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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]

This paper studies the relationship between net primary productivity (NPP) and annual average air temperature (GT) at 0cm above ground in permafrost regions by using revised Chikugo NPP model, cubic spline interpolating functions, and nonlinear regression methods. The source regions of the Yangtze and Yellow Rivers were selected as the research areas. Results illustrate that: (1) There is significant non-linear relationship between NPP and GT in various typical years; (2) The maximum value of NPP is 6.17, 5.87, 7.73, and 5.41 DM·t·hm·a respectively, and the corresponding GT is 7.1, 10.0, 21.2, and 8.9°C respectively in 1980, 1990, 2000 and 2007; (3) In 1980, the sensitivity of NPP to GT is higher than in 1990, 2000 and 2007. This tendency shows that the NPP presents change from fluctuation to an adaptation process over time; (4) During 1980∼2007, the accumulated NPP was reduced to 8.05, and the corresponding carrying capacity of theoretical livestock reduced by 11%; (5) The shape of the demonstration region of ecological compensation system, livelihood support system, and science appraisal system in the source regions of Yangtze and Yellow Rivers are an important research for increasing the adaptation capacity and balancing protection and development. [ABSTRACT FROM AUTHOR]

This paper examines the morphological development of the Yangtze River mouth, which has been diverting southeasterly (dextrally), according to historical (150 years) chart-based digital evolution model and on-site measured tidal flow data. We reveal a significantly narrowing of the northern river mouth branch from formerly >30 km wide to presently 10 km wide due to rapid siltation. Net siltation there, however, decreases gradually, which largely contrasts with the fact that the siltation has shifted to the southern river mouth area, as shown by many newly-emerged estuarine islands, sandy shoals and bifurcated branches. Our data have further demonstrated that the ebb flow that dominates in the study area changes its direction gradually from east to southeast from the inner to outer river mouth area, and its duration is much longer than the flood flow in the inner river mouth area, but nearly equal at the river mouth area. Accordingly, the sediment transport pathway has been diverted from east to southeast. We examine whether the Coriolis Force could explain the dextral diversion of the ebb flow and the altered morphodynamical processes. Although too weak to strengthen the tidal flows, the Coriolis Force can drag the ebb flow southeasterly, and so influence sediment transport paths at the estuarine scale. The Coriolis Force is limited in the inner river mouth, but substantial at and in the outer river mouth area when gradually free of estuarine topographic constraints. The Coriolis Force causes an offset in propagation of in-out flow directions at the river mouth area to form a slack water setting prone to estuarine siltation. Using the present approach also enables explanation of the morphological development of the Holocene Yangtze delta-coast that extends to the southeast. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Jianghan Plain and the Dongting lake area, located in the middle reaches of the Yangtze River are famous for their abundant freshwater lakes. The lakes have undergone changes in size and number over thousands of years due to natural causes and human activities. The 20th century particularly, witnessed dramatic changes in the freshwater resources of this region. This paper traces and analyzes lake evolution in the middle reaches of the Yangtze River over the past century. Lakes greater than 0.1 km2 in size are mapped using Geographic Information System. Data is acquired and integrated from drainage network maps, relief maps, historical maps and remotely sensed images for different time periods. The results indicate that while there has been little change in the number of lakes over the past century, the lake area has experienced a dramatic decrease of 58.06%. The paper also examines the natural processes and human activities that may have contributed to the decrease in lake area. The results show that the decrease in total lake area appears to coincide with periods of rapid land reclamation in the middle reaches of the Yangtze River. Moreover, uncontrolled land reclamation activities can create an increase in sediment deposition in lakes thereby further reducing the lake size. Reduction of the lake area directly affects flood-control and has a negative ecological impact on the environment and on human life and property. [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]

Manufacturing industry is an important part of China's industry and plays an important role in China's economic development and industrialization process. In the face of the increasingly fierce competition, the cultivation of professional technical talents in manufacturing is particularly important. The continuing education of professional technical personnel is an important method for enterprises to cope with competition and break through the predicament. Through the literature review of the development of the manufacturing industry in the Yangtze River Delta region and the questionnaire survey of professional technical personnel, this paper discovers that the continuing education of technical personnel in region does not necessarily meet the needs of technical personnel and that the teaching mode is single. Also, corresponding innovative solutions are proposed. [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]

