Coordinating the relationship between economic growth and land development is a key to improving the quality of economic growth as well as sustainable city.To explore spatial-temporal coupling characteristics of urban land expansion and economic growth, this paper adopts methods of Tapio decoupling index and the shift of gravity center to measure the spatial coupling relationship. Meanwhile, an econometric model is employed to test the influence of socioeconomic factors on urban land expansion. Results show that both economy and urban land area continue to grow. Urban land area of the central and western regions presents more significant increase. Gravity centers of urban land and economy shift to southwest gradually. However, spatial coupling relationship between economic growth and urban land expansion is gradually weakening. The decoupling condition continues to deteriorate. The distribution patterns of decoupling relationship changes significantly. The decoupling condition of the eastern region is generally improved. Social and economic factors are key drivers of urban land expansion. Factors of policy and industrial agglomeration also prompt urban expansion. Control of urban land expansion in the central and western regions should be further strengthened in the future. For the eastern region, a convergence of industry and land-use transformation needs to be sought and pursue a smart growth.

In order to reveal the characteristics of temporal and spatial patterns of interprovincial carbon compensation in China,this paper improves the calculation model of carbon compensation based on absolute carbon deficit, and constructs the calculation model of carbon compensation based on relative carbon deficit.The result of research shows that (1)The total amount of carbon compensation in China showed a downward trend, presenting a significant feature of stage from 2007 to 2017, which was mainly affected by the new normal of China’s economic development and the continuous slowdown of GDP growth across the country.(2) From the perspective of various provinces (cities) in China: The provinces (cities) with the highest carbon compensation mainly includes Shanghai, Liaoning, Jiangsu, Tianjin, Shandong, Zhejiang, Shanxi, and Beijing, while the provinces with the lower carbon compensation are Inner Mongolia, Xinjiang, Guangdong, and Heilongjiang. (3)The hot spots areas of China’s carbon compensation are mainly distributed in the eastern coastal regions such as Jiangsu，Zhejiang and Shanghai,while the cold spots areas are mainly spreaded in both the northwest regions like Gansu ,Qinghai and Xinjiang and the northeast regions like Heilongjiang and Jilin. The overall amount of carbon compensation shows a decreasing spatial pattern from the the eastern coastal areas,Beijing-Tianjin and the northern coastal areas to the periphery, showing that the economically developed regions pay compensation to the economically underdeveloped regions. Moreover, the space pattern of carbon compensation in China changed little from 2007 to 2017, that is to say,the space pattern of carbon compensation has the feature of “inertia”.

The Yangtze River Economic Belt is one of the most conflicted areas in China when it comes to economic development and environmental protection. It’s the key problem to be solved that realizing the dynamic coordination between regional economy and environmental system in the process of sustainable development of the region in the future.The analytical frameworks that “scale-structure-efficiency” for economy and “pressure-state-response” for environment are constructed respectively. The spatial and temporal patterns of the coordination between economy and environment in the Yangtze River Economic Belt from 2007 to 2016 are systematically investigated by entropy method, GIS and coupling coordination degree evaluation model. And the problem areas of coordinated development are also classified and identified. The results show that: （1)The economic level of the Yangtze River Economic Belt almost doubled from 2007 to 2016, which demonstrates the rationality of its position of the main support belt for China’s economic development. At the same time, the pattern of economic level that “high in the east and low in the west” is stable and its path-dependence are obvious. (2）From 2007 to 2016, the environmental level of the Yangtze River Economic Belt and its rate of improvement are still relatively low, which proves the importance of environmental protection in the Yangtze river. Meanwhile, the environmental level show more of “random” characteristics than obvious law in spatial distribution.(3）There is a steady rise of the coordinated development degree between economy and environment in the Yangtze River Economic Belt from 2007 to 2016.Its coordinated index increased from 0.446 8 to 0.602 3, which means it entered the primary coordination stage from the stage of near imbalance. The index presented the overall pattern in space that a descending order of the eastern region、the central region and western region. (4）Based on the combinations among three kinds of data of economic, environmental and coupling degree, the problem areas of coordination development are divided into six basic types to identify. It is found that there are more than 30 problem areas in each research year, in which related to lagging economic occupies an absolute proportion.

