Middle Yangtze Research Articles

Investigating the origins of metals used in the Early Shang capital of Zhengzhou

Lead isotope analysis of crucibles and a metal droplet has revealed new information about the provenance of the lead and copper resources used at Zhengzhou Shang City during the Upper Erligang period. The crucibles were found to be divided into three types and associated with copper smelting/refining, leaded tin bronze alloying, and bronze pouring. The copper smelting/refining crucible contains common lead (206Pb/204Pb = 18.12) and low Pb content in its slag layer. In contrast, the bronze processing crucibles mostly contained highly radiogenic lead (206Pb/204Pb ≥ 19). One bronze pouring crucible was found to have an exceptionally low 206Pb/204Pb ratio (≤17.2), indicating that it was made with recycled bronze from an earlier period. This research is the first to reveal the lead isotope characteristics of the copper material used during the Upper Erligang period, which is strikingly different from the dominant highly radiogenic lead reported in previous research. The Middle Yangtze River Valley is tentatively proposed as the geological source. This result also shows that the Upper Erligang Shang people had a complex metal supply network, including at least southern copper, highly radiogenic lead, and recycled early bronze.

Remote sensing inversion and prediction of land use land cover in the middle reaches of the Yangtze River basin, China.

Land use and land cover (LULC) changes are dynamic and have been extensively studied; the change in LULC has become a crucial factor in decision making for planners and conservationists owing to its impact on natural ecosystems. Deriving accurate LULC data and analyzing their changes are important for assessing the energy balance, carbon balance, and hydrological cycle in a region. Therefore, we investigated the best classification method from the four methods and analyzed the change in LULC in the middle Yangtze River basin (MYRB) from 2001 to 2020 using the Google Earth Engine (GEE). The results suggest that (1) GEE platform enables to rapidly acquire and process remote sensing images for deriving LULC, and the random forest (RF) algorithm was able to calculate the highest overall accuracy and kappa coefficient (KC) of 87.7% and 0.84, respectively; (2) forestland occupied the largest area from 2001 to 2020, followed by water bodies and buildings. During the study period, there was a significant change in area occupied by both water bodies (overall increase of 46.2%) and buildings (decrease of 14.3% from 2001 to 2005); and (3) the simulation of LULC in the MYRB area was based on the primary drivers in the area, of which elevation changes had the largest effect on LULC changes. The patch generated land use simulation model (PLUS) was used to produce the simulation, with an overall accuracy and KC of 89.6% and 0.82, respectively. This study not only was useful for understanding the spatial and temporal characteristics of LULC in the MYRB, but also offered the basis for the simulation of ecological quality in this region.

Ecosystem deterioration in the middle Yangtze floodplain lakes over the last two centuries: Evidence from sedimentary pigments

Water quality of floodplain lakes in the Yangtze region which supports ca. 450 million people is being severely compromised by nutrient pollution, climate change and dam installation resulting from intensive socio-economic development. However, due to a lack of long-term monitoring data, the onset and causes of ecosystem degradation are unclear. Here, we used chlorophyll and carotenoid pigments in dated sediment cores from six lakes spanning the region to reconstruct changes in algae and cyanobacterial HAB (harmful algal bloom) taxa alongside sedimentary nutrient flux measurements and historical archives. Sedimentary N fluxes are linked to changes in agriculture, while urbanization has had greater influences on P fluxes. Over the last 70 years algal and N2-fixing HAB pigments increased markedly in lakes (Luhu, Wanghu) that are strongly influenced by urbanization/industrialization. Algal assemblages in two other lakes (Futou, Honghu) changed gradually and responded primarily to agriculture and associated N fluxes; diazotrophic HAB pigments were absent and the lakes retained macrophyte cover. Local dam installation had no discernible effect on pigment assemblages in three of the four lakes in the past 70 years, but in the two hydrologically-open lakes (Poyang, Dongting), increasing algal production was significantly related to the upstream installation of the Three Gorges Dam (TGD) and to urban/industrial and agricultural stressors. Temperature only influenced phototrophs in the most degraded lakes (Luhu, Wanghu). This spatial and temporal overview identifies that nutrient pollution is the primary regional driver of lake phototrophs, but that diazotrophic HABs are stimulated by P-enriched urban wastewater pollution, and agriculturally-derived N pollution favors non-N2-fixing cyanobacteria. Despite negative effects of the Three Gorges project, free connection to the river appears to help mitigate excess HABs in freely connected lakes. Management thus needs to be tailored appropriately to specific lake conditions and palaeolimnology can be valuable in identifying appropriate strategies.