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In this paper, we estimate the inputs of nitrogen (N) and exports of dissolved inorganic nitrogen (DIN) from the Changjiang River to the estuary for the period 1970-2003, by using the global NEWS-DIN model. Modeled DIN yields range from 260 kg N km-2 yr-1 in 1970 to 895 kg N km-2 yr-1 in 2003, with an increasing trend. The study demonstrated a varied contribution of different N inputs to river DIN yields during the period 1970-2003. Chemical fertilizer and manure together contributed about half of the river DIN yields, while atmospheric N deposition contributed an average of 21% of DIN yields in the period 1970-2003. Biological N fixation contributed 40% of DIN yields in 1970, but substantially decreased to 13% in 2003. Point sewage N input also showed a decreasing trend in contribution to DIN yields, with an average of 8% over the whole period. We also discuss possible future trajectories of DIN export based on the Global NEWS implementation of the Millennium Ecosystem Assessment scenarios. Our result indicates that anthropogenically enhanced N inputs dominate and will continue to dominate river DIN yields under changing human pressures in the basin. Therefore, nitrogen pollution is and will continue to be a great challenge to China. [ABSTRACT FROM AUTHOR]

The Changjiang River is well-known to channel significant anthropogenic influences to the estuary. However, long-term changes in plankton community related to anthropogenic eutrophication in the estuarine water are not well documented. In this paper, data from a nine year study (1996, 1998-2005) on suspended matter, chemical oxygen demand, nutrients and plankton community were collected and analyzed by principal component analysis. These data reveal that N/P ratio was always much higher than 40 and Si/N ratio decreased from 1.35 to 0.94 between 1996 and 2005. As an ecological consequence to such nutrient balance changes, phytoplankton species diversity and the dominance of diatoms decreased, dinoflagellates increasingly dominated the phytoplankton population, and the frequency of harmful algal blooms caused by dinoflagellates also increased. Furthermore, due to the reduced diatom availability, the dominance of copepods decreased, zooplankton diversity increased, and medusae increasingly dominated the zooplankton population. Water column nutrient ratios, therefore, are also important factors affecting anthropogenic eutrophication, as are the contamination loadings from land. [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]

This article investigates a series of projects for the improvement of shipping conditions of the Upper Yangzi in 1805-'40. The enterprise was undertaken by two Hankou merchants, one of whom published his 'Brief Account of the Taming of the Rapids'. An analysis of the detailed data of this source provides insights into navigation conditions and rates of environmental change on a major river, and into a major infrastructure project undertaken as merchant philanthropy. This paper proposes a perspective on water transport in pre-industrial China against a wider temporal and cultural backdrop, with a particular reference to private philanthropy as a set item within the moral economy. [ABSTRACT FROM AUTHOR]

Abstract  This paper presents a new kind of material for use in highway embankments in the soft soil of the Yangzi River delta. The experimental study was carried out first to evaluate the effectiveness of the proposed material, using different mixtures of river sand, cement and expanded polystyrene beads. This was confirmed by numerical modeling which indicated both its suitability as regards strength and a reduced settlement compared with the general lime stabilized soil embankments. The environmental advantage is that it utilized river sand which has to be removed to retain the profile of the river bed. [ABSTRACT FROM AUTHOR]

In 2002, China launched the South-to-North Water Transfer Project after completing a 50-year feasibility study. By 2050, the three-route (i.e., East, Middle, and West) project will be capable of transferring 44.8 billion m3/year of water from the water rich Yangtze River to the arid north to alleviate water shortage and help secure a balanced social and economic development across the nation. However, diversion of such a large quantity of water could profoundly change the riverine environment of the upper Yellow River and the lower reach of the Han River, a tributary of the Yangtze River and the water supplying area of the project’s Middle Route, because of changes in the annual discharge. Secondary salinization seems inevitable in the water receiving areas of the North China Plain, and decrease in the discharge of the Yangtze River will result in seawater intrusion into the Yangtze Delta. This paper describes the project and discusses its environmental implications. Additionally, a long-term monitoring strategy under the umbrella of the Chinese Ecological Research Network is proposed for environmental monitoring. [ABSTRACT FROM AUTHOR]

