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Water level is an important indicator of lake hydrology characteristics, and its fluctuation significantly affects lake ecosystems. In recent years, deep learning models have shown their superiority in the long-time range prediction of hydrology processes, while the application of deep learning models with the attention mechanism for lake water level prediction is very rare. In this paper, taking Poyang Lake as a case study, the transformer neural network model is applied to examine the model performance in lake water level prediction, to explore the effects of the Yangtze River on lake water level fluctuations, and to analyze the influence of hyper-parameters (window size and model layers) and lead time on the model accuracy. The result indicated that the transformer model performs well in simulating the lake water level variations and can reflect the temporal water level variation characteristics in Poyang Lake. In the testing stage, the RMSE values were recorded in the range of 0.26–0.70 m, and the NSE values are higher than 0.94. Moreover, the Yangtze River inflow has a great influence on the lake water level fluctuation of Poyang Lake, especially in flood and receding periods. The contribution rate of the Yangtze River in RMSE and NSE is higher than 80% and 270%, respectively. Additionally, hyper-parameters, such as window size and model layers, significantly influence the transformer model simulation accuracy. In this study, a window size of 90 d and a model layer of 6 are the most suitable hyper-parameters for water level prediction in Poyang Lake. Additionally, lead time may affect the model accuracy in lake water level prediction. With the lead time varied from one to seven days, the model accuracy was high and RMSE values were in the range of 0.46–0.73 m, while the RMSE value increased to 1.37 m and 1.82 m with the lead time of 15 and 30 days, respectively. The transformer neural network model constructed in this paper was the first to be applied to lake water forecasting and showed high efficiency in Poyang Lake. However, few studies have tried to use transformer model coupling with the attention mechanism for forecasting hydrological processes. It is suggested that the model can be used for long sequence time-series forecasting in hydrological processes in other lakes to test its performance, providing further scientific evidence for the control of lake floods and management of lake resources. [ABSTRACT FROM AUTHOR]

Ye, M., 2020. Constraints and solutions for harnessing and revitalizing water resources in Hubei Province of China. In: Hu, C. and Cai, M. (eds.), Geo-informatics and Oceanography. Journal of Coastal Research, Special Issue No. 105, pp. 115–118. Coconut Creek (Florida), ISSN 0749-0208. Water is the source of life, the essence of production, and the foundation of ecology. Considering the extreme importance of water resources, this paper takes Hubei Province as an example to study how to effectively solve natural disasters such as flood, drought, and waterlogging in inland river basins in China. Through in-depth analysis of the dialectical relationship between promoting water conservancy and controlling flood disasters, this paper fully demonstrates the great historical opportunities that Hubei Province is afforded under the national ecological civilization construction strategy. Finally, by learning from the successful experience of western developed countries in sustainable utilization of water resources, this paper proposes specific strategies of scientific development of water resources in Hubei Province as follows: constructing flood-control and waterlogging-reduction systems, optimizing water resources allocation structure, speeding up the construction of farmland water conservancy facilities, and strengthening the sustainable development and recycling of water resources, as well as building a modern water conservancy management system, which provides theoretical reference and scientific basis for scientific, orderly, and high-quality development of water resources in Hubei Province under the premise of ecological protection. [ABSTRACT FROM AUTHOR]

Background: Oncomelania hupensis is the exclusive intermediate host of Schistosoma japonicum in China. Snail control is an essential component of schistosomiasis elimination programme. With 70 years of continuous efforts, the range of O. hupensis had reduced significantly, but slowed down in last decades. A large number of levees against flooding were constructed along Yangtze River and its affiliated lakes in the middle and lower reaches, which influenced the hydrology and ecology in the alluvial plains. The purpose of this study was to assess the impact of levees on the distribution of O. hupensis in the middle and lower reaches of the Yangtze River. Methods: The snail habitats were digitalised by hand-held GPS system. The years for discovery and elimination of snail habitats were extracted from historical records. The accumulated snail-infested range for each habitat was calculated on the basis of annual reports. The current distribution of O. hupensis was determined by systematic and environmental sampling. The geographical distribution of levees was obtained from satellite imagery. To assess the impact of levees, the data pertaining to O. hupensis were divided into two parts: inside and outside the Yangtze River. Joinpoint regression was utilised to divide the study time span and further characterise the regression in each period. The 5-year-period moving averages of eliminated area infested by snails were calculated for the habitats inside and outside Yangtze River. The moving routes of corresponding geographical median centres were simulated in ArcGIS. Hotspot analysis was used to determine the areas with statistical significance clustering of O. hupensis density. Results: Three periods were identified according to Joinpoint regression both inside and outside Yangtze River. The area infested by O. hupensis increased in the first two periods. It decreased rapidly outside Yangtze River year over year after 1970, while that inside the Yangtze River did not change significantly. Furthermore, the latter was significantly higher than the former. It was observed that the present density of O. hupensis inside Yangtze River was lower than outside the Yangtze River. The median centre for eliminated ranges inside Yangtze River wavered between the east (lower reach) and the west (middle reach). In contrast, the median centre for eliminated ranges continuously moved from the east to the west. Conclusions: Our findings indicated that the levees had a considerable negative impact on the distribution of O. hupensis outside Yangtze River. Some hotspots observed in the irrigation areas need a sluice system at the inlet of branch for snail control. The major distribution of O. hupensis located in Hubei might be caused by severe waterlogging. The intensive surveillance should be implemented there. The biggest two freshwater lakes, the major endemic regions historically, were identified as cold spots. The long-term impact of Three Gorges Dam on the distribution of O. hupensis in the lakes should be monitored and evaluated. [ABSTRACT FROM AUTHOR]

Construction and operation of the Three Gorges Dam (TGD) has significantly altered the downstream hydrological regime along the Yangtze River, which has in turn affected the environment, biodiversity and morphological configuration, and human development. The ecological and environmental systems of the middle and lower Yangtze River have been affected adversely, with the ecosystems of Poyang Lake and its deltas being among the most damaged. Besides posing a potential threat to the survival of migrant birds and aquatic species, operation of the TGD has also affected the human population, particularly with respect to water and food security. Though the above mentioned effects have been studied in previous papers, a comprehensive discussion has never been conducted. This paper provides the first ever summary of the impacts of the TGD on the downstream reaches of the Yangtze River. The costs and benefits identified provide a constructive reference that can be used in decision-making for sustainable development of water resources in other nations, especially those in the developing world. [ABSTRACT FROM AUTHOR]