The scientific of water pollution-intensive industry layout is the basis and premise of water resources protection effectiveness in the Yangtze River Economic Belt. By defining 12 industries as water pollution-intensive industries, using the deviation share, Gini coefficient and location quotient to analyze the spatial and temporal evolution characteristics of the water pollution intensive industries in the Yangtze River Economic Belt , Furthermore, we establish the panel regression model to analyze its influencing factors from the influence of traditional geographical location factors, new economic geography factors and institutional factors. The study found that: (1) From the time trend: the proportion of water pollution-intensive industries to total industrial in the Yangtze River Economic Belt’s value has gradually declined, but the proportion of pollution-intensive industries in the country has declined slightly. The industry shift share results show that the industry development of water pollution-intensive industries has differentiated between 2003 and 2016. The chemical industry is in the situation of recession, The problem of “chemical surrounding the river” is gradually improving. (2) From the characteristics of spatial evolution: the Gini coefficient shows that the water pollution-intensive industry is spreading. The location quotient and regional shift share further verified that the water pollution-intensive industries have a tendency to transfer and spread from the downstream to the middle and upper reaches, especially in the midstream areas with good industrial bases.（3）Economic factors, labor costs, and infrastructure are the main factors driving the spatial layout of water pollution-intensive industries in the Yangtze River Economic Belt.

The highway network density, the influence degree of the traffic trunk line and the location advantage degree are used as the evaluation indexes, and the traffic advantage degree model is modified by introducing the terrain fluctuation factor based on the technical process and evaluation method of the provincial main functional area planning. On this basis, taking 29 key cities along the main stream of the Yangtze River as the research area, 108 counties and cities under its jurisdiction as the research units, and the spatial pattern of county traffic advantage along the main stream of the Yangtze River is analyzed and its causes are analyzed comprehensively using GIS spatial analysis, modeling and mapping technology, The results show that: from the regional perspective, the traffic advantage degree of counties along the Yangtze River main stream is generally distributed in a normal way, with obvious spatial difference between the East and the West. The traffic advantage degree of counties and cities in the East is generally higher than that in the West. The traffic advantage degree of counties and cities along the Shanghai Nanjing line and coastal areas is higher, and the higher terrain areas in the West are relatively lower. From the perspective of river basin, the traffic advantage degree of counties and cities along the Yangtze River main stream is generally higher From the perspective of administrative divisions, the traffic advantages of counties and cities under the jurisdiction of Shanghai, Nanjing and Suzhou Wuxi Changzhou are prominent, while those under the jurisdiction of central cities of Wuhan and Chongqing in the central and western regions have higher traffic advantages, while those far away from the central city and lack of traffic trunk lines have lower traffic advantages 。 Strengthen the construction of traffic infrastructure in low value areas, strengthen the economic ties between cities and neighboring cities under the jurisdiction of provinces, so as to improve the traffic advantage level of County cities in the main stream of the Yangtze River, and provide basic support and guarantee for urban development and economic construction in the Yangtze River Basin.

The transformation and upgrading of the industrial structure of the Yangtze River economic belt is an important issue in the national development strategy. The rational industrial layout to take the road of green development is the most important thing for the country to further promote the construction of ecological civilization. This paper constructs a double logarithmic model of the influence of environmental regulation on the upgrading of industrial structure and the rationalization of industrial structure. Based on the data of city agglomeration in Hunan, Hubei Jiangxi and Anhui province from 2003 to 2017, this paper studies the influence of environmental regulation on the upgrading of industrial structure and the rationalization of industrial structure. In order to study the heterogeneity of the influence, this paper introduces the interaction between economic development level and environmental regulation into the model. It is found that there is complementary effect and substitute effect on the level of economic development in the effect of environmental regulation on the transformation and upgrading of industrial structure. And the substitute effect is more than the complementary effect. In the long run, economic development can promote the transformation and upgrading of the overall industrial structure of the middle urban agglomeration of the Yangtze River economic belt. In terms of urban heterogeneity, environmental regulation has significant influence on optimizing the industrial structure of second-tier cities in the middle of the Yangtze River economic belt. At the same time, the positive effect of environmental regulation on the optimization of industrial structure of third-tier cities is greater than that of cities below third-tier.

