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This paper constructs the total-factor ecological efficiency (TFEcE) and the total-factor ecological productivity index (TFEcPI) based on the proposed Shephard ecology distance function which is derived from the combination of ecological footprint (EF) and the framework of Shephard energy distance function. The unified framework of TFEcE and TFEcPI enables a more comprehensive analysis by simultaneously allowing for both static and dynamic performance evaluations. This paper evaluates the TFEcE and TFEcPI of regions in Yangtze River Economic Belt (YREB), China during the period 2000–2014. Findings reveal that the EF in the YREB takes on an ascending trend, and there exist significant differences of EF among various regions. For the YREB and its three areas, TFEcE displays a trend of “decline first and then fluctuate” at different levels, while total-factor ecological productivity (TFEcP) takes on an ascending trend. There exist significant differences of TFEcE across various regions in the YREB, but the regional disparity is found to present a shrinking trend during our study period. The differences of Cumulative TFEcPI between the three areas have expanded due to the remarkable increase of the upper reach from 2007 to 2014 which may be attributed to its backwardness advantages. Further decomposition analysis reveals that TFEcP growth is mainly driven by technological progress, while efficiency change is found to exhibit a negative effect. Finally, a couple of policy recommendations are concluded based on the findings. [ABSTRACT FROM AUTHOR]

Groundings are frequently occurring accidents that pose a serious risk in inland waterways. This paper proposes a flexible decision-support solution for grounded ships in the Yangtze River. The basis of the proposed method is to develop an influence diagram based on a three-layer decision-making framework, to consider the effectiveness of the intervention measures by adding two nodes and establishing the associated conditional probability tables, and to merge the influence diagram and the intervention measures as a flexible decision-support solution. The merits of the proposed method include the intuitive representation of how the influencing factors affect the alternatives using a graphical structure, the flexibility to implement and to consider the intervention measures for grounded ships, and the ability to deal with uncertainty in both numerical data and qualitative information. The results of the case study showed that it is unanimous with the real situations and the intervention measures should be considered to make effective and accurate decision-making for grounding ships. Consequently, the method presented in this paper provides a practical and flexible decision-support solution for grounded ships. [ABSTRACT FROM AUTHOR]

The Xiaohuangshan site is an early Neolithic settlement in the lower Yangzi River dating to 9000–7000 BP. In this paper, starch grains extracted from the surfaces of 9 pottery sherds and 6 grinding slabs unearthed from the early Xiaohuangshan phase (9000–8500 cal. BP) are identified from Oryza , Triticeae Tribe, Coix lacryma-jobi , Nelumbo sp., Dioscorea opposita Trunb , Vigna and Quercus spp. Based on the statistical analysis of percentage presence and the minimum numbers of plants identified by starch grains on the grinding slabs and potteries, it can be found that rice has become one of the major staple foods together with Triticeae grasses, Job's tears and acorns, which indicates rice should have been cultivated intentionally at Xiaohuangshan. The results also suggest that grinding slabs from Xiaohuangshan were used mainly for processing wild plants other than rice, and plant residues extracted from their surfaces cannot be utilized independently to explore human's subsistence strategies in that time. In addition, acorns probably were cooked whole in the pottery vessels before they were shelled or ground on the grinding slabs in the Xiaohuangshan site. This paper provides new evidence for the beginning of rice cultivation during the early Neolithic in the Lower Yangtze River. [ABSTRACT FROM AUTHOR]

Chinese national fiscal reforms and the transfer of power from the central government to local governments impact the governance of inland waterway transport (IWT). In this paper we argue that the development of IWT on the Yangtze River is strongly influenced by institutional changes at different levels of government in line with the path dependent transformation of the Chinese centrally planned economy. This paper deduces how institutional change of IWT on the Yangtze fails to fulfil its purposes because of institutional legacies and conflicts of interests among the various levels of government and the persistent interwovenness of the state with private enterprises (via SOEs). In order to further stimulate IWT on the Yangtze more institutional changes are on the cards, in particular a need for more (foreign) private involvement and more independent SOEs, but these changes will not necessarily break out of the development path. [ABSTRACT FROM AUTHOR]

• A comprehensive comparative empirical analysis on the container shipping network. • Supported by extensive datasets, incorporates the latest development on river basin. • Combine descriptive and explanatory analysis from interdisciplinary approaches. • A large diversity exists in how inland port systems development. The formation of barge networks on rivers and associated inland port systems is subject to a complex set of influencing factors and mechanisms. This paper aims to present a comprehensive comparative empirical analysis focusing on the container shipping (barge) network in the Yangtze and the Rhine. This analysis is supported by extensive datasets on both river basins, incorporates the latest development on both rivers and is grounded on concepts and methods coming from transport geography and economic geography. We find that a large diversity might exist in how inland port systems and related gateway seaports are dealing with cargo flows and supply chains. In view of explaining this diversity, we make a distinction between geographical/nautical aspects, macro-economic factors and institutional/governance factors. In particular, we discuss the role of institutional and governance factors in barge network development by using the concepts of selection, retention and variation. [ABSTRACT FROM AUTHOR]

Abstract: The excavation face stability is crucial for safety and risk management in slurry shield tunneling, especially for the river-crossing tunnel. To avoid face collapse or blow-out, shield operators need to keep air chamber pressure balanced using their own experience, which would be difficult, discontinuous and less reliable in the process of construction. Considering the disadvantage of the manual control process, this paper presents a predictive control system for air chamber pressure in slurry shield tunneling using Elman neural network (ENN) model. It mainly contains a theoretical model, an ENN predictor and an ENN controller to set optimal control parameters automatically tracking the desired air chamber pressure. Moreover, to improve the learning capability of ENN model, a particle swarm optimization (PSO) algorithm is implemented. This system has been tested with collected data of slurry shield operation parameters in the Yangtze riverbed metro tunnel project in Wuhan, China. Analysis revealed that the predictive control system using PSO-based Elman neural network model in this paper has the potential for enhancing face stability in slurry shield tunneling. [Copyright &y& Elsevier]

The present paper focuses on the analysis of dryness/wetness in the Yangtze River Basin from 1960 to 2005 using monthly precipitation data observed at 135 gauges uniformly distributed over the area. The spatial and temporal variation of dryness/wetness has been assessed by means of the Standardized Precipitation Index (SPI). The principal component analysis (PCA) and wavelet transform analysis were applied to the SPI series computed on both 6-month and 12-month time scales. The results demonstrated noticeable spatial patterns with three sub-regions characterized by different climatic variability: the southeastern downstream part of the basin, the midstream and the western upstream part of the study area. In the upstream and lower reaches of the Yangtze River Basin, an obvious trend towards wetter conditions has been detected from 1990 onward. In addition, inter-decadal changes are obvious, indicating 7–8 years fluctuation in most parts of the region sporadically distributed in the studied period in 95% confidence level. The results of this paper will be helpful for an efficient water resources management under different conditions. Furthermore, three sub-regions should be separately considered in the watershed planning process for mitigating the adverse impacts of future extreme drought or flood occurrences. [ABSTRACT FROM AUTHOR]

Abstract: China plays an increasingly important role on the international economic scene and in global supply chains. Initially only coastal regions participated in global supply chains, but in recent years comparative cost advantages have led to an increased participation of inland destinations in China’s economic development. The growth of some inland regions has urged logistics players to revise and reconfigure their extensive logistics networks. This has been particularly the case in the Yangtze region. Upstream cities such as Chongqing are emerging as potential important production centres for the international markets. This paper discusses the challenges for container barge services on the Yangtze River to Chongqing. It is argued that a further strengthening of the global market position of Chongqing and other upstream locations demands further improvements in transport-related and logistical cost control and reliability. The performance of container river services on the Yangtze River is crucial for upstream economic regions to take part in world trade. The paper analyzes the costs aspects linked to transporting goods to the world markets and makes a comparison to gateway region Shanghai. [Copyright &y& Elsevier]

