Using city-level invention patent authorization data published in the CNRDS database from 2000 to 2019, this paper examines the spatial differences and convergence of innovation development in the Yangtze River Delta region. The Dagum Gini coefficient and its decomposition results show that: （1）The overall difference of innovation development in the Yangtze River Delta region shows a gradual downward trend from 2000 to 2019, with the largest difference in innovation development in Anhui Province and the smallest in Jiangsu Province;（2）Inter-provincial differences are the main source of differences in innovation development in the Yangtze River Delta, accounting for about 70% of the overall differences in innovation and development in the Yangtze River Delta;（3）The analysis of the convergence mechanism shows that the innovation and development of the Yangtze River Delta region has typical  β convergence and club convergence characteristics; the overall sample has significant σ convergence characteristics, but the provincial sample σ convergence characteristics are not obvious. The conclusions of this paper are of great significance for narrowing the spatial differences of innovation development and promoting the diffusion and radiation of innovation agglomeration development in the Yangtze River Delta.

Territory space ecological conservation and restoration planning is an important special planning in the territory space planning system, among which the identification and demarcation of the conservation and restoration area is the key content of the planning. At present, the territory space ecological conservation and restoration of provincial research conducted less, so the research taking Jiangsu Province as the study area, by building a multi-level index system for the important area and ecological sensitive area and its hierarchy in the identification of evaluation, and then integrated the two results to demarcate the ecological conservation and restoration areas at all levels in Jiangsu Province. The results showed that: (1) The ecological conservation and restoration area of Jiangsu Province could be divided into the key ecological conservation area, the key ecological restoration area and the general ecological restoration area, with the area of 17 548, 4 688 and 16 981 km2 respectively, accounting for 16.17%, 4.32% and 15.65%. (2) Key ecological conservation areas mainly include lake areas such as Taihu Lake and Hongze Lake, the lower reaches of the Yangtze River transit section and the eastern coastal wetlands, etc. Key ecological restoration areas are mainly distributed in Taihu Lake basin in southern Jiangsu Province, along the Yangtze River, and Yi-Shu-Si river basin in northern Jiangsu Province. The general ecological restoration areas were mainly concentrated in the northern Yi-Shu-Si river basin, Huaihe-Lixia River basin in central Jiangsu Province, the upper reaches of the Yangtze River transit section and the eastern coastal areas, and the rest were scattered in northern Jiangsu Province. (3) The key ecological conservation area is mainly composed of water area and wetland, while the key ecological restoration area and general ecological restoration area are mainly urban peripheral area and agricultural production land.

Peaking carbon dioxide emissions is a key measure for China to cope with the global climate crisis. According to the logic framework of theory-model-demonstration and theoretical analysis，this study constructs the system dynamics model of urban carbon dioxide emissions based on land use and economic development，and carries out multi-scenario simulation of urban carbon dioxide emissions peak in Jiangsu province. It is found that：（1）The economic aggregate and structure of Jiangsu province will continue to grow and optimize in the future. Increasing investment in tertiary industry can effectively promote the upgrading of industrial structure，but it will reduce the economic growth rate.（2）Urban land is increasing，but its growth force is weakening. Under the scenario of carbon dioxide emissions reduction，the total amount of urban construction land will reach a peak of 5 514.96 km² in 2033，showing a phenomenon of urban contraction.（3）Industrial structure and energy efficiency optimization can reduce the demand for urban energy consumption，but it still keeps growing. Under the scenario of carbon dioxide emissions reduction，Jiangsu can achieve a peak of 657.9 million tons carbon dioxide emissions in 2025 at the earliest. Compared with the continuous increase of carbon dioxide emissions，the existing carbon sink land has a limited role in achieving the goal of carbon dioxide emissions peak. Thus，in view of the main factors affecting the realization of carbon dioxide emissions peak，several policy suggestions are put forward. While stabilizing economic growth，we should reduce energy demand and loss of carbon sink land，by improving energy and land use efficiency，accelerate technological innovation and optimize energy supply structure to achieve a peak in carbon dioxide emissions.

