resources for environmental pressure is discussed in this paper. The conclusions are as follows:The scale of the water front of the Yangtze River container port has increased significantly during the study period. The scale of container ports in the downstream region occupies the highest share in the region, while the utilization rate of the upper and middle regions is growing faster. The upper, middle and lower reaches respectively form a relatively dense distribution area of container ports and terminals. Large ports are often located downstream with a continuous development trend, while large or very large ports are only located in the central and upper reaches of the hub city. The development of container ports has a large-scale trend. The replacement of ports is mainly based on small-scale reductions, and the center of gravity of newly-built, reconstructed and expanded ports is inclined to large and medium-sized. The port water front continued to grow while accelerating the invasion of protected shore sections. The scale and proportion of the newly-occupied docks have reached a relatively high level, and many ports and docks have to be kept because most of the available shores in their cities are located in protected areas. Few of the demolished ports are directly related to the environment protection, and there are still a certain number of small and medium-sized ports located in the protected area. As a new type of water front utilization, the construction and operation of container ports should meet the requirements of environmental friendliness and reverse the opposite relationship between development and protection. The relationship can be summed up as two stages of conflict and mitigation. The conflict between ports development and protection is inevitable. The transport capacity of container ports occupying the protected areas has reached a considerable scale. However, during the study period, especially after 2015, the port expansion slowed down and the main direction was to improve the efficiency of water front utilization. The relationship between development and protection has eased. In the subsequent construction of container ports, it is necessary to make the overall use of the water front and correctly handle the relationship between development and protection. Meanwhile, various development activities must meet environmental protection requirements.

The change of the vegetation structure in Hubei Province is greatly affected by natural and human activities. Revealing the spatial change characteristics of the vegetation in Hubei Province is of great significance to the vegetation restoration and improvement. The spatial change and distribution pattern of the vegetation coverage in Hubei Province from 2000 to 2020 were analyzed based on MOD13Q1 NDVI data, and its response to climate change and human activities was revealed. The results show that: (1) From 2000 to 2020, the change of vegetation coverage in Hubei Province shows an overall increasing trend. The increasing areas were concentrated in the northwest of Hubei Province, Shiyan, Shennongjia forest areas and Suizhou;(2) There is vegetation degradation in some areas of Hubei Province, and the degradation area first increased and then decreased. From 2000 to 2005, the areas of the vegetation restoration and improvement in Hubei Province were mainly concentrated in its northwest and southwest, and the areas of vegetation degradation were distributed around Wuhan, Xiangyang, Xiantao and Huangshi; from 2005 to 2010, the overall vegetation coverage of Hubei Province was relatively poor, and the degraded areas were distributed around the cities in the northwest and southeast, especially in Shiyan and Wuhan were more obvious. From 2010 to 2015, the vegetation degradation areas in Hubei province kept to decrease, distributed in the East and northwest; From 2015 to 2020, the vegetation shows a downward trend;(3) The vegetation coverage in the northeast, southwest and Xiangyang of Hubei Province is positively correlated with local temperature and precipitation. With the increase of altitude, the proportion of the positive and negative correlation between temperature, precipitation, wind speed and vegetation coverage gradually decreased; (4) human factors have a positive impact on the ecological environment of Hubei Province, and promote the restoration of local vegetation; They caused negative impact to the surrounding cities of Wuhan, Xiangyang, Jingzhou and other regions mainly.

The phytoplankton sampling was conducted seasonally in the middle and lower Hanjiang River from July 2017 to May 2018. Community structure and the functional groups of phytoplankton were analyzed and water quality evaluated accroding to the phytoplankton functional group classification. A tatal of 145 phytoplankton species, belonging to 75 genera and 7 phyla, were identified during the study period. The dominant species of phytoplankton were species of Bacillariophyta. The density of phytoplankton ranged from 1.51×105 to 4.33×107 ind/L (7.57×106 ind/L in average). The biomass of phytoplankton ranged from 0.088 7 to 17.259 3 mg/L (4.849 5 mg/L in average). Twenty-three different phytoplankton functional groups were constructed in the middle and lower Hanjiang River, and the relative biomass of two functional groups, namely functional groups P and D, was more than 10%. The water quality was comprehensively evaluated by phytoplankton saprobie indicator, Shannon-wiener index and Qr value. Our results indicated that the water quality in the middle and lower Hanjiang River was slightly-moderately polluted. The water quality in summer was worse than in spring and summer.