Grasp the spatial distribution of rural settlements in oasis groups in arid areas and reveal its driving factors, in order to provide basis for settlement planning and management in the implementation of rural revitalization strategy in Xinjiang. Based on GIS spatial analysis technology, landscape rhythm index and econometric statistical method, explore the spatial pattern and influence mechanism of rural settlement in oasis group of Tarim River Basin. Results show that: (1) There is a quite difference of rural settlement scale in oasis of Tarim River Basin, micro settlement account for a large proportion which is distributed by small-scale, low-density and multi-nuclear fragmentation as a whole of Tarim River Basin; （2) From the upstream to the  downstream of the basin, the density, scale, shape and fragmentation degree of rural settlements are obviously different, and there is a decreasing trend in space, it’s significant difference between large and small Corps and Local Settlements.(3) Settlements is mainly distributed in altitude 767~1 746 m, slope 0~ 4°, within 2 km of river. Traffic, economy, policy, military land system and other human factors are important driving factors to promote the evolution and development of settlement space, but under the influence of complex landform and typical inland nature of Tarim River Basin, the development and evolution of settlement pattern is strongly restricted by natural factors.

The evolution characteristics of the natural and wetland environment in the Yangtze River Basin were analyzed from the perspective of the long-term evolution in this study. Based on the situation of wetland resources, the regional characteristics and threat factors of the Yangtze River source area, the Three Gorges Reservoir area, the middle reaches lake group and the river Delta wetland were summarized, respectively. And the demonstration cases of wetland protection and ecological engineering construction in typical important wetland regions were discussed. Aiming at above environmental problems faced by different wetland regions, the study put forward several targeted measures for the protection and restoration of the Yangtze River wetland.

Based on the GIMMS NDVI 3g.v1 data from 1982 to 2015, the trend of vegetation cover change and its influencing factors on the southern slope of Qilian Mountain were analyzed by trend line method and correlation analysis method. The results showed that: (1) The vegetation coverage on the southern slope of Qilian Mountain showed a significant upward trend, and the linear regression growth rate was 0.99%/10a. The average NDVI in each season was summer>autumn>spring>winter, and the order of NDVI change rate was winter>summer. >Autumn>Spring; the monthly NDVI trends in each stage were basically the same, and the summer vegetation coverage was the largest in 2004-2015. (2) In the past 30 years, most of the southern slope of Qilian Mountain belongs to the evergreen area. The area of vegetation increase in the three-time period showed an increase-decrease-increased trend, and the area of vegetation increased between 2004 and 2015 was the largest. 92.66%, the fastest growing area in Menyuan County. (3) From 1982 to 2015, the correlation between NDVI and temperature in the study area (0.58) was greater than that of rainfall (0.27). The vegetation cover in the growing season (April-September) of the study area was affected by both temperature and precipitation.

