It is significant to objectively evaluate the employment situation brought about by the development strategy of the Yangtze River Economic Belt and clarify the influence of the strategy on the employment in order to promote a green and high-quality development and achieve a fuller employment in the area of Yangtze River Economic Belt. Based on the panel data of 268 prefecture-level cities across the country from 2009 to 2017, this paper first uses the difference-in-differences model (DID) to evaluate the net effect of this development strategy on the employment in the area of the Yangtze River Economic Belt；then the multiple intermediary effect model is used to empirically test the impact mechanism of the development strategy of the Yangtze River Economic Belt on employment. It is found that：(1) the development strategy of Yangtze River Economic Belt has significantly promoted the employment in the areas covered by the Yangtze River Economic Belt, which has been proved valid by a series of robustness tests；(2) the development strategy of Yangtze River Economic Belt promotes the employment in the area of the Yangtze River Economic Belt by means of three paths, that is, promoting industrial transformation and upgrading, building comprehensive three-dimensional transportation corridors, and increasing ecological and environmental protection. Governments at all levels should continue to implement and improve the development strategy of the Yangtze River Economic Belt, strengthen industrial transformation and upgrading, accelerate the construction of comprehensive three-dimensional transportation corridors, solidly promote ecological and environmental protection, and jointly stabilize the overall employment situation in the area of Yangtze River Economic Belt.

Exploring the coordinated development of the tourism industry and the eco-environment is very crucial to break the bottleneck of the transformation and upgrading of the tourism industry and initiate the new situation of ecological civilization construction in the Yangtze River Economic Belt. Based on the construction of the evaluation index system of development status, this paper validates the interactive coercive relationship between tourism industry and ecological environment system based on the interactive coercion model, and then using the coupling coordination model, spatial gravity model and other methods, the dynamic evolution characteristics and spatial connection structure of the two systems in the Yangtze River Economic Zone since 1998 are analyzed empirically. The results show that: (1) The evaluation values of the two major systems of the tourism industry and the ecological environment in the Yangtze River Economic Belt both show an increasing trend, and the disequilibrium between regions gradually weakens; (2) There is an interactive stress relationship between the tourism industry and eco-environment in the Yangtze River Economic Belt, and the evolution trajectory conforms to the rhythmic development characteristics of a combination of multiple S-shaped curves; (3) The coordinated development stage of the complex system of the Yangtze River Economic Belt roughly experienced the following evolution process: mild imbalance (1998-2006)-endangered imbalance (2007-2015)-rough coordination (2016-2017); (4) The spatial connection pattern of the regional coupling coordination degree of various provinces and regions is getting closer and closer, and the connection potential energy is steadily increasing. The overall pattern presents a step-type decreasing pattern of “extrude in east-uplift in central-collapse in west”, and the interior of the three major regions also shows significant non-equilibrium characteristics.

The rapid economic and social development has continuously reconstructed the spatial pattern of the built-up area expansion intensity since 1978 in the Yangtze River Delta. The research on its spatial characteristics and driving mechanism can provide support for the scientific, orderly and sustainable region development. The Yangtze River Delta is one of the regions with the most dynamic expansion of built-up area in China. This paper analyzed the spatial-temporal dynamic characteristics of the built-up area expansion intensity for 41 cities in the Yangtze River Delta using an impervious surface dataset from 1978 to 2017. And the geographically and temporally weighted regression (GRWR) model was applied to discuss the driving factor. The results showed that: (1) with the fast urbanization, the regional differences of the built-up area expansion intensity in the Yangtze River Delta has been constantly increased, and the spatial difference has also been obvious. The regions with high intensity have an alternate expansion. The expansion process has gradually appeared in the cities along the Yangtze River and the coastal areas of Zhejiang Province, which has led to a Z-shape spatial pattern. (2) The region including Shanghai, Nanjing, Hefei, Hangzhou, and Ningbo has a more drastic change process in the whole study area. This region has obvious agglomeration effect of core city and path-dependent characteristic. (3) The neighborhood relationship of the built-up area expansion intensity has strong spatial-temporal agglomeration and is dominated by positive collaborative increase. Most of the cities are in a relatively stable spatial state. (4) The factors such as population, economy, administration work together to change the urban built-up area expansion intensity, and the main driving factors are various in different periods. It shows the transformation from economic total quantity to economic quality, and from economic activity to government supply policy.