Wushan Lake is a highly eutrophic, shallow lake connected to the Yangtze River by channel, and a national wetland park. In order to study metazooplankton structural characteristics in the lake stocked densely with silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis), we conducted a field survey on the metazooplankton community and lake trophic status from September 2017 to August 2018. A total of 61 metazooplankton species (genera) were identified including twenty-four species of Rotifer, twenty-three species of Copepods and fourteen species of Cladocera. Thirteen dominant species including twelve species of Rotifer and one species of Copepods were observed. The percentage of Rotifer of the total abundances was more than 70% in 11 months of the year, while Copepods and the Cladocera abundance accounts for a small percentage of the year. The percentage of Rotifer of the total biomass was more than 80% in 10 months of the year. However, the percentage of Copepods increased after winter-fishing, constituting 20.1%, 79.2% and 51.8% of the total biomass in December, January and February, respectively. Redundancy analyses showed that temperature, Chl a and pH were important factors determining the structures of metazooplankton communities. Our results showed that the metazooplankton were mainly Rotifers and the size of Cladocera and Copepods is small in Wushan Lake.

In order to understand the current status of fish assemblages in the Three Gorges Reservoir, both species composition of fish in the mainstream and nine important tributaries of the Three Gorges Reservoir, and fishery resources in the upper (Mudong section), middle (Yunyang section) and lower (Wushan section) reservoir were investigated, from 2017 to 2019. The changes of fish assemblages before and after impoundment were also analyzed by comparing the present results with other published data. A total of 149 fish species, belonging to 10 orders, 25 families and 92 genera, were collected in the Three Gorges Reservoir, of which 30 species were endemic to the upper reaches of the Yangtze River, 20 species were exotic, 67 species were rheophilic and 82 species were non-rheophilic. Compared with historical records of fish species before the impoundment of the Three Gorges Reservoir, the total number was similar. However, the species composition of fish has undergone a remarkable change after the impoundment. The number of both native and rheophilic species dropped notably, whereas that of exotic species increased remarkably. Small-sized fishes accounted for a great proportion in fish catches, while the catches of the middle and large sized fishes declined severely. Rheophilic species only dominated in the catches of the upper reservoir, while non-rheophilic species were dominant in the middle and lower reservoir. Both the number and resources of the endemic species were reduced significantly in the mainstream of the Three Gorges Reservoir, whereas a certain number of endemic species still exist in the tributaries. Exotic species constituted a considerable proportion of fish catches in the middle and lower sections of the reservoir, which suggests that the high abundance and dispersion of these alien species may bring noticeably negative influence to the survival of native species. In conclusion, fish assemblage of the Three Gorges Reservoir has been changed to a great extent by the impoundment.

Fishery regulation is an important instrument to carry out the development strategy of the Yangtze River Economic Belt i.e. “To Prioritize joint protection and to avoid grand exploitation”.It is helpful for better policy making and implementation of fishery regulation such as restriction and prohibition to understand the impact of ecological cognition of fishermen on their willingness to quit fishery or accept compensation. Based on the field survey data and using the theory of planned behavior and structural equation model, this paper discusses the effect of ecological cognition on fishermen’s willingness to participate in the fishery limitation program. The study results show that: (1) ecological cognition has a significant positive effect on fishermen’s willingness to participate in the fishery phasing out program (2) all the three dimensions of ecological cognition, including subjective norms, behavioral attitudes and perceived behavioral control, have significant positive effects on fishermen’s willingness,and there are also significant positive effects between each two of the three dimensions. Among them, subjective norms have the most significant influence on fishermen’s willingness. （3) the mandatory norms in the subjective norms have a greater driving effect on fishermen’s participation in the program than the model norms. The behavior attitude is greatly influenced by the fishermen’s psychological expectation of the government’s no-fishing policy and by the relative recognition of the importance of ecological restoration and protection versus economic development. Perceived behavior control is mainly affected by the impact of the policy on household production and livelihood, and the ability of fishermen to participate in the policy. The policy implication of this study is that it is imperative to establish effective supervision and management system, to employ more mandatory norms in persuading fishermen to participate the program, and to improve fishermen’s cognition of the importance of ecological protection in the Yangtze River Basin. It is also important to nourish the culture and awareness of ecological protection in the river basin to encourage them to actively participate in activities. At the same time, it will be helpful to formulate the alternative livelihood policies and carry out these policies to each of the households affected with sufficient compensation and transparency, which will translate into fishermen’s trust and confidence in the government and finally raise their willingness to participate the government program in fishery regulation.