The time series of vegetation cover reflects the impact of climate change and human activities on the environment. To explore the variation characteristics of vegetation cover and its responses to climate and topography in Gansu Province, multiple methods such as the trend analysis, partial correlation analysis, and topography area correction were utilized to analyze the SPOT_NDVI time series data, as well as the meteorological and topographic data. It was found that, in the past 19 years, the vegetation cover in Gansu Province has recovered, however, there was largest areas with low vegetation cover. The spatial distribution of vegetation cover is generally high in the south and low in the north. It was found that vegetation cover was significantly positively correlated with precipitation in most parts of Gansu Province, especially in the Loess Plateau. In the humid regions of the south and the arid regions of the north, temperature promotes and inhibits vegetation growth respectively. In terms of topography, the semi-sunny slope area with an altitude of 2 500-3 000 m and slope of more than 25° is most suitable for vegetation growth. The study of vegetation cover is conducive to the planning of ecological construction and sustainable development. At the same time, it is of great theoretical and practical significance to the planning of human-land relations and economic development.

Niclosamide (NIC) is one of the commercially molluscicide. With long-term and large-scale using of NIC in China has resulted in ubiquitous environmental and biological safety problems, gradually attracted human attention. Our previous study revealed that acute exposure to NIC disrupted lipid metabolism in zebrafish larvae. Base on that, in our present study, we intended to further study the disruptive effect of NIC on the mechanism in zebrafish embryos/larvae. Healthy zebrafish embryos within 2 h post-fertilization (hpf) were acutely exposed to environmentally realistic concentration of NIC (0, 5, 10, 20 and 40 μg/L, respectively) until 120 hpf. Our results showed that 40 μg/L NIC exposure significantly altered the content of metabolites, such as glucose and lactate, compared with the control. (P < 0.05 and P < 0.05, respectively); additionally, exposure to NIC also significantly inhibited citrate synthase (CS) activity, while a significant increase of lactate dehydrogenase (LDH) activity was observed in 40 μg/L NIC treated group (P < 0.05 and P < 0.05, respectively). Two relative genes, pparα and pparγ, mRNA expressions were significantly increased in 40 μg/L NIC treated group (P < 0.05 and P < 0.05, respectively). Our results indicate that acute exposure to NIC at an environmentally realistic concentration disturbs the metabolism in zebrafish embryos/larvae, as well as alters the expression of genes related to metabolism, changes the activity of enzymes and the contents of metabolites.

Schizothorax dolichonem is an endemic fish species that mainly distributes in main streams and tributaries of the upper reaches of the Yangtze River in China. In the Yanglong River basin, S. dolichonem is one of the main catch objects, playing an important role in fishery production of Yanglong River. In recent years, many factors such as pollution, overfishing, damming, habitat degradation and environmental change, have seriously affect its natural resources, especially the cascade hydropower development in the middle and lower reaches of Yalong River. Fragmentation caused by hydropower stations may disrupt communication of fish populations and influence population genetic structure and diversity. A good understanding of population genetic structure would be useful for better conserving and restoring the natural resources of this schizothoracin. In present study, 118 individuals of S. dolichonem sampled from Ganzi, Yangjiang, Jinping and Jinhe sections of Yanglong River in the year 2018 were analyzed, using the complete mitochondrial cytochrome b gene sequences. The result showed that the length of Cyt b gene of was approximate 1085 bp. 19 haplotypes and 29 polymorphic sites were found among 118 S. dolichonem individuals. The total haplotype diversities (Hd) and nucleotide diversities (π) were 0.850 ± 0.017 and 0.003 35 ± 0.001 89, respectively. The Hd ranged from 0.697 ± 0.069 to 0.831 ± 0.022, and π from 0.000 92 ± 0.000 79 to 0.006 22 ± 0.003 36 among the four groups, respectively. Analysis of molecular variance (AMOVA) showed that most of the genetic variation occurred within groups (84.84%). The neutrality test and mismatch distribution indicated that the population of S. dolichonem in the Yanglong River had experienced an expansion. Pairwise fixation index (FST) values indicated significant differentiation between any two groups (FST ranged between 0.090 48 - 0.199 17, P < 0.05), except between Ganzi and Yangjiang groups (FST = 0.043 47, P > 0.05). Although significant FST values were found among geographical groups, the differentiation level still belonged to intra-population differentiation, suggested that these groups of S. dolichonem in Yanglong River should be considered as a single management unit. In conclusion, this study provided valuable information for restoration of S. dolichonem natural resources in Yanglong River and theoretic knowledge for a rational utilization of the germplasm resources.

