Analyzing urban land development intensity from the perspective of spatial effects can provides a new reference for optimizing the development and utilization of urban land resources. Based on the spatial pane data of 108 cities in the Yangtze River Economic Belt from 2003 to 2017, a comprehensive application of kernel density estimation and spatial autocorrelation methods were used to characterize and identify the spatial and temporal pattern of urban land development intensity in the Yangtze River Economic Belt. By constructing the economic geographic spatial weight matrix, the spatial panel Durbin model and its partial differential decomposition methods were used to analyze the spatial spillover of urban land development intensity in the Yangtze River Economic Belt.The results indicated that:(1) During the study period, the intensity of urban land development in the Yangtze River Economic Belt continued to increase, and inter-city differences continued to expand, accompanied by polarization. (2) The spatial distribution of urban land development intensity in the Yangtze River Economic Belt is not random, but there is a significant positive global spatial autocorrelation. The local spatial pattern is mainly HH and LL, supplemented by LH and HL. (3) The urban land development intensity of the Yangtze River Economic Belt has a significant positive space spillover effect, that is, the local urban land development intensity will drive the neighboring urban land development intensity. (4) Economic development, population urbanization, secondary industry, urban transportation, and real estate investment have a positive direct effect on local cities; economic development, population urbanization, and secondary industry have a negative spillover effect on neighboring cities. urban transportation have a positive spillover effect on neighboring cities.

Based on the perspective of the integration of the Yangtze River Delta, this paper examines not only the evolutionary trend of the balanced development of the two major urban agglomerations in the Yangtze River Delta and the middle reaches of the Yangtze River, but also the promoting role of the polarization-spread effect of the Yangtze River Delta in affecting the economic growth of the middle reaches of the Yangtze River and regional balanced development, when using the Dagum’s Gini coefficient decomposition, the spatial externality theoretical model of economic growth, and the Spatial Autoregressive Model (SAR). The study draws four key conclusions: (1) The integration process of the Yangtze River Delta has not expanded the remaining gap in the development level of the middle reaches of the Yangtze River. In fact, the narrowing of the “gap between groups” of the two urban agglomerations is the main driving force for balanced regional development, while the effect of narrowing “internal differences” is relatively weak. (2) The spread effect of the Yangtze River Delta urban agglomeration on the middle Yangtze River urban agglomeration is greater than the polarization effect, which means that the positive spatial spillover effects in the Yangtze River Delta provides a significant boost to the economic development of the middle reaches of the Yangtze River and narrows the gap in development levels between the two major urban agglomerations in the Yangtze River Delta and the middle reaches of the Yangtze River, thereby promoting balanced development. Nevertheless, with the spatial correlation of the middle reaches of the Yangtze River being ignored, the diffusion effect of the Yangtze River Delta will be significantly overestimated. (3) The estimates imply that the higher the level of balanced development in the middle reaches of the Yangtze River, the more it will help the Yangtze River Delta’s spread effect to be fully realized. (4) Finally, we finds that the spread effect of different cities in the Yangtze River Delta is tied into the interaction of factors such as economic scale, industrial structure and geographical distance, presenting a nonlinear mode.

The environmental problem of industrial agglomeration is a hot topic in academic research in recent years. From the perspective of tourism industry agglomeration, the panel data and spatial panel measurement model of 31 cities in the urban agglomeration in the middle reaches of the Yangtze river from 2005 to 2016 were used to explore the impact of tourism industry agglomeration on ecological efficiency and spatial heterogeneity, the results showed that: The overall ecological efficiency of urban agglomeration in the middle reaches of the Yangtze river is on the rise, with significant internal imbalance. The ecological efficiency of Wuhan Metropolitan area is the highest, followed by urban agglomeration around Poyang Lake and Urban Agglomeration around Changsha-Zhuzhou-Xiangtan.Regional ecological efficiency has a strong spatial linkage and dependence, and is affected by spatial spillover effect. On the whole, the influence of tourism industry agglomeration on ecological efficiency is u-shaped, and the influence of different stages of tourism industry agglomeration on ecological efficiency is obviously different. Regionally, tourism industry agglomeration in Wuhan Metropolitan area and Urban Agglomeration around  Changsha-Zhuzhou-Xiangtan  has a significant positive effect on the improvement of ecological efficiency, while tourism industry agglomeration in Poyang Lake area has no significant effect on the improvement of ecological efficiency.

