Abstract：The new concept of coordinated development requires coordinated development among three industries, and the high-quality development of the Yangtze River Economic Belt is inseparable from the coordinated development of three industries. This paper estimates coordination degree of three industries for nine provinces and two cities in the Yangtze River Economic Belt, and adopts static panel, panel threshold and spatial panel models to estimate the impact of transportation, energy and information, three types of infrastructure construction on coordination degree of the three industries in the Yangtze River Economic Belt. Results state that three types of infrastructure construction all significantly improve coordination degree of three industries in the Yangtze River Economic Belt. The improvement effect of transportation infrastructure in the upper reaches of the Yangtze River is the biggest, and the effect of information and energy infrastructure in the middle and lower reaches is bigger. There is a threshold effect for information and energy infrastructure on the improvement of coordination degree of three industries in the Yangtze River Economic Belt. From the low range to the medium-high range, the improvement effect is progressively increasing. There is a spatial autocorrelation effect on coordination degree among three industries in the provinces and cities of Yangtze River Economic Belt. Under this condition, three types of infrastructure construction still improve the coordination degree of three industries, and the improvement effect of information infrastructure on the coordination development of three industries is the biggest. The Yangtze River Economic Belt needs to expand the total investment of infrastructure construction continuously, and shore up the targeted weak spots of infrastructure construction in different regions, and fulfil the spatial spillover effect of coordination degree of three industries among different regions.

Abstract：Based on the industrial innovation index, the spatial econometric model is used to analyze the spatial and temporal evolution pattern and spillover effect of the innovation capability development of strategic emerging industries in the Yangtze river economic belt from 2001 to 2016. The research finds that :(1) the innovation capacity of strategic emerging industries in the Yangtze river economic belt increases rapidly on the whole, but the spatial difference is expanding on the whole. The spatial non-equilibrium of innovation capability is remarkable, and the “east is strong and west is weak” zonal pattern is stable. (2) the innovation capacity of strategic emerging industries in the Yangtze river economic belt is significantly positively correlated in space. Hot spots in the Yangtze river delta region are stable, while cold spots are increasing. (3) strategic emerging industries each subdivision industry innovation ability development state is differ, high-end equipment manufacturing industry, new material industry, new energy automobile industry are the core shaft schema evolution, a new generation of information technology industry is single center polarization mode evolution, energy conservation and environmental protection industry, biological industry, new energy industry is the core group schema evolution; (4) spatial spillover effect exists in innovation capacity of strategic emerging industries. In addition to human resources, economic development level, industrial structure, government policy, external contact level and innovation environment produce obvious positive effects.

Abstract：Analyzing intercity relations from the perspective of urban networks is an important way to understand the spatial structure and functional relation of regions. Urban networks are multiplex: urban networks constructed by different intercity flows might not have the same structure. In this study, four kinds of urban networks of the Yangtze River Delta were constructed, that is, the Internet network, transport network, corporate network, and knowledge network. Based on social network analysis and nodal region analysis, the structure of these four urban networks were comparatively explored through the lens of local node and dyad, global network and organization pattern, followed by preliminary explanation of their determinants. The results showed that: (1) The Internet network has a most balanced structure. Centered on Shanghai, Nanjing, Hangzhou, and Suzhou, it presents coordinated development organized by “one dominant city+three subdominant cities+hinterland”. (2) Transport network and corporate network are highly similar with a well-connected core region while two weakly-connected sides in the North and South. The flow triangle of Shanghai-Nanjing-Suzhou and the Z-shape flow corridor of Nanjing-Shanghai-Hangzhou-Ningbo are distinct in the core region. The northern side has weaker connectivity than the southern side. Both networks have three independent nodal regions organized by “single core city+surrounding cities”. (3) Knowledge network is sparsest and most polarized. The overall network is weakly connected except for the core region, displaying highly hierarchical development organized by “one dominant city+one subdominant city+two subordinate cities+peripheral cities”. (4) The discrepancies of these four networks are associated with geography, location, industry, academic resources and development strategies.