Highlights • We optimize shipping schedule for steel plants cluster alongside inland river. • The model considers timely demands of steel plants over multiple periods. • A MIP formulation and dynamic programming algorithm are developed. • We explore the iron ore trade volume under various scenarios. Abstract This paper aims to provide an optimal shipping schedule for steel-manufacturing plants cluster alongside the Yangtze River by developing a mixed integer programming formulation. The model takes into account the multi-layer shipping network on the Yangtze River, the dynamic iron ore price and transportation costs, and the timely demands of steel plants over multiple periods. By applying the proposed model to a real-world case, several interesting findings are observed, leading to further useful managerial insights. We also propose an exact solution approach based on a dynamic programming algorithm to a special case of this problem motivated by real-world practice. [ABSTRACT FROM AUTHOR]

Abstract An Inland Waterway Transportation System is often claimed to be safe, efficient and economic. However, traffic congestion and vessel collision have become serious threats to marine safety, especially in the one-way waterways. The aim of this paper is to rank the vessels in the controlled waterways of the upper Yangtze River and to generate the optimal traffic commands for each vessel so as to ensure marine safety and traffic efficiency. In this study, the proposed approach is based on the combination of Fuzzy Analytical Hierarchy Process (FAHP) with an Expert System (ES). Vessel data collected from Automatic Identification Systems (AIS) are first analyzed by experts, and some external environment and internal factors are selected as Significant Influencing Factors (SIFs). FAHP is then used for modelling a hierarchical structure and determining the weight of each SIF. Finally, the sorted vessel sequence and appropriate traffic commands can be achieved using ES. The experiment result shows that the waiting time of vessels is averagely decreased about 22 min compared with the existing Traffic Signal Revealing System. This will not only significantly improve the efficiency and accuracy of the vessel traffic scheduling, but also increase the waterway capacity by reducing the travelling time. Highlights • A novel approach is proposed to enhance vessel traffic scheduling for the controlled waterways in the upper Yangtze River. • Based on Fuzzy Analytical Hierarchy Process and the Expert System, the AIS data are discussed and analyzed in detail. • Traffic congestion and vessel collisions in the controlled waterways could be preventable using the proposed approach. • The reliability and efficiency of proposed method have been verified by comparing with Traffic Signal Revealing System. [ABSTRACT FROM AUTHOR]

Abstract: This paper sheds an empirical light on port development patterns by discussing the structure and the development of the Yangtze River ports system. We argue that the Yangtze River system is going through a regionalization phase, mainly in relation to the port of Shanghai. This process started on the lower Yangtze but is now also moving upstream. The transition towards the port regionalization phase is typically a gradual and market-driven process that mirrors the increased focus of market players on logistics integration. This paper builds on the existing literature on port systems and adapts port development models to river ports. Furthermore, we employ some statistical techniques that are common to the analysis of port systems, and introduce some techniques that have not been used much by transport geographers in ports. This paper will address the dynamics in the Yangtze River ports system by analyzing the level of cargo concentration and the degree of inequality in operations of the container ports. The paper also assesses observed differences in development of ports in different areas along the river (upstream/downstream) and reflects on the role of ownership structures in shaping regional load centre networks. [Copyright &y& Elsevier]

Abstract This paper analyzed the environment significance and hydrochemical characteristics of the main ions on the supra-permafrost water from the view of space-time and different ablations. The study is conducted through collected 330 samples from June to September in 2016 and 2017 in the Source Region of the Yangtze River (SRYR). The results showed the pattern of ionic dominance based on mean value was following as: Cl− > Na+ > SO 4 2− > Ca2+ > Mg2+ > K+ > NO 3 − > NO 2 − > NH 4 + > F− > Li+. Cl− alone contributed 40.57%, and Cl−, Na+, SO 4 2− and Ca2+ accounted for 94.06% of the total ionic concentrations. The spatial variation of ionic concentration was larger at the initial stage of ablation, and more stable in strong ablation and the end of the ablation stage. The area with elevation of 4500 m was the region where the control source of ions was more sensitive to the hydrochemical characteristics of supra-permafrost water in the study area. Through the analysis of the sources of ions, the anions and cations in supra-permafrost water in the study area were mainly controlled by crustal sources including evaporates rocks and carbonate rocks. The recharge effect of precipitation and snow-melt water only affected the concentration of Cl−, NH 4 +, NO 3 −, F−, Li+ and K+, but did not affect NO 2 −, SO 4 2−, Mg2+ and Ca2+. The hydrochemical type of supra-permafrost water was Ca2+-SO 4 2− in high elevation (>4800 m). However, the hydrochemical type of middle elevation (from 4400 m to 4700 m) was Na+-Cl−. The type of hydrochemistry at low altitude was more complex than at high and middle elevation. This study provides insights on the construction of hydrological models in the cold regions and scientific basis for water resources management in the Tibet Plateaus. Graphical abstract The area with elevation of 4500 m was the region where the control source of ions was more sensitive to the hydrochemical characteristics of supra-permafrost water in the study area. The anions and cations in supra-permafrost water in the study area were mainly controlled by crustal sources including evaporates rocks and carbonate rocks. The recharge effect of precipitation and snow-melt water only affected the concentration of Cl−, NH 4 +, NO 3 −, F−, Li+ and K+, but did not affect NO 2 −, SO 4 2−, Mg2+ and Ca2+. The hydrochemical type of supra-permafrost water was Ca2+-SO 4 2− in high elevation (>4800 m). However, the hydrochemical type of middle elevation (from 4400 m to 4700 m) was Na+-Cl−. The type of hydrochemistry at low altitude was more complex than at high and middle elevation. Unlabelled Image Highlights • The supra-permafrost water is the most widely distributed groundwater type in study area; • The area with elevation of 4500 m was more sensitive to the hydrochemical characteristics of supra-permafrost water; • The recharge effect of precipitation and snow-melt water only affected the concentration of Cl−, NH 4 +, NO 3 −, F−, Li+ and K+. [ABSTRACT FROM AUTHOR]

Abstract This paper develops a new paradigm to analyze the eco-efficiency of Yangtze River Economic Belt (YREB) in China and makes a first empirical attempt at examining whether the eco-efficiency in urban agglomerations (UA-s) outperform Non-urban agglomerations (Non-UA-s), or driving the Non-UA-s in promoting eco-efficiency using a dataset of 108 prefectural-level cities during 2003–2014. The main findings are as follows. First, the eco-efficiency of YREB gradually increases during the study period. Cities in UA-s with higher eco-efficiency experience an increasing spatial agglomeration while those in Non-UA-s show a slight downward shift. Second, in terms of eco-efficiency, both statistical test and econometrical test confirm that cities in UA-s outperform those in Non-UA-s. Third, the global and club convergence of eco-efficiency in YREB is ascertained. Forth, the eco-efficiency of UA-s exerts backwash effects on those in Non-UA-s, along with decreasing the convergence speed of eco-efficiency. Special issues are briefly discussed, lastly. Highlights • A new analysis paradigm is developed to explore the YREB's eco-efficiency. • Temporal-spatial evolution and empirical tests are conducted, indicating a proof that eco-efficiency in urban agglomerations outperform that in Non-urban agglomerations. • Urban agglomerations have backwash effects and slight constraints to Non-urban agglomerations in terms of eco-efficiency. • Some special issues are discussed. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The world's W and Sn reserves are about 3.1 and 12 million tons, among which South China accounts for around 45% and 11%, respectively. • W-Sn deposits are concentrated in the Nanling region of central South China and the Yangtze River region of northeastern South China. • Recent studies of W-Sn mineral deposits in South China have advanced our understanding of the distribution and origin of these deposits. • This special issue brings together the latest information in 23 papers that deal with many aspects of the Mesozoic W-Sn mineral deposits. [ABSTRACT FROM AUTHOR]