Industrial land supply is an important embodiment of the industrialization process and industrial economic development. Analyzing the temporal and spatial characteristics of industrial land supply scale is conducive to promoting the structural reform of land supply side, promoting high-quality industrial development and optimizing the spatial pattern of land. Based on the announcement data of industrial land supply in Chongqing from 2009 to 2018, the industrial land supply database of Chongqing was established, and the temporal and spatial variation law of industrial land supply scale in Chongqing was analyzed by locational Gini index, kernel density distribution, hot spot analysis and trend analysis. The results show that: (1) From 2009 to 2018, the supply scale of industrial land in Chongqing was in a general trend of fluctuation and decline, and the districts and counties with large supply scale concentrated in the main urban area of Chongqing and the western area of Chongqing. The supply location showed a more obvious distribution in the direction of northeast to southwest. The locational Gini index has the characteristics of volatility, and the spatial distributions are unbalanced and balanced repeatedly. (2) The scale of industrial land supply points presents the spatial layout pattern of “main ring-dot”, and the main ring presents the inner and outer core density change circle layer of “median value-secondary high value-high value”. The high-density core gradually gathered to the center of the main urban area, which is closely related to the establishment of Chongqing Liang Jiang New Area, the establishment or upgrading of industrial parks, and the development of resource-based industries. The hot spot areas of supply scale change in the east and west sides of the main urban area, and the cold spot areas are concentrated in the northeast corner of Chongqing. (3) The central urban area of Chongqing and its western and southern regions had the advantages of large industrial land supply scale, which was consistent with the changes of industrial economic development of Chongqing and the development layout of the city, and have laid a good foundation for the construction of Chengdu-Chongqing city economic circle.

The purpose of the study is to explore the online initial allocation of various water pollutant emission permits. According to the characteristics of various water pollutants, the specified bidding language is designed base on the value of water environmental capacity. The bidding language can provide an accurate quotation for multiple units of different water pollutant emissions over time. Aimed at each enterprise needs for various combinations of emission permit, the mechanism design model for online auctions is developed. On the basis of the model, the winner determination process and payment calculation process are designed. Thus, the auction mechanism is generated. The mechanism makes allocation decision immediately as each bid is revealed online and without the knowledge of enterprises who will subsequently arrive. The allocation decision determines whether a certain combination is allocated for the enterprise. The mechanism makes payment decision before the enterprise leaves. The theoretical analysis shows that the mechanism not only can attract more enterprises to volunteer for the auction, but also can incentive each enterprise to declare his truthful arrival time, unit value of water environmental capacity and depart time. Compared with the effective allocation under complete information, the mechanism achieves good results in many aspects such as social welfare, transaction rate of enterprises and utilization rate of emission permits. The mechanism helps to make the fair and efficient initial allocation plan of water pollutant emission permits.