• Indicators concerning ecotourism and riparian ecosystem functioning differed among rural, transitional, and urban areas. • The riparian ecosystem functioning index outperformed the recreational activities and values index along the Three Gorges Reservoir. • The impacts of ecotourism on ecological indicators were minor to moderate. • Agricultural activities and boat ramps largely negatively affected ecosystem functioning. • The zoning of waterways requires innovative planning and conservation measures on a global scale. Ecotourism activities in riparian zones have heightened concern about protecting riparian health indicators (RHIs). Ecotourism in riparian zones is growing significantly, but its management requires trade-offs between recreational activities and ecological functions. This paper aims to show how people's recreational activities affect RHIs along mega-reservoirs and around dams. Investigators collected data from 301 transects inside the riparian zones of the Three Gorges Dam Reservoir (TGDR) in China, taking rural, rural–urban transitional, and urban land-use patterns into account. The Kruskal-Wallis tests (p < 0.01) found that the RHI index was significantly greater than the recreational activity and value index along the TGDR, with the RHI index being higher in the transitional basins. The Pearson correlation tests (p < 0.05) revealed that recreational activities were associated with both positive and negative aspects of RHIs, with significant correlations ranging from low to moderate. The key factors of ecotourism and RHIs determined by principal component analysis explained 65.36 % of the total variation. Furthermore, hierarchical cluster analysis revealed that these characteristics were distributed differently in rural, rural–urban transitional, and urban land-use patterns. Findings indicated that zoning might be an essential option for the long-term use of riparian zone ecosystem services around water resources. Consequently, people should be made aware of the importance of RHIs, and governments should support progressive policies that lead to a change in attitudes and actions towards RHIs conservation. [ABSTRACT FROM AUTHOR]

Water transportation has always occupied a large proportion of China's transportation and has become the key to China's economic development. Water transportation is called "green transportation" in the industry due to the advantages of low transportation cost, high safety factor, and large capacity. However, water transportation has caused a great impact on the ecological environment of the waters for a long time, and solving the problem of sewage pollution from ships has also become an unavoidable problem. To control pollution from ships, it is essential to analyze the characteristics of ship domestic sewage discharge. In this study, a ship domestic sewage discharge complex network (SDCN) is established based on the ship voyage data to analyze the discharge characteristics in the Yangtze River. According to the topological analysis, the SDCN is a small-world network with the power-law degree distribution and superliner betweenness-degree correlation as distinguishing characteristics. The top five MDs with the highest in-vertex strength are Chaotianmen MD (S = 165,129,561), Tongling MD (S = 66,426,616), Maanshan MD (S = 62,087,158), Baqu MD (S = 59,964,550), and Shashi MD (S = 55,569,399), which indicates that these MDs receive a large amount of sewage. And the volume of domestic sewage between Chaotianmen MD and Baqu MD is the largest. The results can help us understand the discharge characteristics of ship domestic sewage and how they can be targeted to develop control measures for the countermeasures of "zero discharge" for inland ships. [ABSTRACT FROM AUTHOR]

Poyang Lake in Jiangxi Province is the largest freshwater lake in China and is historically a region of significant floods. Maximum annual lake stage and the number of severe flood events have increased during the past few decades because of levee construction that reduced the area available for floodwater storage. The most severe floods since 1950 occurred during 1954, 1973, 1983, 1995, and 1998. Each of these floods followed El Niño events that influence the Asian monsoon and that are directly linked to rainfall in the Changjiang (Yangtze River) basin. The 1954 flood was the largest ever recorded until the 1990s. That year the peak Changjiang stage at Hukou was 21.6 m, which was 1.6 m above the previous record high. The last major flood on the Changjiang was during 1998, when the peak Changjiang stage reached 22.5 m, higher than during 1954, even though peak discharge was lower. The most severe floods, including those in 1954 and 1998, require both 1) high rainfall and tributary discharge into Poyang Lake and 2) high Changjiang discharge and stage at Hukou that backflows into the lake or slows Poyang Lake drainage. Since gauging stations were established on the Changjiang, these conditions always occurred following an El Niño. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Engineering Geology & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There is no mathematical difference between theoretical extreme value models of maxima and minima because they link to each other by a simple sign reversal transformation. However, other transformations that change sample maxima to sample minima raise the possibility of alternatives to the generalised extreme value (GEV) distribution for annual maxima, while still maintaining extreme value justification. A general class of transformation is proposed that converts positive annual maxima to lower-bounded minima, then amenable to Weibull extreme value analysis for sufficiently large sample sizes. That is, the Weibull distribution of smallest extremes provides a theoretical extreme value model for the transformed maxima, which holds irrespective of any GEV form of the original maxima. This would apply, for example, to the analysis of reciprocals of discharge or rainfall annual maxima. A useful feature of the transformation approach is that alternative prediction expressions with extreme value justification can arise for defining event magnitude as a function of return period. These expressions may result in different hydrological conclusions than from a GEV analysis of maxima. A double exponential transformation is introduced and its prediction function for maxima is noted to have capability to mimic equivalent Type 3 extreme value (EV3) distribution expressions, but without having to introduce an upper bound parameter. The new function gives a good fit to apparent EV3 annual flood maxima recorded from two very different catchments: the Yangtze River in China and the upper Whanganui River in New Zealand. [ABSTRACT FROM AUTHOR]

The third Nanjing Yangtze River Bridge is a steel pylon cable stayed bridge. Such a structure is new in China and therefore brings new challenges to the work of control surveys. This paper describes the survey methods used for building and erecting the steel pylons and for construction of the steel tower. The survey methods adopted have proven successful and can be used as reference for similar projects in the future. [ABSTRACT FROM AUTHOR]

This paper explores the demographic impacts of the implementation of the "Grand Development in West China" policies and environmental rehabilitation projects in the upper reaches of the Yangtze River. It analyses the interaction between the environmental reconstruction and environment-related migration in this region. The intertwined nature of environmental, ethnic, and poverty problems not only bears negatively upon the "alleviation of poverty conducing to the accruement of wealth" of the poverty-stricken population, but also hinders the rehabilitation of the environment. It brings forth some opinions regarding improving the capacity of regional sustainable development through environmental migration. [ABSTRACT FROM AUTHOR]

Under increasing anthropogenic pressure, species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations. The critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), once commonly observed in the Yangtze River-Poyang Lake junction, is now rarely seen in the river-lake corridor. In this study, static passive acoustic monitoring techniques were used to detect the biosonar activities of the Yangtze finless porpoise in this unique corridor. Generalized linear models were used to examine the correlation between these activities and anthropogenic impacts from the COVID-19 pandemic lockdown and boat navigation, as well as environmental variables, including hydrological conditions and light levels. Over approximately three consecutive years of monitoring (2020–2022), porpoise biosonar was detected during 93% of logged days, indicating the key role of the corridor for finless porpoise conservation. In addition, porpoise clicks were recorded in 3.80% of minutes, while feeding correlated buzzes were detected in 1.23% of minutes, suggesting the potential existence of localized, small-scale migration. Furthermore, both anthropogenic and environmental variables were significantly correlated with the diel, lunar, monthly, seasonal, and annual variations in porpoise biosonar activities. During the pandemic lockdown period, porpoise sonar detection showed a significant increase. Furthermore, a significant negative correlation was identified between the detection of porpoise click trains and buzzes and boat traffic intensity. In addition to water level and flux, daylight and moonlight exhibited significant correlations with porpoise biosonar activities, with markedly higher detections at night and quarter moon periods. Ensuring the spatiotemporal reduction of anthropogenic activities, implementing vessel speed restrictions (e.g., during porpoise migration and feeding), and maintaining local natural hydrological regimes are critical factors for sustaining porpoise population viability. [ABSTRACT FROM AUTHOR]