Under the goal of “double carbon”, how to promote high-quality economic development is a practical problem that China needs to be solved, and industrial co-agglomeration is one of the feasible paths to achieve low-carbon development. The article has incorporated carbon intensity, industrial co-agglomeration and industrial structure upgrading into a comprehensive analysis framework and uses data from 283 prefecture-level and above cities in China from 2008 to 2017 to empirically test the impact of industrial co-agglomeration between secondary and tertiary industries on carbon intensity and the path mechanism using dynamic spatial Durbin model and intermediary effect model. The results show that carbon intensity has a strong spatial and temporal correlation, showing positive spatial spillover effects and temporal path dependence; there is an obvious inverted U-shaped relationship between industrial co-agglomeration between secondary and tertiary industries and carbon intensity, which depends on the dynamic game of agglomeration effect and congestion effect. Industrial structure upgrading plays a mediating role in this process. At present, the level of industrial co-agglomeration in China has not yet crossed the inflection point, so we should optimize the labor force structure and industrial layout, and reasonably promote the development of industrial co-agglomeration between secondary and tertiary industries.

Vulnerability is often associated with risks and hazards, and is an important concept used in disaster management research. In the context of urbanization and climate change, assessing regional vulnerability and identifying vulnerable groups is an important part of disaster prevention and mitigation. This research focuses on the residents of urban villages in the Hongshan District of Wuhan City, constructs the social vulnerability evaluation index system of natural disasters according to the “exposure-sensitivity-adaptive capacity” framework from Intergovernmental Panel on Climate Change (IPCC), and uses the questionnaire survey method to obtain the data. On the basis of determining the index weights by principal component analysis (PCA), the social vulnerability of residents is evaluated by the weighted comprehensive evaluation method. The results show that the residents of urban villages in the Hongshan District are relatively vulnerable. And the vulnerability distribution is unbalanced, showing the characteristics of “more in the medium vulnerable level and less at both of high and low vulnerable level”, with significant structural differences, and low adaptive capacity is an important factor leading to their vulnerability. Moreover, there are differences in the vulnerability of residents in different ages, hukou types, and income levels but no distinct differences in gender. The results also show that the vulnerability of rural residents is higher than that of urban residents, in addition, the rural residents have high sensitivity and low adaptive capacity, and they are more vulnerable in the face of shocks and external pressures like disasters and risks; as age increases, the adaptive capacity to external risks decreases, however, in terms of sensitivity, some youth groups in urban villages are at an astonishingly high level; and the increase of income level has a positive impact on reducing the social vulnerability of residents in urban villages, decision-makers can provide practical strategies for reducing the vulnerability of different income groups. The overall social vulnerability of females is slightly higher than that of males, but with no significant differences in exposure, sensitivity, and adaptive capacity with gender.

In the strategic intersection period of land spatial planning system construction and ecological inquiry construction, the existing research lacks attention to the evolution of land spatial pattern in the upper reaches of the Yangtze River Economic Belt with complex terrain, fragile ecology and rapid economic development. This paper analyzes the spatial and temporal evolution characteristics of land use structure and “three-zone space” of 329 county-level administrative units in the upper reaches of the Yangtze River Economic Belt from 2010 to 2019, and explores the driving mechanism of evolution from the perspective of human-land relationship, so as to provide experience reference for optimizing land spatial pattern, coordinating ecological protection and economic development, and realizing efficient and sustainable development. The results show that: （1) In the past 10 years, the urban space in the upper reaches of the Yangtze River Economic Belt has continued to expand, occupying 2 191.25  km² agricultural space and 413.19  km² ecological space, and 4 223.89  km² agricultural space has been converted to ecological space. (2) From 2010 to 2015, dominated by agricultural space to urban space, mainly distributed in Chengdu-Chongqing, central Guizhou, and central Yunnan urban agglomeration areas; from 2015 to 2019, dominated by agricultural space to ecological space, mainly distributed in the eastern mountainous area of Yunnan-Guizhou Plateau. (3) The cross-transformation of the “three-zone space” is affected by the objective carrying environment (land), human development activities (man) and the interaction between the two, which is reflected in the spatial demand of human social development. Restricted by the values of land use and the objective operation law of society, the evolution of the “three-zone space” is driven based on the current situation of natural environment carrying and the development suitability pattern.