The environmentally friendly behavior of tourists is of great significance to the environmental protection and sustainable development of tourist destinations. The fit of tourism environment and local attachment have an important impact on the environmentally friendly behavior of tourists. Based on the tourism environment fit degree theory, this study uses the world heritage site Wulingyuan as the data survey place, and through a questionnaire survey of more than 1 000 tourists who are or have been traveling in Wulingyuan,, AMOS structural equation model is used for multilevel hypothesis test and intermediary effect test, to clarify the impact mechanism of tourism environment fit on tourists’ environmental behavior. Study has shown that the direct influence of tourists ’environmental compatibility on tourists’ environmental behavior is not significant. The degree of tourism environmental fitness positively affects local attachment, and local attachment also has a positive impact on environmentally friendly behavior. Local attachment plays an intermediary role between tourism environment fit and pro-environmental behavior. Based on these, it puts forward management suggestions to the scenic spots of the heritage sites, guides tourists’ environmental-friendly behavior, and promotes sustainable tourism development.

The Duhe River Basin is an important water source in the middle line of the South-to-North Water Transfer Project. The ecological environmental status of the basin is the significant factors affecting the economic benefits and water quality of the project. Based on the MODIS image production (2001-2017), digital surface model (DSM) and meteorological data, this paper analyze the spatio-temporal distribution and influencing meteorological factors of gross primary production (GPP), normalized difference vegetation index (NDVI) and evapotranspiration(ET) in Duhe River Basin using the mean statistical method, the linear regression trend method and the correlation analysis method. The results show that: (1) The monthly average GPP, NDVI and ET in the Duhe River Basin is 1 868.667 gC/(m ²·month^-1 ), 0.605, and 959.975 mm/month respectively. The spatial distribution of the mean annual average GPP, NDVI and ET present a similar result. The value of GPP, NDVI and ET in the basin’s north part is smaller than that in the basin’s south area. The lowest value is distributed in the Zhuxi River Basin, and the highest value is distributed in the high-altitude mountainous areas. (2) The annual average NDVI, ET, and GPP values develop in fluctuation and show an upward trend in general, which indicates that the ecological environment of the basin is improving and developing. The value of NDVI, ET, and GPP is the highest in summer, reaching the maximum in July, and the lowest in winter. (3) The monthly average GPP, NDVI and ET have strong positive correlation. The correlation coefficient between monthly average NDVI and monthly average ET has a same value with the correlation coefficient between monthly average NDVI and monthly average GPP(R2 = 0.65). The correlation coefficient between monthly average and monthly average ET is 0.70. (4) Compare with monthly average temperature, the monthly average GPP is more relevant with monthly average precipitation. The monthly average NDVI and ET have higher correlation coefficient with temperature than does precipitation. The variation tendencies of NDVI, ET and GPP in the basin are consistent with the temperature and precipitation. The response of NDVI, ET and GPP to the climatic factors is less than one month.

The quality of the ecological environment in Poyang Lake region hold special significance for the ecological functions and biodiversity protection to Poyang Lake-an important wetland and ecological area over the world. Based on the remote sensing image data of Poyang Lake region in 1995, 2005, and 2015, this paper uses the InVEST model to analyze the temporal and spatial evolution of the habitat quality around the lake region; then calculating and analyzing the probability density function and cumulative distribution function of habitat degradation by pixel dichotomy for ascertaining the threshold of habitat degradation in the lake region; finally discussing the changes in habitat quality advantages of different ecological types with standard deviation ellipse analysis method. The results show that: （1)The construction land and water in Poyang Lake region increased significantly from 1995 to 2015; while the cultivated land, the grass land and the forest land decreased slightly.（2)The strong disturbance thresholds of cultivated land, woodland, grass land and water habitats in Poyang Lake region are 70%, 85%, 81%, 78% of their respective habitat suitability. The disturbance of waters, woodlands, and grasslands is getting stronger, while the disturbance of farmland is getting weaker. （3)Habitat quality in Poyang Lake region declined slightly from 1995 to 2015. The waters in the central area and the woodland in the northern area have weaker interference, higher regional habitat quality is mainly distributed in these areas; the outer edge of the central area has average habitat quality; while the cultivated land in the southwest has strong interference and the habitat quality of the region is low. The evolution from high-quality habitats to low-quality habitats is severe. （4)The change of cultivated land reflects the strictness of the protection policy to cultivated land; the change of forest and grassland is affected by topographic gradient factors; and the change of waters is affected by the combination of lake reclamation and urban expansion, which reveals the limitations in explaining the evolution of wetland water habitat quality only in the land use level. The research results have certain theoretical significance and practical value for the ecological environment protection and ecosystem regulation of Poyang Lake region.

