Promoting the coordinated development of the Ecological-Economic-Society (EES) system is the core requirement of the development strategy of the Yangtze River Economic Belt. By constructing a EES system coordination evaluation index, and by using coordinated development, ESDA and panel data models, the spatial and temporal differentiation characteristics and driving mechanisms of the coordinated development of the EES system above the prefecture level in the Yangtze River Economic Belt from 2000 to 2016 were measured and analyzed. The results show that: (1) The coordinated development of EES system is on the rise and the regional differences are gradually narrowing, but the overall development level is low; the Moderately dysfunctional type occupies the main body of development type; the development pattern of “northeast high and southwest low” is formed in the space, and the high-coordination zone is located in the core cities such as the Yangtze River Delta and the provincial capital of the central and western regions.(2) The coordinated development of EES system is hierarchical, the coordination degree is a pyramid type distribution from high to low, showing “clustering” characteristics, the degree of urban coordination in urban agglomeration is higher overall; the regional difference characteristics of coordination degree are significant, the downstream is more developed than the middle and upper reaches, and the cities along the river are better than the non-river cities. (3) The coordinated development of EES system presents strong positive spatial autocorrelation, H-H type is concentrated in the hot spot area, and the L-L type is more distributed in the cold spot area.; The local area correlation and cold hot spot space pattern generally shows that the coastal area is superior to inland, the downstream is more developed than the middle and upper reaches.(4) The spatial and temporal pattern of coordinated development of the EES system are driven by various factors, including the development of EES subsystems, geographic location, strategy and policy, spatial proximity effect, and so on.

In order to study regional sustainable development, this paper established a comprehensive evaluation system for large regions, which included economic development, social progress and ecological environment. The coupling and coordinated development of the Yangtze River Economic Belt(YREB) was evaluated from two latitudes of time and space based on the relevant data of 109 cities in the YREB from 2000 to 2015. The results pointed out that the integral coordinated development of the YREB was better than before, and it has changed from primary coordination to intermediate coordination during the past fifteen years. The results also showed obvious regional differences: the east was superior to the west, and the provincial capital cities had evident advantages. Meanwhile, the results indicated that the economic development played the most important role in the process of coupling coordination development of the YREB, and the ecological environment was the cornerstone. Based on the aforementioned findings, relevant strategies should be put forward from the aspects of developing human capital, building infrastructure, jointly governing and protecting the ecological environment.

Regional development gap is one of the key academic issues for economic researchers. Although to some degree it favors to factor flow and resource allocation, long-term and over-huge disparity may weaken the cooperative efficiency between regions. With expanding regional development gap, the way of narrowing the gap has also become the attentive focus of the society. Based on methods of population-economy growth elasticity, center of gravity, geographic concentration and inconsistent index, this paper examines the coordinated evolution law of the population-economy of Yangtze river delta within 2000-2015, and through this perspective explores the driving factors of regional development gap at different periods using spatial panel model. Results show that: the agglomeration pattern of regional population-economy changes responding to the evolution of development environment and policy. The approaching gravity center of pop and economy indicates the gradual narrowing development gap. Economic concentration shows a “Z” shape, while population concentration shows significant north-south difference. Inconsistent index of the population-economy exhibits relatively stable pattern of “core-edge” with the phenomenon of increasing developed cities and decreasing less developed cities, which respectively indicates the significant differences in regional development as well as the evolution of equilibrium trend. Driving factors of regional development gap vary in different periods, overall, the market force strengthens and government influence is weakening. Ordinary panel regression overestimates the effect of many influencing factors, and the declining spillover effects indicates the transition of regional development towards equilibrium. This paper selects one of China’s economic powerhouses-Yangtze River Delta as study area, aiming at offering scientific reference for regional coordinated development.