Based on the 20-year high-resolution precipitation data from TRMM and GPM radar products, diurnal features over complex terrains along the Yangtze River (YR) are investigated. Using the Fast Fourier Transform (FFT) method, the first (diurnal) and second (semi-diurnal) harmonic amplitude and phase of precipitation amount (PA), precipitation frequency (PF), and intensity (PI) are analyzed. The diurnal amplitudes of PA and PF have a decreasing trend from the west to the east with the decreasing altitude of large-scale terrain, while the semi-diurnal amplitudes of PA and PI depict the bimodal precipitation cycle over highlands. For the eastward propagation of PA, PF is capable of depicting the propagation from the upper to the middle reaches of YR, while PI shows the eastward propagation from the middle to the lower reaches of YR during nighttime and presents sensitivity to highlands and lowlands. According to the contribution of different-sized precipitation systems to PI over the highlands and lowlands, the small (<200 km2) ones contribute the least while the large ones (>6000 km2) contribute the most, but the medium ones (200–6000 km2) show a slightly larger contribution over the highlands than over the lowlands. The propagation of each scaled precipitation system along the YR is further analyzed. We found that small precipitation systems mainly happen in the afternoon without obvious propagation. Medium ones peak 2–4 h later than the small ones, with two eastward propagation directions at night from the middle reaches of YR to the east. The large ones are mainly located in lowlands at night, with two propagation routes in the morning over the middle and lower reaches of YR. Such a relay of the propagation of the medium and large precipitation systems explains the eastward movement of PI along the YR, which merits future dynamic studies. [ABSTRACT FROM AUTHOR]

Several studies have indicated that glaciers in the Qinghai-Tibet plateau are thinning, resulting in reduced water supplies to major rivers such as the Yangtze, Yellow, Lancang, Indus, Ganges, Brahmaputra in China, and south Asia. Three rivers in the upstream of Yangtze River originate from glaciers around the Geladandong snow mountain group in central Tibet. Here we used elevation observations from Ice, Cloud, and land Elevation Satellite (ICESat) and reference elevations from a 3-arc-second digital elevation model (DEM) of Shuttle Radar Terrestrial Mission (SRTM), assisted with Landsat-7 images, to detect glacier elevation changes in the western (A), central (B), and eastern (C) regions of Geladandong. Robust fitting was used to determine rates of glacier elevation changes in regions with dense ICESat data, whereas a new method called rate averaging was employed to find rates in regions of low data density. The rate of elevation change was -0.158 ± 0.066 m·a-1 over 2003-2009 in the entire Geladandong and it was -0.176 ± 0.102 m·a-1 over 2003-2008 in Region C (by robust fitting). The rates in Regions A, B, and C were -0.418 ± 0.322 m·a-1 (2000-2009), -0.432 ± 0.020 m·a-1 (2000-2003), and -0.321 ± 0.139 m·a-1 (2000-2008) (by rate averaging). We used in situ hydroclimatic dataset to assess these negative rates: the glacier thinning was caused by temperature rises around Geladandong, based on the temperature records over 1979-2009, 1957-2013, and 1966-2013 at stations Tuotuohe, Wudaoliang, and Anduo. The thinning Geladandong glaciers led to increased discharges recorded at the river gauge stations Tuotuohe and Chumda over 1956-2012. An unabated Geladandong glacier melting will reduce its long-term water supply to the Yangtze River Basin, causing irreversible socioeconomic consequences and seriously degrading the ecological system of the Yangtze River Basin. [ABSTRACT FROM AUTHOR]

The Yangtze River Basin, one of China's five major watersheds and a primary source of drinking water for the country, is experiencing serious environmental pollution as heavy metals are discharged into its rivers. To evaluate the water quality of the river, determined water quality parameters were compared with the maximum permissible limit values recommended by the World Health Organization and Chinese drinking water standards. Physical and chemical analyses were conducted on water samples taken from 19 locations along the river's path. The study quantified the contents of sodium (Na), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), lithium (Li), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), scandium (Sc) and mercury (Hg). The results show that the average values of Mg, Sr, Co, Cu, Fe, Mn and Sc are higher than the historical background values. Moreover, through a correlation analysis it was concluded that these nutrients and trace metals have high values due to anthropogenic pollution in the study area. The computed WQI values range between 9.59 and 20.26, indicating excellent water quality in the river basin. Finally, hazard quotient (HQ) values show that exposure to the detected pollutants will have no adverse effects on human health and does not pose a potential non-carcinogenic risk. [ABSTRACT FROM AUTHOR]

The CORONA satellite image preserves the landscape from half a century ago, and has played a great role in landscape archaeology in many regions of the world. In recent years, with the rapid development of UAV (Unmanned Aerial Vehicle) Photogrammetry technology, Archaeologists can easily obtain the digital surface model (DSM)and Digital Ortho Map (DOM) of a site in the fieldwork. In the archaeological survey of bronze age sites in the middle of the Yangtze River project, we combined the UAV photogrammetry results with CORONA satellite photography, which can help us extract the surface landscape feature of the sites. This strategy has shown significant advantages in reconstructing the settlement layout, detecting the unknown linear features (such as walls, moats and canals) of sites and comparing the landscape between different sites. [ABSTRACT FROM AUTHOR]

Copyright of People & Nature is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding the distribution patterns and shaping factors of bacterial pathogens in aquatic ecosystems, especially in natural waters, are critical to the control of pathogen transmission. In this study, using 16S rRNA gene amplicon sequencing, we explored the composition and biogeographic dynamics of potential bacterial pathogens in the middle and lower reaches of the Yangtze River, as well as its two vast adjoining lakes (Dongting Lake and Poyang Lake). The pathogen community belonged to 12 potential pathogenic groups, with "intracellular parasites," "animal parasites or symbionts" and "human pathogens all" occupying 97.5% in total. The potential pathogen community covered seven phyla with Proteobacteria (69.8%) and Bacteroidetes (13.5%) the most predominant. In addition, 53 genera were identified with Legionella (15.2%) and Roseomonas (14.2%) themost dominant. The average relative abundance, alpha diversity and microbial composition of the potential bacterial pathogens exhibited significant biogeographical variations among the different sections. An in-depth analysis reflected that environmental variables significantly structured the potential bacterial pathogens, including water physiochemical properties (i.e., chlorophyll-a, total nitrogen and transparency), heavy metals (i.e., As and Ni), climate (i.e., air temperature) and land use type (i.e., waters). Compared to the overall bacterial community which was composed of both pathogenic and non-pathogenic bacteria, the pathogen community exhibited distinct microbial diversity patterns and shaping factors. This signifies the importance of different variables for shaping the pathogen community. This study represents one attempt to explore pathogen diversity patterns and their underlying drivers in the Yangtze River, which provides a foundation for the management of pathogenic bacteria. [ABSTRACT FROM AUTHOR]