The Three Gorges Reservoir Area is a region with sensitive, fragile and complicated ecological environment in the upper reaches of the Yangtze River. The construction of its ecological security pattern plays an important role in maintaining regional ecological security and achieving regional sustainable development. In this study, the Chongqing section of the Three Gorges Reservoir area was used as the research area, using 2018 land use status data and remote sensing data to build an evaluation system of the importance of ecological services and ecological sensitivity to comprehensively determine ecological source areas; Determine the resistance value and use the minimum cumulative resistance model to build an ecological corridor to form an ecological security pattern in the Chongqing section of the Three Gorges reservoir area. The research results show that the ecological source area of the Chongqing section of the Three Gorges Reservoir area is 13 660.80 km ², accounting for 29.61% of the total area of the study area, which is mainly distributed in Wuxi, Fengjie, Shizhu, Kaizhou and other counties; 81, with a total length of 3 069.29 km, the corridors are distributed in a tree-like radiation, showing the spatial pattern of "Northeast-Southwest" tree-like distribution; The ecological security pattern of "one corridor and two circles" in the northeast of the Three Gorges Reservoir, the southwestern urban ecosphere of the Three Gorges Reservoir, and the central corridor connecting the two gorges is formed by the ecological source and the corridor. The results of the study are of great significance to the protection of the ecological safety of the Three Gorges Reservoir area and can provide a scientific basis for the environmental protection of the Three Gorges Reservoir area.

Statistical downscaled and bias corrected climatic outputs of four global climate models (GFDL-ESM2M, HadGEM2-ES, IPSL-CM5A-LR, MIROC5) under historical simulation experiment (1861-2005) and RCP4.5 scenario (2006-2018) are used to drive the SWAT hydrological model to analyze the climate change and its impacts on river runoff in the Wujiang River Basin (WJRB). Meanwhile, pre-industrial control experiment (piControl) for 1861-2018 from four GCMs is also used to compare the differences of climate and streamflow changes in the WJRB under the ‘natural’ forcing and the ‘anthropogenic+natural’ forcing. Following results are reached: (1) according to the multi-model ensemble mean, annual mean temperature in the WJRB for 1861-2018 has shown an significant upward trend with a rate of 0.03℃/10a, and annual precipitation has shown a significant downward trend with rate of -10.9mm/10a. The annual average discharge has shown a significant downward trend with a rate of -20.8 m ³/s/10a. Seasonal average discharge has shown declining trend with rates of -10.8 m ³/s/10a, -46.1 m3/s/10a, -20.1 m3/s/10a, and -5.9 m ³/s/10a, respectively, for spring, summer, autumn and winter. Trends of all seasonal average discharge were statistically significant. Significant decreasing trend was detected with rate of -7.6 m ³/s/10a and -43.5 m ³/s/10a, respectively, for low flow (Q90) and high flow (Q10). (2) Under the ‘nature’ forcing, no obvious trend was detected for annual mean temperature in WJRB for 1861-2018, and an insignificant upward trend was found for annual precipitation with rate of 1.9 mm/10a. The annual average discharge was in a slight positive trend with rate of 0.1 m3/s/10a. Insignificant decrease trend was detected with rate of about -1.1 m ³/s/10a for spring average discharge, while significant one was detected with rate of about -18.6 m ³/s/10a for summer average discharge. Autumn and winter average discharge has shown increasing trend with rate of 11.0 m ³/s/10a and 8.9 m3/s/10a. The trend of autumn average discharge was statistically unsignificant, while winter average discharge was statistically significant Change of extreme discharge was insignificant, and rate of change was 2.5 m ³/s/10a and -9.5 m ³/s/10a, respectively, for low flow and high flow. (3) With relative to the ‘natural’ forcing, seasonal average discharge decreased 7.1%、9.7%、8.7%、11.9% , respectively, for spring, summer, autumn and winter, and decreased 9.3% and 5.0%, respectively, for low flow and high flow for 1861-2018.