Heavy metal content and health risk assessment of atmospheric particles in China: A meta-analysis

In recent decades, China has devoted significant attention to the heavy metals pollution in particulate matter. However, the majority of studies have only focused on the field monitoring in relatively remote areas, which may not be representative of air quality across the country. This study reevaluated the characteristics, temporal and spatial changes, and health concerns associated with heavy metal pollution in atmospheric particulates on a national scale by coupling Meta-analysis and Monte Carlo simulation analysis. In terms of spatial distribution, the heavy metals pollution levels in the northern coast and northeastern regions are relatively high, whereas it is low along the middle Yellow River, middle Yangtze River, as well as Southwest. With the exception of Cu, the distribution of all elements in PM2.5 steadily decreased over time Moreover, PM10 and PM2.5 performed similar where Cd and Ni both first increased followed by a decline while, Cr displayed a decrease before it showed an increment. And since the implementation of prevention and control policies about the atmospheric release, the focus of industrial emission has gradually shifted from energy production and processing to living products manufacturing. Moreover, the carcinogenic risk was shown to be Cr > As, Pb > Ni, Cd, while the non-carcinogenic risk was as follows: As, Ni > Cr, Cd. Among all contaminants, Cd, As, and Cr in PM2.5 and PM10 exceeded the WHO standard in the cities with worst air quality. It was observed that As posed the largest non-carcinogenic risk to adults while, Cr caused the most carcinogenic risk to adults and children, where the carcinogenic risk of children remains higher than that of adults. Therefore, the findings of this study may offer data support to the China's heavy metal pollution standards in airborne particles and offer theoretical data support for pollution management.

Spatiotemporal Distribution and Driving Factors of Polycyclic Aromatic Hydrocarbons (PAHs) in Inland Sediments of China

This study reviewed the spatial and temporal distributions of polycyclic aromatic hydrocarbons (PAHs) during 2000-2010 in inland sediments of China and quantified the underlying socioeconomic determinants based on the structural equation model and gravity model. We found that PAHs concentrations in the sediments of eight different regions followed the order of Northern coast>Northeast>Eastern coast>Southern coast>Middle Yellow River>Middle Yangtze River>Southwest>Northwest. The Southern coast, Middle Yangtze River, and Southern coast regions showed large contributions to the high-molecular weight PAHs, whereas the Northeast, Northwest, and Middle Yellow River regions showed high contributions to the low-molecular weight PAHs. PAHs concentrations continuously increased from the year 2000 followed by a gradual decline after 2006, with significant differences in the year when PAHs levels reached their peak. PAHs concentrations of sediment in developed regions declined in recent years following a continuous increase in the 2000s; however, they still increased rapidly in developing regions owing to fast economic development. In addition, the increment rate of PAHs concentrations in sediment at the remote or less-developed regions was slower than that at the developed regions. Urbanization and industrialization had an important effect on PAHs in the sediments, and the largest influencing factor was the economic development.

R-statistic based predictor variables selection and vine structure determination approach for stochastic streamflow generation considering temporal and spatial dependence

Stochastic streamflow generation is crucial for water resources planning and management as well as water conservancy project design and operation. This study proposes an accurate, reliable and parsimonious approach for stochastic streamflow generation considering temporal and spatial dependence on the basis of regular vine copula model. The emphasis is on advancing an R-statistic based strategy of vine structure determination that divide the vine copula model construction into two independent parts and avoid continuous accumulation of uncertainty in the traditional Kendall's tau based method. Two study regions (the Upper Colorado River basin and Middle Yangtze River basin) with diverse hydrology regime and available data length are selected as case studies to showcase the performance of the proposed approach in practice. The results indicate better performance than two existing models in terms of streamflow estimation, and demonstrate that stochastic simulation series can preserve distribution and statistical characteristics of observed records. R-vine copula model constructed by the proposed approach is confirmed to possess low sensitivity to the number of predictor variables as well as good adaptability and robustness to streamflow series with diverse characteristics and abundances. The enhanced capability and performance stem from the accurate identification of predictor variables and characterization of complex and diverse dependence structures among different streamflow series, on the basis of a comprehensive and precise dependence measure, R-statistic.