The flood control ability of cascade reservoirs is affected by many factors, such as the inflow flood form, and flood control scheduling rules. When large cascade reservoirs were built, it is necessary to evaluate the overall flood control ability of the reservoirs and explore the best joint scheduling strategy. In this study, cascade reservoirs in the upper reaches of the Yangtze River in China were selected as the research case. A stochastic model of inflow floods and a dynamic capacity flood regulation model for the Three Gorges Reservoir (TGR) were established, and the most dangerous inflow floods for downstream flood control were generated. Different scheduling strategies for the cascade reservoirs were set to block the TGR inflow flood to explore the flood control risk in the Jingjiang area under joint operation of the TGR and the upstream cascade reservoirs. The research results show that the joint flood control scheduling strategy has a huge impact on the flood control ability of cascade reservoirs, and different scheduling schemes must be adopted according to the inflow flood characteristics of the reservoirs. This study provides a new idea for systematically evaluating the flood control ability of large cascade reservoirs and selecting appropriate scheduling strategies. [ABSTRACT FROM AUTHOR]

Abstract: Habitat fragment owning to obstruct of dams and barriers badly affect the aquatic faunas. Many spawning sites of migration fishes are lost, and their growth and reproduction are affected. The Yangtze River with connected lakes is the most important fresh water fishery area in China. The Yangtze''s four major carp species (YFMCS) are the most typical migration fish lived in this area. They reproduce in river and grow in lake. Distributaries lies between the Yangtze River and Dongting Lake are the passages for these migration fishes. Due to the construction of dams and barriers, some original passages were out of use. Up to now, only four channels exist between the river and lake, there are Songcikou, Taipingkou and Ouchikou normally called “three outlets”, and Chenglingji inlet. Diverted Water Volume (DWV) and the Percentage of Diverted Water (PDW) through the three outlets reflect the relationship between the Yangtze River and the Dongting Lake.The variation of river-lake relation caused by dam construction, and the effect on migration fishes are discussed in this paper. The relationship of DWV and fry output in middle reach of the Yangtze river and the Dongting Lake, PDW and the percentage of the YFMCS in a total catch of fish, DWV and flux of carp fry at the Jianli station, DWV and yield of the YFMCS were analyzed. The results show that dams and barriers constructed on the Yangtze River threaten some fish species in this area, especially the migration fishes. The connectivity degree of river and lake decide the growth and reproduction of emigration fishes, the yield of the YFMCS increase by the DWV increase, and hydraulic project have important influence on reproduction of fishes. In order to reduce the ecological influence of hydropower projects, reservoir management especially in spawning season should integrate ecological demand. [Copyright &y& Elsevier]

Since the construction of the Gezhouba Dam in the 1980s, the number of Chinese sturgeon in the Yangtze River has been rapidly declining. The Gezhouba Dam has cutoff the migration path of these sturgeon, resulting in an overall reduction of suitable sturgeon habitat. This paper describes a habitat suitability index model that is used to evaluate the impacts of the Gezhouba Dam and Three Gorges Project on Chinese sturgeon spawning sites. Based on research concerning the reproduction characteristics of Chinese sturgeon, ten major ecological factors that influence reproduction were analyzed, including: water temperature, velocity, water depth, substrate, suspended sediment concentration, and the amount of egg predatory fish. The suitability index (SI) curves based on these ten ecological factors were obtained, and a habitat suitability function was developed. A two-dimensional mathematical model was also created to simulate and predict physical habitat situation (such as hydraulic, sediment, and substrate) of the Chinese sturgeon. By coupling the habitat suitability function and a two-dimensional mathematical model, a habitat suitability index model for Chinese sturgeon was established. The habitat suitability index model was validated by comparing measured data with predictions from the model. These comparisons showed that the computed results agreed well with the measured results, and the high calculated habitat suitability index (HSI) corresponded to high measured quantity of eggs per unit (1000m3) discharge (CPUEd). The calculated habitat suitability index for Chinese sturgeon also showed that the habitat suitability index was better in 1999, before the impoundment of the Three Gorges Project, compared with the habitat suitability in 2003. Simulation results of different discharges from Gezhouba Dam predicted that flow discharges between 10,000 and 30,000m3/s were most suitable for sturgeon spawning. [Copyright &y& Elsevier]

Abstract: Intensive anthropogenic disturbances have affected the channel of the middle Yangtze River since the 1950s. This paper selects the Jianli reach as an example to examine human impact on channel change in the middle Yangtze River. 1:100,000 channel distribution maps from 1951, 1961 and 1975 and 1:25,000 navigation charts from 1981 and 1997 were employed to reconstruct channel change in the study reach. The result indicates that the channel, under the constraint of levees along the riverbanks, underwent a minor widening but frequent bank failure due to susceptible bank structure and increase in water discharge. The bank failure promoted bar growth in the channel. Cross-section changes and quantitative calculations of erosion and deposition based on the DEM derived from navigation charts present a pattern of over-bank sedimentation and riverbed incision. The stage and duration of floods have increased following levee construction and bank revetment. [Copyright &y& Elsevier]

Variations in glacier meltwater in the source regions of the Tibetan Plateau's (TP) largest lake (Selin Co) and China's longest river (Yangtze River) regulate the local and downstream water balance under the warming climate. However, the magnitude of their variations over the past four decades is still unknown. Here, we examine long-term changes in glacier mass balance over 1976–2017 using KH-9 and CoSSC-TanDEM-X data. We find that the mean rate of glacier mass loss (GML) has accelerated from −0.21 ± 0.11 m a–1 over 1976–2000, to −0.28 ± 0.14 m a–1 over 2000–11, and subsequently to −0.48 ± 0.10 m a–1 over 2011–17. Changes in temperature and precipitation are the major causes of GML. Over 1976–2017, the contribution of decadal GML to Tuotuohe sub-basin runoff ranges from 4.3 to 8.0%, while its contribution to increased lake volume change in Selin Co and Chibzhang Co-Dorsoidong Co ranges from 3.5 to 16.3% and 19.2 to 21.4%, respectively. The GML of source regions made relatively small contributions to river runoff and lake supply, but plays a vital role when precipitation decreases. The quantitative evaluation of the water balance for the sources of great rivers and lakes over the TP is therefore important for water resource management and hydrological cycle studies. [ABSTRACT FROM AUTHOR]

Detailed organic carbon isotope (δ13Corg) measurements were conducted on two peat sequences recovered from the north bank of the Yangtze River, East China. Seven radiocarbon dates provided firm age control of this δ13Corg record and reveal palaeoclimatic changes since the Late Glacial period. The results show that the Holocene Megathermal Maximum occurred between 8385 and 7040 cal. yr BP. The Late Glacial climate was generally cold but fluctuated frequently between 12940 and 11815 cal. yr BP. The Older Dryas (from 12940 to 12810 cal. yr BP) and the Younger Dryas (from 12645 to 12170 cal. yr BP) were characterised by cold climate conditions. In contrast, 12810 to 12645 cal. yr BP (corresponding to the Allerød Warm Period) and 12170 to 11815 cal. yr BP (corresponding to a rapid warming period after the Younger Dryas, marking the beginning of the Holocene) were relatively warm phases. In contrast to other high-resolution records, it shows that the δ13Corg records of our study peats are largely controlled by a common forcing mechanism of solar insolation changes in the Northern Hemisphere, and exhibit similar variability to δ18O records obtained from stalagmites and GISP2 during the Late Glacial and early-mid Holocene. [ABSTRACT FROM AUTHOR]