Accounting for residents’ domestic water use, clarifying the dynamics of the evolution of spatial-temporal patterns, and quantifying the driving effects of spatial-temporal differences are important to improve the efficiency of residents’ domestic water use in the Yangtze River Economic Belt. By calculating urban and rural residents’ domestic water consumption, a center of gravity model is established, and LMDI is used to decompose residents’ domestic water into consumption intensity effect, per capita consumption effect, urbanization effect, and population scale effect from time and space. The results show that: (1) The urban and rural residents’ domestic water consumption is increasing and decreasing respectively, the former has less upstream than the middle and lower reaches, and the latter has more balanced upstream, middle and lower reaches. (2) The center of gravity of domestic water use of urban and rural residents moves to the northwest, from Xianning and Yueyang to Jingzhou respectively. The imbalance between the two shows an increasing and decreasing trend respectively, and the former is greater than the latter. In this process, the upstream and downstream provinces and cities play a significant role. (3) The intensity of urban and rural consumption water consumption and per capita consumption level are the main factors that promote and inhibit the reduction of residents ’domestic water consumption. Urbanization and population growth will lead to an increase in residents’ domestic water consumption. The effect of changes in the proportion of urban and rural population is heterogeneous. (4) In terms of narrowing the difference with the average level, regardless of the overall perspective or the urban-rural perspective, consumption water intensity and per capita consumption level have opposite effects, and urbanization has spatial heterogeneity. Based on this, it puts forward suggestions on paying attention to the impact of residents’ consumption on residents’ domestic water consumption and improving water consumption quotas, and points out that it is necessary to further reduce accounting errors and further explore the impact of household, behavior, gender and other factors on residents’ domestic water consumption.

Under the influence of strong tide, the north bank of Hangzhou bay is affected by human activities such as reclamation. Base on the measured data in 1982 and 2017, this paper analyzes the dynamic variation characteristics of the tide dynamics, suspended sediment concentration (SSC), salinity and morphology of the north bank of Hangzhou Bay in 35 years. Compared with 1982, the tidal current fields is unchanged in the region, appearing the character of reciprocating flow. Flood velocity is faster than fall. The depth-average SSC in the study area decreased by 22%. The spatial distribution of the high SSC area moved from Luchaogang to the inward bay, the bottom SSC was concentrated, the concentration gradient of surface and bottom layer increases. The SSC in the Jinshan Trough increased by 79% over the years. In the study area. In consideration of the changes of coastline and topography, it is closely related to the sediment load reduction of the Yangtze River, topography erosion and deposition, and local human activities. The north bank of Hangzhou Bay will still face the risk of erosion.

An investigation was carried out at Yichang section in the middle reaches of the Yangtze River from May to July in 2018 and 2019 to study the status of early-stage fish resources of this river section. The survey focused on the spatial distribution abundance patterns of fish eggs by difference analysis. It turned out that the total of 15 963 eggs was collected. About 24 species of spawning drifting eggs in 4 families in 1 order were identified. The dominant species of fish eggs were Hypophthalmichthys molitrix (32.94% of the total numbers), followed by Pseudolaubuca sinensis (30.80%) and Ctenopharyngodon idellus (12.65%). In 2018, it was estimated that the average density for eggs was 5.61±9.72 ind./100 m ³. In 2019, there was 9.80±16.09 ind./100 m ³. There were significant differences in the main emergence time of different kinds of fish eggs. Difference analysis results showed that there were significant differences(P<0.05) between the drifting density of fish eggs in spatial distribution. In horizontal distribution, the highest density of fish eggs was found at the middle of river（7.54±20.04 ind./100 m ³ in 2018,13.15±25.49 ind./100 m ³ in 2019）and the density of fish eggs at the south of river (6.20±7.92 ind./100 m ³ in 2018, 9.25±14.12 ind./100 m ³ in 2019) was clearly greater than at north of river(3.07±4.71 ind./100 m ³ in 2018, 7.00±11.65 ind./100 m ³ in 2019). In vertical distribution, the density of spawn at surface layer was the lowest. The dispersal characteristics of the fish eggs in the river would be an important support for the study of the location of the spawning ground and the estimation of spawning scale in Yichang section.