To analyze the hydrochemical types and the degree of heavy metal pollution in surface water of Amu Darya Basin, the water chemical parameters and the concentration of trace metals in the basin were studied. Results showed that the hydrochemical types and metal concentrations of surface water in the study area displayed significant spatial variations. Ca-HCO3 type (type I), with the lowest metal concentrations, was found near the mountain-pass, and controlled by rock weathering and atmospheric precipitation. While the Ca-Mg-Cl-, Na-SO4-Cl-, and Na-Cl types (type III), with the highest metal concentrations, distributed in the estuary or near urban and were dominated by evaporative crystallization. The Ca-Mg-SO4 type (type II) was observed in the middle and lower reaches of rivers, and dominated by rock weathering. Furthermore, by using the method of Nemerow index, the comprehensive pollution degree of heavy metals (As, Hg, Cd, Pb, Cr, Cu) in surface water was evaluated. The Pn mean values of type I and type II surface water were 0.28 and 0.18, respectively, indicating the safety level. However, the Pn mean value of type III was close to 0.7, which was significantly higher than that of others, and the values of Pn were greater than 1 in some water samples of type III, indicating relatively heavy pollution. The results of risk assessment had a good consistency with the spatial distribution of hydrochemical types, which were affected to varying degrees by human activities in this studied area. In general, the level of heavy metal pollution in surface water of Amu Darya Basin is relatively low, suggesting low risk.

In order to reveal the diurnal variation of surface soil respiration and its influencing factors in the dolomite region of Shuanghedong National Geopark, Suiyang, Guizhou. In this study, the soil respiration measurement system (SRS-SD2000, ADC, UK) was used to monitor the four different land use methods of shrub forest, bamboo forest, dry land and artificial grassland in the karst area of Shuanghedong National Geopark without the influence of precipitation The characteristics of the diurnal variation of the surface soil respiration flux, combined with environmental parameters such as soil temperature and humidity and atmospheric temperature and humidity, explore the key factors affecting the diurnal variation of soil respiration. The results showed that the soil respiration rates of the four different land use patterns all showed a unimodal pattern of “the day is high and the night is low”, with the maximum daily variation occurring 12∶00-14∶00 and the lowest occurring at 5∶00-7∶00; the soil respiration rate and soil temperature in each plot showed a significant positive correlation (P<0.001), and the soil respiration rate in shrubbery land, bamboo forest, and dry land had a significant negative correlation with soil moisture (P<0.001), there is a low correlation between soil respiration and soil moisture in artificial grassland (P<0.05); air temperature is the key factor affecting the change of soil respiration rate. The measured data show that soil respiration will not continue with the temperature after reaching the peak There are differences in the day and night response characteristics of soil respiration rate to soil temperature and humidity.

Based on the microscopic data of 1710 farmers in Hubei province, this paper empirically analyzed the impact of land fragmentation on farmers′ environment-friendly technology adoption decisions using Double-Hurdle model. The main research conclusions are as follows: (1) In general, land fragmentation has a negative impact on the decision that whether farmers adopt environment-friendly technology and density decision. (2) For men and farmers with low self-efficacy perception, land fragmentation has a negative impact on the adoption decision and density decision; However, there was no significant effect on women and farmers with high self-efficacy perception. (3) Land fragmentation has a negative impact on the adoption decision for farmers with strong social network, but has no impact on the density decision. Land fragmentation has a negative impact on the adoption decision and density decision for farmers with weak social network. (4) Land fragmentation has negative influence on the density decision for low agricultural income dependent farmers and the adoption decision for high agricultural income dependent farmers, but has no influence on the adoption decision for low agricultural income dependent farmers and the density decision for high agricultural income dependent farmers. (5) Land fragmentation has no influence on the adoption decision, but has an influence on the density decision for farmers living in plain areas. Land fragmentation has a negative influence on both the adoption decision and density decision for farmers living in non-plain areas. Therefore, this paper suggests that the policy of promoting the construction of high-quality farmland and encouraging farmers to adopt environmental-friendly technologies, which should fully consider the heterogeneous influence of farmers and implement precise policies, and also consider the effects of different natural environment characteristics (such as topography), adopting differentiated incentive strategies for farmers in plain and non-plain areas.