The sustainable development of a city should occur via the harmonious development of the urban comprehensive carrying capacity (UCC) and economic growth. To study the 84 cities in the Yangtze River Economic Belt (YREB) from 2006 to 2014, this paper uses a spatial econometrics model to evaluate the relationship between the UCC and economic growth, and explore the sustainability of urban development. The results infer some novel findings. First, the impact of economic growth on the UCC has inverted “U”-type characteristics. The economic growth pattern of the urban agglomeration weakens the UCC. Second, the impact of the UCC on economic growth has “U”-type characteristics. The development of the UCC plays a significant supporting role in the economic growth of the YREB. In 2014, 84 cities stayed in the descending phase of the inverted “U” curve, and approximately 50 cities of them lied on the rising segment of the “U” curve. Therefore, reconstructing economic growth models to enhance the UCC represents an important method of realizing a city's sustainable development. [ABSTRACT FROM AUTHOR]

Abstract Flocculation plays an important role in sedimentation of estuaries and continental shelves. The process of flocculation in estuary or shelf is extremely complicated. In this paper, the flocs observed at five sections that include 36 stations within the Yangtze Estuary of the East China Sea were studied systematically using scanning electron microscopy and energy dispersive X-ray spectrometry. The characteristics and spatial distributions of the flocs were obtained, and the factors about the spatial distributions of the flocs were discussed. The flocs were divided into 6 types according to their components: mineral flocs, bio-detritus flocs, mineral-biological flocs, organic-mineral flocs, organic-biological flocs and complex flocs. The percent of the mineral flocs is the highest. The mean particle size of the flocs ranges from 4.00 to 5.00 Ф. The sizes of the mineral flocs are the finest, while the sizes of the complex flocs are the coarsest. The percent of mineral flocs is high near the coastal areas and decreases toward the open sea; this trend is similar to those of organic-mineral flocs and complex flocs. High percentage of bio-detritus flocs and organic-biological flocs is observed to the east of the Taiwan Warm Current. The types and spatial distributions of the flocs are restricted by the properties of the water masses, and they are affected by the interactions of electrolytes, organic matter, biological processes and estuarine authigenesis process. The formation of flocs increases the settling velocity of suspended particles and has an important effect on the formation of mud areas on the continental shelf of the East China Sea. Highlights • Approximate 6 types of flocs within Yangtze River Estuary and its adjacent seas were discerned. • The characteristics of grain-size patterns and spatial distributions of the flocs were obtained. • Spatial distributions of flocs are mainly controlled by electrolytes interactions, biological and authigenesis processes. [ABSTRACT FROM AUTHOR]

Abstract Yangtze River Delta (YRD) area is one of the important economic zones in China. However, this area faces increasing environmental problems. In this study, we use ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) network in Eastern China to retrieve variations of NO 2 , SO 2 , and formaldehyde (HCHO) in the YRD area. Three cities of YRD (Hefei, Nanjing, and Shanghai) were selected for long-term observations. This paper presents technical performance and characteristics of instruments, their distribution in YRD, and results of vertical column densities (VCDs) and profiles of NO 2 , SO 2 , and HCHO. Average diurnal variations of tropospheric NO 2 and SO 2 in different seasons over the three stations yielded minimum values at noon or in the early afternoon, whereas tropospheric HCHO reached the maximum during midday hours. Slight reduction of the pollutants in weekends occurred in all the three sites. In general trace gas concentrations gradually reduced from Shanghai to Hefei. Tropospheric VCDs of NO 2 , SO 2 , and HCHO were compared with those from Ozone Monitoring Instrument (OMI) satellite observations, resulting in R 2 of 0.606, 0.5432, and 0.5566, respectively. According to analysis of regional transports of pollutants, pollution process happened in YRD under the north wind with the pollution dissipating in the southeast wind. The feature is significant in exploring transport of tropospheric trace gas pollution in YRD, and provides basis for satellite and model validation. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Abstract: Eutrophication is a world-wide environmental issue. Lake Taihu is a typical large, shallow, eutrophic lake located in delta of River Changjiang (Yangtze River). A large-scale ecological engineering experiment targeted at water quality improvement was implemented in Meiliang Bay, Lake Taihu. In this special issue, there are six papers related to water purification and algal bloom control techniques applied in this experiment. Four papers address the validity and efficiency of water quality improvement of this ecological engineering and one paper presents a similar but small-size ecological engineering. The others focus on macrophyte restoration, aquatic plant management and recycling exploitation. The editorial paper highlights the main results and conclusions from these papers. [Copyright &y& Elsevier]

As the fourth phase of the Three Gorges reservoir project commenced in 2008, the rate of water flow in the Yangtze River has obviously decelerated further downstream and water clarity within the storage facility has decreased. Meanwhile, the rate of urbanization in the region is adding to the amount of municipal solid waste (MSW) being generated by every day life. The composition of the waste is becoming more diversified and complicated, thereby presenting an increasing threat to the ecological environment and water resources of the Three Gorges region. This paper is a probe into MSW in terms of its characteristics as well as methods of storage, collection, transportation, recycling, treatment and disposal, the protection of environmental ecosystems. Municipal solid waste management (MSWM) is one of the major environmental problems in the Three Gorges region, and indeed the whole of China. Based on the analysis of the present situation of MSWM and its treatment/disposal, some methods of sorting, recycling, decomposing, incineration and reuse are described, sanitary landfill as the main disposal method in Chongqing city, incineration being the second. Sanitary landfill or dump was also used for MSW treatment in the Three Gorges region, and this paper also provides some suggestions for improving MSWM in the Three Gorges region. [Copyright &y& Elsevier]

Abstract: Inter-city cooperation in the Yangtze River Delta region is a new phenomenon and has received much governmental and scholarly attention in recent years. This paper examines inter-city cooperation from partnership perspective. In this study, three typical cases of inter-city cooperation, Suzhou–Wuxi–Changzhou City-region Planning, the Forum for the Coordination of Urban Economy of Yangtze River Delta Region and Jiangyin Economic Development Zone in Jingjiang are selected to examine three types of partnership arrangements, namely, hierarchical partnership, spontaneous partnership and hybrid partnership. This research applies the partnership approach to regional scale based on Chinese experiences. The research focus of this paper is the effectiveness of three types of inter-city cooperation. Through tracing the process of partnership formation and investigating stakeholder interactions, this paper argues that the effectiveness of inter-city cooperation depends on cooperation mechanism, the nature and scope of the cooperation, and partner selection and the roles of actors in partnership formation. [Copyright &y& Elsevier]

Abstract Different modes of governance will certainly have different impacts on the development of the inland waterway network and inland shipping economy on the Yangtze River and Pearl River in China. The inland waterway transport (IWT) economy on both rivers has recently been considered part of the national economic strategy, and it is necessary to analyze the differences between the two modes of governance applied on the arteries of the Yangtze River and the Pearl River and to explore their different impacts on the development of waterway systems. First, this paper considers the Pearl River Economic Belt as an example for comparing the effects of different modes of governance on the development of IWT systems. Second, from the perspective of systems theory, the economic structures of IWT systems under different modes of governance are described. Third, data are collected from inland shipping industries in the Pearl River system, and system dynamic (SD) models of the IWT system are constructed using the Vensim PLE software suite. Finally, the SD models are employed to compare the differences in the development of spatial patterns of waterway systems under two modes of governance and different investment structures. Highlights • A measurement of capacity of inland waterway network was proposed. • The governance modes of inland waterway transport system in China was analysed. • The impacts of two governance modes on the structure of inland waterway network were compared with SD model. [ABSTRACT FROM AUTHOR]