The coordinated and coupling development of ecological civilization construction and urbanization plays an important role in promoting regional sustainable development, so it is very necessary to study the coupling coordination of ecological civilization construction and urbanization. This paper takes the 26 cities of Yangtze River Delta Urban Agglomerations as an example, and evaluation indexes of ecological civilization construction and urbanization are established. The evolution of coupling coordination degree of ecological civilization construction and urbanization in 26 cities from 2008 to 2015 are analyzed by using the method of entropy TOPSIS and coupling coordination model. The results show that: (Ⅰ) The levels of ecological civilization construction and urbanization in Yangtze River Delta Urban Agglomerations are on the rise, and the higher the level of urbanization, the higher the level of ecological civilization construction. (Ⅱ) The level of coordinated and coupling development of ecological civilization construction and urbanization in Yangtze River Delta Urban Agglomerations is on the rise, but it is still at a low level. The coupling degree and coordination degree of ecological civilization construction and urbanization in Yangtze River Delta Urban Agglomerations are all fluctuating and rising. In 2015, the coupling degree was antagonistic and the coordination degree was slightly unbalanced on the whole. (Ⅲ) The spatial difference of coupling-coordination of the ecological civilization construction and urbanization in Yangtze River Delta Urban Agglomerations is obvious. The distribution of regions with high coordination degree has changed from “three points” (Hangzhou, Nanjing and Shanghai) in 2008 to “Z type” (Nanjing-Shanghai-Hangzhou-Zhoushan) in 2015. (Ⅳ) According to the level of ecological civilization construction and urbanization, 26 cities are divided into four types and several measures of ecological civilization construction and urbanization are proposed. It is expected to provide some help to the improvement of ecological civilization construction and urbanization of cities in Yangtze River Delta Urban Agglomerations.

Conflicts between ecosystem conservation and urbanization has threatened the human well-being. This study evaluates both supply and demand of water yield, carbon sequestration, and food production in the Hang-Jia-Hu region in 2000, 2005 and 2010 from perspective of “Water-Energy-Food” nexus. Spatial Gini-coefficient model, supply-demand ratio model and correlation model are applied to analysis spatial heterogeneities. Results show: (1) The yielding water decreased first and then rebounded, while the total amount of carbon sequestration and food production decreased slightly. The demand of water and food increased slightly, while the demand of carbon sequestration increased sharply. (2) The supply of water and carbon sequestration is significant within the hilly area located in the southwest. While the food production is clustered in the eastern plain. The demand of all three ecosystem services is inevitably concentrated in the densely populated areas. (3) The spatial distribution of evaluated ecosystem services is basically balanced, but the mismatch between supply and demand is prominent. Most areas suffered shortage of water, and urban area had hard pressure of carbon sequestration. (4) Water supply has a “trade-off” relation with carbon sequestration supply, while a “synergy” relation with food supply. Carbon sequestration supply is positive with food supply. Demand of all the three ecosystem services is positive with each other. WEF nexus is proved to show an interactive and supportive relationship in the region. Several adaptive polices are promoted to improve the regional ecosystem.

The paper focused on the evalution of county forest ecological carrying capacity of Zhejiang province that based on Pressure-State-Response(PSR) model with entropy weight and expert method to calculate the weight and combined the state-space techniques and vector mode with GIS to analyze the space-time distribution patterns and its spatial correlation of 71 counties from years of 2001 to 2016. As a result, firstly, Zhejiang province’s forest ecological carrying capacity (ZFEC) is in a moderate loading area with continuously improvement in the whole, and the indexes of the tree cutting intensity, forest fire disaster rate, unit area GDP, unit area industrial output value expressed maximum weight. Secondly, the distribution of ZFEC is exceptionally unevenly distributed, with the highest level of carrying capacity in the southwestern part ,followed by the middle part and the lowest in the northen part. Finally, the ZFEC shows significant spatial auto correlation and spatial aggregation with the most significant high-high clustering and mainly concentrates in the southwest districts of Zhejiang province.