The fishing ban compensation policy in the Yangtze River has changed the livelihood strategies of retired fishing households. Effectively analyzing the livelihood capacity changes of households under the policy impacts is the premise to improve livelihoods. Taking the retired fishing households of Anhui, Jiangsu and Hubei Province as research objects, this paper constructs the livelihood capital evaluation index system to analyze the policy effects on livelihood capitals from total amount, structure and mobility before and after retiring. The results indicate that: (1) The total livelihood capital index of all objects has increased significantly, and the human capital, material capital, financial capital and social capital indexes increased significantly. (2) The households’ livelihood capital coupling coordination index has increased significantly, and the livelihood capital structure has changed from imbalance to coordination. (3) The livelihood capital of retired households has high relative mobility, which reduced the gap between the rich and the poor. (4) The heterogeneity exists in policy effects among different regions. The livelihood capitals and coupling coordination index of households in Anhui Province have been significantly improved, and the mobility of livelihood capital is the highest; The psychological capital index of households in Jiangsu and Hubei Province decreased significantly. There is no significant difference in financial capital index, total livelihood capital index and coupling coordination index in two periods, and the livelihood capital mobility  of households in Jiangsu Province is the lowest. In general, the implementation of the ecological compensation policy in the Yangtze River has promoted the households’ livelihood sustainability, but the stagnation of livelihoods, the social harmony and stability of retired areas and the new round stratum solidification of the livelihood capital are still issues that need continuous attention in the ten-year fishing ban.

The otolith microstructure was used to identify the daily age of grass carp and silver carp larvae collected in the Jianli section of Yangtze River during 2018 to 2020, and then their hatching and spawning dates were speculated. The spawning ground and the impact of the ecological operation of the Three Gorges Reservoir on the larvae in Jianli section were also analyzed. The results showed that both the otolith microstructure and daily age composition of grass carp and silver carp larvae were similar. The age of larvae in 2018 and 2019 ranged from 8 to 15 days, about 90% of which aged 9-12 days. The day-age in 2020 ranged from 10 to 22 days, and 12-15 days of larvae were dominant. The day-age and size ranges were narrow, implying that these larvae spawned in the same or neighbor’s spawning grounds. Based on day-age and hydrologic characteristics of Yangtze River, we inferred that the Yichang section was the main spawning ground of flood larvae in Jianli section. From 2018 to 2020, the Three Gorges Reservoir carried out four ecological operations during fish spawning season, only one of which in mid-June 2018 had a corresponding larvae flood in the Jianli section. The deduced larvae flood in Jianli section based on the rest three ecological operation carried out in late May did not be found. The lower temperature and poor food in the middle reaches of the Yangtze River in late May affected the early growth and mortality of the fish larvae. Accordingly, it is suggested to strengthen the ecological operation in late June, which may play a better role in supplementing the downstream larval fish resources.