River sand and gravel are industrial construction materials that are an essential part of rivers. Therefore, an important issue is to determine how to produce the maximum economic benefit of river sand and gravel resources under the premise of ensuring river stability and health, as well as flood control security. This study analyzed the limited quantities of sand and gravel mining during the mining planning period, including the total quantity of sand and gravel mining, the minimum annual quantity of sand and gravel mining, the maximum annual quantity of sand and gravel mining, as well as the maximum quantity of sand and gravel mining quantity in two consecutive years. Taking the above restrictions as constraints, this paper constructed optimization models of annual and multi-year exploitation of river sand and gravel resources with economic benefit as the objective function. Through exploring the regulating capability of sand market, we put forward that the sand and gravel supply price should be regulated by controlling sand and gravel supply quantity appropriately under sand and gravel mining permission system, and discussed the characteristics of different quantity-price relationships of river sand and gravel. On the basis of discussing the relationship between quantity and price, cost and price, we analyzed the optimization models for annual and multi-year exploitation of river sand and gravel resources. Lastly, we take the sand and gravel mining in a section of the Yangtze River as a calculation example to validate the optimization models' rationality and feasibility. This study can serve as a reference for sand and gravel mining planners, and provide support for the optimal utilization of river sand and gravel resources in the future. [ABSTRACT FROM AUTHOR]

Many waterbird populations have become increasingly dependent on agricultural habitats for feeding. While habitat destruction has been proposed as a key reason forcing waterbirds to move from natural habitats to agricultural habitats, few have used long‐term data to test this hypothesis. The Siberian crane (Leucogeranus leucogeranus) is an IUCN Critically Endangered species. About 98% of its global population winters at Poyang Lake, China. Recently, many cranes shifted from feeding in natural wetlands to agricultural habitats. Here, we integrate bird surveys, Vallisneria tuber (the traditional food of cranes in natural wetlands) surveys, water level data, and remotely sensed images from 1999 to 2016 to explore the drivers of this habitat shift. Changes in Siberian crane numbers in natural wetlands and agricultural fields indicated that the habitat shift occurred in the winters of 2015–2016. Analyses using generalized linear mixed models suggested that crane numbers in natural wetlands were positively related to tuber density and the interaction between dry season (October–March) water level and tuber density. The changes in tuber density and dry season water level in 2015–2016 indicated that tuber disappearance may have been the primary driver of the habitat shift, with a smaller effect of high water level. Submerged plants at Poyang Lake have degraded seriously in the past two decades. The plant degradation at Shahu Lake, a sublake of Poyang Lake, may have been caused by high spring water, high winter temperature, and low summer temperature. However, the drivers of tuber disappearance at Poyang Lake may not be restricted to these variables. Because Poyang Lake is an important refuge for many waterbirds in the Yangtze River floodplain, it is urgent to take effective measures to restore its submerged plants and ecosystem health. Agricultural fields can be important refuges for Siberian cranes, mitigating the negative impacts of wetland deterioration. [ABSTRACT FROM AUTHOR]

Background: As the longest river in Asia, the Yangtze River flows through the most industrialized cities in China and provides critical ecological services for agriculture, industry, and transportation. Polychlorinated biphenyls (PCBs) have been banned for many years, but trace amounts of PCBs still exist as persistent organic pollutant in drinking water and are an ecotoxicological problem. In this work, we collected water, sediment, and suspended particulate matter (SPM) samples along the Yangtze River, to study the distribution and transport of PCBs for the risk assessment of the Yangtze River as a drinking water source. Results: The ΣPCBs concentrations in water, sediment, and SPM ranged in 0.04–11 ng/L, 0.33–69 ng/g, and 0.72–153 ng/L, respectively. The main pollutants were PCB17, 18, 28, 47, and 118 in the Yangtze River. The ffSW value of PCB18 and PCB28 all exceeded 0.50, whereas the ffSW value of PCB47 and PCB118 (except for PCB118 at Y-4) was less than 0.50. The toxic equivalent quantity (TEQ) range of PCBs in water and in sediment was ND–5.55 pg-TEQ/L and ND–2.51 pg-TEQ/g, respectively. Conclusions: In both water and sediment, lower chlorinated PCBs are dominant in the middle reaches and higher chlorinated PCBs are dominant at downstream. In contrast, SPM is dominated by tetra-CBs. The ffSW values reveal a net redissolution of lower PCBs from sediments to water but a net sorption of higher PCBs from water to sediment. The PCBs in water and sediment at downstream pose potential ecological risk, but the drinking water does not have a non-carcinogenic risk for humans. [ABSTRACT FROM AUTHOR]

In this study, a large dataset for the three largest freshwater lakes (Poyang, Dongting, and Taihu) of the Yangtze River floodplain in China was analyzed to quantitatively compare the ecological structure and function of the Yangtze-connected (Poyang and Dongting) and Yangtze-isolated (Taihu) lakes on a broad scale. Discriminant analyses were performed to determine and correlate the composite gradient of physical-chemical variables that separated the six study regions, East Poyang Lake (LPY), Open LPY, North LPY, Dongting, Meiliang Bay, and Taihu center, with variables including suspended solids (SS), Secchi depth (SD), water temperature (WT), chemical oxygen demand (COD), flow velocity, and total nitrogen-to-total phosphorous (TN:TP) molar ratio. A regression analysis showed that the interactions between the SS and TP concentrations affected the phytoplankton biomass in the lentic (Meiliang Bay and East LPY) and partly lotic (Open LPY and Dongting) zones. The trophic level index (TLI)-phytoplankton, SS-phytoplankton, and TP-phytoplankton relationships revealed that hydrological (water velocity) and physical (underwater light penetration) conditions had the greatest effect on the algal biomass in the eutrophic Yangtze-connected lakes, whereas phytoplankton growth was mainly related to nutrients in the eutrophic Yangtze-isolated lake. [ABSTRACT FROM AUTHOR]

China's five largest freshwater lakes (Poyang, Dongting, Taihu, Hongze, and Chaohu) are all located in lowland regions and differ greatly in lake morphology, hydrology, and water chemistry. However, basic knowledge of diversity patterns and factors driving macroinvertebrate community structure is lacking. We analyzed the composition and diversity of benthic macroinvertebrates and evaluated the roles of environmental factors and dispersal processes in determining beta diversity at both the lake and regional scales. The two Yangtze-connected lakes (i.e., Lakes Poyang and Dongting) were highest in taxonomic diversity. Differences in taxonomic composition were evident among the five lakes, with the two Yangtze-connected lakes dominated by bivalves and/or gastropods, while Lake Taihu showed great changes in taxonomic composition among sites in accordance with its high habitat heterogeneity. Lake Hongze was dominated by polychaetes, crustaceans, and bivalves. The eutrophic-hypertrophic Lake Chaohu was exclusively dominated by chironomids and oligochaetes. At the lake scale, total γ-diversity was mainly attributed to β -diversity (among sites) ranging from 57.9 to 87.6%. The total γ-diversity at the regional scale was primarily related to higher β-diversity, with β and β (among lakes) accounting for 30.4 and 58.8% of total taxa richness, respectively. Environmental conditions appear to be important in structuring benthic macroinvertebrate communities at both the lake and regional scale. Dispersal does not appear to affect distribution of macroinvertebrates at the lake scale. [ABSTRACT FROM AUTHOR]