On the basis of eddy covariance technique and flux data from June, 2016 to May, 2017, the characteristics of carbon flux in the mixed broadleaf-conifer forest ecosystem in Jinyun Mountain and its response to environmental factors are analyzed. The results show that the mean inteRdiuRnal variation of monthly CO2 flux presented a “U” shape during the study, and the minimum value is -0.95 mg·m ^-2·s ^-1 in July and the maximum value is 0.43 mg·m ^-2·s ^-1 in December. Moreover, there is obvious seasonal variation in the transition time of CO2 flux positive and negative values, among them, the time of daily carbon sink is the longest in summer and the shortest in winter; the NEE cumulant is negative and presented as carbon sink in 12 months of one year except December, in which is positive (20.38 gC·m ^-2·mon^-1) and presented as carbon source, the largest carbon accumulation is in July (-129.53 gC·m^-2·mon_-1), NEE, ER and total GEE are -566.49, 1 196.68 and -1 761.63 gC·m^-2·a^-1·respectively.Furthermore, PAR is the dominant factor affecting the NEEd, the relationship between them is consistent with the Michaelis-Menten model, NEEd decreases with the increase of PAR, and PAR can explain the change NEEd of 14.1%-58.2%; VPD is the limiting factor of NEEd, whose optimal range is 0.5-1 kPa, because too high or too low will reduce the response of NEEd to PAR; 5cm Ts is the dominant factor affecting NEEn,the relationship between them is consistent with the Van’t Hoff model, and NEEn increases with the increase of 5 cm Ts; SWC is the limiting factor of NEEn, when SWC is greater or less than 0.28 m-^3·m^-3, it will inhibit the NEEn with little effect. To sum up, the NEE capacity of mixed broadleaf-conifer forest in Jinyun Mountain is basically equal to that of other forest ecosystems at similar latitudes, while the total ecosystem exchange capacity and ecosystem respiratory intensity are larger.

The upper reaches of Minjiang River is not only an important part of the ecological barrier in the upper reaches of the Yangtze River, but also a vital water source lifeline for the Chengdu plain. InVEST model and shadow engineering method were used to assess the ecosystem water retention and its value in the upper reaches of Minjiang River, and this work had important significance for water conservation planning and establishment of payment for ecosystem service mechanism. The results showed that the average annual water retention amount of sub watersheds in the upper reaches of Minjiang River was 219.36 mm, the total water retention amount was 49.19 billion m ³ and the water retention value was 4.083 billion Yuan. Water retention amount and its value in our study area displayed some obvious spatial variation with high value areas mainly distributed in south central Wenchuan County and low value areas relatively concentrated in the regions of Songpan and Maoxian County. Due to the limitation of the evaluation method, the relevant findings of this watershed were obviously different and had poor comparability. However, it is sure that the upper reaches of the Minjiang River has huge water retention value. The quantitative assessment results and mapping can directly reflected the spatial variation in water retention and its value. It had strong applied value in the establishment of payment for ecosystem service mechanism and compensation efficiency analysis etc.

In order to study the larval resources conditions of fishes spawning drifting eggs in the lower reaches of the Minjiang River, the surveys of fish resources of early life stages were carried out in the lower reaches of the Minjiang River during May 7-July 30, 2016-2017. The results showed that there were 18 species of fish with drifting eggs, among which 8 species were endemic species in the lower reaches of the Minjiang River. They were Leptobotia microphthalrna, Leptobotia elongate, Leptobotia rubrilaris, Xenophysogobio boulengeri, Xenophysogobio nudicorpa, Sinibrama taeniatus, Jinshaia sinensis and Jinshaia abbreviata. Three important spawning grounds of fish with drifting eggs mainly located in the towns of Xijie, Gaochang and Juexi. The largest spawning scale of fish were Leptobotia microphthalrna and Leptobotia elongate, with the egg quantit w 652.75×106 ind. and 368.01×106 ind., respectively. The result of Canonical correspondence analysis showed that the increase of the flow stimulated the spawning of Hypophthalmichthys molitrix and Ctenopharyngodon idellus, as well as decreased the transparency and increased the density. High transparency stimulated the spawning of Rhinogobio typus. As the velocity increased, the drift densit of both the Jinshaia sinensis’s and Jinshaia abbreviata’s eggs  higher.