As an important carrier to support the high-quality development of the regional economy, urban agglomerations, a reasonable spatial structure is an important guarantee for urban agglomerations to maximize their spatial effects. Based on the “density-scale-network” urban agglomeration spatial structure analysis framework, this paper uses mathematical analysis, spatial analysis and spatial measurement models to measure the spatial and temporal evolution characteristics of the urban agglomeration in the middle reaches of the Yangtze River from 2007 to 2017 and its multi-center structure spatial effects. The results show that: (1) “Small economic groups” have become increasingly prominent and have become emerging areas for the development of urban agglomerations. The Poyang Lake City Cluster is a shortcoming in the coordinated development of the entire region, and the Jiujiang and Xinyiping areas have a trend of cross-regional integration; (2) Urban agglomerations form a tightly connected network, with significant clusters of economically connected cities and significant traffic axial agglomeration, weak cross-administrative ties, and economic ties in peripheral cities need to be strengthened; (3) The level of urban agglomeration in the middle reaches of the Yangtze River is not high, the spillover effect is not significant, and human resources， Industrialization level, government participation and transportation infrastructure are all positive factors that promote regional economic development. In the future, we should promote the clustering of factors, break administrative barriers, strengthen inter-regional connections, improve transportation networks, and create new overflow channels.

Exploring the law of interaction between urban construction and low-carbon economic development is of great significance to achieving high-quality sustainable development in the region. Based on this, this paper takes the Changsha-Zhuzhou-Xiangtan urban agglomeration as the research area, comprehensively use the decoupling development model and gray correlation method to analyze the interactive relationship and driving factors between urban compactness and carbon emission intensity. The results show that: (1) From 2005 to 2017, the coupling compactness of the average compactness and various types of functional compactness of the Changsha-Zhuzhou-Xiangtan showed an overall upward trend, but the coupling coordination degree of each urban area still has a large room for improvement. （2) During the study period, the carbon emission intensity of Changsha-Zhuzhou-Xiangtan showed a year-on-year downward trend. The rate of change of carbon emission intensity varies slightly among the urban areas. In general, it can be roughly divided into three types: high carbon emissions stage (2005-2007), continuous emission reduction stage (2008-2011) and low-carbon optimization stage (2011-2017). (3) The average compactness and carbon emission intensity of the Changsha-Zhuzhou-Xiangtan urban agglomeration are in a strong decoupling relationship in most years. A few years are characterized by recession decoupling and other conditions. The decoupling status and degree of each urban area vary slightly over the years. （4) The temporal and spatial correlation characteristics of the decoupling state of UC and CEI in Changsha-Zhuzhou-Xiangtan urban agglomerations and the value of each drivers are different. On the whole, the degree of influence from weak to strong is government participation, technological innovation, population quality, urbanization level and industrial structure. We should pay more attention to the coupling and coordination of all operating systems in the process of urban construction in the future. And we should combine the resource endowment of the city to innovate and create a low-carbon development model while attaching importance to high-quality urban development model.