Miscanthus lutarioriparius is an endemic species that grows along the middle and lower reaches of the Yangtze River and is a valuable source of germplasm for the development of second-generation energy crops. The plant that propagates via seeds, stem nodes, and rhizomes shows high phenotypic variation and strong local adaptation. Here, we examined the magnitude and spatial distribution of genetic variation in M. lutarioriparius across its entire distributional range and tested underlying factors that shaped its genetic variation. Population genetic analyses were conducted on 644 individuals from 25 populations using 16 microsatellite markers. M. lutarioriparius exhibited a high level of genetic variation ( HE = 0.682-0.786; Ar = 4.74-8.06) and a low differentiation ( FST = 0.063; Dest = 0.153). Of the total genetic variation, 10% was attributed to the differences among populations (df = 24, P < 0.0001), whereas 90% was attributed to the differences among individuals (df = 619, P ≤ 0.0001). Genetic diversity did not differ significantly across longitudes and did not increase in the populations growing downstream of the Yangtze River. However, significant associations were found between genetic differentiation and spatial distance. Six genetic discontinuities were identified, which mostly distributed among downstream populations. We conclude that anthropogenic factors and landscape features both contributed to shaping the pattern of gene flow in M. lutarioriparius, including long-distance bidirectional dispersal. Our results explain the genetic basis of the high degree of adaptability in M. lutarioriparius and identify potential sources of new germplasm for the domestication of this potential second-generation energy crop. [ABSTRACT FROM AUTHOR]

Copyright of Knowledge & Management of Aquatic Ecosystems is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study examines the effects of hydrologic sorting and mixing of sources on the Sr-Nd isotopic compositions of suspended sediments at different water depths. The samples were collected from three layers (surface, middle and bottom) at Datong hydrological station of Yangtze River during the flood season of 2010. Our results show that, Sr/Sr values decrease from surface to bottom, ranging from 0.730332 to 0.720857. ɛ(0) values range from −14.75 to −10.09, with surface sediments being the most negative. The isotope composition at the middle layer can best represent the mean isotopic composition of the total suspended sediments transported by a river. It is believed that the stratification of Sr-Nd isotope is attributable to mixing of sediments from different sources due to hydrological sorting. Sediments from the upper stream are found to be coarser, and tend to contribute more to the lower water column. Although Sr-Nd isotope is a well acknowledged tool to trace sediment provenance, the current study suggests that the grain size of the samples and the sampling locations should be taken into consideration when applying this method to provenance study. [ABSTRACT FROM AUTHOR]

The significant differences of atmospheric circulation between flooding in the Huaihe and Yangtze River valleys during early mei-yu (i.e., the East Asian rainy season in June) and the related tropical convection were investigated. During the both flooding cases, although the geopotential height anomalies always exhibit equivalent barotropic structures in middle to high latitudes at middle and upper troposphere, the phase of the Rossby wave train is different over Eurasian continent. During flooding in the Huaihe River valley, only one single blocking anticyclone is located over Baikal Lake. In contrast, during flooding in the Yangtze River valley, there are two blocking anticyclones. One is over the Ural Mountains and the other is over Northeast Asia. In the lower troposphere a positive geopotential height anomaly is located at the western ridge of subtropical anticyclone over Western Pacific (SAWP) in both flooding cases, but the location of the height anomaly is much farther north and west during the Huaihe River mei-yu flooding. Furthermore, abnormal rainfall in the Huaihe River valley and the regions north of it in China is closely linked with the latent heating anomaly over the Arabian Sea and Indian peninsula. However, the rainfall in the Yangtze River valley and the regions to its south in China is strongly related to the convection over the western tropical Pacific. Numerical experiments demonstrated that the enhanced latent heating over the Arabian Sea and Indian peninsula causes water vapor convergence in the region south of Tibetan Plateau and in the Huaihe River valley extending to Japan Sea with enhanced precipitation; and vapor divergence over the Yangtze River valley and the regions to its south with deficient precipitation. While the weakened convection in the tropical West Pacific results in moisture converging over the Yangtze River and the region to its south, along with abundant rainfall. [ABSTRACT FROM AUTHOR]

Copyright of Hydrological Sciences Journal/Journal des Sciences Hydrologiques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Concentration and composition of polychlorinated biphenyls (PCBs) in the typical drinking water sources in Jiangsu Province were studied by scene investigation and physical and chemical analyses as well. Total amount of PCBs in some surface water and surface microlayers exceeded the standard (20 ng/l) in the “Environmental Quality Standard of Surface Water”. There were less PCBs in suspended substances and bottom mud. It reflected that there was less PCB pollution in drinking water sources in Jiangsu Province for quite a long period. The main kind of PCBs in the typical drinking water sources was dichlorobiphenyl. Monochlorobiphenyl and trichlorobiphenyl ranked next to dichlorobiphenyl. In the study of PCB distribution in drinking water sources, it was found that the concentration of PCBs in surface microlayer was higher than that in deep water. The concentration of PCBs along the Yangtze River bank was more than that in the middle of Yangtze River. PCBs in the typical drinking water sources mostly came from by-products in industrial production. [ABSTRACT FROM AUTHOR]

The quantitative attribution of changes in streamflow to climate change (CC) and land cover change (LCC) for the Yangtze River Source Region (YRSR), China, was assessed. We used a combination of the SWAT model along with the statistical technique one factor at a time (OFAT) and innovative trend analysis (ITA) to achieve the study objectives. The climate and hydrology data from 1961 to 2016 and land-cover maps of 5 years' difference from 1985 to 2015 were used. The model was calibrated (1964–1989) using a land-cover map of 1985 and validated for 1990–2016. This validated model was further validated for all other land-cover maps used in this study. The SWAT model simulation showed that streamflow had been significantly influenced by CC compared to LCC using land-cover maps of 1985–1990, 1990–1995. However, the SWAT model simulations did not result in further changes in streamflow for land cover maps of 2000–2005, 2005–2010, and 2010–2015 because there have not been any significant changes in land cover after 2000 while the main contributing factor was climate change. The SWAT model simulations showed that the main driver of changes in streamflow in the Yangtze River Source Region is climate change. This study shows that the individual impacts are more critical than combined impacts for designing hydraulic structures, water resources planning and management, and decision-making policies at the regional/basin scale. [ABSTRACT FROM AUTHOR]

Although satellite radar altimetry was developed and optimized for open oceans, it has been used to monitor variations in the level of inland water-bodies such as lakes and rivers. Here, for the first time, we have further used the altimetry-derived variation of water level for estimating the fluctuation of water storage as an addition to the present in situ water storage estimation systems to be used in remote areas and in emergency situation such as in the events flooding monitoring and for studying the effect of climate change. Lake Dongting, the second largest lake in China, influenced frequently by flooding, was, therefore, chosen to demonstrate the potential of the technique. By using the concept of an “assumed reference point”, we converted Topex/Poseidon satellite altimetry data on water level variations in Lake Dongting to “water level” data. The “water level” time-series data and in situ water storage were used to establish a rating curve. From the rating curve, we converted data on “water level” derived from seven years (1993–1999) of Topex/Poseidon data to actual water storage in Lake Dongting. The result reveals that the seasonal and annual fluctuations of water storage occurred during the 1990s with a more frequent flooding at the late 1990s' especially the flooding in whole catchment level in 1998 and 1999. The study supports the usefulness of satellite altimetry for dense and continuous monitoring of the temporal variations in water dynamic in moderate to large lakes. [ABSTRACT FROM AUTHOR]