Abstract：Since the reform and opening up, rural labor forces have been poured into the city in large quantities. As promoting national economy, those labor forces have also exerted some influences on the urban ecological environment. With resident population increasing and environment pollution aggravating, it is of great value and practical significance to study the effects from the perspective of labor transfer. In this research, carbon footprint methods are adopted to analyze the outcomes in terms of production and consumption based on transferred population survey in Wuhan City, and to further explore the differences and related factors of carbon footprint before and after labor migration. The results show that 17.69 million tons carbon emissions are produced by nonlocal labor force per year, in which the consumption carbon footprint is 1.95 million tons, and production carbon footprint is 15.74 million tons. Compared with that before the move, carbon emissions of 0.46 million tons and 14.39 million tons are increased respectively. This difference is mainly affected by gender, age, off-farm working hours and technical skills. It is negatively correlated with gender and sex, while positively correlated with working hours and technical skills. Besides, contract and language communication could also have positive effects.

Abstract：The researches of the spatial and temporal characteristics as well as driving mechanism of land expansion of Changsha-Zhuzhou-Xiangtan urban agglomeration, a typical agglomeration in Hunan province, is of great benefit to formulate the high-quality development planning of the urban agglomeration and land spatial development planning.A variety of analysis methods including Expansion Intensity Index, Landscape Expansion Index and SAR Probit model were used to study the characteristics of urban land expansion and driving mechanism. The results indicate: (1) The characteristics of urban land expansion varied when the urban agglomeration was at different stages. Its intensity was strengthened first and weakened later, forming a spatial pattern of “core-periphery” expansion. (2)The urban expansion process of urban agglomeration changed from diffusion to coalescence, which was consistent with the urban growth theory“diffusion-coalescence”.The growth type of leapfrogging was dominant during the urban land expansion period during 1995-2010;the growth type of edge-expansion,became the mainstream during 2010-2018.(3)With the factors like socio-economy, geography, accessibility and spillover effects, dual impacts were made in the process of urban land expansion.The socio-economy and spillover effects turned out to be the dominant factor controlling the urban land expansion. Furthermore, this paper puts forward a driving mechanism framework of land expansion, which was in the name of “four forces” model. These research findings will do good to the better understanding of urban land expansion of urban agglomerations and provide a scientific theory for the integration and construction of Changsha-Zhuzhou-Xiangtan urban agglomeration.

Abstract：Fractional vegetation coverage is an important index to measure vegetation growth and describe ecosystem environment. Based on the MODIS NDVI data set from 2001 to 2018, the fractional vegetation coverage in China was calculated using mixed pixel dichotomy model. Then, the spatial and temporal characteristics of annual fractional vegetation coverage in China are analyzed. To explore the response mechanism of fractional vegetation coverage to climate and human disturbance, and the future change characteristics of human disturbance to fractional vegetation coverage. The results show that: (1) fractional vegetation coverage in China is on the rise as a whole. The fractional vegetation coverage in Northwest China is significantly lower than that in Southeast China. Except the fractional vegetation coverage of the Qinghai-Tibet Plateau is declining, the others are on the rise, which has a certain sustainability. (2) Among all vegetation types, the average annual fractional vegetation coverage of mixed forest is the highest, while that of grassland is the lowest. The change rate of crop vegetation is the largest, while that of mixed forest is the smallest, and it will change from improvement to degradation in the future. The other types showed continuous improvement. (3) Fractional vegetation coverage is negatively correlated with temperature and positively correlated with precipitation in China. Moreover, precipitation has a stronger impact on fractional vegetation coverage than temperature. This indicates that precipitation is the main factor affecting the change of fractional vegetation coverage. (4) The impact of human activities on fractional vegetation coverage in China shows an increasing trend as a whole. In the future, the influence of human activities will be mainly reverse persistence. This indicates that the fractional vegetation coverage in China will be affected by human activities in the next 18 years.