The formation and geomorphic evolution of the Jiuduansha Shoal are investigated over the past 50 years in this paper. The sedimentary processes, formation, and geomorphic evolution of the Jiuduansha Shoal in the Yangtze River Estuary, eastern China, are analyzed based on digitized sea maps from 1945 to 2001, satellite images from 1975 to 2001, and field survey data in the spring-neap tidal cycle in the dry and flood seasons in 2003. The suspended sediment concentration and hydrodynamics of the North Passage and South Passage during the dry and flood seasons in the spring-neap tidal cycle in 2003 were investigated, and relations between the North Passage and South Passage of the Jiuduansha Shoal are analyzed. Results show that seasonal and spring-neap tidal cycle variations in sediment and water discharge from the drainage basin correspond to erosion and deposition on the Jiuduansha Shoal. The results and data can provide useful information for the management of the Yangtze River Estuary and restoration of the estuarine tidal flat ecology. [ABSTRACT FROM AUTHOR]

A new static-based method for damage detection of cable-stayed bridges using the changes in cable forces is presented in this paper. In recognizing the fact that damage incurring in bridge girders will cause a redistribution of forces in stay cables, the proposed method uses the measured changes in cable forces to detect the damage in bridge girders. In this method, the damage identification is formulated as an optimization problem in which the cable force error between measurement results and analytical model predictions is minimized. The sensitivities of cable forces with respect to the structural parameters of bridge girders for the linear and geometrically nonlinear bridge structures are obtained by using the direct differentiation method and the finite difference method, respectively, and are used to solve the optimization problem. Regularization technique is used to alleviate ill-conditioning in the solution course of the optimization problem. The validity of the method is illustrated by numerical studies of damage detection of the cable-stayed Sutong Bridge with a main span of 1,088 m. The effect of measurement noises and the number of measured cable forces on the accuracy of damage quantification is investigated. The proposed method correctly identifies the damage locations and damage magnitudes in bridge girders when using noise-free cable forces. It is also shown that structural damage can be quantified with acceptable accuracy in the case of low-level measurement noises and the damaged members being well spaced, and the identification accuracy is greatly improved when the forces in the cables connected to the damaged members are available for damage quantification. [ABSTRACT FROM AUTHOR]

This paper presents a water quantity operation scheme to resolve series of environmental problems which some waterfront bodies are faced with, such as frequent water-level fluctuation, sediment deposition, water quality degradation, water transparency depravation, and submerged aquatic plant disappearing. Neijiang, which is a typical tide-influenced waterfront body located within the Changjiang Delta, China has been considered as the research area. A 2-D environmental and ecological model coupled with water current, water quality, suspended sediment, algae growth, and water transparency is established and validated against the field investigated data, and the model can well reflect the dynamic processes of these factors in Neijiang. Three water quantity operation modes including self-introducing, pumping, and keeping quiescence are proposed. Based on different kinds of water demand of Neijiang and the actual water exchange ability, detailed water quantity operation schemes under different hydrologic conditions are studied with the established numerical model, and the changes of some living condition factors after water operation are forecasted and evaluated. Results show that water exchange and sediment deposition in Neijiang are apparently reduced after water operation in different level years. In addition, the water quality and transparency in Neijiang can keep a good status, and the living environment is improved for submerged aquatic plant restoration. This study provides an example to resolve environmental problems, improve living conditions and keep a healthy ecosystem for similar waterfront bodies. [ABSTRACT FROM AUTHOR]

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]

This paper reviews the land cover changes on the Tibetan Plateau during the last 50 years partly caused by natural climate change and, more importantly, influenced by human activities. Recent warming trends on the plateau directly influence the permafrost and snow melting and will impact on the local ecosystem greatly. Human activities increased rapidly on the plateau during the last half century and have significant impacts on land use. Significant land cover changes on the Tibetan Plateau include permafrost and grassland degradation, urbanization, deforestation and desertification. These changes not only impact on local climate and environment, but also have important hydrological implications for the rivers which originate from the plateau. The most noticeable disasters include the flooding at the upper reaches of Yangtze River and droughts along the middle and lower reaches of Yellow River. Future possible land cover changes under future global climate warming are important but hard to assess due to the deficits of global climate model in this topographically complex area. Integrated investigation of climate and ecosystems, including human-beings, are highly recommended for future studies. [ABSTRACT FROM AUTHOR]

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]