Regarding the status of water shortage in Kunming and the complexity of water system, this paper establishes a system dynamics model of water resources carrying capacity in Kunming（SD）with the system dynamics method, considering water demand, water supply, reuse of wastewater, field water supply, water shortage and other factors. By simulating the dynamic changes of water resources carrying capacity in Kunming from 2015 to 2030 under five schemes for the continuation of the status, economic development, resource conservation, environmental friendly and coordinated development type, we want to seek ways to improve the carrying capacity of water resources in Kunming city. The results show that the current continuation pattern of water resources water ha serious water shortages, and the water resources carrying capacity can easily reach the ultimate load-bearing value, and the sustainable development of resource, environment and social economy in Kunming cannot be realized; Although the economic development model ha improved the economic level, it ha exacerbated the problems of ecological environment pollution and water shortage, and the supply and demand ratio is lower than 0.25;Although the resource-saving or environmental friendly pattern ease the ecological environment pollution and shortage of water, but with the passage of time, water shortage s still severe;Coordinated development plan that appropriate to slow the growth of the scale of urban development, implementation of intensive use of water resources, sewage treatment and regeneration, strengthen the field of water supply under the premise of building a resource conserving and environment friendly society,can achieve a balance between supply and demand for water resources ,resource environment and social and economic sustainable development in Kunming. The coordinated development plan is the best of the five options.

Tourism development is an important way for ecosystem to provide ecosystem service values and it has a value-added effect. Taking Huangshan Scenic Area as a case, based on field surveys and interviews, by means of the functional value method, this paper analyzes the dynamic change of ecosystem service values in Huangshan Scenic Area (including core area and buffer zone) and the value-added effect of tourism development from 2005 to 2015. This paper argues that: （1） The value of ecosystem services kept growing annually. The total value of ecosystem services in Huangshan Scenic Area increased from 2.359 billion yuan in 2005 to 4.893 billion yuan in 2015. （2）The value of ecosystem services showed spatial differentiation as it increased from 1.045 billion yuan in 2005 to 1.948 billion yuan in 2015 in the core area, while the buffer area increased from 1.314 billion yuan in 2005 to 2.945 billion yuan in 2015. The average annual service value increase per unit area of the core area was 1.12 yuan/(hm ²·a), significantly higher than the buffer zone of 0.55 yuan /(hm ²·a). （3）Tourism development had a value-added effect on ecosystem services values. From 2005 to 2015, the change of land use in Huangshan Scenic Area was subtle, with change rates of the area of forest land, grassland, water area and unused land were less than 1% during 10 years, which had little impact on the increase of the value of ecosystem services. The value of tourism and leisure services accounted for the highest proportion both in the core area and buffer zone, with 78.99% of the total value of ecosystem services in the core area and 48.55% in the buffer zone. The increase in the value of tourism and leisure services played the most important role in increasing elosystem service values in Huangshan Scenic Area. This study shows that the development of tourism is an important way to practice the idea of ‘Lucid waters and lush mountains are invaluable assets’. However, we need to strengthen the protection of ecosystem and environment during tourism develop, in order to effectively provide ecosystem service values in tourism destinations.

Land renting is highly associated with farmers’ life. Based on the survey data of rice farmers in the Jianghan Plain of Hubei province, this paper introduced instrumental variables and applied the IV-oprobit model to control certain endogeneities to examine the impacts of land renting on farmers’ life satisfaction. The results found that when controlling the income level, land renting does not directly affect farmers’ life satisfaction, but it could indirectly improve life satisfaction by increasing agricultural income. To make further analyses, we divided the farmers into four groups according to their per capita net income from low to high, which are 0%-25%, 25%-50%, 50%-75% and 75%-100%.The results of stratified research showed that, the subjective welfare brought by land renting cannot be ignored especially for the farmers with lower income. Among the farmers in the lowest-income group, which is 0%-25%, the probability of feeling “very satisfied” will increase by 14.4% if the famer rent land from others. Moreover, for those who are in the income group of 25%-50%, farmers renting land have a higher chance, which is 28.4%, to be “very satisfied” with their life. However, land renting can also significantly decrease the life satisfaction of high-income farmers. Our research indicates that, land renting can improve farmers’ life satisfaction by exerting income effect and psychological effect as well. This result has a strong empirical significance for policies design particularly aiming at enhancing the welfare of poor farmers. In addition, this research also found that other driving factors such as the farmers’ health status, the purchase of real estate in the county town, the purchase of cars and washing machines, and the type of housing have significant impacts on farmers’ life satisfaction. The possible explanation is that they might affect life satisfaction by benefiting their lives or improving agricultural productivity. Finally, the results were discussed based on the perspective of improving the welfare of low-income farmers and some prospects for future research were put forward as well.