Abstract: In order to study the influences of urban lakes eutrophication on the elemental compositions of aquatic macrophytes, carbon (C), nitrogen (N), and phosphorus (P) ecological stoichiometry studies were conducted on six common aquatic macrophytes in three lakes during the growing season, and key environmental factors that driving the changes of the leaf elements were explored. The results showed that: (1) The changing ranges of C, N, P contents in leaves of aquatic macrophytes in different lakes were respectively from 397.03 to 672.70 mg/g, 10.63 to 39.16 mg/g and 1.15 to 13.30 mg/g; the ranges of C/N, C/P and N/P were respectively from 13.15 to 50.36, 31.39 to 458.60 and 1.88 to 19.06, among which P contents in leaves varied the greatest and C contents varied the smallest. (2) Spearman’s correlation analysis suggested that the elemental compositions of leaves of Phragmites australis,Nymphaea tetragona and Ceratophyllum demersum had significant correlations with the eutrophication index of water bodies; P contents in leaves increased with the rise of the lake eutrophication index, but C/P and N/P in leaves decreased accordingly. (3) RDA analysis showed that the changes of C, N, P contents and C/N/P in leaves of aquatic macrophytes in spring were mainly affected jointly by the permanganate index (CODMn) of the water and the total organic carbon contents of sediment (SOC); while in summer they were affected mainly by the concentrations of total phosphorus in water (TPW), and in autumn by the contents of the total phosphorus in sediment (TPS).

Abstract：with operation of reservoirs in the upper Yangtze River with the Three Gorges Reservoir as the core on the period of 2003-2017, the temporal and spatial distribution of sediment in upper Yangtze River has been changed Macroscopically, Jinsha River is no longer the largest sediment supply area for the TGR. The water and sediment transport in the upper Yangtze River is concentrated in the flood season from May to October, the peak of water and sediment between 1956 and 2002 is basically synchronized, but it has changed in the period of 2003-2017, and the flow characteristic curve changed from clockwise to counterclockwise. Though sedimentation in the TGR has been reduced sharply from 2014 to 2017, sediment siltation rate is still high (85.2%). Sedimentation of sediment d < 0.031 mm which can easily flocculated takes up the highest proportion in the backwater area of the TGR（63.5%，2009-2013）, In addition, a large number of sediment flocs observed in the typical river reaches suggest that there is a high probability of fine-grained sediment flocculation in the TGR. Unbalanced water and sediment transport also caused sediment erosion in the reach of Zhutuo-Qingxichang.

Abstract：Land use and land cover change (LUCC) has been a force of global importance, affecting the spatiotemporal variations of vegetation coverage, land surface temperature (LST), albedo and other land surface parameters. Since the construction of the Three Gorges Project (TGP) was commenced, LUCC in the Three Gorges Reservoir Catchment (TGRC) has received increasing attention. In this study, the land cover classification data with a spatial resolution of 300 m acquired from the European Space Agency (ESA) were used to analyze the land use change in the TGRC from 2000 to 2015. The Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI), LST and albedo data were obtained through the advanced Google Earth Engine (GEE) platform, and then their spatiotemporal patterns were analyzed. The relationships between seasonally integrated NDVI (i.e., SINDVI), LST, and albedo were investigated, respectively. The influences of land use change on SINDVI, LST, and albedo were analyzed. Our results show that the remarkable land use change has appeared in the TGRC from 2000 to 2015. The cultivated land, grassland, and shrubland decreased by 2.4%, 0.05%, and 0.62%, respectively, while the forest, waterbody, and artificial surface increased by 1.98%, 0.04%, and 1.06%, respectively. During the research period, SINDVI increased by 2.89, LST decreased by 0.224℃, and albedo decreased by 0.002. The spatial distribution of SINDVI showed an increasing trend, while the LST and albedo showed declining trends. There was a negative relationship between SINDVI and LST, as well as a negative relationship between SINDVI and albedo in most areas of the TGRC. Different land use types present various effects on SINDVI, LST, and albedo. The quantitative relationships between LUCC and the key land surface parameters in the TGRC were analyzed systematically from 2000 to 2015, and the results will provide guidelines for the evidence-based policy for better management of the natural environment and land resources in the TGRC region.