A total of 325 samples collected from cultivated land profiles were analyzed to investigate the factors affecting soil organic matter (SOM) variability in different horizons (0-20 cm, 20-40 cm, and 40-60 cm). Factors including parent materials, land types, and elevation were examined by classical statistics and classification and regression trees (CART). The results showed that the CART models could explain 57%, 44%, and 35% variability of SOM in 0-20 cm, 20-40 cm, and 40-60 cm, respectively. SOM decreased with the increase of soil depth. More specifically, the mean value of SOM in the 0-20 cm soil horizon was 1.5 times higher than that in the 20-40 cm, and 2 times higher than that in the 40-60 cm. The factors affecting SOM variability differed with soil horizons. The most important parameters were parent material, land type, and elevation for 0-20 cm. Elevation was the critical variable for 20-40 cm and parent material was the key one for 40-60 cm. The interaction between elevation and parent material had a significant effect on the variation of SOM in different horizons. Soils developed from alluvial and limestone parent material had higher values of SOM content at an elevation range of 500-1 000 m. Elevation was positively significantly correlated with SOM in soils developed from purple parent material.

The purposes of this study are to explore the impact of the rapid development of rice-crayfish integrated on the utilization of cropland, and how to balance the development of rice-crayfish fields with the food and ecological security. The results show that: (1) The change process of the spatio-temporal pattern of cropland has been expanding westward to Guanghua town and southwest to Yangshi town with the center of the Yuanlin town in the past 20 years. Cropland was converted into newly added construction land for 28.64 km2 and about 18.59 km2 water body; (2) The fragmentation of cropland is mainly caused by the expansion of construction land occupation of cropland in urban development, and the special planting characteristics of rice-crayfish fields rapid development; (3) Rice-crayfish fields are mainly converted from paddy fields. A part of dry land and water are also converted into rice-crayfish fields. The continuous expansion of rice-crayfish fields, especially the conversion of dry land and water to rice-crayfish fields, has brought about a certain degree of fragmentation of cropland. In conclusion, reducing farmland fragmentation is not the only development direction of agricultural production, especially under the factors of serious fragmentation of cropland, serious lack of rural agricultural power, low income of farmers and weak enthusiasm for farming in South China, rice-crayfish fields planting mode has a good potential and space in the agricultural development of South China.

Based on the gridded dataset of monthly precipitation from 1961 to 2015, precipitation regionalization is firstly carried out by spatial hierarchical cluster method in the middle and lower reaches of the Yangtze River (MLYR). Then, standardized precipitation index is employed to explore the temporal evolution of drought events, and wavelet method is used to detect the drought periodicity in each sub-region of MLYR. The results show that: (1) Spatially, MLYR can be divided into six sub-regions, namely, Daba Mountain (Region I), Intersection of Hunan-Hubei-Guizhou-Chongqing (Region II), Central and eastern plain of Hubei province (Region III), Hilly plain area of Hunan-Jiangxi (Region IV), Poyang Lake Plain (Region V), Yangtze River Delta Plain (Region VI). (2) There are obvious differences in the alternating processes of dry and wet events in different sub-regions. The dry and wet evolution in Region VI differs greatly from other sub-regions. The wet and dry events in Region II, Region IV and Region V have similar temporal evolution patterns. Except for the Region VI, the frequencies of drought in other sub-regions have increased significantly after 2000. (3) There are differences in the first main cycles of meteorological drought in different sub-regions. Drought periods of the northern (Region I, Region III and Region VI) and southern (Region II, Region IV and Region V) regions have obvious regional differentiation characteristics, but a significant cycle of about 3.5 years exists in the most of the sub-regions. The results of this paper can provide reference for the interpretation of meteorological drought driving factors, the formulation of drought monitoring plan, the management of water resources and the prevention and control of drought in the sub-regions of MLYR.