The influencing factor analysis of the scale evolution of water conservancy scenic spot (WCSS), can provide reference for promoting the construction of this kind of scenic spot, and enhancing regional sustainable development. With LMDI model, the factor contribution of scale evolution of WCSS along Yangtze River Economic Belt (YREB) are quantified. The factors include the construction intensity of WCSS, the development degree of water conservancy projects, the structure of water resources allocation and the endowment of water resources for the first time. The results show that: (1) For the WCSS scale evolution of the whole YREB,the influence of the endowment of water resources is the strongest positive,while the structure of water resources allocation shows the weakest impact. (2) For the WCSS scale evolution in each provinces along the YREB, among the four factors, the construction intensity of WCSS, and the development degree of water conservancy projects, play the strongest positive role in Sichuan, Chongqing and Guizhou, have respectively the most important positive and negative effect in Hunan, Hubei, Anhui and Zhejiang, and contrarily play respectively significant negative and positive roles in Yunnan. The most significant factor with positive influence in Jiangxi and Jiangsu is the development degree of water conservancy projects. The main negative influencing factor in Sichuan, Chongqing and Jiangsu is the structure of water resources allocation, while the water resource endowment of YREB shows negative effect in Guizhou and Jiangxi. Then some focalized suggestions are put forward on the construction of the WCSS for YREB.

Soil is not only main sink but also potential source of persistent organic pollutants (POPs) in their long-range atmospheric transportation over the world. Atmosphere-soil exchange of POPs is a key process of their environmental fate, including atmosphere-surface gas (or diffusive) exchange, wet and dry deposition (or atmospheric bulk deposition). Many factors influence the process, including physico-chemical property of POPs, micrometeorological conditions, physico-chemical property of surface soils and land-covered vegetation. This paper briefly reviews the current reports on atmosphere-soil exchange of POPs and related influence factors, and outlooks the need-to-do works in the future, as well as the relative models and equations on the exchange process were listed in this work. Ambient temperature controls partitioning behavior between gas and solid phases (including between gas and particle in atmosphere and between atmosphere and soil compartments), which impact the processes of atmospheric bulk deposition and diffusive exchange between atmosphere and soil compartments. Moreover, temperature vertical profile caused by solar radiation results in a vertical eddy diffusion in air layer close to ground. Horizonal wind speed further improves the eddy diffusion, while atmospheric turbulence reduces deposition of particulate POPs in atmosphere. Soil organic matters, including organic carbons and black carbons, control the sorption and desorption processes of POPs in soil. Furthermore, temperature and humidity in surface soils impact partitioning coefficient of POPs between atmosphere and soil. Soil mineral composition also influences the sorption and desorption of POPs in soils. Vegetation can catch gaseous and particulate POPs from atmosphere by absorption and adsorption, and release them into surface soils by litter, while they can also reduce temperature variation of surface soil covered by vegetation, further decrease volatilization of POPs from soils. Although many positive results in atmosphere-soil exchange have been reported until now, there are still many works needed to develop, e.g., quantification of coupling effects of multiple factors in the atmosphere-soil exchange process, dynamic estimation on the diffusive exchange flux of POPs between atmosphere and soil under in-situ complicate conditions based on typical field study, and quantification of the effect of urban vegetation on removal of atmospheric POPs and accumulation of soil POPs in urban scale.

The short-term leaching process of salt marsh litters has an important effect on the water quality for Chongming Dongtan Wetland. In this paper, litters of typical salt marsh plants in the Chongming Dongtan Wetland which divided into stems and leaves were collected and inundated in the laboratory for simulating the leaching process in 48 hours. The concentration of dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) was measured by total organic carbon analyzer then converted to the amount of cumulative release. UV-visible spectroscopy parameters were the indicator of the concentration of chromophoric dissolved organic matter (CDOM), and change characteristics of fluorescent components in CDOM were determined by fluorescence excitation emission matrix spectra (EMMs) combined with parallel factor (PARAFAC) analysis. Results showed that in the first 48 hours of leaching process, the release process of DOC,TDN, CDOM, two humic-like fluorescent components and two protein-like fluorescent components show a logarithmic curve, which increase rapidly in the first 8 hours but increase slowly or decline slightly from 8 to 48 hours. The differences of initial matrix properties among plants and their parts have a significant effect on the release amount of DOC and TDN from litter. The maximum cumulative release of TDN was positively correlated with the initial organic carbon and nitrogen contents. nitrogen which in litters is more easily lost than organic carbon. The relative amount of each fluorescent component changed little, but there were significant differences among different plant species, which is indicate that the initial leaching of litter is dominated by physical process. Our results show that the leaching of salt marsh litter has a significant impact on the quality of tidal water.