Abstract：In order to study the structure and spatial and temporal distribution of phytoplankton communities in the main stream of Jinsha River, 14 sections of the main stream were investigated and analyzed in the spring and autumn of 2017-2018. The results showed that there were 100 species (including varieties) of phytoplankton in 8 phyla in the main stream of Jinsha River, mainly composed of diatoms (56%), cyanobacteria (22%) and green algae (11%). The density of phytoplankton ranged from 0.019 3×106 to 0.341×106 cells/L, and the biomass of phytoplankton ranged from 0.016 to 0.434 mg/L. There were significant differences among the river sections. Shannon diversity index ranged from 1.168 to 2.519, Pielou evenness index ranged from 0.559 to 0.876, Margalef index ranged from 1.573 to 3.36, and The diversity index of each river section varies. The water environment of Jinsha River mainstream was moderately polluted by comprehensive evaluation. The results of hierarchical clustering and ordination showed that the sample plot communities in spring and autumn of 2017 and 2018 were divided into three groups. The upper, middle and lower reaches show similarities in different seasons and years, and the spatial and temporal differences of phytoplankton communities are caused by the environmental differences of different sections. In time, the phytoplankton community structure in the main stream of Jinsha River has obvious succession in each season, both continuation and alternation; in space, the more uniform and vigorous the phytoplankton community is from upstream to downstream, the more obvious the spatial heterogeneity is. The cluster and ordination of phytoplankton revealed the distribution of dominant species, the number of species and the similarity of habitats.

Abstract：In this study, an extended hydrological sensitivity method was proposed to quantify the impacts of climate change and human activities on seasonal river runoff. The second-order mixed partial derivate, which was obtained based on the Taylor's expansion of runoff change, was taken to be the magnitude of the interaction impact between climate change and human activities. We applied the equation to separate the extent of the impact of climate change, human activities and their interactions on dry season runoff. Moreover, an ABCD model including snowmelt module was used to calculate the change of the soil water storage and the groundwater storage. By taking the Lhasa River Basin as a case study, it was found that the runoff in the dry season exhibited a less significant upward in the last 60 years. Climate change, which causes an increase in the dry season runoff, is the dominant factor leading to the increase of runoff, followed by human activities and their interaction effects which cause varying degrees of decreases.

Abstract：ENSO is one of the most significant air-sea factors affecting global and regional rainfall, and has obvious periodic characteristics. Based on the daily precipitation data of 545 meteorological stations in China from 1961 to 2016 and according to the daily rainfall intensity standard defined by the Central Meteorological Observatory of the China Meteorological Administration, this study classified the rainfall into eight intensity types, diagnosed the multi-attribute temporal variation characteristics of eight different intensity rainfall amounts and their responses to ENSO in different time and frequency domains. The results showed that: Firstly, low intensity rainfall amounts in China mainly decreased from 1961 to 2016, while high intensity rainfall amounts mainly increased. The contribution rate of rainfall amounts with different intensity to total rainfall amounts also had similar variation characteristics, so as the contribution rate of storm rainfall amounts with different intensity to total storm rainfall amounts. During the transition from low intensity rainfall to high intensity rainfall, the intermediate intensity rainfall amounts and its contribution rate increased first and then decreased. The above showed that rainfall in China was developing towards extreme direction. Secondly, except for heavy rainfall and total rainfall amounts, other rainfall amounts with different intensity had oscillation periods of 4 years or less, which was in good agreement with the occurrence and development cycle of ENSO events. Thirdly, except for light rainfall amounts, the abrupt changes of other rainfall amounts with different intensity had passed the test of 0.05 significance level. Among them, moderate rainfall, heavy rainfall, heavy rainfall, storm rainfall, heavy storm rainfall, extremely storm rainfall, total storm rainfall and total rainfall amounts changed abruptly in the year of 1967, 1972, 1995, 1995, 1996, 1994 and 1973, respectively. Among the abrupt changes mentioned above, most of the abrupt changes of low intensity rainfall occurred in La Nina year, while those of high intensity rainfall occurred in El Nino year. Fourthly, except for light rainfall, other rainfall amounts with different intensity had a good correlation with ENSO from 1961 to 2016, and passed the test of 0.05 significance level. In different time and frequency domains, rainfall with different intensity in China and ENSO had better consistency in four years and shorter scales. Especially in the low energy spectral region, the high intensity rainfall amounts and total rainfall amounts were consistent with ENSO in the long term change.