Land ownership adjustment is an important part of rural land consolidation project, and also an important tool to solve cultivated land fragmentation. Through making the fragmented contracted land centralized in one place, land ownership adjustment attempts to improve the fragmented status of farmers’ contracted land which caused by household contract responsibility system. Taking the rural land consolidation area in Jiangxia district, Xian’an district and Tongshan county of Hubei province as a study area, binary Logistic regression model was employed to analyze the effect of cultivated land fragmentation on farmers’ willingness to land ownership adjustment in rural land consolidation based on data from a farming household sampling survey. Results indicated that the number of parcels had a significant positive impact on the farmers’ willingness to land ownership adjustment. The per capita contracted land area and the degree of worry about the consequences of land ownership adjustment had a significant negative impact on the farmers’ willingness to land ownership adjustment. Farmers’ attitudes towards agricultural modernization had a significant positive impact on the farmers’ willingness to land ownership adjustment. Therefore, pay enough attention to the number of parcels in prompting farmers’ willingness to land ownership adjustment in rural land consolidation. By replacing the land with other farmers, and then merging and leveling, the number of parcels is reduced, and at the same time to increase the average area of parcels and reduce the average distance between parcels, and the degree of cultivated land fragmentation is finally reduced. Moreover, attaching great importance to the publicity of land ownership adjustment policy and the formulation of land ownership adjustment plan through intensive consultation with farmers to dispel misgivings about land ownership adjustment.

In view of the present situation of farmers’ little behavior with strong willingness in organic fertilizer application, 372 samples of fruit,vegetable and tea growers in Zigui and Dangyang city, Hubei province were used to explore the obstacles to the expression of farmers’ organic fertilizer instead of chemical fertilizer behavior from the perspective of technology environment, using coefficient bundle method.The results show:(1)The willingness to use organic fertilizer is deviated from the behavior of the farmers, and there are still 31.45% of them who have no real application of organic fertilizer with willingness in that case. (2) The technical environment obviously influenced the application of organic fertilizer, and massif elements and material acquisition are the two main factors. (3)The application of organic fertilizer for farmers is mainly influenced by amount of agricultural labor, soil fertility, agricultural products’ value recognition and difficulty in sales, acquisition costs, mean slope, government propaganda, weather livestock and poultry are farmed and organic fertilizer subsidy policy is enacted. Therefore, we should focus on the development of organic fertilizer technology promotion in the areas of crop-breeding coordination and soil remediation, the interests of farmers, what’s more creating a good policy and market environment, and strengthening the innovation and research and development of organic fertilizer technology, enhancing the matching degree between technical environment and technical attributes, promoting the popularization and use of organic fertilizer technology are also required.

A laboratory experiment was set up to explore the effects of biochar and calcium peroxide on the emissions of CH ₄, CO ₂, N₂O and microbial activity in upland red soil. Four treatments were tested in the experiment, which included CK (control), Ca (calcium peroxide, 1.72 g·kg^-1), C (biochar, 21.46 g·kg^-1), C+Ca (biochar, 21.46 g·kg^-1 and calcium peroxide, 1.72 g·kg^-1). The results showed that single application of biochar and calcium peroxide could reduce CO₂ and N₂O fluxes, and combined application (C+Ca) has the most significant effect on emission reduction of CH ₄, CO₂ and N₂O. Soil amendments has seriously alleviated the greenhouse effect based on the judgement obtained through the dynamic of global warming potential (GWP). Biochar and calcium peroxide increased soil pH, soil microbial biomass carbon and soluble organic carbon content to a certain extent. Soil amendments (biochar and calcium peroxide) can improve soil invertase, amylase and urease activity, and especially combined application (C+Ca) had the best effect. Therefore, the combined application (C+Ca) can effectively reduce the greenhouse gas emissions in upland red soil, and the application of amendments, such as biochar, played a certain role on emission reduction of upland red soil.