This paper takes the Yellow River ECO-Economic Belt as the research object, including qinghai, Ningxia, Gansu, Henan, Hebei, Shaanxi, Shanxi, Inner Mongolia, Beijing, Tianjin and Shandong, and uses the air quality monitoring data from 2015 to 2018 to study its spatiotemporal variation characteristics.The results show that: (1)The overall air quality of the Yellow River ECO-Economic has been improved, but the improvement of PM10, NO2 and O3 is not obvious.(2)In the spring, autumn and winter when the temperature is low, the pollutant concentration will increase. The lower the temperature is, the pollutant emission of some cities in the middle and eastern regions will significantly increase, which makes the difference in air quality of the whole Yellow River eco-economic belt greater, among which the seasonal fluctuation of SO2 is the most obvious.(3)The gap of air quality between regions is widening. Shaanxi, Shanxi and Henan are becoming the air pollution center of the Yellow River ECO-Economic Belt , and the core area of pollution is gradually moving to the west.

To understand geographical presentation of rapid urbanization and dense river network in Suzhou China, the authors utilize remote sensing information of different spatiotemporal resolution (2002-2018) to map the built-up areas and river network within the city through standardized processes. A vertical analogous quantitative method is applied to analyze the spatiotemporal relationship between urban expansion and river network recession at regional and pixel scales. Such relationship is essential in order to predict likely responses of river network recession induced by accelerating urbanization around rivers in terms of characteristic parameters such as river network density, river chains, nodes, connection rate and fractal dimension, and shows the following results: (1) The urban constructions in Suzhou have changed from expanding in all directions around the regional downtown to expanding around the multiple downtown associated with a networked connection. (2) The river network density has decreased during the urban expansion, with a stable connection rate induced by similar connectivity index, and a slightly decreased fractal dimension indicated slightly decrease of river network complexity. In the meantime, outside of the downtown, the river network has not shown obvious changes in the farmland and vegetation area. (3) The river network is significantly affected by urban expansion. Before 2010, the river network density has decreased evenly distributed in all grid cells. But after 2010, the decreases of the river network are more concentrated in grid cells with a lower proportion of built-up increment, which meant the decreases mainly occurred in the border of the urban expansion. The method in this research can provide scientific basis for the spatial planning decision making of urban ecosystem and the remote sensing scale effect research.

Soil aggregate is an important indicator of soil quality and sustainable land utilization, and impacts the retention abilities of water and fertilizers. The differences of the aggregate stability in the small watershed scale are sensitively affected by the land pattern of human interference, while the influence of land uses on the aggregate is rarely reported in the small tributary of Yangtze River, located in the hilly region of western Hubei. The purpose of this study was to figure out the effects of five land use patterns (cypresses forests (CF), vegetable field (VF), stone dike terrace(ST) abandoned farmland (AF) and natural forest(NF)) on the distribution and stability of soil water-stable aggregate. The soil from the 0-10 cm and 10-20 cm layer under different land uses were collected to analyze the composition and differences of soil aggregate stability by the wet sieving method. The result showed that ⅰ)The dominant size fraction of soil aggregate in CF, ST, AF and NF was >2 mm, mean proportion of which was 57.66%. While that of VF was dominated by <0.25 mm microaggregate, with an average of 60.86%. It was indicated that the stability of water-stable macroaggregate(> 0.25 mm) was significantly affected by land uses; ⅱ)The soil stability and erosion resistance of woodland were superior to those of agricultural land, and abandonment of cropland was conducive to the restoration of soil stability; ⅲ) fractal dimension(D) was positively correlated with the proportion of macroaggregate(>0.25 mm), the percentage of aggregate destruction, and soil erodibility(K), but negatively correlated with the aggregate diameters (MWD&GMD). D of soil water-stable aggregate could definitely reflect structural stability and erodibility of soil in a small watershed. Therefore, it is considered that the conservation of forest land and underground cover layer is the optimal management mode to improve the stability of soil structure in this area. These research results can provide theoretical reference for the rational land utilization and the melioration of soil structure in the small watershed region of Western Hubei Province.