Based on the investigation of the amount, quality and utilization situation of dredged soil in Yangtze Estuary navigation channel, this paper evaluates the suitability of dredged soil for different utilization modes, and puts forward suggestions for comprehensive utilization of dredged soil during the 14th Five-year Period. The conclusions are drawn as follows: the annual output of channel dredged soil is estimated to be more than 58 million m3 in the 14th Five-year Period, and the soil quality is fine and clean. The dredged soil from the South Channel and Yuanyuansha section of Deepwater Channel (SYDC) and the South Passage Channel (SPC) upstream of Jiuduansha Lightship (JL) is suitable for diking and filling, while the dredged soil from the Middle-lower section of North Passage of Deepwater Channel (MNDC) and the SPC downstream of JL can be used for wetland restoration and filling. In the 14th Five-year Period, it’s suggested to use dredged soil of the MNDC to restore Hengsha Shoal, and to use dredged soil of SPC to reserve resources in the siltation promoting project of East Nanhui Shoal. On the basis of solving of relevant constraints, the dredged soil of the MNDC and the SPC downstream of JL can be used for conservation and restoration of Jiuduansha wetland, and the dredged soil of the SYDC and the SPC upstream of JL can be used for embankment construction in the adjacent wading project.

Increasingly scarce water resources restrict agricultural development. In the new period, the development of the Yangtze River Economic Belt, the ecological conservation and high quality development of the Yellow River Basin have become major national strategies. Most of the areas where the Yangtze and Yellow rivers flow are important agricultural production areas in China. Their agricultural production must move to a higher quality stage. In this context, the study and comparison of agricultural water use efficiency along the Yangtze River area and the Yellow River area has important reference value for the high-quality agricultural development of the two regions. In the framework of data envelopment analysis, based on panel data of provinces in China from 2000 to 2019, this paper constructs EBM model to measure agricultural water use efficiency according to the measurement idea of “ideal value/actual value of agricultural water”. In addition, multi-level analysis and comparison are made in the two areas from the aspects of spatio-temporal evolution and regional differences. The results show that, firstly, except for Shanghai, efficiency of other provinces in the two areas improve obviously. The efficiency of the area along the Yellow River is obviously lower than that of the area along the Yangtze River before 2016. After 2016, the area along the Yellow River exceeds the Yangtze River. Secondly, although the distribution pattern development of efficiency in the two areas differ greatly in the early sample period, the two areas show high similarity in the later period, with the main peak position moving to the right and the phenomenon of left trailing. Thirdly, the interaction degree within the area along the Yangtze River is low, and its spatial effect is not obvious. The area along the Yellow River shows a “low-low, high-high” agglomeration phenomenon, and has a strong spatial correlation. Fourthly, the regional differences in the two areas show a trend of fluctuation and decline. Ultra-variable density and between-region differences are the main driving forces of the regional differences in the area along the Yangtze River and the Yellow River respectively. Therefore, all provinces in the area along Yangtze River should give full play to their comparative advantages and take targeted measures to improve agricultural water use efficiency. The area along the Yellow River should strengthen coordination and adhere to the road of benign development of “promotion in coordination and coordination in promotion”.

To explore the community structure of metazooplankton (referred to as zooplankton) and the status of water quality in Jinshuitan reservoir, the zooplankton community and water quality parameters were investigated and analyzed from October 2019 (autumn), January 2020 (winter), May 2020 (spring), and August 2020 (summer). Totally 33 species of zooplankton distributed in 21 genera and 3 phyla were identified. Among them, the species of cladocera were the most (13 species), followed by rotifer (11 species) and copepods (9 species), Cladocera and ritifer were the dominant zooplankton.. The abundance of zooplankton was the highest in summer (311.7 ind.·L^-1) and the lowest in winter (135.5 ind.·L^-1). Cladocera and copepods were more abundance. Moreover, the result of cluster analysis indicated that the zooplankton structures from spring and winter were similar, and zooplankton structures from summer and autumn were similar. Only three species, Thermocyclops vermifer, Bosmina longirostris, and B. coregoni, were dominant, demonstrating low dominance and simple structure of zooplankton community in the reservoir. The diversity indices (1.75<H′<2.64, 0.71<J<0.90, and 1.93<D<3.80) showed that the pollution levels of water quality in the reservoir is slight or intermediate. The results of redundancy analysis (RDA) indicated that water temperature (WT), water depth (WD), total nitrogen (TN), pH, total phosphorus (TP) and dissolved oxygen (DO) were main factors affecting zooplankton community structure, while transparency (SD) and permanganate index (CODMn) also have effects on the zooplankton community structure.