Based on the survey data of farmers in Shaanxi, Gansu, Ningxia and Qinghai provinces, this paper empirically analyzes the influential effect of household borrowing and land scale on farmers′ willingness of land management, and analyzes the choice of farmers′ land management behavior from the perspective of differentiation. Results show that:(1) Household borrowing is an important inducement to stimulate farmers′ business demand for land management  and has a significant positive effect on the transfer of land management right.(2) The land scale has a significant influence on the transfer willingness of farmers′ land management right, which is different with the scale differentiation. Compared with small farmers, the medium farmers and large farmers have the strongest willingness to transfer out the land management right,but weakest willingness to transfer into it. (3) The land management income has the most sensitive positive effect on farmers′ land management willingness. It can be considered that the steady growth of land management income and the continuous improvement of its guarantee system are the basic support for farmers to engage in land management and development. This paper to a certain extent expands the theoretical explanation of economies of scale and efficiency in neoclassical economics, and provides effective references and suggestions for the agricultural development mode to promote the moderate scale of farmers’ land management and improve the comparative income.

Based on the theory of social embeddedness and reputation mechanism, using the survey data of 560 households in Hubei、Hunan and Anhui, the structural equation model was used to empirically analyze the influencing path and group differences fo network embeddedness and reputation on farmers’ pro-environment behavior, robustness test about the structural equation model had been done by variable substitution and multivariate statistical regression analysis. It was found that (1) Network embeddedness and reputation have significant positive effects on farmers’ pro-environment behavior, and reputation plays intermediary role on the influence of structural embeddedness and cognition embeddedness on farmers’ pro-environment behavior, while reputation was the fully mediator between relationship embeddedness and farmers’ pro-environment behavior. (2) The influence of adoption degree on farmers’ pro-environment: cognition embeddedness was greater than structural embeddedness, structural embeddedness was greater than relationship embeddedness. (3) The actual land area operated by the family has significant effect on the influence of network embeddedness on farmers’ pro-environment and enhance the mediation. So governments should pay attention on the establishment of reputation mechanism, and guide large-scale farmers’ pro-environment,providing demonstration effect for small-scale farmers. Meanwhile, governments should also create chances and platform to learn and cooperate for farmers.

Controlling cropland non-point source pollution plays an important role in the battle of agricultural and rural pollution prevention and control in China. Strengthening cropland non-point source pollution control is conducive to promoting the transformation of agricultural development mode, and achieving the sustainable utilization of cultivated land resources. Farmers are the main body of micro decision-making in agricultural production, whose willingness to accept is the key to their effective participation in cropland non-point source pollution control. Based on 353 questionnaires of farmers in the Dongting Lake Basin, this paper analyzed the mechanism of action among farmer differentiation, ecological cognition, and farmers’ willingness to accept for cropland non-point source pollution control with the PLS-SEM method. The research shows that: (1) Farmer differentiation has a significant positive impact on the willingness to accept. Besides, the farmers with a high degree of differentiation have a higher willingness to accept; (2) Ecological cognition plays a mediating role in the process of the impact of farmer differentiation on the willingness to accept for cropland non-point source pollution control. Farmer differentiation can positively affect farmers′ ecological cognition, and then enhance farmers′ willingness to accept for cropland non-point source pollution control; (3) Farmers’ age and labor ratio have a significant impact on their willingness to pay for participating cropland non-point source pollution control. Therefore, it is necessary to understand the interests of farmers, formulate reasonable compensation policies for cropland non-point source pollution control and improve farmers’ ecological cognition for arising farmers’ enthusiasm for participating in cropland non-point source pollution control.

Based on the panel data of 30 provinces (cities and autonomous regions) in the mainland of China from 1978 to 2016, this paper analyzes the temporal and spatial changes of agricultural machinery technology input and agricultural irrigation technology inputs in rice production in China, and uses the panel threshold regression model to empirically analyze the impact of the two technologies in rice production in China. The results show that the increase of agricultural machinery technology factor input is greater than that of agricultural irrigation technology factor input. The provinces with both increasing are mainly located in the north, with the biggest increase in northeast China and the biggest decrease in south China. The impact of agricultural machinery and agricultural irrigation technology input in rice production in China has the same double threshold, 1981 and 1989. But the action paths of two kinds of technology impact on rice production are not the same. Agricultural machinery technology input is from the initial mismatch with rice production reality leading to the excess to the increasing effect on rice production. However, the impact of agricultural irrigation technology factor input on rice production is always positive and the impact degree is increasing. Therefore, the development policy of agricultural production technology elements should be implemented differently to improve the utility level of agricultural technology and ensure the national food security.