The role of landscape evolution in the genetic diversification of a stream fish Sarcocheilichthys parvus from Southern China.

Sarcocheilichthys parvus (Cypriniformes: Gobionidae) is a stream fish which is endemic to sub-tropical coastal drainages in southern China, thus offering a valuable model for understanding how genetic divergence arises in stream-adapting freshwater fishes in this region. Using the mitochondrial Cyt b gene, integrative analyses of phylogeny, population demography, and ancestral area and paleo-drainage reconstructions are carried out to explicitly explore the role of landscape evolution in genetic diversification of S. parvus. The time-calibrated phylogeny of S. parvus indicates the splitting of two major lineages (A and B) at ∼3.66Ma. Lineage A inhabits the Poyang Lake sub-drainage of the middle Yangtze River, Han River and Pearl River, and can be split into two sub-lineages (A-I and A-II), where sub-lineage A-II can be further sub-divided into three infra-sub-lineages (A-IIa, A-IIb and A-IIc). Except for the infra-sub-lineage A-IIc, which is restricted to the Han River and Pearl River, the other sub-lineages and infra-sub-lineages live exclusively in the Poyang Lake sub-drainage. Lineage B lives in the lower Yangtze River, Qiantang River, Jiaojiang River and Ou River, displaying close genetic relationships among the drainages. Rapid population expansion has occurred since the Late Pleistocene. Our findings indicate that the splitting of lineages A and B could be attributed to geographic isolation due to the Zhe-Min Uplift, acting as a biogeographic barrier before the late Early Pleistocene. Furthermore, the strong genetic divergence within Lineage A could be explained by the isolation role of the Nanling Mountains and Poyang Lake acting as an ecological barrier; while the lack of phylogenetic structure within Lineage B may have been the result of paleo-drainage connections or episodic freshwater connections during the eustatic low stand of sea level in the late Middle-Late Pleistocene.

A new formula of recovery factor for non-equilibrium transport of graded suspended sediment in the Middle Yangtze River

A new formula of recovery factor for non-equilibrium transport of graded suspended sediment in the Middle Yangtze River

Shijiahe and its Implications for Understanding the Development of Urbanism in Late Neolithic China

The late Neolithic site of Shijiahe in the middle Yangtze River Valley of China is important for understanding variation in the development of urbanism in China. Here, a core sector developed that was centred on the walled Shijiahe locus, c. 180 ha in size, and surrounded by a moat. Our paper is the first English publication synthesizing decades of scholarship about Shijiahe and explaining its significance for the development of urbanism. The available data reveal characteristics of urbanism not known elsewhere in China. We discuss possible ritual and economic strategies for increasing socio-political integration among the dispersed clusters of settlement. We also discuss evidence for methods of transportation and communication between different settlement loci.

Longitudinal variation of channel evolution along the middle Yangtze River after the operation of the Three Gorges Project