Chromophoric dissolved organic matter (CDOM) is an important part of aquatic ecosystem, systematic and comprehensive understanding of CDOM dynamics is critically important for aquatic ecosystem management. In this study, the data of water samples and water quality parameters from 24 sampling sites of Huanggai Lake and inflowing rivers in 4 batches were collected from October to November 2021. Composition characteristics and sources of CDOM in the water of Huanggai Lake were analyzed by three-dimensional fluorescence excitation-emission matrix spectra combined with parallel factor analysis. The results indicated that three fluorescence components were identified by PARAFAC, including two humic-like component and one protein-like component, named C1 (240,310/390)、C2 (265, 350/460) and C3 (220, 280/320). The contribution rates to the total fluorescence intensity of C1, C2 and C3 were 39.58%, 29.34% and 31.08%, respectively. The analysis of the spectral characteristic parameters of fluorescence index (FI), biological index (BIX) and humification index (HIX) showed that there were significant differences in humification degree among different lakes (ANOVA, p<0.05), and the western lake area > the central lake area > the eastern lake area. Correlation analysis showed that C1 was significantly positively correlated with C2 (R= 0.55, P<0.01), C1 in Huanggai Lake was probably derived from the transformation of C2 by microorganisms or the activity of algae. The CDOM in the Huanggai Lake was mainly composed of recent autochthonous components, which were obviously affected by human activities. The main sources may include domestic sewage and farmland leachate using poultry manure in the watershed, microbial biodegradation of residual phytoplankton and terrestrial humic components.

Runoff is an important driving factor for water volume changes in Dongting Lake and other lakes in middle-lower Yangtze River, while Land use and cover change (LUCC) strongly changes the hydrological process of the basin by changing the characteristics of the underlying surface, which further affects the change of lake water volume. However, due to the complex interaction of multiple factors such as climate change, the influence and contribution characteristics of LUCC on the relationship between “runoff-lake water volume” still have some strong uncertainties, which has become the key theoretical issue for water resources planning and management in the basin. Therefore, in order to solve the above problems, the paper uses the 2001-2019 MODIS remote sensing data products and the SWAT hydrological model to systematically analyze the influence characteristics of LUCC in the Dongting Lake Basin on “runoff-lake water volume”. The results show：(1) The multi-year average runoff and lake water volume in the Dongting Lake Basin are 237.1 billion m3 and 68.2 billion m3, respectively. Seasonally, they show a unimodal distribution with a higher level in May-September and a smaller one in October-April. The change trend of runoff was gentle （y =14.926x+2 222.1，R² = 0.043 9，p<0.01）, while the water volume showed a slowly downward trend （y = -4.147 3x + 723.880，R² = 0.066 7，p<0.01）;(2) There is a significant positive correlation between the water volume in Dongting Lake and the watershed runoff. On an annual scale, the relationship between the two can be expressed as y=0.173x+272.11（R²=0.588 5，p<0.01）; On the monthly scale, it can be expressed as y=0.249 4x+7.257 4（R²=0.565 7，p<0.01）, which is more significant than the annual scale; (3) LUCC has a strong impact on the relationship between “runoff-lake water volume”. The multi-year average annual runoff caused by LUCC increases by nearly 36.4 billion m³, accounting for 15.4% of the annual average runoff, and the lake water volume has increased by about 6.3 billion m3，accounting for 9.2% of the average water storage. The research results help to correctly understand and grasp the internal influence mechanism of water volume changes in Dongting Lake and other river-connected lakes, so as to provide scientific auxiliary support for the water resources protection, governance and planning in the basin.