The displacement of pipe-soil contact points in the radial direction and the wedging effect of surrounding soil on the pipe perimeter during pipe pulling-back may have a substantial effect on predicting pulling forces for horizontal directional drilling installations. However, the influence of pipe-soil interaction on pulling force predictions is not considered in existing methods to predict the required pulling force. This paper provides a model representing the interaction between pipe and borehole. The mechanical characteristics of the pipe-soil interaction were numerically investigated with program ANSYS. Two parameters, the wedging coefficient and pipe displacement, were defined and associated parametric studies were performed to analyze the influences of relative factors based on a Yangtze River crossing project. The wedging coefficient is shown to increase with external load and ovality of the borehole, and decrease with increasing over-cut ratio, Poisson’s ratio and elastic modulus of soil. It can improve the prediction accuracy to consider the wedging effect since the difference among predicted results caused by wedging effect can differ up to 7.7% in example analysis. [ABSTRACT FROM AUTHOR]

The Yangtze River Economic Belt (YREB) is the prior region for achieving China’s strategic development with both economic and ecological goals. Since YREB covers more than 500 million people within a large area, the unbalanced urban sustainable development cannot be neglected. Different from the previous studies, this paper adopts an index of urban state carrying capacity (USCC) to assess the sustainable development in YREB. USCC can reflect the positive effects clearly, and evaluate the carrying capacity without the distortion from the opposite side. The assessment method combines the framework of Indicator-Benchmark Comparison (IBC) and the method of Analytical hieratical process (AHP), and sets up the indicator system for USCC from four perspectives. Based on the panel data for the years 2006–2014 in three scale levels, the analyses of temporal and spatial differentiation are conducted to discuss the unbalanced development in YREB. The results present that the eastern sub-UAs have much higher USCC values than the western ones significantly. The provincial cities and municipalities with higher USCC have strong impacts on their neighborhood cities around them. Further policies are suggested to support for other unbalanced sustainable development urban agglomerations like YREB. [ABSTRACT FROM AUTHOR]

This paper presents the first attempt to investigate the emission source control of the Middle Reaches of Yangtze River Urban Agglomerations (MRYRUA), one of the national urban agglomerations in China. An emission inventory of the MRYRUA was developed as inputs to the CAMx model based on county-level activity data obtained by full-coverage investigation and source-based spatial surrogates. A classification technology method for priority control of atmospheric emission sources was introduced and applied in the MRYRUA for the evaluation of the emission sources control on the region-scale and city-scale, respectively. The results demonstrated that the emission sources in the Hefei-centered urban agglomerations contributed the biggest on the mean PM 2.5 concentrations of the MRYRUA and should be taken the priority to control. The emission sources in the Ma'anshan city, Xiangtan city, Hefei city and Wuhan city were the bigger contributors on the mean PM 2.5 concentrations of the MRYRUA among the cities and should be taken the priority to control. In generally, emission sources in cities along the Yangtze River and the tributary should be given the special attention for the regional air quality target attainments. This study can give an understanding of Chinese emissions and provide a valuable preference to policy makers for finding effective mitigation measures and control strategies for reducing national and regional air pollution in China. [ABSTRACT FROM AUTHOR]

Based on the sequential generalized directional distance function (SGDDF) and Metafrontier non-radial Malmquist index (MNMI), the dynamic changes, saving potential, efficiency decompositions, and influencing factors of industrial land use efficiency are analyzed. This paper is a case study on the urban agglomeration in the middle reaches of the Yangtze River focusing on the years between 2003 and 2012. The results show that (1) potential for significant improvement in industrial land use efficiency exists, and the saving potential of industrial land shows a rising trend. With the least saving potential, the Poyang Lake city group enjoys the highest efficiency. With the greatest saving potential, the efficiency in Wuhan city group is the lowest. (2) A positive catch-up effect and technological progress can be observed in industrial land use efficiency in the examined region, but the lack of technology innovators inhibits the promotion of industrial land use technology. (3) The analysis of the influencing factors shows that the relationship between per capita GDP and industrial land use efficiency follows an “N” shape. With the further economic development, industrial land use efficiency will decline slightly. Enhancing industrialization and land investment policies is thus conducive to increasing industrial land use efficiency, while industrial labor surplus and the governance of “Land Finance” have the opposite effect. Specific countermeasures to promote industrial land use efficiency are as follows: optimize industrial structure and improve labor skills; expand local industrial economy size properly to absorb surplus labor; perfect the land circulation system, and give full play to the resource allocation function of the land market; promote cross-regional flow of production factors; and strengthen regional cooperation among cities in the middle reaches of the Yangtze River. [ABSTRACT FROM AUTHOR]

The eastern Nanhui mudflat (ENM), located in the southern flank of the Changjiang (Yangtze River) Estuary, plays a key role in storm protection, defense against sea level rise, and land resource provision for Shanghai, China's largest city. Recently, there has been a great deal of concern for its evolutionary fate, since a drastic reduction in the Changjiang sediment discharge rate and an increased number of estuarine enclosures might negatively impact the environmental protection functions that this mudflat provides. In this paper, a novel method, which employed the envelope lines of instantaneous shoreline positions identified in 436 Landsat satellite images from 1975 to 2016, was used to demonstrate the evolution of the mudflat high and low tide lines in a detailed, quantitative way. Our study reveals the southeast progradation rate of the mudflat doubled from 24 m/yr in 713–1974 CE to 49 m/yr in 1975–1995 CE, probably due to the influence of the estuarine turbidity maximum zone shifting to the ENM. Under the ample sediment input directly from the turbidity maximum zone, the spatial evolution of the ENM was governed predominantly by the changing morphology of the South Passage due to the quick progradation of the ENM, which narrowed the South Passage by pushing the South Passage Trumpet southeastward. Therefore, the ENM experienced rapid accretion during 1975–2016. The accretion rate of the high tide line increased 2–13 times due to vegetation and intertidal enclosures, resulting in the rapid reduction of the intertidal area. The area decreased from 97 km 2 in 1976 to 66 km 2 in 1995, mainly due to vegetation, and continued decreasing to 12 km 2 in 2006 due to the intertidal enclosures. In contrast, the accretion rate of the low tide line increased by 25 times due to subtidal enclosures and caused the intertidal area increased to 78 km 2 in 2015. The almost disappeared intertidal zones in 2006 reappeared. However, this reappearance might be a temporary transitional state, and once the subtidal enclosures are completed, most of the intertidal zones will be replaced by enclosure land. Our study reveals that the drastic reduction in the Changjiang sediment flow to the sea has not caused a decline in the ENM. In contrast, the ENM has experienced rapid accretion in the past 40 years, resulting in the strengthening of its functional abilities to protect Shanghai, an unexpected outcome. [ABSTRACT FROM AUTHOR]