To document patterns in diversity, altitudinal range and body size of freshwater fishes along an elevational gradient in the Yangtze River basin.The Yangtze River basin, China.We used published data to compile the distribution, altitudinal range and body size of freshwater fishes. Correlation, regression, clustering and graphical analyses were used to explore patterns in diversity, altitudinal range and body size of freshwater fishes in 100-m elevation zones from 0 to 5200 m.Species richness patterns across the elevational gradient for total, non-endemic and endemic fishes were different. The ratio of endemics to total richness peaked at mid elevation. Land area on a 500-m interval scale explained a significant amount of the variation in species richness. Species density displayed two peaks at mid-elevation zones. The cluster analysis revealed five distinct assemblages across the elevation gradient. The relationship between elevational range size and the midpoint of the elevational range revealed a triangular distribution. The frequency distribution of log maximum standard length data displayed an atypical right-skewed pattern. Intermediate body sizes occurred across the greatest range of elevation while small and large body sizes possessed only small elevational amplitudes. The size-elevation relationship between the two major families revealed a very strong pattern of body size constraint among the Cobitidae with no corresponding elevational constraint and a lot of body size and elevational diversification among the Cyprinidae.The data failed to support either Rapoport's rule or Bergmann's rule. [ABSTRACT FROM AUTHOR]

The upstream Yangtze River is located in the southwest of central China, where it flows through several ecosystems and densely populated regions that constitute a unique complex coupled system. To determine how the characteristics of supply and demand in a water-coupled system will vary under the influence of climate change and human activity in this area in the next 85 years, the upper Yangtze basin was considered as the study area and was divided into seven sub-basins according to seven main control sections: Shigu, Panzhihua, Xiluodu, Xiangjiaba, Zhutuo, Cuntan, and Yichang; a method for water supply and demand research considering climate change was proposed. Based on simulated runoff in the study area under changing environmental conditions, this study analyzed the available water supply and constructed a long-term water demand forecasting model using the classified water use index method under macro regulation in the study area from 2016 to 2100. The results show that the total water demand in the upstream Yangtze River appears to first increase and then decrease in 2016–2100 and will reach its peak around 2028. The ecological pressure in the upstream Yangtze River increases gradually from upstream to downstream but will not reach the surface water utilization stress threshold (hereinafter referred to as stress threshold) for the next 85 years. The contradiction between monthly supply and demand is more prominent under ecological restrictions. Under the RCP4.5 scenario, water demand exceeds the stress threshold in each sub-basin across several months (mainly March, April, and May), and the water demand nearly reaches the damage threshold in May as the basin extends below the Zhutuo section. [ABSTRACT FROM AUTHOR]

Accurate seasonal streamflow forecasting is important in reservoir operation, watershed planning, and water resource management, and streamflow forecasting is often based on hydrological models driven by coupled global climate models (CGCMs). To understand streamflow forecasting predictability, this study considered the three largest rivers in China and explored deterministic and probabilistic skill metrics on the monthly scale according to ensemble streamflow hindcasts from the hydrological model Hydrologiska Byråns Vattenbalansavdelning (HBV) driven by multiple climate forcings from the climate system model by the Beijing Climate Center (BCC_CSM1.1m). The effects of initial conditions (ICs) and meteorological forcings (MFs) on skill were investigated using the conventional ensemble streamflow prediction (ESP) and reverse-ESP (revESP). The results revealed the following: (1) Skill declines as lead time increases, and forecasting is generally the most skillful for lead month 1; (2) skill is higher for dry rivers than wet rivers, and higher for dry target months than wet months for the Yellow and Yangtze Rivers, suggesting greater skill in potential drought forecasting than flood forecasting; (3) the relative operating characteristic (ROC) area is greater for abnormal terciles than the near-normal tercile for all three rivers, greater for the above-normal tercile than the below-normal tercile for the Yellow and Yangtze Rivers, but slightly greater for the below-normal tercile than the above-normal tercile for the Xijiang River; and (4) the influence of ICs outweighs that of MFs in dry months, and the period of influence varies from 1 to 3 months; however, the influence of MFs is dominant in wet target months. These findings will help improve the understanding of both the seasonal streamflow forecasting predictability based on coupled climate system/hydrological models and of streamflow forecasting for variable rivers and seasons. [ABSTRACT FROM AUTHOR]

Wang, H.Z., Zhong, H.P., Lu, J.Z., Yan, Q.Q., Li, S., and Zhou, Y., 2020. Understanding the river-lake relationship after the operation of TGR based on SWAT model. In: Guido Aldana, P.A. and Kantamaneni, K. (eds.), Advances in Water Resources, Coastal Management, and Marine Science Technology. Journal of Coastal Research, Special Issue No. 104, pp. 593–600. Coconut Creek (Florida), ISSN 0749-0208. It is an important issue how the operation of Three Gorges Reservoir (TGR) has impacted upon the hydrological relationship between the Yangtze River and the Poyang Lake. A SWAT model was built to simulate the runoff of the River and the Lake, and the energy difference (Fe) index was selected to characterize the river-lake relationship. The results show: (1) The SWAT model was verified suitable to simulate the runoff of the study area. (2) The monthly trend of River-lake relationship after the operation of the TGR from 2010 to 2018 was studied. The successive monthly strong effect of the River (Fe<-0.1) appeared in August and September of 2010, which corresponded to the period of severe flood of the Lake basin. The successive monthly strong effect of the Lake (Fe>0.1) appeared in November and December of 2013, which corresponded to the period of severe draught of the Lake basin. (3) The yearly trend showed the constant increase of the role of the Lake and the constant decrease of effect of the Yangtze River main stream. (4) Under the operation of the TGR, the Yangtze River plays a stronger role during the drainage and flooding periods, leading to the increase of the flood control pressure in the Poyang Lake basin; the effect of the Poyang Lake is enhanced during the water storage and dry period, leading to the increase of the risk of drought disasters in the Poyang Lake basin. The study systematically reveals the change pattern of the river-lake relationship after the operation of the TGR at different time scales. [ABSTRACT FROM AUTHOR]