The Eurocentric growth model has been the basic workhorse for numerous Chinese economic historians. This deep seated Eurocentric paradigm is concerned mainly with conterfactuals and tends to ignore past reality. To illustrate the problems of this Eurocentric approach, this paper examines the rural economy of Jiangnan, also known as the Yangzi Delta, during late imperial times. A main characteristic of the villages in the Wuxi county in Jiangnan were the mixture of the rural–urban lifestyle and development. Jiangnan's developmental patterns, in the Song and the Qing dynasty, from the Maoist period (pre-1979) to post-1979 development, contrast sharply with the predictions of the Western development models. [ABSTRACT FROM AUTHOR]

This paper is a response, both to Fuller et al.'s recent criticism of Chinese research on rice domestication, as lacking evidence, and to their argument for the beginning of rice domestication around 4000 BC in the lower Yangzi River. We first survey previous publications that discuss the process from wild rice collection to rice domestication in China, and then examine early rice remains from the perspectives of rice morphology and archaeological context. We focus on three aspects: the timing of the initial rice domestication in the Yangzi River region; the earliest presence of domesticated rice in the Lower Yangzi and Huai River regions; and the implications of changes in rice grain sizes in archaeological assemblages. We also discuss problems relating to the presence of immature rice remains in the archaeological record, grain size increase and overall grain shape, which are three of the criteria used by Fuller et al. for distinguishing domesticated from wild rice. Based on published data and our research on rice, we demonstrate that by the early Holocene (9000 cal. BP), Neolithic people in both north and south China may have been harvesting wild rice and initiating rice cultivation that eventually led to domestication. [ABSTRACT FROM AUTHOR]

Container ports located in a delta of navigable waterways generally strive to develop the inland river services as a competitive transport mode, with a view to serving local and distant hinterland regions. The spatial and functional development of river-based container networks is location-specific and time-specific. While each barging network and associated seaport system has its own dynamics, similarities in development patterns cannot be excluded. This paper discusses similarities and dissimilarities between the spatial and the functional development of the container river service networks of the Yangtze River and the Rhine River. It is shown that the Yangtze service network has the tendency to converge, in more than one aspect, with the (historical) development pattern of inland container services in the Rhine basin. [ABSTRACT FROM AUTHOR]

The lower Yangtze, eastern China, was colonized by several Neolithic and Bronze Age cultures giving rise to possibly the highest concentration of prehistoric sites in the world. Early Neolithic cultures in the delta region cultivated rice (Oryza sativa) and agricultural developments appear to have occurred throughout the Neolithic with abrupt socio-economic changes possibly associated with the terminal Neolithic. Given the extensive history of environmental exploitation and well-preserved archaeological sites, the Yangtze delta is an ideal setting to explore the complex interactions between humans and their environment. Multiproxies of environmental changes, namely pollen, charcoal and phytoliths, in a 14C AMS-dated sequence of sediments from an exposed profile at Qingpu, Yangtze delta, were investigated. 14C AMS dating indicates that the age range of the sedimentary sequence analysed is from c. 1800 to 6000 BP, and therefore encompasses the terminal Neolithic and subsequent Bronze Age in the region. This paper reviews this sediment-based evidence in the light of current understanding of human-environment interactions during a critical phase of the development of the Yangtze delta and associated human cultures. [ABSTRACT FROM AUTHOR]

The ability to extract mitochondrial and nuclear DNA from ancient remains has enabled the study of ancient DNA, a legitimate field for over 20 years now. Recently, Y chromosome genotyping has begun to be applied to ancient DNA. The Y chromosome haplogroup in East Asia has since caught the attention of molecular anthropologists, as it is one of the most ethnic-related genetic markers of the region. In this paper, the Y chromosome haplogroup of DNA from ancient East Asians was examined, in order to genetically link them to modern populations. Fifty-six human remains were sampled from five archaeological sites, primarily along the Yangtze River. Strict criteria were followed to eliminate potential contamination. Five SNPs from the Y chromosome were successfully amplified from most of the samples, with at least 62.5% of the samples belonging to the O haplogroup, similar to the frequency for modern East Asian populations. A high frequency of O1 was found in Liangzhu Culture sites around the mouth of the Yangtze River, linking this culture to modern Austronesian and Daic populations. A rare haplogroup, O3d, was found at the Daxi site in the middle reaches of the Yangtze River, indicating that the Daxi people might be the ancestors of modern Hmong-Mien populations, which show only small traces of O3d today. Noticeable genetic segregation was observed among the prehistoric cultures, demonstrating the genetic foundation of the multiple origins of the Chinese Civilization. [ABSTRACT FROM AUTHOR]