Sediment activity refers to the percentage of time that seabed sediments are active within a certain period of time. The Changjing River is a typical example in that the construction of dams to store water and sand has led to a sharp decrease in sediment flux to the sea. In this context, the sediment activity of the Yangtze River estuary and its adjacent waters is not only related to the geomorphological evolution of the Changjiang River submerged delta, but also affects the coastal stability of Shanghai and the surrounding areas. Based on the surface samples and box samples collected in the Changjiang River estuary in March and October 2019 and hydrodynamic characteristics collected in the front edge of the Changjiang River Delta, this paper analyses the sediment activity by using CSM (Critical Shear-stress Metre) to test critical sheer stress, and analyzing grain size data as well as hydrodynamic characteristics. The result shows that: (1) In terms of the critical shear stress, the measured value given by CSM is close to the theoretical calculated ones, and CSM can accurately describe the characteristics of sediment threshold. (2) Comparing samples collected in different seasons, the average value of the critical shear stress measured by CSM is lower in summer than in winter, suggesting that the surficial sediments have a looser structure during the flood season and are prone to be eroded. (3) In summer, the shear stress of coupling waves with current decreases in flood tide and increases in ebb tide, and the calculated sediments activity is more than 60% within a 25-hour tiddal cycle. Assuming that the effective wave height in winter is 0.8 m higher than that in summer, while maintaining the same intensity of other hydrodynamic forces (currents), the calculated sediment activity of surficial sediment in winter is similar to those in summer. (4) Compared with the situation before the completion of the Three Gorges Dam, the average particle size of the sediments in the Changjiang River subaqueous delta is coarser, the activity of the sediments is reduced, and their resistance to erosion is slightly increased.

In order to understand the characteristics of zooplankton community structure in the water ecological function zoning of the Taihu Lake Basin during the normal season, the zooplankton community survey and water quality monitoring were carried out at 201 sampling points in the Taihu Lake Basin in May 2018.122 species of zooplankton were detected, belonging to 49 genera of 3 categories, with the majority of rotifers and cladocera. Class Ⅰ，Ⅱ，Ⅲ and Ⅳ areas are dominated by rotifers. Shannon-Wiener index(H), Simpson index(D) and Pielou index(E) were the largest in Class Ⅰ areas, which were 2.28, 0.84 and 0.47. A total of 19 dominant species were detected, 60 % of which were eutrophic indicating species. The dominant species in Class Ⅱ area were the most. Keratella cochlearis and Brachionus angularis were the most， which affected the water quality in Class Ⅱ area. Canonical correspondence analysis(CCA) results showed that the community structure of dominant zooplankton species was significantly positively correlated with TP and TN. According to Pearson analysis, species in Class Ⅰ，Ⅱ，Ⅲ and Ⅳ areas were significantly positively correlated with TP. With the increase of zoning grade, the correlation with TP was significantly increased, and the correlation with CODMn and TN was also significantly increased. The dominant factor for the change of zooplankton population structure and eutrophication of water body is P. In summary, in 2018, the Taihu Lake Basin was in a eutrophic state in the normal water period, and the water quality was in a medium pollution state. The treatment of algal blooms in the Taihu Lake Basin should be focused on limiting phosphorus emission and reducing TP content. The structure of zooplankton community influences the division of ecological functional zones.

In order to understanding the status of fish diversity in the upper Renhe River, field investigations were conducted during the period from 2016 to 2018 at 18 sampling sites. Specimens were collected by electro-fishing covering different habitat unit. A total of 36 fish species, including 34 natives and 2 exotics, was collected. Among these species, Leptobotia hansuiensis and Metahomaloptera omeiensis have been listed as the key protected fishes of Chongqing municipality, Scaphesthes macrolepis, Schizothorax prenanti and Pseudobagrus pratti have been listed as vulnerable by Red list of China’s Vertebrates. Small-sized and lotic species, such as Phoxinus oxycephalus, Gnathopogon herzensteini, Zacco platypus and M. omeiensis, distributed wildly in the upper Renhe river. Fish assemblages were mainly dominated by Phoxinus oxycephalus and other small-sized and lotic species. Species richness increased with the longitudinal gradient. Compared to the historical data, fish resources in the upper Renhe River have been declined seriously. Firstly, the number of fish species decreased dramatically. Secondly, the distribution range of some sensitive species reduced obviously. Thirdly, the miniaturization trend of some commercial targets was still serious. In order to effectively protect the fish diversity in the upper Renhe River, controlling the development of hydropower, reinforcing the fishery management and strengthening the scientific research were suggested.