Ponds and small reservoirs are small water bodies which spread widely across the basin of the Dongting Lake. Understanding the diurnal of nitrogen(N) and phosphorus(P) component contents of water bodies in ponds and reservoirs helps to assist in the formulation of fine water quality observation and pollution prevention in the Dongting Lake basin. In this paper, four typical land-use landscape ponds and reservoirs were used to study the diurnal variation of the contents of N and P components, pH, DO and temperature in water bodies in the small agricultural headwater watershed of Jinjin in Dongting Lake basin. The experiments results showed that the types of land use landscapes around the ponds and reservoirs not only significantly affected the diurnal changes of pH, dissolved oxygen (DO) and water temperature but also caused differences in the contents of N and P components and their the ratios. The values of pH, DO and temperature of water bodies changed significantly during the day and night for the ponds and reservoirs in residential areas, farmland and tea plantation, and their curves showed an inverted U shape. However, the changes of N and P component contents were relatively insignificant in water bodies of ponds and reservoirs during the observation period. The contents of total nitrogen and phosphorus (TN, TP), dissolved nitrogen and phosphorus (TDN, TDP) and particulate nitrogen and phosphorus (PN, PP) of ponds and reservoirs in residential areas, farmland and tea gardens were significantly higher than those in forest land use. Moreover, the ecological stoichiometric ratios of different N and P components in the water bodies (TN∶TP, TDN∶TDP, PN∶PP) are ranked as follows: forest (TN∶TP:67.97, TDN∶TDP:65.12, PN∶PP:74.13) > tea plantation (TN∶TP: 30.03, TDN∶TDP: 15.10, PN∶PP: 52.95) > Farmland and Residential Areas (TN∶TP: 19.40 and 16.21, TDN∶TDP: 23.31 and 11.91, PN∶PP: 18.83 and 21.36). This indicates that agricultural land use/discharge of domestic sewage leads to the changing nutrient status of N and P in ponds and reservoirs, which shifts from being limited by P in the natural state to being limited by N under human disturbance in the study area. The research results show that time interval of water sampling not more than 12 hours is more helpful to understand the characteristics of water quality in ponds and reservoirs. Strengthening the water quality management to reduce the inputs of phosphorus pollutants into ponds and reservoirs in residential areas and farmland, will contribute to the prevention and control of phosphorus pollution in ponds and reservoirs of Dongting Lake Basin.

In order to understand the community structure and influencing factors of metazooplankton in Dongting Lake, evaluate the water ecological environment quality of Dongting Lake, and provide a certain scientific basis for supporting the assessment of water ecology in the Yangtze River Basin. We conducted three surveys of metazooplankton in 16 sections of Dongting Lake, respectively in March (dry season), June (normal season) and September (wet season), and monitored 12 environmental parameters simultaneously in 2019．The results showed that the metazooplankton community belonged to 2 phyla and 26 genera, including Rotifera 9 genera, Cladocera 12 genera, Copepoda 5 genera. The average density of metazooplankton was 84.4 ind·L^-1, with Rotifera as the most dominant class (accounted for 84.3% of the total density), followed by Copepoda (13.3%) and Cladocera(2.4%). On the spatial distribution, the density of metazooplankton was highest in East Dongting lake, followed by South Dongting lake, estuary, West Dongting Lake and lakeoutlet. The dominant species of metazooplanktonin were Polyarthra vulgaris, Trichocerca pusilla, Keratella cochlearis, Bosmina sp. and Nauplius. The response of rotifers to water nutrient level was relatively significant, and the nutrient status of East Dongting Lake was significantly higher than that of other lakes. Eutrophication of Dongting Lake resulted in the miniaturization of metazooplankton community structure, metazooplankton can be used as indicators of lake water environment changes. Canonical correspondence analysis (CCA) showed Chlorophyll A, total nitrogen, total phosphorus and transparency were the key factors controlling the community structure of metazooplankton, it is consistent with the influence factors of zooplankton in most lakes in China. The shannon-Wiener diversity index and Pielou evenness index were used to evaluate the water quality of Dongting Lake, the results showed that the water quality of Dongting Lake was light pollution, it is suitable to evaluate the water ecological status of Dongting Lake by metazooplankton.