Residues of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) and their environmental risks in surface sediments collected from the rivers and lakes in Yangtze River Catchment of Wuhan, China, are investigated in this paper. Based on dry weight (dw), the concentrations of ΣHCH ( α-, β-, and γ-HCH) and ΣDDT ( p p′-DDT, o p′-DDT, p p′-DDE, p p′-DDD) in sediments ranged from 0.10 to 21.10 ng g−1 (mean, 4.03 ng g−1 dw) and 0.79 to 35.61 ng g−1 dw (average, 6.93 ng g−1 dw), respectively. Compared with some published guideline values of organochlorine pesticides (OCPs) in sediments, the concentrations of HCHs were at safe levels while the DDT residues would pose adverse biological effects in this studied catchment. The distribution of OCPs in sediments indicated that the input of tributaries was an important factor for OCP residues in the mainstream of the Yangtze River. Levels of OCPs in the sediments were influenced by total organic carbon contents, clay contents, water contents, and pH values of sediments. The present study suggested that historical usage of technical HCH and DDT was the main reason for OCP residues in the sediments from both rivers and lakes. Furthermore, the composition of OCPs reflected additional sources of the holding usage of lindane and fresh inputs of dicofol mixture in this region. [ABSTRACT FROM AUTHOR]

Very often, inexact, uncertain, or vague hydrological data are encountered in water researches. Statistical and fuzzy set theories are applied to deal with hydrological uncertainty problems. In this paper, the basic concept of the rough set theory is introduced and its application to hydrological data is illustrated. The proposed method is applied to water environment and environment quality evaluation of the Hang Jiang River, a major branch of the Yangtze River, in China. Our numerical applications suggest that the rough set theory is a useful tool for analysis of inexact, uncertain, or vague hydrological data. [ABSTRACT FROM AUTHOR]

Soil erosion in the upper reaches of the Yangtze River in China is a major concern and the Central Government has initiated the Grain-for-Green Programme to convert farmland to forests and grassland to improve the environment. This paper analyses the relationship between land use and soil erosion in Zhongjiang, a typical agricultural county of Sichuan Province located in areas with severe soil erosion in the upper reaches of the Yangtze River. In our analysis, we use the ArcGIS spatial analysis module with detailed land-use data as well as data on slope conditions and soil erosion. Our research shows that the most serious soil erosion is occurring on agricultural land with a slope of 10∼25 degrees. Both farmland and permanent crops are affected by soil erosion, with almost the same percentage of soil erosion for corresponding slope conditions. Farmland with soil erosion accounts for 86⋅2 percent of the total eroded agricultural land. In the farmland with soil erosion, 22⋅5 percent have a slope of <5 degrees, 20⋅3 per cent have a slope of 5∼10 degrees, and 57⋅1 percent have a slope of >10 degrees. On gentle slopes with less than 5 degrees inclination, some 6-percent of the farmland had strong (5000∼8000 t km-2y-1) or very strong (8000∼15000 t km-2y-1)erosion. However, on steep slopes of more than 25 degrees, strong or very strong erosion was reported for more than 42 per cent of the farmland. These numbers explain why the task of soil and water conservation should be focused on the prevention of soil erosion on farmland with steep or very steep slopes. A Feasibility Index is developed and integrated socio-economic assessment on the feasibility of improving sloping farmland in 56 townships and towns is carried out. Finally, to ensure the success of the Grain-for-Green Programme, countermeasures to improve sloping farmland and control soil erosion are proposed according to the values of the Feasibility Index in the townships and towns. These include: (1) to terrace sloping farmland on a large scale and to convert farmland with a slope of over 25 degrees to forests or grassland; (2) to develop ecological agriculture combined with improving the sloping farmland and constructing prime farmland and to pay more attention to improving the technology for irrigation and cultivation techniques; and (3) to carry out soil conservation on steep-sloping farmland using suggested techniques. In addition, improving ecosystems and the inhabited environment through yard and garden construction for households is also an effective way to prevent soil erosion. [ABSTRACT FROM AUTHOR]