In order to explore the key environmental factors affecting phytoplankton community characteristics in spring and autumn in the Dongting Lake, a systematic survey of water environmental parameters and phytoplankton was conducted at 30 sampling sites of the Dongting Lake in April and October of 2018. The results showed a total of 157 species of phytoplankton belonging to 7 phyla and 51 genera were identified, and species number in April (105 species) and October (120 species) accounted for 66.9% and 76.4% of the total, respectively. The dominant groups in two surveys were all Bacillariophyta, Chlorophyta and Cyanophyta. Besides, community structure gradually changed from Bacillariophyta-dominated type to Bacillariophyta-Chlorophyta-dominated type from April to October. The average densities of phytoplankton in April and October were 19.0×104 cells/L and 18.7×104 cells/L, respectively, which indicated that abundance in two seasons did not vary significantly. The average biomass increased from 0.67 mg/L in April to 0.83 mg/L in October. Comparing the Shannon-Wiener diversity (H), Marglef diversity (d), Pielou evenness index (J) and Beta diversity in two seasons, it was found that the difference of phytoplankton community among sampling areas of the Dongting Lake in spring was larger than that in autumn, while biodiversity and richness were lower than those in autumn. The redundancy analysis (RDA) showed that pH, water velocity, conductivity and transparency were the key environmental factors affecting the phytoplankton community characteristics in April. Ammonium, water temperature, transparency and total nitrogen were the key environmental factors affecting the phytoplankton community characteristics in October. Based on previous studies in the river-connected and isolated lakes, it was found that the biodiversity of the isolated lakes were far lower than river-connected lakes, while the phytoplankton abundance and biomass of the isolated lakes were significantly higher than river-connected lakes, which was ascribed to the loss of flowing water habits and the decrease of the habitat heterogeneity in isolated lakes. It’s demonstrated that hydrological and hydrodynamic conditions are the primary factors determining phytoplankton community differences among river-connected and isolated lakes, and water physico-chemical factors (i.e., transparency, suspended solids and nutrients) are the secondary influencing factors. The results of this study can provide a scientific basis for ecological conservation of the river-connected lakes such as the Dongting Lake.

As an important parameter of terrestrial ecological processes, leaf area index (LAI) is of great significance to the ecosystem’s carbon cycle and regional water and soil conservation. Based on MOD15A2H/LAI data set from 2001 to 2018, the spatio-temporal distribution pattern and change trend of vegetation LAI were studied. Then based on the meteorological data, land cover data and DEM data, the response of LAI to climate change was analyzed emphatically by using Theil-Sen media analysis method, Mann-Kendall testing method and correlation analysis method. Results showed that: (1) the mean value of vegetation LAI was 1.22 with a spatial distribution feature of high in the south and low in the north of HM from 2001 to 2018. (2) Vegetation LAI is affected significantly by topography factor. Vegetation LAI presented a feature of “elevation-down-stability” with elevation increasing, while vegetation LAI value showed an upward trend with increasing of the slope. (3) In the recent 18 years, the vegetation LAI increased at a rate of 0.07· (10a)^-1, among which 68.92% showed an increasing trend and 31.08% showed a degradation trend. (4) The LAI was found to be positively correlated with air temperature and sunshine duration, while negatively correlated with precipitation. At the significance level of P<0.05, the areal proportion of significant correlation LAI with air temperature, precipitation and sunshine duration were 22.7%, 33.58%, and 31.80%, respectively, which indicating precipitation and sunshine duration were the dominant climate factors on LAI, and air temperature on LAI was weaker relatively.