In order to explore the spatial characteristics of reservoir hydrochemistry and dissolved inorganic carbon in karst geological environment. Pingzhai Reservoir is selected as the study area which is the water source of Qianzhong Water Conservancy Project in Guizhou Province located in typical karst area. Stratified sampling of Pingzhai Reservoir is conducted during the summer thermal stratification period (July 2019), analyzing the main physical and chemical data and dissolved inorganic carbon isotope of water bodies. The results show that: 1) Pingzhai Reservoir has obvious thermal stratification in summer: surface water layer (1~-10 m), thermocline (-10~-30℃ m), constant temperature layer (-30~-60 m). The water temperature decreases with the increase of depth, and finally stabilizes (T (average): 25.62~12.43℃). The pH, dissolved oxygen (DO), electrical conductivity (EC), chlorophyll a (Chl-a) and other physical and chemical properties of water also show obvious stratification in vertical direction. 2) The hydrochemistry type of Pingzhai Reservoir is HCO3+SO4-Ca, and its hydrochemistry is mainly controlled by the carbonate balance system; 3)Change of dissolved inorganic carbon. (DIC) and its isotopic composition (δ13CDIC) in water: DIC concentration gradually increased with the increase of water depth (DIC (average): 1.8~3.03℃mmol/L), δ13CDIC shows a slight trend (δ13CDIC (average): -6.23‰ ~-11.45‰). According to the analysis, solar radiation, the distribution of aquatic organisms, photosynthesis, respiration intensity and the degree of decomposition of organic matter are different at different depths, resulting in significant stratification of the physicochemical properties of water and DIC, which further affects the fractionation of δ13CDIC. The dissolution and precipitation of carbonate rocks have little effect on the content of DIC and its stable isotope fractionation.

It is very important to study the influence of reservoir construction on the water temperature of the river channel and to know the changing rules of the water temperature of the reservoir, the temperature of the released water and the water temperature of the river channel. They are of great significance to the restoration of ecological environment and the biodiversity of river channel.In this paper, the laterally-averaged 2D reservoir water temperature model is used to simulate the water temperature distribution and the discharge temperature of Jiangjiakou reservoir, and the one-dimensional longitudinal temperature model is used to simulate the water temperature of downstream river waters at different years, and we focus on the research on the change of the water temperature situation in the National Aquatic germplasm resources reserve of fish at 23.6 km below the dam. The results showed that the water temperature in the reservoir is obviously stratified, resulting in the significant phenomenon of "cold-temperature stagnation" and " heated-temperature stagnation " in the river. The drop in spring and summer can be up to 3.6℃, and the increase in autumn and winter can be up to 4.1℃. By means of the one-dimensional longitudinal temperature model which is used to simulate changes in water temperature along the river with or without the influence of tributary inflow, we found that due to the water river tributary import and solar radiation influence, the water temperature along the river has effectively alleviated. The reserve 's water temperature is close to the natural water temperature, and it did not change the reserve's the original water temperature environment of fish. It will not adversely affect the normal growth and reproduction of fish in the reserve.