The Yangtze River is one of the largest and most important rivers in the world. Over the past several decades, the natural sediment regime of the Yangtze River has been altered by the construction of dams. This paper uses multi-scale entropy analysis to ascertain the impacts of large dams on the complexity of high-frequency suspended sediment dynamics in the Yangtze River system, especially after impoundment of the Three Gorges Dam (TGD). In this study, the complexity of sediment dynamics is quantified by framing it within the context of entropy analysis of time series. Data on daily sediment loads for four stations located in the mainstem are analyzed for the past 60 years. The results indicate that dam construction has reduced the complexity of short-term (1–30 days) variation in sediment dynamics near the structures, but that complexity has actually increased farther downstream. This spatial pattern seems to reflect a filtering effect of the dams on the on the temporal pattern of sediment loads as well as decreased longitudinal connectivity of sediment transfer through the river system, resulting in downstream enhancement of the influence of local sediment inputs by tributaries on sediment dynamics. The TGD has had a substantial impact on the complexity of sediment series in the mainstem of the Yangtze River, especially after it became fully operational. This enhanced impact is attributed to the high trapping efficiency of this dam and its associated large reservoir. The sediment dynamics “signal” becomes more spatially variable after dam construction. This study demonstrates the spatial influence of dams on the high-frequency temporal complexity of sediment regimes and provides valuable information that can be used to guide environmental conservation of the Yangtze River. [ABSTRACT FROM AUTHOR]

The Chinese central government has released detailed carbon emissions abatement targets at the provincial level, but provides no specific emissions reduction targets at the city level. Most provincial governments simply allocate carbon emissions reduction tasks to their cities based on the GDP of their cities. Allocation approaches, however, should emphasize the most effective distribution to reach overall targets that reflect actual reduction capacities of cities. This paper proposes an allocation method at the city level by combining a data envelop analysis method, an entropy weight method and a clustering analysis method using the Yangtze River Delta region as a case study. Results of our analysis indicate that cities with higher carbon emissions abatement potentials, financial abilities, a larger number of above-scaled industrial enterprises and higher GDP are better positioned to reduce carbon emissions and should be assigned proportionately higher reduction targets. The merits and policy implications of the proposed approach are discussed in comparison to simply using GDP to allocate emission reduction targets. [ABSTRACT FROM AUTHOR]

Early Neoproterozoic tectonics of the Yangtze block remains poorly understood because very limited igneous records are available from the time interval of ∼1000–870 Ma. In this paper, our new SIMS U–Pb dating results demonstrate that the Liushudian mafic intrusion and Pinghe alkaline complex in the northwest Yangtze block were emplaced at 888 ± 6 Ma and 891 ± 7 Ma, respectively, representing the products of a ∼890 Ma igneous event. Gabbros from the Liushudian intrusion have rather depleted zircon ɛ Hf( t ) (mean = 10.4) and normal mantle-like zircon δ 18 O (mean = 5.97‰). Their parental magma was thus probably derived from asthenospheric mantle. Geochemically, these mafic rocks have an affinity to continental flood tholeiitic basalts rather than ocean island basalts, as previously thought. In contrast, an ijolite sample from the Pinghe complex has less depleted zircon ɛ Hf( t ) (mean = 5.7) and anomalously high zircon and apatite δ 18 O (mean = 13.76‰ and 13.80‰, respectively). Such a characteristic δ 18 O signal, among the highest yet known for igneous zircons, could be either inherited from a magma source in metasomatized lithospheric mantle or acquired by assimilation of high-δ 18 O supracrustal materials (e.g., limestone, chert) during magma evolution. An intra-plate extensional environment is suggested for the ∼890 Ma igneous event in the northwest Yangtze block, although it is as yet unclear whether this igneous event is related to a mantle plume or not. It could be concluded that magmatism on the western periphery of the Yangtze block was not shut down between ∼1000 and ∼870 Ma, and the ∼890 Ma intra-plate igneous event may mark either the onset of Neoproterozoic continental rifting or the ending of Late Mesoproterozoic to Early Neoproterozoic lithospheric extension. [ABSTRACT FROM AUTHOR]

Under the background of global warming, occurrence of heat waves has increased in most part of Europe, Asia and Australia along with enhanced ozone level. In this paper, observational air temperature and surface ozone in the Yangtze River Delta (YRD) region of China during summer of 2013, and the regional chemistry-climate model (RegCM-CHEM4) were applied to explore the relationship between heat wave and elevated ground-level ozone. Observations indicated that YRD experienced severe heat waves with maximum temperature up to 41.1 °C, 6.1 °C higher than the definition of heat wave in China, and can last for as long as 27 days. Maximum ozone reached 160.5 ppb, exceeding the national air quality standard (secondary level) as 74.7 ppb. Moreover, ozone was found to increase at a rate of 4–5 ppb K − 1 within the temperature range of 28–38 °C, but decrease by a rate of − 1.3 ~ − 1.7 ppb K − 1 under extremely high temperature. A typical heat wave case (HW: 24/7–31/7) and non-heat wave case (NHW: 5/6–12/6) were selected to investigate the mechanism between heavy ozone and heat waves. It was found that chemical reactions play the most important role in ozone formation during HW days, which result in 12 ppb ozone enhancement compared to NHW days. Chemical formation of ozone can be influenced by several factors. During heat waves, a more stagnant condition, controlled by anti-cyclone with sink airflow, led to less water vapor in YRD from south and contributed to less cloud cover, which favored a strong solar radiation environment and ozone significantly increasing. High temperature also slightly promote the effect of vertical turbulence and horizontal advection, which beneficial to ozone remove, but the magnitude is much smaller than chemical effect. Our study suggests that the chemical reaction will potentially lead to substantial elevated ozone in a warmer climate, which should be taken into account in future ozone related issues. [ABSTRACT FROM AUTHOR]

Unplanned indirect (de facto) wastewater reuse occurs when wastewater is discharged into surface waters upstream of potable drinking water treatment plant intakes. This paper aims to predict percentages and trends of de facto reuse throughout the Yangtze River watershed in order to understand the relative contribution of wastewater discharges into the river and its tributaries towards averting water scarcity concerns. The Yangtze River is the third longest in the world and supports more than 1/15 of the world's population, yet the importance of wastewater on the river remains ill-defined. Municipal wastewater produced in the Yangtze River Basin increased by 41% between 1998 and 2014, from 2580 m 3 /s to 3646 m 3 /s. Under low flow conditions in the Yangtze River near Shanghai, treated wastewater contributions to river flows increased from 8% in 1998 to 14% in 2014. The highest levels of de facto reuse appeared along a major tributary (Han River) of the Yangtze River, where de facto reuse can exceed 20%. While this initial analysis of de facto reuse used water supply and wastewater data from 110 cities in the basin and 11 gauging stations with > 50 years of historic streamflow data, the outcome was limited by the lack of gauging stations at more locations (i.e., data had to be predicted using digital elevation mapping) and lack of precise geospatial location of drinking water intakes or wastewater discharges. This limited the predictive capability of the model relative to larger datasets available in other countries (e.g., USA). This assessment is the first analysis of de facto wastewater reuse in the Yangtze River Basin. It will help identify sections of the river at higher risk for wastewater-related pollutants due to presence of—and reliance on—wastewater discharge that could be the focus of field studies and model predictions of higher spatial and temporal resolution. [ABSTRACT FROM AUTHOR]

This study presents the spatial distribution of total dissolved Cu, Zn, Co, and V during an autumn survey in the East China Sea (ECS). Dissolved Fe and its organic complexation were also investigated. The present study aimed to evaluate the relationship between Cu, Zn, Co, V, D-Fe and its organic ligands and total dissolved phosphate (TDP) in the coastal waters of the ECS. A correlation analysis shows that Cu, Zn and D-Fe were nutrient-like metals, whereas Co and V were non-nutrient-like metals. A multivariate statistical analysis showed that TDP was associated with D-Fe, Cu, Zn and Co, but was not associated with V. Furthermore, TDP was observed to be positively related with D-Fe, while negatively with Fe′, which indicated that the limitation of TDP decreased the uptake of Fe′. This paper improves our understanding of the association among trace metals, TDP and phytoplankton biomass in the ECS. [ABSTRACT FROM AUTHOR]