Sand extraction from the mid-lower Yangtze has increased rapidly since the 1980s, in contrast to a rapid decrease in sediment discharge from the Yangtze River into the sea. In-channel sand extraction poses great risks to flood protection, navigation channels and railway bridges. This paper reviews the recent history of in-channel sand extraction, discussing the present status and potential problems in legislation and management. It is concluded that the share of interests, the involvement of local criminal gangs and official corruption were the main difficulties for the ban on illegal sand extraction. It is proposed that the sites and amounts permitted for in-channel sand extraction should be re-evaluated under the new sediment budget after closure of the Three-Gorges Dam. It is necessary to explore the use of alternative materials in order to reduce the demand for natural sand while meeting the market needs for socio-economic development. [ABSTRACT FROM AUTHOR]

This paper presents major findings from a recent study aiming to systematically determine suitable river sections for local domestic water supply along the Yangtze River in Jiangsu Province, China. On the basis of analysis on the current riverbank utilization and bank stability, accessible and stable river sections in the region were selected. The water quality in these river sections was then studied using a two-dimensional unsteady flow and pollutant transport/transformation model, RBFVM-2D. The model was calibrated and verified against the hydrodynamic data, water quality data and remote sensing data collected from the river. The investigation on the pollution sources along the river identified 56 main pollution point sources. The pollution zones downstream of these point sources are the main threat for the water quality in the river. The model was used to compute the pollution zones. In particular, simulations were conducted to establish the relationship between the extent of the pollution zone and the wastewater discharge rate of the associated point source. These water quality simulation results were combined with the riverbank stability analysis to determine suitable river sections for local domestic water supply. [ABSTRACT FROM AUTHOR]

This paper describes the use of numerical weather and climate models for predicting severe rainfall anomalies over the Yangtze River Basin (YRB) from several days to several months in advance. Such predictions are extremely valuable, allowing time for proactive flood protection measures to be taken. Specifically, the dynamical climate prediction system (IAP DCP-II), developed by the Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP), is applied to YRB rainfall prediction and flood planning. IAP DCP-II employs ensemble prediction with dynamically conditioned perturbations to reduce the uncertainty associated with seasonal climate prediction. IAP DCP-II was shown to successfully predict seasonal YRB summer flooding events based on a 15-year (1980–1994) hindcast experiment and the real-time prediction of two summer flooding events (1999 and 2001). Finally, challenges and opportunities for applying seasonal dynamical forecasting to flood management problems in the YRB are discussed. [ABSTRACT FROM AUTHOR]

In a flood-prone region, quick and accurate flood forecasting is imperative. It can extend the lead time for issuing disaster warnings and allow sufficient time for habitants in hazardous areas to take appropriate action, such as evacuation. In this paper, two hybrid models based on recent artificial intelligence technology, namely, the genetic algorithm-based artificial neural network (ANN-GA) and the adaptive-network-based fuzzy inference system (ANFIS), are employed for flood forecasting in a channel reach of the Yangtze River in China. An empirical linear regression model is used as the benchmark for comparison of their performances. Water levels at a downstream station, Han-Kou, are forecasted by using known water levels at the upstream station, Luo-Shan. When cautious treatment is made to avoid overfitting, both hybrid algorithms produce better accuracy in performance than the linear regression model. The ANFIS model is found to be optimal, but it entails a large number of parameters. The performance of the ANN-GA model is also good, yet it requires longer computation time and additional modeling parameters. [ABSTRACT FROM AUTHOR]

Abstract This paper reviews changes in the use of short-term climate information for water management in China after the 1998 Great Flood in the Yangtze River basin. This devastating flood is now believed to have been caused mainly by the 1997–98 El Niño event. Although the short-term climate forecasts and weather forecasts are considered to be useful in planning for flood prevention activities and for making key decisions during combating floods, the gap between the meteorological services (producers of climate forecasts) and water management agencies (users of climate forecasts) has grown in terms of credibility given to climate forecasting: weather services put more efforts on improving the technology for increasing forecast accuracy, whereas water managers put their efforts and investment into upstream ecological restoration and flood control systems. By reviewing the published and ‘gray’ (unpublished) literature, we found that assessments of the 1998 Great Flood in the Yangtze River basin really helped the central government and water resources agencies to recognize the weaknesses of the existing flood control system, the mismanagement in the ecological systems, and the need for developing a national water resource management plan to deal with the problems of ‘too much water, too little water, and very polluted water’. [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]

This article presents abstracts of research papers published in previous issues of the publication "Proceedings of the Institution of Civil Engineers." The paper "Weathering Steel Bridges," by C.N. Dolling and R.M. Hudson, highlights the benefits of weathering steel bridges, describes the limitations, and comments on both the material availability and the appearance of such bridges. Another paper "Jiangyin Yangtze River Bridge, China," by J. Young, outlines the studies undertaken to select the preferred location and form of the bridge. The development of the design of the principal elements of the bridge is discussed and the construction process described.