Characterized by increasing surface air temperature, global warming has altered the hydrological cycle at global and regional scales. In order to adapt water resources management under the context of global warming, attribution analysis on regional differentiation of water resources in the Yangtze River basin (YRB) was conducted in this study. Meteoro-hydrological variations across the basin were examined for the period 1960–2013, and then a statistic-based method was applied in quantifying the contributions of climate variability and human activities on annual runoff variations in different tributary sub-basins in the YRB. Our observation indicates that both the annual increasing rate and the inter-annual fluctuations of temperature in China and in the YRB were higher than that of the global average since the turn of the century. Climate change analysis indicates that the YRB experienced a hot-wet period during 1994–2002 and a hot-dry period during 2003–2013, since the step change of temperature in 1993. Contributions of climate change and human activities on runoff variations varied spatially in the basin. With reference to the baseline period of 1960–1993, the contribution of climate change played a dominant role in most regions of the basin, especially in those upstream sub-basins. The effect of human activities in the basin was quite complicated, not only its regional differentiation, but also its contribution were opposite during the hot-wet period and the hot-dry period in some sub-basins. The result of this study is helpful in understanding the impacts of climate change and human activities on water resources variation in both temporal and spatial scales. [ABSTRACT FROM AUTHOR]

Zhang, Y.; Chen, S., and Wang, N., 2020. The impact of educational level on ecological efficiency: An empirical analysis in the middle reaches of Yangtze River. In: Gong, D.; Zhang, M., and Liu, R. (eds.), Advances in Coastal Research: Engineering, Industry, Economy, and Sustainable Development. Journal of Coastal Research, Special Issue No. 106, pp. 388–395. Coconut Creek (Florida), ISSN 0749-0208. How to coordinate the relations among economic development, resource consumption, and environmental protection is an important issue for China's current development. This research measured the temporal and spatial effects of the ecoefficiency of the urban agglomeration in the middle reaches of Yangtze River. The results show that the ecoefficiency of urban agglomeration in the middle reaches of the Yangtze River has increased year by year, and the ecoefficiency of some cities vary greatly. There are significant spatial correlations and dependencies, and the level of education is positively correlated with ecological efficiency. Improving the level of education increases people's awareness of environmental protection and conservation, thereby reducing pollution emissions and resource consumption, and the ecological efficiency will be further improved. By exploring the impact of population and economic and human factors on ecological efficiency, the hope is to provide reference policy suggestions for urban planning, economic development, and environmental protection in China. [ABSTRACT FROM AUTHOR]

Trend analysis of streamflow provides practical information for better management of water resources on the eve of climate change. Thus, the objective of this study is to evaluate the presence of possible trends in the annual, seasonal, maximum, and minimum flow of Yangtze River at Cuntan and Zhutuo stations in China for the period 1980 to 2015. The assessment was carried out using the Mann–Kendall trend test, and the innovative trend analysis, while Sen's slope is used to estimate the magnitude of the changes. The results of the study revealed that there were increasing and decreasing trends at Cuntan and Zhutuo stations in different months. The mean annual flow was found to decrease at a rate of −26.76 m3/s and −17.37 m3/s at both stations. The minimum flow was found to significantly increase at a rate of 30.57 m3/s and 16.37 m3/s, at a 95% level of confidence. Maximum annual flows showed an increasing trend in both regions of the Yangtze River. On the seasonal scale, the results showed that stations are more sensitive to seasonal flow variability suggesting a probable flooding aggravation. The winter season showed an increasing flow trend, while summer showed a decreasing trend. The spring flow was found to have an increasing trend by the Mann–Kendall test at both stations, but in the Zhutuo Station, a decreasing trend was found by way of the innovative trend analysis method. However, the autumn flow indicated a decreasing trend over the region by the Mann–Kendall (MK) test at both stations while it had an increasing trend in Cuntan by the innovative trend analysis method. The result showed nonstationary increasing and decreasing flow trends over the region. Innovative trend analysis method has the advantage of detecting the sub-trends in the flow time series because of its ability to present the results in graphical format. The results of the study indicate that decreasing trends may create water scarcity if proper adaptation measures are not taken. [ABSTRACT FROM AUTHOR]

Background: An "integrated control" strategy has been implemented within seven provinces at highest risk for schistosomiasis along Yangtze River in Peoples' Republic of China (P. R. China) since 2004. Since Oncomelania hupensis is the only intermediate host of the blood fluke (Schistosoma japonicum), controlling the distribution of snails is considered an essential and effective way to reduce the risk of schistosomiasis infection. The study aimed to determine the snail area burden and annual trend among provinces with potential risk for schistosomiasis along the Yangtze River, above and below the Three Gorges Dam (TGD). Methods: This retrospective study utilized data previously collected from the National Parasitic Diseases Control Information Management System (NPDCIMS) on annual snail surveys from 2009 to 2017. Descriptive statistics were performed for analyzing the snail burden by provinces, counties, type of environmental location and year, and mapping was conducted to present the snails distribution. Results: From 2009 to 2017, the total snail infested area decreased by 4.22%, from 372 253 hm2 to 356 553 hm2 within the seven high risk provinces. The majority of snails were found in the marshland and lake regions, outside of control embankments. The total snail burden trend remained relatively stable in upstream regions above the TGD from 2010 to 2015, while the trend decreased within downstream regions during this period. In 2016 and 2017, the total snail burden trend increased in both upstream and downstream provinces, however, upstream saw a larger increase. From 2009 to 2017, there were a total of 5990 hm2 of newly developed snail areas in the seven study provinces and the majority were concentrated in regions below the TGD, accounting for 5610 hm2 (93.70%). Conclusions: There has been a decline in total snail counts from 2009 to 2017. Meanwhile, new snail breeding areas were formed mainly within provinces downstream the TGD due to spread of snails, indicated that the oncomelanid snail would be difficult to completely eliminate. We suggest that the national schistosomiasis integrated control strategy, including mollusciding and environmental modification, will need to be enhanced significantly going forward to achieve a greater reduction in snail burden and ultimately to achieve elimination. [ABSTRACT FROM AUTHOR]

Channel bars are a major depositional feature in channels, and are considered as an important part of the morphodynamics of an alluvial river. The long-term morphodynamics of bars have been intensively investigated. However, relatively little is known about the response of channel bars to a major river flood, which is considered to be the predominant force in shaping bar morphology. This is especially the case for the monsoon-affected Yangtze River, where fluvial geomorphic work is largely carried out during monsoon floods. In this study, multi-temporal satellite images and river stage data were used to examine the morphodynamics of four large channel bars in the middle Yangtze River in response to a major monsoon flood in 2002. Based on bar surface areas estimated with Landsat images at different river stages, a rating curve was developed for each of the four bars, which was used to estimate bar volume through an integral process. Our study shows that two of the bars tended to be stable, while the other two experienced severe erosion during the flood. The results reveal that the flood caused a total bar surface area decrease of 1,655,100 m2 (or 8.30%), and a total bar volume decline of 5.89 × 106 m3 (or 6.10%) between the river stages of 20.81 m and 25.75 m. The volume decrease is equivalent to a sediment loss of approximately 8.25 × 106 metric tons, based on an average bulk density of 1.4 metric tons per cubic meter. The results imply that channel bars in the middle Yangtze River can also be large sediment sources rather than depositional areas during the flood. The decrease of sediment load in the middle of Yangtze River was found to be responsible for the dramatic morphodynamics of channel bars, which could last for a long period of time, depending on the operation of the Three Gorges Dam, which opened in 2003. Hence, we suggest making management efforts to protect the bars from further erosion. [ABSTRACT FROM AUTHOR]