Applying a parameterized directional distance function approach, this paper estimates the regional eco-efficiency and pollutants' marginal abatement costs in China based on provincial panel data covering the years 2003–2012. We find that China could potentially save capital, labor, land, energy and water by 18.07%, 11.47%, 11.20%, 12.28% and 11.19%, and reduce emissions of carbon dioxide (CO 2 ), household refuse and waste water by 11.75%, 11.02% and 11.46%, respectively, on condition that all provinces produced fully efficiently, The south and east coastal areas were the most eco-efficient, while the middle Yangtze River and southwest areas performed relatively poor. For the whole country, the average shadow prices of CO 2 , household refuse and waste water were 717.27 Yuan/tonne, 42,936.98 Yuan/tonne and 306.65 Yuan/tonne, respectively. The shadow price of CO 2 revealed significant regional disparities and that of household refuse showed a rapid increase throughout the study period. Our estimates suggest that policymakers should take measures to avoid ineffective capital investment and improve economic output efficiency in inland provinces, especially in the middle Yangtze River, northwest and southwest areas, and facilitate technological cooperation between developed and undeveloped areas. The regional heterogeneity and flexible price mechanism of various pollutants should be taken into consideration when making the reduction allocations among different areas. [ABSTRACT FROM AUTHOR]

Economically developed coastal areas have a high water demand, and their groundwater resources can be threatened by salinization. Many methods and tracers have been used to discriminate the source of salinization because a single method does not yield reliable results. In this paper, the shallow confined coastal plain aquifer, north of the downstream Yangtze River in China, is used as a case study to investigate the origin of the salinity and the relevant geochemical processes for this aquifer. Multiple environmental tracers of major ions, minor ions (Br − , I − ), and isotopes ( 18 O, 2 H, 13 C, 87 Sr, 3 H, 14 C) were used so as to provide reliable conclusions. The TDS distribution of the aquifer has an increasing trend, from below 500 mg/L in the inland areas to more than 20,000 mg/L around the southeast coastline. The water chemical type evolves from HCO 3 -Ca to Cl-Na as the TDS increases. The results suggest that the groundwater salinity is influenced by seawater intrusion. The seawater proportions in the groundwater samples range from 0.07% to 94.41% and show the same spatial distribution pattern as TDS. The 3 H and 14 C values show that the highest salinity was mainly caused by a seawater transgression around 6000a B.P. The aquifer is also affected by other hydrogeochemical processes: base exchange has enriched Ca 2+ and depleted K + and Na + , sulfate reduction has reduced the concentration of SO 4 2− and enriched HCO 3 − , and iodine-rich organic matter decomposition has enriched the concentration of I − . The iodine enrichment also suggests paleo-seawater intrusion. In addition, the precipitation of carbonate minerals has decreased the concentration of Ca 2+ , Mg 2+ , and HCO 3 − , albeit to a limited extent. [ABSTRACT FROM AUTHOR]

With the continuous increase of traffic volume in recent years, inland waterway transportation suffers more and more from congestion problems, which form a major impediment to its development. Thus, it is of great significance for the stakeholders and decision makers to address these congestion issues properly. Fuzzy Techniques for Order Preference by Similarity to an Ideal Solution (TOPSIS) is widely used for solving Multiple Criteria Decision Making (MCDM) problems with ambiguity. When taking into account fuzzy TOPSIS, decisions are made in a static scenario with fixed weights assigned to the criteria. However, risk conditions usually vary in real-life cases, which will inevitably affect the preference ranking of the alternatives. To make flexible decisions according to the dynamics of congestion risks and to achieve a rational risk analysis for prioritising congestion risk control options (RCOs), the cost-benefit ratio (CBR) is used in this paper to reflect the change of risk conditions. The hybrid of CBR and fuzzy TOPSIS is illustrated by investigating the congestion risks of the Yangtze River. The ranking of RCOs varies depending on the scenarios with different congestion risk conditions. The research findings indicate that some RCOs (e.g. “Channel dredging and maintenance”, and “Prohibition of navigation”) are more cost effective in the situation of a high level of congestion risk, while the other RCOs (e.g. “Loading restriction”, and “Crew management and training”) are more beneficial in a relatively low congestion risk condition. The proposed methods and the evaluation results provide useful insights for effective safety management of the inland waterway congestions under dynamic risk conditions. [ABSTRACT FROM AUTHOR]

Despite of the high demand for liquefied natural gas (LNG) in demanding countries, an ideal means for establishing the LNG supply system has not yet been found in many regions. In this paper, a three-stage stochastic programming method has been proposed for LNG supply system infrastructure development and inventory routing in demanding countries. The minimum daily cost is set as the objective function; and the cost consists of the delivery cost, liquefaction cost, purchase cost, and construction cost. Under the constraints of delivery mode, volume, vehicle, time, and infrastructure construction, a multi-scenario MILP model was established and solved by a hybrid computational method (ACO-MILP), and the optimal infrastructure development and inventory routing were presented as the result. Finally, the method was successfully applied to the LNG supply system along the Yangtze River in China. Furthermore, compared with the other methods, the superiority of the method was verified. [ABSTRACT FROM AUTHOR]

The earliest pottery in East Asia, as is found in several cave sites in southern China, emerges in Upper Paleolithic contexts dating from the Last Glacial Maximum, ∼20 Ka cal BP. The making of simple pottery vessels in Late Pleistocene East Asia also has been noted in eastern Siberia and Japan but not yet in the Central Plains of China. This paper summarizes the better-reported evidence for early pottery sites across the vast region of China south of the Yangtze River, providing details on two dating projects conducted in the cave sites of Xianrendong (Jiangxi Province) and Yuchanyan (Hunan Province). The excavated contexts in these two caves and a few others clearly indicate that this early pottery was the creation of hunter-gatherers who hunted available game and foraged a variety of plant foods. The nature of the cave occupations is ephemeral, and where the published animal and plant remains allow, we suggest that there were repeated, seasonal occupations. In sum, there is no basis yet to suggest that the making of early pottery in South China marked sedentary or plant-cultivating communities. [ABSTRACT FROM AUTHOR]

Recently, dramatic flood disasters have occurred incrementally in several regions of the world. Land-use change as one of the main affecting factors becomes a key component in flood risk management. This study strives to deal with quantifying how changes in land use to affect the dynamic evolution of flood vulnerability. The floodplains of Wuhan, which are located in the Yangtze River Basin, have been selected as an example. In this paper, we use GIS to gather different historical geometric data as sources of land-use information. By proposing the Simpsons-dominance index and location index to analyze the characteristics of land-use changes, and building a quantitative model to measure flood vulnerability, a series of flood vulnerability maps demonstrate differential flood vulnerability of floodplains of Wuhan in three inundation scenarios and four historical periods. Finally, the non-parametric correlation is used to reveal the interactive effect of land use and flood vulnerability. Based on this study, comprehensive flood disaster management strategies for land-use planning are proposed for government decision-makers to reduce the flood vulnerability of Wuhan in future. [ABSTRACT FROM AUTHOR]