As the largest hydroelectric power project in the world, the construction and operation of the Three Gorges reservoir have a significant impact on the soil environment in the littoral zone of the Three Gorges reservoir. Previous studies focused more on the changes of soil environment in the littoral zone of a river section or a tributary of the Three Gorges reservoir, and lacked the understanding of the changes of soil environment in the littoral zone of the whole reservoir area. This study investigated and analyzed the distribution characteristics of soil nutrients and ecological stoichiometry in the littoral zone at the scale of the whole reservoir and at different altitudes (155-165 m and 165-175 m), including soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) content and stoichiometric ratios (C/N, C/P and N/P) a in the whole reservoir (eight sample sections). The results showed that, 1) compared with the unsubmerged area, the contents of SOM, TN, TP and TK in the submerged area of the littoral zone were lower, and the values of C/N, C/P and P/K were higher. 2) The contents of SOM and TN in 165-175 m horizontal fluctuation zone were 21.27 g·kg^-1 and 1.14 g·kg^-1, which were significantly lower than those of the altitude of 155-165 m and 175-178 m. And the T/N and N/P value in 165-175 m were 11.07 and 2.68, which were significantly different with the unsubmerged area. Besides, the content of SOM and TP were 6% and 24%, which were the lowest and highest variability during all soil nutrients. 3) For the whole reservoir area, the soil nutrient content in the upper reaches（Fuling）and middle reaches (Zhongxian, Wanzhou, Yunyang and Fengjie) of the reservoir area is significantly higher than that in the lower reaches (Wushan and Zigui), while the nutrient metering ratio of the upper reaches and middle reaches is significantly lower than that in the lower reaches. The highest value of SOM, TN, TP and TK were found in Zhongxian and Wanzhou district, and the lowest value of C/N, C/P and N/P were found in Fuling district. 4) The distribution characteristics of soil nutrients and stoichiometric ratio in the water-level fluctuation zone were significantly affected by the altitude of the water-level fluctuation zone and the environmental characteristics of the sampling site, and the environmental characteristics of the sampling site had a greater impact. The research shows that the nutrient loss in the littoral zone still existed after the flooding of 175 m after 2010, and the soil nutrient retention ability of the littoral zone of the downstream and 165-175 m littoral zone in the reservoir area is poor. Therefore, soil conservation in this area and the elevation area in the middle of the littoral zone should be strengthened to maintain the health of the littoral zone and aquatic ecosystem of the Three Gorges reservoir.

Based on the current status of land cover in Anhui Province in 2017, the carbon density parameters are set in combination with literature research. Under the framework of three control lines, five possible future land cover scenarios in 2035 are constructed to evaluate the response to the change of carbon storage. The results show that: (1) The total carbon storage of terrestrial ecosystems in Anhui Province were 1 005.4 Tg in 2017. The carbon storage of mountain forest areas in Western and Southern Anhui are higher, the farmland and urban areas in Northern Anhui plain and Jianghuai hilly area are lower, and the rivers and lakes along the Huaihe River and the Yangtze River are the lowest. (2) Under the five scenarios, due to the expansion of construction land (lower carbon density) and the occupation of surrounding farmland and forest land (higher carbon density), the total carbon storage decreased by 16~50 Tg. The decline range depends on the carbon density of the type of construction land occupation. The enhancement of ecological restoration has a relatively good effect on reducing the loss of carbon storage in Northern Anhui, Jianghuai and along the Yangtze River areas. (3) It is suggested that the Spatial Planning of National Land should pay attention to the optimization of green and low-carbon oriented land use structure and layout, improve the quality of urban renewal and reduce the loss of carbon storage.