三峡工程运行后,坝下游河道发生持续冲刷。本文研究了长江中游(955 km)不同河段沿程演变差异及其原因。总体而言,河床形态调整幅度自上而下减弱,这是因为在河床持续冲刷过程中,水流含沙量沿程恢复,故越往下游冲刷相对缓慢。平面形态方面,长江中游岸线崩退及洲滩变形的强度均呈沿程减弱趋势,且在荆江河段最为显著。断面形态方面,河床冲深幅度在宜枝下段＞荆江河段＞宜枝上段＞城汉河段＞汉湖河段。理论上距离三峡工程最近的河段冲刷应最为剧烈,但由于宜枝上段床沙粗化显著,限制了冲刷的进一步发展。过流能力方面,宜枝河段由于距洞庭湖较远,并未受到入汇顶托作用,故其平滩流量的调整基本由进口水沙条件控制,并随着河床冲深下切而增大;对于荆江、城汉和汉湖河段,河床冲刷虽显著,但支流或湖泊的入汇顶托对平滩流量产生的影响大于前者,故平滩流量总体随上下游水位差同步波动。;Significant degradation have occurred in the middle Yangtze River since the operation of the Three Gorges Project. In the current study, longitudinal evolution differences of different reaches along the middle Yangtze River were quantitatively compared, and the main reasons were investigated. In terms of planform geometry, the intensity of bank retreat and central-bar deformation showed a decreasing trend along the reach, and it was most significant in the Jingjiang Reach. With respect to cross-sectional geometry, channel degradation developed gradually from the Yizhi Reach to downstream reaches. It is uncommon that the adjustments of bankfull channel geometry in the upper Yizhi Reach were smaller than those in the downstream reaches. The reason is that the significant coarsening of bed-material composition in the upper Yizhi Reach hindered the development of channel degradation. In terms of discharge capacity, the variations of reach-scale bankfull discharge in the Yizhi Reach were mainly controlled by the incoming flow and sediment conditions, and it increased with the process of channel degradation. In the other subreaches, the variations of bankfull discharge were mainly influenced by the backwater effects owing to the confluences of tributaries and lakes.

Hydrologic and geomorphic effects on the reduction of channel discharge capacity in the Middle Yangtze River

A systematic increase in the occurrence of flood events has been noted in rivers worldwide. However, our understanding remains unclear of how the flood level is affected by the change in channel discharge capacity. Therefore, the reduction of channel discharge capacity was quantified in the Middle Yangtze River (MYR) based on extensive measured data. It is confirmed that the variation in channel discharge capacity is a superposition result of channel-morphology and channel-resistance changes, as well as the change in local base-level at the outlet. Then a series of numerical simulations were carried out to quantitatively identify the contribution of each factor to the reduction of channel discharge capacity in the MYR for the years of 2004 and 2020. Simulated results reveal that channel degradation increased the flow passage area, helping the channel to convey floods, with the effect being weakened along the reach; however, the decline in flood level under the same discharge was not observed, which was primarily attributed to the increases in channel resistance and local base-level at the outlet. These two factors accounted for 16–91 % and 9–84 % of the total impact at four hydrometric stations in the MYR. It should be noted that the dominant factor to influence the discharge capacity varied greatly at different stations, which depended on the degree of bed-material coarsening, the distance from the confluence of lakes, etc. At the stations immediately downstream of the dam, the contribution of the increased movable bed roughness usually played a more essential role; while at the stations close to the outlet with the confluence of large lakes, the increase in local base-level became the main factor that accounted for the rise of high-flood levels under the specified large discharge.

Global seamless and high-resolution temperature dataset (GSHTD), 2001–2020

Land surface temperature (Ts) and near-surface air temperature (Ta) are key parameters in multiple research fields. In this study, a global seamless (without missing values) and high-resolution (30 arcsecond spatial resolution) temperature (for both Ts and Ta) dataset (GSHTD) from 2001 to 2020 was developed. First, a method called the estimation of the temperature difference (ETD) was proposed to reconstruct both clear- and cloudy-sky Ts. A global seamless 8-day and monthly average all- and clear-sky Ts data were then created using the MODIS Ts data and the ETD method. The seamless monthly average of the mean, maximum and minimum Ta data were further developed using the seamless Ts data, in situ Ta data and Cubist machine learning algorithm. GSHTD has four main advantages. First, GSHTD includes seven types of temperature data: clear-sky daytime and nighttime Ts, all-sky daytime and nighttime Ts, and mean, maximum and minimum Ta. Second, it has global coverage and high spatial resolution. Third, using the ETD method proposed in this study, GSHTD has no missing values. Fourth, the accuracy of GSHTD is high; the average mean absolute errors (MAEs) of ETD in reconstructing the 25 × 25 and 150 × 150 pixel clear-sky daytime (nighttime) Ts data were 0.724 (0.552) and 1.024 (0.895) °C, respectively. The MAEs of ETD were on average 23.2% and 23.7% lower than those of Remotely Sensed DAily land Surface Temperature reconstruction (RSDAST) and interpolation of the mean anomalies (IMAs). The MAEs of the estimated monthly average of the mean, maximum and minimum Ta data were 0.797, 0.994 and 1.056 °C, respectively. The developed GSHTD is freely available at Middle Yangtze River Geoscience Date Center (https://cjgeodata.cug.edu.cn/#/pageDetail?id=97), which will be useful in many studies related to climate change, environmental science and ecology, and epidemiology and human health.