Global urbanization and urban sprawl have made urban land efficiency (ULE) a significant issue for sustainable development. The Yangtze River Delta (YRD), the largest globalizing city region in China, has experienced dramatic urbanization, and land for future development has become a scarce commodity. This paper explores the spatial patterns and underlying determinants of ULE in the YRD, focusing on accessibility and economic transition. We find that the spatial agglomeration effect of ULE has intensified with the development of transportation accessibility and has mainly spread from southern Jiangsu to other areas. The integrated transportation and spatial autoregressive (TSAR) model suggests that accessibility and globalization play a significantly positive role in ULE, and that marketization as well as decentralization also have significant effects. Furthermore, a geographically weighted regression (GWR) shows that the drivers of ULE vary across the YRD. ULE in northern Zhejiang is more sensitive to foreign direct investment (FDI) and tertiary industry development, while ULE in southern and central Jiangsu are more likely to be associated with globalization and labor-intensive manufacturing. [ABSTRACT FROM AUTHOR]

Remote sensing-based retrieval of the concentrations of water components relies largely on the accuracy of the atmospheric correction. Although a variety of atmospheric correction algorithms have been developed for turbid waters, the water-leaving reflectance is still underestimated in extremely turbid waters, such as in the Changjiang (Yangtze) estuary and the adjacent coast. To address this issue, this paper proposes an improved algorithm that is based on a spectral optimization algorithm (ESOA) with a coupled water-atmosphere model. The model combines an aerosol model that is constructed from Aerosol Robotic Network (AERONET) observation data and a simple semi-empirical radiative transfer (SERT) model (Shen et al. 2010) for water component retrieval. Four unknown parameters are involved in the coupled model: the relative humidity (RH), fine-mode fraction (FMF), aerosol optical thickness in the near-infrared (NIR) wavelength τ a (λ 0 ) and suspended particulate matter (SPM) concentration ( C spm ). These parameters are estimated by a global optimization approach that is based on a genetic algorithm (GA) without any initial inputs. Validation results of the atmospherically corrected remote sensing reflectance R rs (λ) from matchups between Geostationary Ocean Color Imager (GOCI) data and in situ data show that the algorithm has satisfactory accuracy. The root mean square error (RMSE) and the absolute percentage difference (APD) are 0.0089 and 35.12, respectively. By contrast, the R rs (λ) values retrieved from the same matchups using the GOCI data processing system (GDPS) have higher RMSE and APD of 0.0104 and 69.15, respectively. The ESOA method can be implemented conveniently within the open source code of SeaDAS (v7.1) as an alternative and operational tool for atmospheric correction of ocean color data, including GOCI, MERIS and MODIS, over highly turbid estuarine and coastal regions, such as the Yangtze estuary, the Hangzhou Bay and most of the coastal ocean in Eastern China. [ABSTRACT FROM AUTHOR]

The Indo–Asian collision resulted in extrusion of the Indochina Block along the Ailao Shan–Red River (ASRR) shear zone in the Cenozoic, with the emplacement of widespread potassic magmatic rocks. In this contribution, we investigated five potassic felsic intrusions exposed in the western Yangtze Block adjacent to the ASRR shear zone, including the Xiaoqiaotou, Jianchuan, Yuzhaokuai, Laojunshan and South Taohuacun intrusions. New LA–ICP–MS zircon U–Pb results in combination with previous data indicate that these felsic rocks have identical crystallization ages of ∼36–35 Ma. They are characterized by high Ba (mostly >1500 ppm) and Sr (mostly >1000 ppm) abundances, with high K 2 O contents and K 2 O/Na 2 O ratios. They exhibit similar Sr-Nd isotopic components as the coeval shoshonitic mafic rocks exposed in the studied area. Elemental and isotopic data suggest that the five intrusions were likely derived from fractional crystallization of shoshonitic mafic magmas originating from an enriched lithospheric mantle. On the basis of previously published data and results in this paper, we considered that the lithospheric mantle underneath the western Yangtze might have undergone enrichment events twice at least, including the Neoproterozoic oceanic subduction and the Neo-Tethyan oceanic subduction. [ABSTRACT FROM AUTHOR]

The construction of multi-function reservoirs is important to guaranteeing the development and utilization of water and hydropower resources, but the construction of any hydrologic projects will inevitably affect the downstream flow regime that provides the driving force for riverine ecosystems. This paper therefore aims to propose a framework for assessing multi-objective reservoir operation models based on flow regime using the middle and lower Yangtze River as a case study. Using indicators of hydrologic alteration (IHA) and the histogram matching approach (HMA), critical influential factors for flow were investigated at the Yichang and Datong gauges, which are typical of the middle and lower Yangtze River. This found the magnitude of annual extreme minimum water flow rates to be the most dramatically changed indicator, with an overall degree of hydrologic alteration at the Yichang and Datong gauges of 41.98% and 34.58%, respectively. The monthly mean discharges of February and October at Yichang have been significantly changed as a result of the Three Gorges Reservoir (TGR) operation. Meanwhile, an improved range of variability approach (IRVA) was developed to obtain ideal target ranges for monthly average flow. A multi-objective ecological reservoir operations model was created for the TGR; the Non-dominated Sorting Genetic Algorithm II (NSGA-II) was applied to the model. Three typical years of wet, normal and dry years were selected, and the operation results with corresponding ideal target ranges were analyzed for the downstream Yichang and Datong cross sections. The results showed that there should be a reduction by 23.57%, 28.10% and 39.92% in the monthly mean flow of February and an increase by 34.48%, 112.36% and 52.12% in the monthly mean flow of October at Yichang cross section in wet, normal and dry years, respectively. Close attention therefore needs to be given to integrating ecological objectives with appropriate flow regimes into multi-objective operation models. [ABSTRACT FROM AUTHOR]

The absence of a high-quality seamless global digital elevation model (DEM) dataset has been a challenge for the Earth-related research fields. Recently, the 1-arc-second Shuttle Radar Topography Mission (SRTM-1) data have been released globally, covering over 80% of the Earth’s land surface (60°N–56°S). However, voids and anomalies still exist in some tiles, which has prevented the SRTM-1 dataset from being directly used without further processing. In this paper, we propose a method to generate a seamless DEM dataset blending SRTM-1, ASTER GDEM v2, and ICESat laser altimetry data. The ASTER GDEM v2 data are used as the elevation source for the SRTM void filling. To get a reliable filling source, ICESat GLAS points are incorporated to enhance the accuracy of the ASTER data within the void regions, using an artificial neural network (ANN) model. After correction, the voids in the SRTM-1 data are filled with the corrected ASTER GDEM values. The triangular irregular network based delta surface fill (DSF) method is then employed to eliminate the vertical bias between them. Finally, an adaptive outlier filter is applied to all the data tiles. The final result is a seamless global DEM dataset. ICESat points collected from 2003 to 2009 were used to validate the effectiveness of the proposed method, and to assess the vertical accuracy of the global DEM products in China. Furthermore, channel networks in the Yangtze River Basin were also extracted for the data assessment. [ABSTRACT FROM AUTHOR]