In order to analyze the effect of land cover change resulted from rapid urban expansion on karst thermal environment of Guilin city in Southwest China, land surface water and heat fluxes were estimated with the modified METRIC（Mapping EvapoTranspiration at high Resolution with Internalized Calibration）model from Landsat images in the study area, and validated with the ground measurements. The change effect of the percent cover of land cover such as vegetation, building, water, bare soil and bare rock on land surface water and heat fluxes was analyzed. Results show that the changes of land cover percentages in the middle of the ranges show significant impact on water and heat fluxes than in the extremely low or extremely high values of the ranges. The significant ranges are from 0.1 to 0.8 for vegetation cover percentage, from 0.2 to 0.8 for building cover percentage, from 0.2 to 0.9 for bare soil cover percentage and bare rock cover percentage.  Within the significant ranges, latent heat fluxes rise 4.0%～12.0% and 2.0%～5.0% while sensible heat fluxes drop 5.0%～16.0% and 3.0%～11.0% in response to the 0.1 increase of vegetation cover percentage and water cover percentage respectively. In contrast, sensible heat fluxes increase 5.0%～17.0%, 3.0%～11.0% and 4.0%～14.0% while latent heat flux decrease 3.0%～9.0%, 2.0%～8.0% and 4.0%～9.0% in response to the 0.1 increase of building cover percentage, bare soil cover percentage and bare rock cover percentage respectively. The increment of vegetation cover percentage shows more significant effect on enhancing latent heat flux and reducing sensible heat flux than that of water cover percentage. Meanwhile, the increment of building cover percentage has more significant impact on enhancing sensible heat flux and reducing latent heat flux than those of bare soil cover percentage, a little than those of bare rock cover percentage.

In the context of climate change, the mitigating effect of the heat island effect of sponge city reconstruction has become one of the most concerning issues. Accurately obtaining the surface temperature before and after reconstruction of the sponge city is an important prerequisite to precisely evaluate the mitigation of sponge city reconstruction of the urban heat island. Meteorological observation sites often have a relatively long spatial distance from the sponge reconstruction area, and the non-applicability of their data greatly limits the development of evaluation. In this paper, Qingshan District and Sixin District in Wuhan city are taken as research areas. Based on the remote-sensing monitor and infrared thermal imaging technology to estimate the surface temperature of the spongy areas from the macro and micro view. The regional comparison is an important approach to take the strategy space for time to get the surface temperature changes before and after construction that is used to evaluate the results of sponge city construction on the mitigation of the urban heat island effect. Studies have shown that the sponge city reconstruction has a certain effect on reducing heat island effect on the industrial site (Qingshan District) from the macroscopic point of view, but the reconstruction has no obvious effect on Sixin District with a low degree of exploitation and development. Seeing from the microscopic point of view, the different transformation methods, the various layout types, and even the different colors of the same material have an impact on the mitigating effect of the sponge island heat island. The establishment of regional comparison and the approach to take the strategy space of time can set up an effective evaluation system for the mitigation effect of the sponge city reconstruction of the urban heat island. This method has a great practical and applied value which provides a new way to evaluate the mitigating effect of sponge city reconstruction on urban heat island effect.

Based on natural disaster data from 1900 to 2018 in the Global Emergency Disaster Database EM-DAT (EM-DAT), the trend test methods and space statistical methods were used to explore the temporal and spatial features and correlation of global natural disasters. The results show that: (1) Floods, droughts and storms are the most harmful. Floods occur most frequently, droughts cause the most deaths, and storms cause the most economic losses; (2) The frequency of disasters increased first and then decreased slightly, showing an overall upward trend; the number of deaths due to disasters decreased significantly after 1932,  showing a downward trend; economic losses from disasters continued to increase, showing an overall upward trend; (3) The disaster frequency pattern shows a tendency to expand in the north-south direction and shrink in the east-west direction, and has the trend moving to the southeast; The number of disaster deaths first showed a “northwest-southeast” distribution pattern, and then transformed into a “southwest-northeast” pattern, and this pattern continued to weaken until finally it reappeared the “northwest-southeast” pattern; The average center of disaster economic loss has a greater distance in the east-west direction than in the north-south direction, and has the trend moving to the northwest; (4) Floods, storms, earthquakes, epidemics, and landslides are significantly positively correlated with all disasters, with correlation coefficients above 0.57. Among them, the correlation coefficient between earthquakes and storms is the highest (0.906).