Chinese traditional villages are one of the important carriers of farming civilization and traditional cultural heritage with protection value. However, with the repid progress of the urbanization, traditional villages are gradually declining or even disappearing. Therefore, exploring the characteristics of land use change in traditional village gathering places is of great significance for promoting the protection and development of traditional villages and their gathering places. This article takes Xijiang Town, Leishan County, where traditional villages gather in Guizhou Province, as the research area. Based on the four phases of remote sensing image data, by using the land use intensity index, land use degree change model to scientifically analyze the spatial-temporal variation of Xijiang Town land use change from 2000 to 2017. And elevation, slope, distance to town government, distance to village committee, distance to public service land, distance to road, distance to river and policy factors were selected as driving factors in this paper. With the help of GeoDetector, we analyzed the role of these eight factors in Xijiang Town land use chnge. The results indicated that: (1) On time series, high-intensity land use in the study area doubled from 2000 to 2017, increasing from 22.59% to 47.63%; spatially, the change of land use intensity presents the evolution pattern of “road directivity” and “village center directivity”; (2) Under the background of tourism development in the traditional villages of ethnic minorities in mountainous areas, the land use has undergone a transformation from traditional agriculture to multifunctional tourist villages that combine life and production; (3) The change of land use in traditional village gathering places is the result of multiple factors. Changes in land use development trends are constrained by the natural environment and socio-economic factors, such as elevation, distance to highways, distance to public services, distance to village center. (4) The traditional villages of Xijiang Town have gradually increased their decisive force to the land use changes in the study area. The decisive power increased from 0.000 4 in 2000-2005 to 0.023 9 in 2010-2017, rising from the 8th to the 5th in the ranking of the determinants of the driving factors.

Using spatial data of PM_2.5 emissions and concentrations, this study examined their spatial distribution and the temporal-spatial changes in multi-scales, elevated their relationship both quantitatively and qualitatively, and analyzed regional inequity through their relationship. Main conclusions are drawn: total PM_2.5 emissions in China were increasing between 1970-2015, while, the decreasing trend occurred in periods 1998-2001 and 2012-2015; PM_2.5 concentrations also increased between 1998-2016, but with obvious fluctuations compared with the emissions; In different studied periods, annual changes of PM_2.5 emissions and concentrations have significant differences; during 1998-2012, there existed obvious correlations between PM_2.5 emissions and concentrations at provincial scale, while, for annual changes within different periods and regions, their changing trends did not match each other well; There existed obvious differences for distribution pattern for regional inequity analysis based on PM_2.5 emissions and concentrations. Generally, many provinces along the east and south coastline had taken advantages, while, many provinces in China’s inland area of north and northwest were under inferiority.

Effects of heavy metals on soil denitrification rates in wetland ecosystems has attracted much attentions with accelerated global warming and anthropogenic activities, but few studies have evaluated the low-dose effects under various plant types. In the present study, soils were collected from bare beach, Spartina alterniflora and Phragmites australis in Chongming Dongtan wetland, Shanghai, China. Gradient doses of Cd (0, 0.05, 0.1, 0.3, 0.5, 1.0, 3.0 and 5.0 mg·kg^-1) were added into the soils, and the Den rates were determined based on 15N isotope tracer technology. The results showed that mean Den rate in soils with Phragmites australis (9.2±0.3 μg·kg^-1·h^-1) was higher than that of Spartina alterniflora (4.7±0.5 μg·kg^-1·h^-1). The presence of Cd resulted in the significant decrease of Den rates under the two vegetation (P<0.05). The soil Den rates under Phragmites australis and Spartina alterniflora decreased to 6.3 μg·kg^-1·h^-1 and 3.2 μg·kg^-1·h^-1, respectively. Under Cd stress, the change of Den rate showed a "step-like" mode with doses. In the low dose (0.05-0.3 mg·kg^-1) interval, the inhibition rate of Den rates remained stable at 13.3%-14.8%. When the dose of Cd increased to 0.3-0.5 mg·kg^-1, the inhibition rate increased from 14.8% to 50.0%. At high doses (0.5-5.0 mg·kg^-1), the inhibition rate reached a higher level and stabilized again (50.0%-55.0%). Correlation analysis showed that the soil NO3^--N contents were significantly positively correlated with Den rates under Spartina alterniflora and Phragmites australis (P<0.05). This indicated that the presence of low-dose Cd did not change the dominance of NO3^--N on the Den process in the coastal wetland. 