Abstract：Multi-beam bathymetric measurements made during November 2014 were used to investigate micromorphology of the North Passage of the Yangtze River estuary. The physical properties of the micromorphology were assessed by grain size analysis of bottom sediment samples collected. The morphological changes of the riverbed channel were assessed by the digitized bathymetric data. Results show that channel erosion occurred in the North Passage from 1979 to 2019 because of human activities. net volume loss and mean annual net volume loss reached 0.36 × 108 m ³ and 0.009 × 108m ³ yr ^-1 in the North Passage. Increase of depth water in the North Passage may aggravate the saltwater intrusion. The sediment supply at Datong Hydrological Gauging Station showed a declining trend because of the influence of the Three Gorge Dam (TGD), which may have contributed to channel erosion of the outer estuary. Channel erosion occurred in main channel and distinct accretion occurred in the northern side and southern side because of the Deepening Waterway Project. In addition to three kinds of common bedforms: smooth surface, gully and dune, there are also two kinds of micromorphology under the human intervention: hollow, low-lying land and dredging mark. The mean length and mean height of dunes in the middle reach is 39.41 and 0.48 m, respectively, and the mean length and mean height of dunes in the lower reach is 11.11 and 0.33 m, respectively. The value of bed roughness (ks) associated with the dunes in the middle reach and lower reach is 0.14 and 0.19, respectively. A small area of dunes in the middle and lower reaches of the North Passage was observed for the first time in the turbidity maximum zone of the Yangtze River Estuary.

Abstract：With the acceleration of urbanization, air pollution has become one of the major problems faced by every city.We used the concentration data, meteorological data and land use type data of 2017 PM2.5 monitoring station in Hefei，and we combined the random forest algorithm (RF) and land use regression model (LUR), to simulated the spatial distribution characteristics of PM2.5 concentration in Hefei.And the influencing factors of PM2.5 were analyzed by principal component analysis.The results showed that: (1) The daily variation characteristics of PM2.5 concentration in Hefei City showed two peaks, most of which appeared at 8∶00-9∶00 in spring, summer and autumn, while appeared at 10∶00-11∶00 in winter.The low values are generally between 15∶00 and 17∶00. The change trend of PM2.5 concentration in the whole year is similar to that in spring. The change of PM2.5 concentration is the most stable in summer.(2) In 2017, the concentration distribution of PM2.5 in Hefei weakened from the city center to the outside, forming a spatial distribution pattern of high in the north and low in the south, high in the West and low in the East.(3) In terms of influencing factors, the change of PM2.5 concentration is negatively correlated with precipitation, wind speed and relative humidity, sunlight has a greater influence on PM2.5 concentration, air pressure and other pollutants have a positive correlation with the change of PM2.5 concentration, and NO2 among atmospheric pollutants has a greater influence on the change of PM2.5 concentration.

Abstract：In order to evaluate the health conditions of rivers and solve the problem of the highly subjective weights of evaluation indicators in river health assessment, BP neural network is used to simulate respectively the ecological status and social service function of the Yuan River and to judge by coordination degree whether they are developing in a coordinative way. The results show that: (1) The comprehensive evaluation index of the river health within Yichun section and Xinyu section in 2016 is greater than 0.6, which indicates that the river is healthy. The coordination index of Yichun section is 0.8, which shows it is well coordinated. In comparison, the coordination index of Xinyu section is 0.79, which means it is moderately coordinated. (2) Compared with the previous year, the natural ecological status index  fx of Yichun section and Xinyu section in 2006 and 2010 decreased, comparative indicator data ,which was mainly caused by the degraded water quality of the Yuan River that went down from the previous Grade III to the present Grade IV;(3) The natural ecological status index fx of Xinyu section in 2016 stands at 0.59, which is much smaller than the social service function index of 0.68. Therefore, it is suggested that the natural ecological restoration be privileged in the future river policy for Xinyu section of the Yuan River.

Abstract：Based on the monthly precipitation data of 103 meteorological stations from 1960 to 2017 in the Dongting Lake Basin, the monthly mean reanalysis data from NCEP/NCAR and Z-Index, we analyzed spatial-temporal variation characteristics of seasonal drought in recent 58 years in the Dongting Lake Basin and displayed the features of synchronous atmospheric circulation with different range levels of drought, in order to enhance the understanding of seasonal drought. The results shows that, the Z-index in the Dongting Lake basin exhibits significant inter-annual and inter-decadal variation characteristics in the past 58 years. To be more specific, the Z-index is characterized by relatively severe drought in 1960s, obvious inter-annual transitions of drought and flood in 1970s and 1980s, wet phase in 1990s, and an inter-decadal transition of drought and flood after entering 21st century. The droughts in spring, summer and winter occurred mostly before 1990, and the seasonal drought in the basin exhibits different spatial distribution characteristics in different ages. The multi-annual average drought frequency of each station in the basin intermediates between 10% and 30% nearly. Through the features of synchronous atmospheric circulation, the Eurasian pattern teleconnection wave train exerts an important effect on the drought in every season in the basin. The East Asia/Pacific pattern and the Silk Road pattern teleconnection have noticeable effect on the intensity and position of the western pacific subtropical high in summer and autumn. The drought are mainly affected by the cold airflow from the north in spring and winter, and the drought with larger area is more likely to occur in the summer(autumn) when the subtropical high is weak(strong) and northerly.