Taking Nanjing city as an example, based on the assessment of resource and environment carrying capacity and the trend of environmental coercive pressure in each district, this study comprehensively judged the monitoring and early warning level of resource and environment carrying capacity in Nanjing city, analyzed the causes of overload, and proposed corresponding control countermeasures and suggestions. In this study, the monitoring and early warning levels of resource and environment carrying capacity in Nanjing city were divided into five levels: red early warning zone, orange early warning zone, yellow early warning zone, blue early warning zone and green no early warning zone. The results show that the current early warning level of resource and environmental carrying capacity in Nanjing city is generally at a high level. Although the environmental coercive pressure of social and economic development in Nanjing city is relatively small and has a slowing trend, the overload status of resource and environment carrying capacity determines the main urban area as a red early warning zone. Jiangning, Liuhe and Pukou districts are orange early warning zones and Lishui and Gaochun Districts are yellow early warning zones. There is no blue early warning zone and green no early warning zone in the city.

With the accelerated development of urbanization and industrialization in China, air pollution is becoming more and more serious, which seriously endangers public health. Based on the hourly PM2.5 concentration monitoring data of Anhui, the backward trajectory model, the Potential Source Contribution Function (PSCF) and the Concentration Weighted Trajectory (CWT) were used to construct the PM2.5 source analysis model, and the source of PM2.5 in Anhui was analyzed. Combined with geographical detector, the driving factors affecting the concentration of PM2.5 local emission were analyzed. The results show that: (1) The three dynamic processes of local contribution, local spillover and external transmission of pollution have important influence on the temporal and spatial variation of PM2.5 concentration in Anhui; (2) Monthly cumulative measured concentration, total concentration, external transport concentration, local contribution concentration, local spillover concentration and monthly average local contribution rate of PM2.5 all showed a high trend of southwest and the opposite in the northeast, but the first three appeared high value in northwest of Anhui, such as Fuyang, Bozhou and Huaibei; (3) Approximate 97.5% of external transport contribution rate is more than 50% in Anhui, and the contribution rate of PM2.5 local emission in the cities is 30% ~ 50%, indicating that the pollution in January is mainly from external transmission. (4) The explanatory power q values of factory density, vehicle ownership density and population density for monthly cumulative local contribution concentration of PM2.5 are 0.33, 0.47 and 0.61, respectively. By comparing with the results of geographical detector of monthly cumulative measured concentration of PM2.5, it is indicated that the relationship between artificial factors and monthly cumulative local contribution concentration of PM2.5 is closer. The results can provide a scientific reference for the control of regional air pollution.

The spatio-temparal variations of hydrological components caused by land use change is of great significance for understanding of runoff generation process, and optimizing land use structure and water resources planning. Based on three scenarios of land use data in 1980, 2000 and 2015 this study systematically investigates the impacts of land use change on the spatial-temporal variations of major hydrological processes such as runoff generation, evaporation, infiltration and runoff from perspective of hydrological response unit, by applying the SWAT model in Ganjiang River Basin as an example. Results show that land use change of the basin during 1980-2015 was mainly reflected by the reduction of cultivated land and forest land as well as the increase of urban and rural construction land. The reduction of forest land and increase construction land mainly contributes to the increase of runoff generation and the decrease of evaporation and infiltration. Generally, land use change has a greater impact on local hydrological processes, while the integrated hydrological effects are significantly reduced at watershed scale due to the mutual transformation of land use types and their overlapping effects, . The modelling result revealed that the effect of land use change has caused to an increase of average annual runoff of by 2.33×108m3 in the Ginjiang River Basin, which is quite small with reference to the observed runoff reduction in recent years. On this basis, the runoff decrease of Ganjiang River was mainly affected by climate change and other human activities, especially dramatic increase of water utilization for industry and agriculture in the basin. It is concluded that hydrological modelling should fully consider the spatio-temporal variations of hydrological effects of land use change, and pay attention to the coupling of natural and social water cycles, only in this way can watershed hydrological processes be more truly reflected and the scientific basis for the optimization of land use structure and the efficient management of water resources in the river basin be better provided.