Based on the remote sensing retrieval of PM2.5 data in the long-time series, the temporal-spatial pattern of PM2.5 as well as its variation and sources of pollution in China from 1998 to 2014 were revealed by using the Theil-Sen median trend analysis, Mann-Kendall test and correlation analysis methods. The results showed that PM2.5 concentration reached the annual average criterion value of 10  μg/m³ specified by the World Health Organization (WHO) in the land area of only 24.67% during the period from 1998 to 2014. PM2.5 concentrations were less than 10 μg/m³ mainly in the Qinghai-Tibet Plateau, Taiwan, northern Xinjiang, north of Inner Mongolia and northwest of Heilongjiang, while the average annual PM2.5 concentrations were greater than 95 μg/m³ mainly in southern Xinjiang and North China Plain. During the period from 1998 to 2014, the concentration of PM2.5 increased by an average of 3.91 μg/m³ and the maximum value was 39.1 μg/m³ in 61.84% of the national land area. Among them, the central and western regions and the North China Plain exhibited a significant rising trend and some regions still show an increasing trend in the future. The driving factors of increase in PM2.5 concentration included natural factors and emissions from human activities, wherein it mainly came from the sand dust aerosol in the Taklimakan Desert in the southern Xinjiang, while those in the other areas mainly came from emissions in the human activities.

To understand the spatial distribution of total mercury (THg) and methyl mercury (MeHg) levels in sediments of park lakes in Shanghai City, the samples were collected from total 24 park lakes, including the central urban (CU) and the suburbs (SU) areas, respectively. The concentrations of THg and MeHg, and other parameters in sediments were determined and the risk of Hg pollution was assessed using geo-accumulation index methods. The results showed that the concentrations of THg (mean: 222.6 ± 138.4 μg/kg) and MeHg (mean: 0.52 ± 0.51 μg/kg) in the surface sediments of lakes in CU were significantly higher than those (mean: 91.8 ± 87.1 μg/kg THg; mean: 0.29 ± 0.26 μg/kg MeHg) in SU (p< 0.01). Moreover, THg and MeHg in the sediments were positively correlated with loss on ignition (LOI) (p< 0.05), while a weak correlation between the ratio of MeHg to THg (MeHg/THg) and LOI, indicating that organic matter in sediments may play an important role in inhibiting Hg methylation. The geo-accumulation index of THg revealed that lakes in CU was slightly polluted by Hg, however, lakes in SU was not polluted, indicating that the potential environmental risk of Hg in the surface sediments of park lakes could be low in Shanghai City.

Abstract：Impervious surface is one of the key factors impacting regional spatial planning and ecological development, thus effectively indicative of change in urban development. As the central city of Huaihai economic zone, Xuzhou has been shifting its focus from rapid urbanization to ecologicalization; there, therefore, are broad implications for characterizing the dynamics of its urban impervious surface. In this study, we first identified the best impervious surface extraction approach by comparing four different impervious surface indices, namely ISA (Imperious Surface Area Index), BUAI (Built-up Area Index), BCI (Biophysical Composition Index), and ENDISI (Enhanced Normalized Difference Impervious Surface Index). By combining the fractal theory and a landscape ecology approach, we then analyzed the spatial-temporal heterogeneity of impervious surface of Xuzhou urban area (consisting of eight districts) from 2000 to 2007 and to 2017, from the perspectives of administrative division, profile lines, and landscape pattern indices, in order to characterize the dynamics of impervious surface in the context of urbanization, and provide suggestions for the future development of Xuzhou city. Results show that (1) BUAI can map impervious surface effectively and its resultant accuracy (Kappa coefficient=0.81) was by higher than the other three indices; that (2) while each district varied in impervious surface area with the Old City district (mainly for business and financial purposes) and Jinshanqiao district (the economic and technological development zone) having the highest proportions of impervious surface, growing impervious surface has been observed in the east and southeaster parts of the study area according to our BUAI based profile line analysis; and that (3) the impervious surface landscape pattern of the study area tends to be fragmented (from filled growth to dispersed expansion), complex, and irregular, suggesting its increased overall heterogeneity. Our study can provide a scientific basis for the urban development planning and land use planning.