Influence of Underlying Surface on Distribution of Hourly Heavy Rainfall over the Middle Yangtze River Valley

The variation of boundary layer circulation caused by the influence of complex underlying surface is one of the reasons why it is difficult to forecast hourly heavy rainfall (HHR) in the middle Yangtze River Valley (YRV). Based on the statistics of high-resolution observation data, it is found that the low resolution data underestimate the frequency of HHR in the mountain that are between the twain-lake basins in the middle YRV (TLB-YRV). The HHR frequency of mountainous area in the TLB-YRV is much higher than that of Dongting Lake on its left and is equivalent to the HHR frequency of Poyang Lake on its right. The hourly reanalysis data of ERA5 were used to study the variation of boundary layer circulation when HHR occurred. It can be found that the boundary layer circulation corresponding to different underlying surfaces changed under the influence of the weather system. Firstly, the strengthening of the weather system in the early morning resulted in the strengthening of the southwest low-level air flow, which intensified the uplift of the windward slope air flow on the west and south slopes of the mountainous areas in the TLB-YRV. As a result, the sunrise HHR gradually increases from the foot of the mountain. The high-frequency HHR period of sunrise occurs when the supergeostrophic effect is weakened, the low-level vorticity and frontal forcing are strengthened, and the water vapor flux convergence begins to weaken. Secondly, the high-frequency HHR period of the sunset is caused by stronger local uplift and more unstable atmospheric stratification, but the enhanced local uplift is caused by the coupling of the terrain forcing of the underlying surface and the enhanced northern subgeostrophic flow, which causes the HHR to start closer to the mountain top at sunset than at sunrise.

The Industrial Sprawl in China from 2010 to 2019: A Multi-Level Spatial Analysis Based on Urban Scaling Law.

Studying the spatial-temporal distribution industrial sprawl in China is important to solve industrial sprawl problems and promote urban sustainable development. This paper constructed a multi-level spatial analysis of the Chinese industrial sprawl during 2010-2019 by mainly using urban scaling law, supplemented by GIS methods. Results showed that: (1) China had obvious industrial sprawl with a growth rate of 31.79%, reaching 2762.37 km2 between 2010 and 2019. (2) There was a stronger industrial sprawl in large cities with a larger population according to urban scaling law, especially in the East. (3) The industrial sprawl was mainly concentrated in the cities in the Northeast, Beijing-Tianjin-Hebei region, Shandong Peninsula, Yangtze River Delta region, Pearl River Delta region, Middle Yangtze River region, Fujian Province, and some cities in the West. (4) The gravity center of industrial sprawl generally moved southwest and distributed in Hubei Province. This study provided references for improving the efficiency of industrial land use and promoting high-quality urban development.

Coupling coordination development of energy-economy-carbon emissions in China under the background of "double carbon".

Based on the panel data of 30 provinces in China from 2010 to 2019, this paper measured the coupling coordination development of energy-economy-carbon emissions and investigated its regional differences and spatial convergence. The research methods in this paper include entropy weight technique method for order preference by similarity to an ideal solution, coupling coordination degree model, Dagum Gini coefficient and decomposition method, Moran's I index, σ convergence model and β convergence model. The study found that the coupling coordination degree of energy-economy-carbon emissions in China has been continuously improved and has obvious regional and stage characteristics, but it is still on the verge of imminent disorder; the overall difference in the coupling coordination degree of energy-economy-carbon emissions shows a decreasing and then increasing trend, the main source of which is inter-regional differences; the coupling coordination degree of energy-economy-carbon emissions has a positive spatial correlation; except for the Southern Coastal Economic Zone and the Middle Yangtze River Economic Zone, there is no significant σ-convergence and β-convergence in the coupling coordination degree of energy-economy-carbon emissions system in other economic zones; the coupling coordination degree of energy-economy-carbon emissions changes fastest in the Middle Yangtze River Economic Zone. The innovation of this paper is to measure the coupling coordination degree of energy-economy-carbon emissions and to analyse its regional differences and spatial effects. It is of great practical significance to promote the coupling coordination development and regional balanced development of energy-economy-carbon emissions in China under the background of "dual carbon".