The purse seine and cage culture are primary inner lake pollutant sources in Jianghan Plain.  After the implementing of the action of “purse seine demolition of lakes and reservoirs” in Hubei Province, it is quite necessarily to discuss and evaluate the effectiveness of the lake seine demolition and its ecological environment benefits. Therefore, a method was realized to rapidly monitor the effect of purse seine demolition, based on the modified normalized difference water index (MNDWIn), texture analysis, et al., taking the Honghu Lake, the largest lake in Hubei Province, as a case. Based on the monitored area changes information of purse seine, the environmental benefits of demolition were estimated, according to the pollutant share ratio of aquaculture type in the Honghu Lake and the production and discharge coefficient method. The results showed that: (1) Due to the action of “purse seine demolition”, the purse seines in the Honghu Lake have been completely removed. The area of purse seine culture has been removed by 117.81 km2, and the natural water surface area has increased by 110.49 km2. The coastal landscape of the Honghu Lake has greatly improved. The effect of demolition was most significant especially in the western and northern regions. However, there were still some non-water substances need to be cleaned in the north and south of the Honghu Lake. (2) The pollutants that discharged into the lake were reduced by 1 265 284.38 kg, in which the concentrations of total nitrogen and total phosphorus nutrients were reduced by 0.848 mg/L and 0.185 mg/L respectively. The water quality levels of these two indicators would be raised up to Class II from Class III before demolition, if there is not any other new pollutant source added. So, the eutrophication pollution of the Honghu Lake would also be greatly decreased. The study provides a rapid monitoring method to evaluate the effect of the implementations of the action of “purse seine demolition of lakes and reservoirs”, which can be applied to regional lake management and watershed ecological environment protection.

Monitoring the long-term changes of water area is of great significance for the flood and drought monitoring in the East Dongting Lake. In this paper, the remote sensing data set of Landsat series Collection 1, which has been corrected by radiation consistency from 2000 to 2017, is used to extract the long-term sequence water surface area data of the East Dongting Lake area. Four common water extraction methods (single band threshold, multi band spectral relationship, water index, support vector machine) are used under ENVI software to carry out the comparison of the best or most suitable water surface area extraction method in study area. And then, the annual and inter-annual changes of the water surface area of the East Dongting Lake in the past 18 years are studied, also the correlation between the water surface area and the water level of Chenglingji hydrological station is discussed.Our results show that: (1) The remote sensing data set of Landsat collection 1 has a high spatial and temporal resolution, which can meet the requirements of long-time series water surface area extraction in our study area, also the accuracy of water surface area extraction is high regardless of the flood period or water lowering period; (2) During our study period, the average value of multi-year water surface area extracted by support vector machine of the East Dongting Lake is 569.9 km2 , which fluctuates greatly in wet season, but changes little in dry season; (3)There is a close relationship between the accumulation water area change and the water level change in Chenglingji hydrological station. Both linear model and polynomial model can accurately describe the relationship between them; (3) Influenced by the topographical distribution characteristics of the East Dongting Lake, the relationship between the water area and water level is relatively close in the wet season, while the relationship between the two is significantly reduced in the dry season.

Taking Anhui Province which is the main producing area of agricultural products as an example, based on the coupling coordination degree model and the scissors difference model, the entropy weight method is used to determine the comprehensive weight, and the ecological carrying capacity of the main agricultural producing areas in Anhui Province and the coordinated development of the industry are calculated in 2007-2018. Coupling coordination degree and difference in rate of change between the two systems. The results show that during the research period, the two systems are at a low level of basic coordinated development. In 2007-2010, they are in the basic coordinated development of economic lag. In 2011-2018, they belong to the basic coordinated development of ecological lag; the difference between the two systems is stable at \[0.0219, 0.0373\], showing an inverted U-shaped trend. After discussion and analysis, it proposes to optimize the overall layout of the main producing areas of agricultural products, industrial development, integrated development, and green transformation and development.