Soil losses and soil deposits in the Upper Yangtze River watershed have been increasing for decades, with serious negative effects on the agriculture along the Yangtze River and the Three Gorges Dam. The Chinese Government has carried out the Return Farmland into Trees (Grass) Project since the early 1990s. The effectiveness of the project has been estimated in some testing sites in the Upper Yangtze River watershed. In this paper, we carried out a test in the Minjiang River Valley, one of the largest river valleys in the Upper Yangtze River watershed. It was very difficult to calculate the amount of soil losses for the valley when a traditional sample method was used to collect the data for the Universal Soil Loss Equation (USLE model). In order to develop the capability to monitor soil losses in the Minjiang River Valley, we assessed the use of remote sensing data, DEM data, land use and land cover GIS data. The key point of the procedure was data fusion, which was based on an image pixel un-mixing technique. The values of parameters extracted from satellite sensor data for soil erosion USLE model calculation was based on pixels. In this way it improves the accuracy for every parameter calculation. Before making the final calculation, we carried out a field survey along the river valley in July 2000. There was ±5% soil erosion difference between our calculation results from Landsat Enhanced Thematic Mapper (ETM) data in 2000 and in situ statistical results in 1999. The method used in the Minjiang River Valley can be used as an example for soil loss calculation for other rivers in the Upper Yangtze River watershed. [ABSTRACT FROM AUTHOR]

This paper provides an evaluation of current arrangements made for compensation and resettlement to farmers who will be displaced by the construction of the Three Gorges Project (TGP) on the Yangtze River. Kaixian County is used as a case study. Under present regulations the specific value of peri–urban land is underestimated, neither cash–in–hand arrangements nor land–for–land swaps are adequate. There are other problems. The availability of suitable land for resettlement is scarce and rarely of equivalent quality. The inflexibility of the ‘household responsibility system’ contributes to the problem. It is suggested that some of those facing displacement should be encouraged to accept resettlement in places at considerable distance from their current homes and that a more creative approach should be taken to the issue of compensation to enable people to develop their trade and business skills. [ABSTRACT FROM AUTHOR]

Traditional garden is a vital element of traditional cultural heritage in China, and it is a common concern of the public to protect, inherit and develop traditional cultural heritage. This paper, on the basis of investigating current protection of royal gardens, private gardens in southern regions of the Yangtze River, and gardens in different regions, summarized 4 fundamental modes of traditional garden protection, namely protective development mode, developmental protection mode, controlled protection mode, no-protection mode. Advantages and disadvantages of different modes were reviewed, protective development was proposed as a traditional garden protection mode adaptive to actual conditions of China. [ABSTRACT FROM AUTHOR]

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 fallout radionuclide 210Pb has been widely used as an environment tracer for estimating deposition rates and revealing sedimentary processes. However, a comprehensive evaluation of different grain size fractions effects on the adsorption of 210Pb is a prerequisite for effective utilization of the tracer. In this paper, 11 cores were collected from different sub-sedimentary environments in the Yangtze Estuary and its adjacent area, x-radiographs of the sediment cores were taken, and the grain size and radioactive 210Pb levels were analyzed systematically; the relationship between grain size and 210Pb was discussed in detail. The results indicated that 226Ra was relatively stable, with no systematic variation from the Yangtze Estuary to inner shelf region or with depth and was unaffected by grain size. In contrast to 226Ra, significant positive correlations between the fine fraction (<32 µm) and 210Pbex were found, particularly between the clay component (<4 µm) and 210Pbex, in all the sediment cores. The 210Pbex profiles were improved significantly after using the linear relationships for quantitatively normalizing the activities to the <4 µm components, and the calibrating 210Pbex profiles of different zones matched the sub-sedimentary environments of the recent reduction in sediment discharge after Three Gorges Dam (TGD) impoundment very well. Also, through the normalization procedure, it was found that the Yangtze-derived clay component may play the most important role in the distribution of 210Pbex in sediments, especially in upper layer 10–15 cm of the cores. When applying 210Pb data to establish the geochronology or study sedimentary processes in the East China Sea or similar sedimentary environments, the grain size effect should be fully considered. [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]