Quantitative research on the spatiotemporal variation of drought is of great significance for regional drought monitoring and disaster reduction. Using the meteorological observation data of 26 meteorological stations in Poyang lake basin from 1961 to 2017, spatiotemporal variation of drought is analyzed by means of the standardized precipitation evapotranspiration index (SPEI). The results show that: (1) The Poyang lake basin presents wet in the south and dry in the north, and obvious differences are showed in the four seasons. (2) The annual SPEI of Poyang lake basin shows a significant wetting trend(p<0.05).The four seasons presents a wetting trend, the summer and the winter rises notably(p<0.05). From the perspective of spatial variation, the annual scale of all the stations show a wetting trend, especially in the central and the north. The Poyang lake basin represents a wetting trend except for some stations in the northwest of Ganjiang basin and the eastern of Raohe basin and Xinjiang basin in spring and some individual stations (Dexing、Suichuan and Longnan) in autumn, but there are certain differences in the increase rate and the significant level. (3) There are significant inter-decadal differences in the occurrence of different levels of drought in Poyang lake basin. In addition to the low frequency of drought in the 1990s and the last decade, the frequency of drought in other decades were relatively frequent, especially in the 1960s. (4) The SPEI of Poyang lake basin is positively correlated with precipitation but is negatively correlated with temperature. The correlation between SPEI and precipitation is higher than that of temperature. The change of SPEI is driven by the global scale of Air-Sea Interaction, with a half year lag effect.

This paper analyzed the water vapor transportation of the heavy rainstorm in western Sichuan Basin during August 14-17, 2020 by using meteorological data from a weather station 5001 in Sichuan Province, the global data assimilation system (GDAS), and the reanalysis data from national centers for environmental predication (NCEP). The Lagrange mixed single particle orbit model (HYSPIT4) is used in the analysis. The analysis results show that the heavy rainstorm has obvious diurnal variation, and the precipitation at night is severe with 4 peaks. In the initial stage of the heavy rainstorm, the water vapor mainly came from the Bay of Bengal, and with the precipitation event continues, the water vapor from the eastern Arabian Sea, the southern Bay of Bengal and the Gulf of Thailand was continuously transported to the Sichuan Basin. According to the quantitative analysis of the contribution of different water vapor sources, the Bay of Bengal was the dominant water vapor source, followed by the Arabian Sea, and the Gulf of Thailand was the lowest.

PM _2.5 exerts significant impact on the regional environment and human health. Huaihai Economic Zone serves as a core that supports the development of the eastern coastal economic development zone so the analysis of its temporal and spatial characteristics of PM _2.5 and its influencing factors are of great significance to carry out the joint prevention of regional air pollution in the Beijing-Tianjin-Hebei region and the Yangtze River Delta urban agglomeration. Firstly, this paper uses time series analysis to analyze the characteristics of PM _2.5 concentration in the study area. Secondly, spatial analysis is used to analyze the temporal and spatial characteristics of PM _2.5 in the Huaihai Economic Zone. Finally, this paper further explores the influencing factors of PM _2.5 concentration and its spatial heterogeneity by using a geographical weighted regression model based on the spatial autocorrelation characteristics of PM _2.5 in the Huaihai Economic Zone. The results show that: (1)The daily PM _2.5 concentration in Huaihai Economic Zone shows a periodic pulsed fluctuation rule, and the overall trend is “U” shaped, high in winter and autumn and low in spring and summer. The oscillation period of daily PM _2.5 concentration is 2-3 days in a short period and 6-7 days in a long period. (2)The spatial local correlation of PM _2.5 concentration in Huaihai Economic Zone shows a periodic changing rule. Hot spots throughout the year are mainly concentrated in Heze City in the northwest and Xuzhou City in the southwest of the study area while cold spots are mainly in coastal areas. (3)The influencing factors of PM _2.5 concentration in Huaihai Economic Zone mainly include average air temperature, average precipitation, average wind speed, proportion of forest land and road network density. Different factors have significant spatial heterogeneity on the influence of PM _2.5 concentration.