As the “ballast stone” of China’s food security, heilongjiang province’s rational and effective use of water resources provides an important guarantee for food production.Based on the water footprint theory, this paper calculated the water footprint and gray water footprint of grain production in 14 regions of heilongjiang province from 2000 to 2017 as input and output indicators, and used the three-stage super-efficiency SBM-Malmquist model to analyze the spatial and temporal characteristics of the green water efficiency of grain production in heilongjiang province.The results showed that the total water footprint of grain production in heilongjiang province increased first and then decreased, with great differences among different regions, which were mainly caused by the changes of grain yield, planting structure and yield per unit area.Affected by the demand of fertilizer for grain production and the policy of zero growth of fertilizer, the total footprint of grainy water increased first and then decreased.After removing the random error and environmental factors, the external factors have a significant effect on the pure technical efficiency.The green efficiency of water used for grain production in heilongjiang showed a trend from rising to stable. Except for Harbin and the general administration of agricultural reclamation, the efficiency among different regions was low.The change of green total factor productivity (TFP) of water used in grain production mainly depends on the change of technological progress and is limited by the change of pure technological efficiency.It is suggested that heilongjiang province should further develop modern agriculture, expand production scale according to regional characteristics, increase scientific and technological input and technological innovation, optimize and adjust the input and output factors in the production process from the perspective of grain production structure and fertilizer application amount, which is an important way to improve the green efficiency of water use in grain production.

Based on the micro survey data of 603 peasant households in Hubei Province,this paper incorporates social context factors of rural acquaintances and constructs a three-dimensional analysis framework of interpersonal trust, institutional trust, and group identity, and discusses the behavioral logic and influencing factors of peasant households participating in the ecological governanceof villages.The research results show that:(1)Interpersonal trust, institutional trust and group identity all have significant positive effects on farmers' participation behavior in the village ecological governance .(2)Interpersonal trust plays an intermediary role in group identity and the participation behavior of farmers in villageecological governance; at the same time, group identity plays a negative regulatory role in institutional trust and farmersparticipation behavior in village ecological governance.(3)With the acceptance of group identity, the interpersonal trust and institutional trust play an opposite role in the village ecological governance, that is, there may be an “alternative” relationship between interpersonal trust and institutional trust.Based on this, it is possible to increase farmers participation behavior  in the village ecological governance by creating a reciprocal and mutually beneficial social fashion, allowing the contents of ecological governance policies and village collective actions to better meet the needs of farmers and embody the will of villagers.

Virtual cultivated land resources are widely regarded as one of the important measures to relieve the pressure of domestic cultivated land resources and promote agricultural economic growth. Based on the analysis of the effect mechanism of virtual cultivated land resource trade on agricultural economic growth, this paper calculates the trade volume of virtual cultivated land resources of China's main agricultural products from 1996 to 2018, and empirically analyzes the contribution share of virtual cultivated land resources to agricultural economic growth, which provides references for adjusting foreign trade strategy and optimizing cultivated land resource strategy. The results show that: virtual cultivated land resources can realize the optimal allocation of cultivated land resources in a larger range; The huge trade deficit of major agricultural products determines that China is a big net importer of virtual cultivated land resources, among which oil is the largest one; The contribution rate of virtual cultivated land resources to agricultural economic growth is 0.26%, which proves the viewpoint. At the same time, this paper also puts forward some policy suggestions, such as the pilot implementation of virtual cultivated land resources to make every effort to complete the strategy of trade policy adjustment, making full use of “two kinds of resources and markets” at home and abroad to force the structural adjustment of main agricultural products, building a new model of virtual cultivated land resources management to promote the combination of “going out” of agriculture and market diversification.