In this study, a total of 30 water samples (15 samples in each season) in Le’an River (Poyang Lake Basin, Jiangxi Province, China) were collected in December 2016 (dry season) and July 2017 (wet season) separately. Twenty-two physicochemical characteristics were analyzed, those included major ions, nutrients, and dissolved heavy metals, etc. Multivariate Statistical Analysis was used to analyze the hydrochemical characteristics and influencing factors. The results indicated that hydro-chemical types were different in three sections of the Le’an River, those were  HCO₃-Ca type in the upstream, SO₄-Mg-Ca type in the midstream, and SO₄-Ca-Na type in the downstream. The water chemical ions in the upstream were controlled by natural weathering of rock, while those in the midstream and downstream were most affected by anthropogenic activities. The concentrations of nutrients in the midstream and downstream water were higher than those from upstream water, while those nutrients had no significant differences between the midstream and downstream water. Additionally, the concentrations of nutrients in the dry season were higher than those in the wet season, and the concentrations of NH4⁺-N and TP in several water samples were higher than China's surface water Ⅲ quality standards. No significant difference of the dissolved heavy metals concentrations was observed between the midstream and the downstream waters. The main influencing factors of hydrochemical characteristic in the Le’an River were as follows: NH4⁺-N and Cl^- were affected by urban sewage; Cr, Cu, Zn, Fe, Pb and SO₄^2- were mainly attributed to industrial and mineral activities; NO^3- -N were affected by urban sewage, agriculture and mining activities jointly. The influencing factors of TP were complex in the wet season, which may be affected by soil soluble organic matter and agricultural fertilization, and in the dry season, the urban sewage was the main factor of TP. The results in this study could provide reference for the Poyang Lake Basin environmental protection.

A total of 102 samples were collected from the topsoil at a depth of 20 cm to predict and map the spatial distribution of soil pH over the Caotang River Basin in the Three Gorges Reservoir Area. The samples were divided into calibration (85%) and validation (15%) sets. Random Forest (RF) method was applied to predict the spatial distribution of soil pH based on parent materials and terrain indicators (Elevation, Slope, Aspect, Slope Height, Valley depth, Topographical wetness index, Vertical Distance to Channel Network, Multi-resolution index of valley bottom flatness, Slope Length). The major influencing environmental factors on soil pH spatial variability were investigated by the RF model. The results showed that soil pH was significantly positively correlated to Valley depth and Slope Length, while significantly negatively correlated to Elevation, Vertical Distance to Channel Network and Slope Height. Soils developed from Limestone of Triassic Daye formation had higher values of pH than that developed from Sandstone of Triassic Xujiahe Formation. The RF model had a good performance with the mean absolute error (MAE), the root mean square error (RMSE) and the determination coefficient (R²) of 0.47, 0.59 and 0.85, respectively. The model could explain 85% variation of soil pH in the study area. The major factors to soil pH variations were soil parent material and elevation. Therefore, RF model can serve as an effective method to predict the spatial distribution of soil pH, and can provide the basis and reference for other soil properties prediction at watershed scale.

According to the interpretation of high-resolution remote sensing images and field investigation on both sides of Jinsha River in the Xiluodu reservoir area, 161 landslides were identified. This paper started with the mechanism of landslide formation, and seven evaluation indies including elevation, height difference, slope, aspect, lithology, earthquake and rainfall were chosen to evaluate the hazard of landslides by AHP(Analytic Hierarchy Process) and information value method. The spatial distribution relationships between landslides and various factors were analyzed at first. The results showed that: (1) The landslide easily occurs in the regions with the elevation in the range of 600 - 1300 m, the height difference between 100 - 700 m, the slope between 15° - 40°, and with large rainfall. Moreover, the different slope aspects also had influence on the landslide, and there were relatively more landslides in the east, southeast and northwest direction. (2) The extremely high areas and the high risk areas accounted for 27.86% of the total study area, where 76.4% of the landslides locate, indicating that the landslides were very dense in these areas and the risk was relatively high, which was consistent with the actual situation. (3) The extremely high risk areas and the high risk areas mainly concentrate in the Xiluodu dam site along the river, which was the right bank area of the Jinsha River about 25 to 35 km away from the site of the dam, and the left bank area of the Jinsha River with 20 km away from the reservoir tail. And most of the areas in the middle section of the reservoir were moderate risk areas. (4) The correlation coefficient between the spatial distribution of landslide hazards and the risk assessment grade was 0.970 3. Verified by ROC curves, the evaluation results were ideal with the accuracy of 81.88%, which can provide theoretical supports for the disaster prevention and mitigation work in the reservoir area.