Based on the remote sensing image interpretation data of land use/cover change (LUCC) in Jiangsu Province in 2005, 2010, 2015, and 2018, the equivalent factor in the second-level classification ecosystem was applied to quantitatively assess the total value of ecosystem services and the function value of single ecological service in Jiangsu Province. Then, the spatial autocorrelation analysis method was adopted to study the temporal-spatial evolution characteristics of ecological service value changes in each county unit. The results showed that: (1) From 2005 to 2018, the area of cultivated land, forest land and grassland in Jiangsu Province decreased, while the area of wetland, construction land and unused land increased. The increase and decrease of cultivated land, wetland, and construction land area in each period dominated the regional land use change. (2) From 2005 to 2018, the total value of ecosystem services in Jiangsu Province increased by 60.076 2×108 yuan. Hydrological regulation was the leading ecological service function. Maintaining wetland area not only led the change of the total value of ecosystem services, but also was the key to maintain the value of hydrological regulation services and ensure regional ecological security. (3) The regional average value of ESV in all counties over the years showed significant positive spatial correlation, with local spatial agglomeration. The temporal-spatial evolution in the high-value cluster area remained stable. The massive occupation of cultivated land and forest land by construction land during the rapid urbanization development and the regional effective wetland protection and restoration work were the important reasons for the evolution of low-value cluster area and spatial differentiation characteristics of the regional average ESV variation. The research results can provide scientific basis to formulate scientific and reasonable ecological protection policies and establish long-term mechanism of ecological protection and restoration for Jiangsu Province.

Under the background of global climate change, accurate monitoring and comprehensive assessment of drought are of great practical significance to the sustainable development of regional agriculture. Considering multiple causes and the complexity of the occurrence of droughts, this paper employs multiple input variables, i.e., precipitation, temperature, evapotranspiration and surface water content to construct a modified composite drought index (MCDI). The derived MCDI was calculated as a multivariate drought index to measure the drought conditions and verify its accuracy in Hubei Province in China. Compared with the widely used single/multivariate drought indexes, i.e., standardized precipitation index (SPI) and meteorological drought composite index (CI), the accuracy of drought monitoring results is verified. Moreover, combined with the historical records in Hubei Province, it is found that the drought process monitored by MCDI is more consistent with the actual drought condition. MCDI can be employed as a new method for comprehensive assessment of regional droughts. 

With the rapid industrialization and urbanization in eastern China, urban ecological security (UES) pattern was gaining attentions in the typical geographical region, with the high climatic sensitivity, biological diversity and environmental complexity, especially in the China’s north-south transitional zone. In this paper, based on land cover type and social statistics datas for the period of 2008-2017, the spatiotemporal variation of the UES pattern was analyzed in north and south of Qinling-Huaihe region. More importantly, the obstacle degree model was introduced to explore the influencing factors of the UES in China’s north-south transitional zone. The results showed, (1) Between 2008 and 2017, the UES grade in the study area was being a critical risk level and showed a slight increase with a linear tendency being 0.003%/10a. That implied the UES tended to be better and stable; (2) The spatial pattern of UES in north and south of Qinling-Huaihe region presented the east was higher than the west, while the UES index in the south area is higher than that in north area. In detail, high value of UES was mainly distributed in the middle and lower reaches of the Yangtze River and the east of the Huaihe Plain; (3) In the aspect of future tendency, the characteristics of the spatial pattern evolution of UES shown that about 24.2% of the study area experienced the increasing trend, which was continuously concentrated in Yangtze River Delta and Jianghan Plain. The areas with UES decreasing mainly distributed in Guanzhong Plain and the west of the lower reach of the Yellow River, accounting for about 35.2%; (4) In terms of influencing factors, the main factors affecting UES had consistency in different areas of China’s north-south transitional zone and they were water and wetland coverage, per capita green area, total water resources and proportion of tertiary industry. It can be effective to improve the UES by means of industrial structure optimization, increasing the proportion of ecological land and guaranteeing the total resource security.