Optimizing phosphate fertilizer input to reduce phosphorus loss in rice-oilseed rape rotation.

Identifying the major sources and critical periods of P loss from agricultural fields provides important guidance for reducing P loss. A rice-oilseed rape rotation with no P fertilization (NP, control), medium P fertilization (MP, 90kg P2O5 ha-1 season-1), and high P fertilization (HP, 180kg P2O5 ha-1 season-1) was conducted from 2019 to 2021 in the middle Yangtze River Basin. Runoff and leaching P losses were measured simultaneously using runoff event monitoring and a percolation device. Applying P fertilizer increased the P concentration in the field ponding water and percolation water of the rice-oilseed rape rotation. During the rice growing season, total P (TP), dissolved P (DP), and particulate P (PP) concentrations in the field ponding water and percolation water peaked 1day after P was applied, and then decreased rapidly. After 10days of fertilization, P concentration in the field ponding water of the MP treatment decreased to a minimum and stabilized, while the HP treatment extended this period to 20days. The highest P concentration in percolation water was observed at the first sampling during the oilseed rape season, and then it continued to decrease. Inputting P fertilizer increased P loss by 55.0-109.9% compared to the NP treatment, with annual P losses of 0.89-1.10kg P ha-1, of which runoff loss accounted for 61.7-62.9%. Fertilization and precipitation resulted in varied P loss within and between seasons. Runoff from heavy precipitation during the rice season was the main source of P loss, while PP accounted for 54.7-77.6% of runoff P loss. The strong utilization of soil P by rice resulted in a lower demand for exogenous P fertilizer than oilseed rape. Excessive P input increased the soil P surplus and vertical migration. Therefore, reducing rice season P fertilizer inputs to achieve annual P balance in rice-oilseed rape rotation can effectively reduce soil P surplus and loss while ensuring crop P demand, and the initial 10 d after fertilization in the rice season was a critical period for reducing P runoff loss.

Mechanisms of bar adjustments in the Jingjiang Reach of the Yangtze River in response to the operation of the Three Gorges Dam

Dams alter downstream river flow and sediment regimes, causing significant changes in river morphologies. The middle Yangtze River downstream of the Three Gorges Dam (TGD) has experienced rapid erosion in recent years, and the associated morphodynamic changes have negatively impacted the riverbank stability, navigation waterways and ecological functioning. Earlier studies have analyzed recent channel adjustments in the Yangtze River; however, our understanding of changes in the bar morphodynamics remains incomplete. In this study, we collected and analyzed flow and sediment data (1991–2016) and river bathymetry data (1975–2017) and investigated the mechanisms of bar adjustments along the Jingjiang Reach in the post-TGD period. The results indicate that most steady bars with a higher elevation and better vegetation coverage have experienced lateral erosion, while their elevations have remained stable overall. The unvegetated migrating bars with a lower elevation have experienced severe surficial erosion and area shrinkages. A new assessment method of the dominant discharge range on downstream bars is provided after dam closure. The dominant discharge range that determines bar adjustments corresponds to the flow stages between the submersion of migrating bars (∼12,500 m3/s) and the overtopping of vegetated steady bars (∼27,500 m3/s) in the Jingjiang Reach. A quantitative relationship exists between bar erosion in response to changed dominant discharge regimes and sediment decline. The significant bar erosion after the operation of the TGD can be attributed to the increased flow duration and the sharp decline in the suspended sediment concentration (SSC) of the dominant discharge range, and changes in SSCs play a primary role. The bar area will decrease by ∼0.003 km2 when the annual cumulative duration of the dominant discharge increases by one day and by ∼0.234 km2 when the annual average SSC of the dominant discharge decreases by 0.01 kg/m3. Furthermore, vegetation encroachment and colonization play a positive role in stabilizing bar morphologies and limiting surficial erosion, whereas vegetation soley cannot prevent the lateral erosion of steady bars. These findings suggest that multiple controls of discharge, sediment and vegetation on the evolution of fluvial bars and have important implications for river management and ecological evaluation in response to the operation of large dams.