Using small watershed as sampling unit to carry out watershed landscape ecological risk assessment is of great significance in establishing early warning mechanism of watershed landscape ecological risk, improving watershed ecological environment and constructing ecological security pattern .Based on the land use data from 2000 to 2015, in the paper, the landscape ecological risk assessment model was constructed based on landscape pattern method, and the landscape ecological risk and spatial and temporal characteristics in Wujiang river basin in Guizhou province were evaluated and analyzed . The results showed that the landscape pattern of Wujiang River Basin changed significantly in the past 15 years and were showed as below: 1)The woodland area increased 2.85%, the wetland increased 0.13%, the cultivated land decreased 4.52%, the other land use increased 0.02%; 2)The ratio of block gold value to base value of landscape ecological risk during the year of 2000,2005,2010 and 2015 were individually 11.81%,12.05%,13.29%,14.04% and the change ranges during the year 2000,2005,2010 and 2015 were individually 10.9 km,22.8 km,10.7 km,12.8 km in Wujiang river basin.3)During the 15 years, different landscape ecological risk grades show different changing trend in area, among which, the area of the high and extremely high risk areas increased by 8.46% and 5.57% respectively; and the area of weak and low risk area decreased by 6.28% and 7.28% respectively. Therefore, because of the frequent human activities, the landscape ecological risk in the river basin is overall rising trend.

Ecosystem resilience is an important index to measure the health of regional ecosystem.Based on the resilient force coefficient of ecosystem and the limit coefficient of ecosystem resilience, the comprehensive evaluation model of ecosystem resilience is constructed, and the calculation results are classified by the standard gap leveling method.and the spatio-temporal evolution of ecological system resilience in 2000, 2005, 2010 and 2015 in Guiyang was quantitatively studied.The results showed that：(1) The resilience of the ecosystem in Guiyang City was mainly relatively-strong, medium and relatively-weak, accounting for about 95% of the total area, and the rest was very weak and strong, accounting for about 5%. (2) The resilience of the ecosystem in Guiyang City was weakened by fluctuation from 2000 to 2015, and the resilience was classified as weak and relatively-weak areas grew by 3.24% and 1.12% respectively, while the stronger areas decreased by 2.60%. (3) But the area with strong resilience increased by 0.83%, and the resilience of ecosystems in some areas increased.

The connection between rivers and lakes is an important measure to improve the aquatic environment, restore freshwater ecology and improve the living environment of human beings. However, the quantitative evaluation of the dynamic connectivity of the lake water system connectivity project in the city is few. Based on the plan of Bajiao-South Lake connecting project in Yueyang City of Human Province, the water from the Yangtze River to Bajiao Lake will be self-flowing to the South Lake through a newly excavated river channel in the Wangjiahe River Basin to improve water quality and aquatic ecological functions of Wangjiahe River and South Lake. The MIKE21 hydrodynamic model was used to simulate the 12 operating conditions at the minimum control water levels of 25.86 m and 26.06 m at the South Lake exit under the flow rates of 6 m³/s, 12 m³/s, and 24 m³/s in flood season and non-flood season, respectively. The connectivity of the two lakes under water diversion conditions was analyzed and a quantitative evaluation index was proposed. The results showed that when the initial flow was 24 m ³/s and the minimum water level was 25.86 m, the connectivity between the flood season and the non-flood season reached the best state. The water exchange period was shortened to 5.59 d and 5.17 d, respectively. Judging from the changes in the connectivity index, the “leading to the lake” and the “two lakes connected” promoted water system connectivity and improved the ability of the water body to circulate.