Alternanthera philoxeroides is an exotic perennial weed whose invasion has caused great damage to our ecosystem and socio-economy. To effectively observe and assess the extent of the invasion of Alternanthera philoxeroides on abandoned farmlands, the Chi-square test, association coefficient, match coefficient, Spearman rank correlation coefficient, and Gordon M's stability measure were used to study the interspecific association and community stability in 60 plots with a specification of 1 m ×1 m (20 each for 1 year of abandonment, 3 years of abandonment and 5 years of abandonment) set up in Jianghan Plain Lake Area.The results indicated that：(1)The number of species in the communities abandoned for 1 year was 62 belonging to 32 families and 57 genera, in the communities abandoned for 3 years was 61 belonging to 26 families and 54 genera and in the communities abandoned for 5 years was 49 belonging to 23 families and 45 genera. Gramineae and Asteraceae were the main species in the three communities, where the dominance of Alternanthera philoxeroides and Echinochloa crusgalli was remarkable.Compared to 1 year of abandonment, the dominance of the invasive plant Alternanthera philoxeroides in the communities increased by 3.031% and 8.408% in 3 and 5 years of abandonment, respectively. (2)From the VR value, there was a non-significant negative association for the invasive communities of Alternanthera philoxeroides for 1 year of abandonment and a significant positive association for both 3 and 5 years of abandonment. Chi-square tests and AC values showed that Alternanthera philoxeroides, Echinochloa crusgalli, and Cynodon dactylon were similarly adapted to environmental conditions, and the remaining species were less resistant to Alternanthera philoxeroides invasion. (3)Chi-square tests and Spearman rank correlation analysis reflected that the three types of Alternanthera philoxeroides invasive communities were loosely linked between species pairs and relatively independent between species. The community stability results showed that the intersection coordinates of the 1-year, 3-year and 5-year communities were (32.52, 67.48), (32.93, 67.07) and (32.09, 67.91), respectively, all three of which were some distance from the ideal stability point coordinates (20, 80), indicating that there was more intense competition among the populations.Therefore, it is recommended that alternative control methods should be used in the restoration and management of abandoned farmlands, with Echinochloa crusgalli and Cynodon dactylon as alternative species for the integrated management of Alternanthera philoxeroides in abandoned farmlands.

Extreme heat waves have become more frequent and intense as a result of global warming, posing a serious threat to human health and to the sustainability of society as a whole. Using meteorological data and social statistics, a set of quantitative indicators is developed to quantify the temporal and spatial characteristics of heatwaves across 1 067 counties within the Yangtze River Economic Belt, including high-temperature days, high-temperature intensity, heat wave frequency, heat wave duration and heat wave intensity. In addition, an evaluation index system based on “exposure-sensitivity-adaptability” is being conducted to assess the vulnerability to heat waves. Afterwards, a spatial distribution map of heat wave vulnerability is developed, and the causes of heat wave vulnerability are explored. Based on the results, it can be concluded that: (1) Events of high temperatures and heat waves within the Yangtze River Economic Belt appear to share a similar pattern of “one belt and one point”; (2) The exposure index to heat waves within the Yangtze River Economic Belt shows a clear tendency to decrease northwest to southeast, but the spatial distribution of the sensitivity and adaptability index within the region is fragmented. The vulnerability index exhibits a clear spatial agglomeration characteristic, despite the absence of obvious spatial agglomeration characteristics; (3) In the analysis of brittle types, 67.4% of the counties are vulnerable as a result of a lack of adaptive capacity, followed by 24.5% of the counties vulnerable due to extreme heat waves, and only 8.1% of the counties vulnerable due to sensitivity. In contrast to the west, which is less vulnerable and brittle due to a lack of adaptability, the eastern and central regions are more vulnerable and fragile as a result of high temperature exposure. Accordingly, the results of this study may provide a scientifically sound basis for preventing extreme heat wave disasters and increasing adaptability to heat wave events in the future.