Abstract：In order to understand surface runoff in deep hilly region of northern of Sichuan province, Lizikou catchment acted as the research area in Jialing River watershed. Based on the observed rainfall and runoff data from 2005 to 2016, correlation analysis, elastic coefficient of precipitation and flow duration curve applied to reveal the change regularity and correlation between rainfall and runoff. The results were as followed: (1) Annual precipitation and runoff was uneven distribution under inter-annual scale. The increase tendency of precipitation and runoff was not significant. The increase tendency of runoff is less than that of rainfall. (2) The monthly distribution of rainfall and runoff is extremely uneven. From June to September, the rainfall and runoff depth accounted for 67.4% and 78.5% of that in whole year, respectively. As a result, it prone to flooding in summer. (3) Extremely high flows, normal flows and extremely low flows were 2.9, 0.2 and 0.01 m ³/s, respectively. Extremely high flows caused by prolonged rainstorm. Normal flows often emerged during no rainfall in the wet year or during the heavy rain and rainstorm in the dry year. Extremely low flows were mostly due to no rainfall or only a small amount of rainfall. (4) In the typical individual rainfall, the flow during curve under heavy rain, moderate rain and light rain transferred from sharp-thin to flat. The lag times for peak flow ware 1.5 h, 3.67 h and 5 h for light rain, moderate rain and heavy rain, respectively, which became longer with the decrease of rainfall. Peak flow became lower with the decrease of rainfall. All in all, the correlation between rainfall and runoff is extremely significant in yearly, monthly, and daily (P<0.01). There are great differences among different time scales.

Abstract：Based on the micro-data of rice growers in Jiangsu Province in 2018, this paper uses logit model to empirically analyzes the influence of farmers' labor endowment characteristics and risk aversion degree on the willingness to adopt and adopt behavior of the all-inclusive forms of pest control. The study found that: First, the family labor status has a significant impact on farmers' technology adoption behavior. When the household labor force is short, the willingness and behavior of farmers to adopt have been significantly improved. At the same time, the main left-behind labor force in the part-time situation, farmers are also more willing to adopt this prevention and control technology. Second, the higher the risk aversion of farmers, the more unfavorable the improvement of their willingness to adopt technology, and the negative impact on actual adoption behavior. Third, there is a scale threshold for farmers' technology adoption willingness and behavior, with a threshold value of 15 mu. The number of Left-behind labor force has no significant difference on technology adoption behavior under different scales. The improvement of risk aversion degree has a significant negative impact on the willingness and behavior of different scales of households. The conclusion of the study provides some suggestions and references for further promoting the service of unified defense rule.

摘要： 基于可持续生计框架，选择生计资本总量和结构作为中介变量，采用“双重差分-中介效应”模型和农户调查面板数据，实证分析了不同模式农地整治对农民生活满意度的影响效应及其作用机理。结果表明：（1）地方政府主导模式和新型农业经营主体主导模式不仅对农民生活满意度具有显著的直接正向效应，而且通过增加生计资本总量和改善生计资本结构，进而对农民生活满意度产生显著的正向间接效应；（2）相比于地方政府主导模式，新型农业经营主体主导模式更能显著增加生计资本总量和改善生计资本结构，进而更能显著提升农民生活满意度；（3）地方政府主导模式通过增加生计资本总量提升农民生活满意度的作用更强，而新型农业经营经营主体主导模式通过改善生计资本结构提升农民生活满意度的作用更强；（4）通过winsorize缩尾处理进行稳健性检验，证实研究结果具有相当的稳健性。