In spite of providing considerable economic benefits, the operation of the Three Gorges Reservoir causes many ecological and environmental problems, especially the sediment deposition caused by the impoundment of the reservoir. The sediment deposition of the reservoir has profound impacts on the ecological environment of its water-level-fluctuating-zone (WLFZ). For example, the sediment deposition can change the topography and geomorphology of the WLFZ and bring nutrients to the WLFZ, which is beneficial to the plant growth and ecological functions of the WLFZ in barren patches. In order to determine the factors influencing the sediment deposition in the WLFZ during the impoundment of the Three Gorges Reservoir, and to provide a scientific basis for the protection and management of the ecological environment of the WLFZ, we selected twelve typical WLFZ sites along the Three Gorges Reservoir and monitored the sediment deposition depth from August 2017 to June 2018. The environment characteristics of each site were investigated. The results showed that: (1) During the impoundment of the Three Gorges Reservoir, the thickness of deposited sediments on the WLFZ of the Three Gorges Reservoir was determined by a set of environmental factors, such as the water course distance from the dam, elevation, riparian morphology, slope, and vegetation coverage of the WLFZ. (2) Among these environmental factors, the geological position of the WLFZ to the dam was the most important factor, the rest were elevation, vegetation coverage, and riparian morphology according to the degrees of their importance, and the slope has the weakest influence on the sediment deposition depths of the WLFZ.

The average occupied land of global mining waste storage yard is 1.3 km2, the China is 0.363 km2, while the Jialing River Basin is only 0.11 km2 from 132 mining waste storage yards (mainly tailings ponds), which is a typical small-scale cases. Small-scale mining waste yard is hard to attract authority attention, and readily lead to landslide, debris flow, and waste diffusion pollution. Based on field surveys, combined with Remote Sensing, GIS and watershed geographic factors, it reveal that mining waste is located in the upstream of the Jialing River, and seriously affects the water safety of Guangyuan and Nanchong City in Sichuan province, and Chongqing City. In addition, the proportion of “overhead storehouse” in the mining waste storage yard is close to 90%, the non-standard storage yards is 38.6%, the wastes sites which threatened by landslides are greater than 43.2%. Under the water/wind erosion, 5.4-7.2 ton/year of toxic metals (mainly Pb and Zn) diffuse to the adjacent soil and water systems, eventually causing permanent contaminant. The terrain, climate, dumped scale, supervision and management are the factors that affect the safety of mining waste, relevant departments should focus on the preliminary layout of mine tailings ponds and strengthen the management of small-scale mining wastes yard.

Improving the economic efficiency of water use for crop production in China′s major grain-producing areas (MGPA) is greatly significant to promote national food security, water safety, rural revitalization, the Yangtze River protection, as well as the ecological protection and high-quality development of the Yellow River Basin. Regional economic efficiency of generalized water use for crop production (EEGWUC) was represented by the ratio of regional crops output value to the total amount of blue and green water consumption in the crop production. Considering both the five major staple crops like rice and wheat, and 12 non-staple crops such as sugarcane, peanut, cotton, etc., the spatio-temporal evolution characteristics of the EEGWUC was analyzed in the 13 provinces of MGPA in China during 2000-2018. With the improvement and supplement of the influencing factors in existing researches, this study analyzed the influencing factors of EEGWUC in MGPA based on the panel data regression method. The results show that: (1) from 2000 to 2018, annual mean of EEGWUC in any of the 13 provinces in China′s MGPA were in fluctuating upward trend, and the annual average of EEGWUC in MGPA increased from 140 CNY/ million tons to 267 CNY/ million tons. This efficiency in Jilin showed the most obvious fluctuation, while that in Hubei embodied the weakest fluctuation. The inter-provincial difference of EEGWUC in MGPA decreased with fluctuation, and the 13 provinces can be ranked by the EEGWUC annual average from the highest to the lowest as follows: Jiangsu (265 CNY/ million tons), Hunan, Jiangxi; Liaoning; Henan, Sichuan; Jilin, Hubei; Hebei, Anhui, Inner Mongolia, Heilongjiang and Shandong (144 CNY/million tons). (2) The significantly positive factors of EEGWUC in MGPA included fertilizer application per unit sown area, water use in the irrigation per unit area, the ratio of sown area of food crop to the regional sown area, the ratio of effective irrigation area to regional cultivating area, water-saving irrigation index, reservoir capacity per unit sown area, utilization coefficient of irrigation water. Meanwhile, amount of agricultural plastic film used per unit sown area, proportion of fixed asset investment in the GDP of the primary industry, provincial water use structure and educational level of the rural population, impacted the EEGWUC significantly and negatively. Based on this, suggestions were put forward to improve the EEGWUC in China′s MGPA, such as adjusting the mode of agricultural production, strengthening the construction and operation of water conservancy infrastructure, increasing agricultural subsidies and preferential policies for agriculture, allocate water resources scientifically and strengthening education and publicity, and improving the management of government financial expenditure.