Numerous environmental archaeology studies have been undertaken in the middle and lower reaches of the Yangtze River, but limited research has been carried out in the upper reaches of the Yangtze River (UYR). During the period of the Baodun Culture (approximately 4500–3700 cal. yr BP), the inhabitants of the Chengdu Plain (CDP) in the UYR of southwestern China were confronted with a dynamic climate. Archaeological sites, including 9 walled sites located in a relatively small region, were built during the migration process. This paper attempts to demonstrate the linkage between the evolutionary history of the Baodun Culture and paleoclimate change. Subsistence strategies during the Baodun period, such as farming, tool use and food resources were investigated. Furthermore, the spatiotemporal distribution of the archaeological sites, the construction method of the sites' walls, and the growth of weeds were examined and assessed based on archaeological excavations and the literature. The ancient water network at the Baodun site was investigated based on auger surveys and borehole data. By comparing multiple paleoclimatic proxies from regions mainly controlled by the Indian Monsoon, we found that: (1) the drying and cooling climate conditions were responsible for the increases of proportions of millet and supplementary food resources and for the transformation of tool assemblages during the late Baodun period; (2) the increasing numbers of flood events were caused by the weakening of the monsoon and the dramatic climate during the Baodun period, and the interconnected river networks at low elevations in the CDP exacerbated the impact of flooding, which may have partially caused the frequent human migration and the construction method of the site walls; (3) the Baodun people that originally lived in the southwestern and western CDP were forced to gradually migrate to higher elevations in the northern and central territories because of the rapid climate change; and (4) the topography and river-grade also influenced human migration and settlement selection. Climate deterioration hindered the sustainable development of the Baodun Culture and eventually caused it to decline. Common subsistence strategies in human history, such as site location, migration, flood-control methods, agricultural changes, and food diversification, played important roles in the Baodun people's adaptation to climate change. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the velocity characteristics of compound rivers in mountain areas, featured with substantially different roughness between the main channel and floodplain. A series of flume experiments have been conducted to investigate the velocity distribution affected by different roughness in the main channel and its floodplain. The experimental data are analysed to obtain a new empirical formula to determine the velocity ratio between the main channel and the floodplain. In addition to the roughness, the ratio between the water depth in the main channel and the floodplain also affects the flow velocity. Therefore the velocity characteristics vary with the roughness and depth in the subsections of the compound channel. The new empirical formula is applied to estimate velocity in the upper reach of Yangtze River, in Chongqing, China. The calculated results are found to be consistent with the field measurements, demonstrating the potential of the formula for estimating velocity distribution in mountain rivers. [ABSTRACT FROM AUTHOR]

This paper examines geochemical properties of detrital magnetite, in order to link sediments in a Plio-Quaternary core taken in the delta area to their sources in the Yangtze River basin. A total of 40 sediment samples were collected from both the main river channel/tributaries and a sediment core from the Yangtze delta. The geochemical compositions of detrital magnetite in these sediments were analyzed by electron microprobe, including FeO, TiO 2 , CoO, MgO, Cr 2 O 3 , MnO, ZnO, Al 2 O 3 and V 2 O 3 . The results revealed that the detrital magnetite grains with anomalously high Cr 2 O 3 occurred exclusively in the upper reaches of the Yangtze (upstream of the Three Gorges Dam), where the E'mei Basalt block is located. This type of magnetite could therefore be considered a unique sediment proxy of the upper river basin to help identify sediment source in the delta area. Our analysis found such magnetite grains with high Cr 2 O 3 occurring throughout the core depth above 186.5 m, in contrast to the extremely low Cr 2 O 3 below this depth. The boundary between high and low Cr 2 O 3 in magnetite grains of the core sediments was dated by paleomagnetism at ca. ~ 1.2–1.0 Ma, signifying that the linkage between the Yangtze River course and the sea was before ~ 1.2–1.0 Ma. This demonstrates that the sediment provenance of the Yangtze delta has experienced a change from local to distal Yangtze River, which took place with the uplift of the Tibetan plateau and coastal subsidence during the Plio-Quaternary. [ABSTRACT FROM AUTHOR]

Increasingly large, high-tonnage containerships are becoming a common sight on the Yangtze River, and the shipping network is being transformed accordingly. This paper reports the design of a hub-and-spoke network for a shipping company that is consistent with the characteristics of the Yangtze River. We first explore the economies of scale for container shipping by applying empirical data. Next, we propose a mixed-integer linear programming model, factoring in ship-operating and container-handling costs. We then conduct a numerical experiment and test the effectiveness of the model, and finally discuss the implications of hub-and-spoke shipping network design. The findings reported herein support the trends toward cargo concentration and port regionalization along the Yangtze River. [ABSTRACT FROM AUTHOR]

This paper presents the results of an investigation of the Gongjiafang landslide with the volume of about 500,000 m 3 in the Three Gorges Reservoir region (TGR), occurred on 23 November, 2008. In this study, detailed geological and geomorphological surveys, in-situ and laboratory tests, and numerical simulation are carried out to reveal the failure mechanism of this landslide. The anaclinal rock slope is characterized mainly by a set of outward dipping and non-persistent joints, a hard stratum (limestone) in the middle portion and an underlying soft base (argillaceous limestone interbedded with shale). Because of the long-term intensive river erosion caused by periodic fluctuation of the reservoir water level, the soft rock masses at the toe of the slope were softened, or even washed away, inducing the first sliding-toppling failure at the toe. The collapse at the toe leaves the hard strata in the middle unsupported, like a “beam”. Thus, a conceptual “cantilever beam” model is proposed to explain the failure mechanism of the landslide. The DEM simulation further highlights the failure process with a complex rock topple-rock slide failure mode, i.e., first composite sliding and toppling occurred at the toe, a composite shear and flexure failure of the middle “cantilever beam” and a simultaneous overall sliding failure of the rock masses in the upper part of the slope. The results imply that preventing water erosion at the toe could be an effective way in landslide prevention and treatment in the study area. [ABSTRACT FROM AUTHOR]

Summary Much has been written on the hydrology of the Yangtze River in China, especially since the construction of the Three Gorges Dam. Given the range of views in the literature on the impacts of dams and other natural and anthropogenic activities in the catchment on monthly flows, we here set out to analyse the behavior of monthly flows over the period of record 1955–2014. In the literature, the Three Gorges dam has been singled out for particular comment, mostly adverse. In this paper we analyse trend in temperature, precipitation and discharge of the Yangtze River at the monthly time scale over a period that includes the 11 years since the Three Gorges Dam came into operation. The results show that for the upper basin, there has been a marked increase in discharge in the low flow months of January to March that began abruptly in 2003 and an abrupt decrease in flow in October at the same time. Similar changes are found for discharge from the lower basin but in that case the changes have occurred gradually over the period of record. These changes are the outcome of the operation of hydroelectric and flood control dams that have been built continuously in the lower basin since 1955 while in the upper basin the building of the Three Gorges Dam began a phase of rapid dam building not seen in the lower basin. The decreased flows in the late summer and autumn are not of sufficient magnitude to cause any problems for navigation or water supply. The enhanced flows in the winter low flow period are beneficial in that they reduce the likelihood of salt water intrusions in the estuary adversely affecting the supply of freshwater to Shanghai. [ABSTRACT FROM AUTHOR]

The tidal residual current may play an important role in the mean flow in the Changjiang Bank region, in addition to other residual currents, such as the Taiwan Warm Current, the Yellow Sea Coastal Current, and the Yellow Sea Warm Current. In this paper, a detailed structure of the tidal residual current, in particular the meso-scale eddies, in the Changjiang Bank region is observed from model simulations, and its role in the mean flow is quantified using the well-validated Finite Volume Coastal Ocean Model. The tidal residual current in the Changjiang Bank region consists of two components: an anticyclonic regional-scale tidal residual circulation around the edge of the Changjiang Bank and some cyclonic meso-scale tidal residual eddies across the Changjiang Bank. The meso-scale tidal residual eddies occur across the Changjiang Bank and contribute to the regional-scale tidal residual circulation offshore at the northwest boundary and on the northeast edge of the Changjiang Bank, southeastward along the 50 m isobath. Tidal rectification is the major mechanism causing the tidal residual current to flow along the isobaths. Both components of the tidal residual current have significant effects on the mean flow. A comparison between the tidal residual current and the mean flow indicates that the contribution of the tidal residual current to the mean flow is greater than 50%. [ABSTRACT FROM AUTHOR]