The farmland transfer is an inevitable choice for the realization of agricultural modernization. Based on the internal and external constraints of farmland transfer, this paper analyzes the impact of farmers ’livelihood capital and factor flowing decisions on farmland transfer. Based on the CFPS survey data, the MVP model is used to empirically test that the impact of farmer households' livelihood capital on farmland transfer and the impact of other livelihood factor allocation behaviors on farmland transfer. The results show that: ① natural capital, physical capital and financial capital can promote the farmland transfer-in and inhibit the transfer-out; human capital can promote the transfer-out and inhibit the transfer-in; social capital has a positive impact on the transfer-in and transfer-out of farmland.②Natural and physical capital can inhibit the transfer of labor, while human, financial and social capital can promote the transfer of labor; natural and social capital will inhibit the purchase of mechanical services, while human, physical and financial capital will promote the purchase of mechanical services.③farmers' farmland transfer behavior is not only restricted by their own livelihood capital, but also affected by the allocation behaviors of other livelihood factor. Farmers' labor transfer will promote farmers' transfer out of farmland and inhibit farmland transfer in; farmers' purchase of mechanized services will inhibit the farmland transfer out and promote the transfer in. Finally, in order to improve the development of farmland transfer market, the paper puts forward the policy enlightenment of improving the management and service system of farmland transfer, improving the livelihood capital of farmers, and improving the relevant factor market.

Family farm is an effective way of rural revitalization, and the influential factors of its performance have received widespread attention. Based on the resource dependence theory and a survey data of planting family farms in the three cities in the Yangtze River Delta, this paper analyzed the impacts of the operating environment on the performance of family farms by a structural equation model. Results show that: The operating environment has overall significant and specific effects on the performance of family farms. Among them, infrastructure construction environment and marketing management environment have the most significant effect on the survival performance of family farms, vocational education environment has the most significant effect on the growth performance of family farms, vocational education environment has the most significant effect on the innovation performance of family farms. This study shows that "to promote survival by improving markets and building facilities" and "to stimulate growth and innovation by strengthening vocational training" are more efficient development paths for family farms. Therefore, the optimization mechanism of operating environment of family farms should follow the principle of efficiency optimization, that is, allocating more policy resources to a more favorable operating environment, and then promoting the multi-level performance of family farms more effectively.

The adoption of eco-agricultural technology by farmers is the key point to promote the green agricultural development. Market and government both significantly affect farmers' adoption behavior, and their function is worth discussing. Based on the micro survey data of 925 farmers in Hubei, Hunan and Anhui province through Heckman sample selection model, this study explores the impact of market profits and government incentives on farmers' adoption of eco-agricultural technology from two aspects: adoption behavior and adoption degree. This research shows: (1) The economic effect has a significant positive impact on farmers' technology adoption behavior and degree, and the income fluctuation has a significant negative impact on farmers' technology adoption behavior and degree; (2) There are significant differences between the impacts of technology policy on technology adoption behavior and degree. Specifically, technology subsidy policy has a significantly positive impact on farmers' technology adoption behavior and adoption degree, while technology publicity policy only has a significantly positive impact on farmers' adoption behavior; (3) From the perspective of interaction effect, economic effect will significantly mitigate the positive impact of technology subsidies on farmers' technology adoption behavior, while income fluctuation will significantly reduce the positive impact of technology subsidies on farmers' technology adoption behavior. The research shows that market profit is the key factor to stimulate farmers to adopt eco-agricultural technology. Therefore, we should pay attention to the impact of market profit on farmers' technology adoption behavior in future technology promotion.