Based on the household survey data from Hubei, Hunan and Henan provinces in the central part of China, this paper examines the impacts of farmers’ health and non-farm employment on their use intensity of clean energy. Conditional mixed process(CMP) is employed. Results show that farmers with poor health or non-farm employment are more likely to use clean energy. Because of the institutional and market constraints, the interaction effect between health status and non-agricultural employment on clean energy use intensity is not statistically significant. Heterogeneity analysis shows that age, income, and the perception of ecological environment do not influence the impact of health status on the use of clean energy. Whereas, young and middle-aged farmers, farmers with low income or farmers with strong perception of ecological environment are influenced by non-agricultural employment and are more likely to use clean energy intensively. Therefore, to upgrade the energy use structure of rural households, the government should improve rural health services, strengthen the promotion of  knowledge of clean energy in rural areas, and help to eliminate the system and market obstacles to more rural residents’ participation in non-agricultural employment. This can help to enhance the whole nation’s health and to promote Clean Energy Priority Development Strategy.

Identifying spatial differences in the factors influencing farmers' ecological farming is of great significance for guiding farmers' ecological farming and promoting ecological conservation of farmland. Based on 1 203 peasant household ecological farming questionnaires from 47 counties in 11 cities of Jiangxi Province, spatial autoregressive and geographically weighted regression models were first used to explore the spatial distribution of peasant household ecological farming, and then the statistical relationship between ecological farming and its influencing factors were analyzed from both the global and local scales. The results show that: (1) Ecological farming of peasant household shows a typical spatial autocorrelation distribution characteristic, which are mainly influenced by government subsidies, the proportion of labor force, the degree of part-time employment, the distance to the county seat and whether the farmland is permanent basic farmland; (2) From a global perspective, except for the distance to the county seat, the other four factors have a positive influence on ecological farming. The coefficients of government subsidies, whether it is permanent basic farmland and the degree of part-time farming are 0.71, 0.58 and 0.32 respectively; (3) From a local perspective, the degree of influence of each factor shows typical spatial differentiation characteristics, and there are differences in different spatial locations, so the incentive policies for farmers should be developed in a zonal way. Finally, based on the spatially differentiated characteristics of the factors influencing ecological farming, three suggestions were put forward, including the full implementation of a permanent basic farmland protection system, maintaining and increasing government agricultural subsidies, and encouraging and guiding farmers to work outside the farm during their leisure time.

With the rapid socio-economic transformation and development, although the housing conditions of farmers have been improved, the differences in housing allocation have also been sustained and strengthened, which has led to a series of social problems. This paper uses the questionnaire survey data of 813 households live in the urban and suburban villages of Wuhan city. The T-test, the Gini coefficient and Thiel index were used to measure and compare the housing differentiation between urban villages and suburbs. On this basis, the nonlinear Blinder-Oaxaca regression decomposition method was applied to analyze the contribution of capital endowment and location conditions to the differentiation of housing allocation between urban and suburb villages. The results were as follows: at first, under the same level of capital endowment, there are significant differences between housing allocation in urban and suburban villages. Second, the difference in housing area allocation of farmers in urban villages is greater than that of suburban villages, while the housing conditions are opposite. Furthermore, the differentiation of the housing area between the two regions is mainly determined by the difference in capital endowment (58.62%), while the differentiation of housing conditions is mainly derived from the location conditions difference (57.77%). In conclusion, it is suggested that the authorities should pay attention to the improvement of the living conditions of vulnerable groups and the accumulation of farmers capital endowment, guide farmers to build reasonable and appreciate housing, strengthen the construction of suburban public infrastructure and housing facilities, and promotes the construction and management of central villages by village planning. Altogether contributes to improve farmers housing conditions and guarantee the harmonious development of society.