Surface treatment of red painted and slipped wares in the middle Yangtze River valley of Late Neolithic China: multi-analytical case analysis

Red slipped and painted wares (RSW and RPW) were manufactured to cook, serve, or store foods and liquids in the middle Yangtze River valley (MYRV) of China some 8500 and 7800 years ago, respectively. Their primary use narrowed down to serving and drinking in the Upper Qujialing (5300–4500 cal BP) and Shijiahe (4500–4200 cal BP) periods when initial states (bang guo) took shape and developed in the region. The increasing social complexity in MYRV correlated with the formation of community and neighborhood identity through rituals and socio-economic ties involving the widespread use of RSW and RPW. How the two wares were produced and used helps us understand the relationships among productive activities, identity, and social inequality in MYRV. This paper presents the first overview of RSW and RPW in the Neolithic MRYV. It introduces a multi-analytical study of the two wares—mostly dating to the Shijiahe period—unearthed from the site of Fenghuangzui in Xianyang City of Hubei Province, China. Optical microscopic examination revealed that the paint of RPW—50 μm thick on average—was applied using a brush while the slip of RSW is thinner and finer and possibly formed by self-slipping. Handheld X-ray fluorescence (hhXRF) and benchtop micro-XRF analyses ascribed the red paint or slip to iron and iron oxide. Raman and X-ray absorption fine structure analyses confirmed that iron was present in the paint or slip in the form of hematite with a poorly developed crystalline structure. Furthermore, thin-section petrography implied that different pastes were used to produce RPW and RSW, and hhXRF data indicated that the Upper Qujialing and Shijiahe pottery differ in the concentrations of five elements (Zr, Fe, Mn, Ti, and Ba), which might be helpful in future provenance studies of RSW and RPW. Our study discloses the complexity of the manufacture of RSW and RPW at Fenghuangzui. More details of RSW and RPW production and use from our ongoing project shall reveal the role of the two wares in the social dynamics of the Late Neolithic MYRV.Graphic

Temporal variations and trends prediction of water quality during 2010-2019 in the middle Yangtze River, China.

Water quality plays an important role in river habitats. This study revealed the annual and seasonal variations and trend prediction of water quality in the middle Yangtze River after the third impoundment stage of the Three Gorges Reservoir. Multivariate statistical methods including principal component analysis/factor analysis (PCA/FA), Mann-Kendall (M-K) tests, discriminant analysis (DA), rescaled range (R/S) analysis, and the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI) were used. Herein, eight water quality constituents including pH, electrical conductivity (EC), chloride (Cl), dissolved oxygen (DO), ammonia nitrogen (NH3N), total phosphorus (TP), water temperature (T), and permanganate index (CODmn) were monthly monitored in the Jiujiang hydrological transaction during 2010-2019. The information of eight water quality constituents, related to salinity, nutrient status, and oxidation reactions efficiency, was extracted. Water quality status remained as fair-good during 2010-2019 based on the results of CCME-WQI, with the seasonal significance ranked as T > DO > Cl > pH > EC > TP > NH3N > CODmn. In the future decade, annual average T was predicted to continue to increase although it might decrease in the wet season. EC was predicted to continue increasing annually especially in the wet season while Cl might decrease. NH3N and TP might maintain a significant decreasing trend in the future wet and dry seasons. DO maintained significantly increasing especially in the future dry seasons, whereas CODmn will continue to decrease annually and seasonally. The continued alkalization trend of waterbody was predicted, which is more significant in the wet season. The results provide helpful references for the ecological protection of the middle Yangtze River.

The Foraging Window for Greater White-Fronted Geese (Anser albifrons) Is Consistent with the Growth Stage of Carex

Food resources are key limiting factors for migratory waterbirds, and the foraging strategies adopted by herbivorous waterbirds are affected by food availability in wetland habitats. The greater white-fronted goose (Anser albifrons) is mainly dependent on Carex in the lower and middle Yangtze River floodplain. Exploring the relationship between the growth conditions of Carex and the foraging strategies adopted by wintering greater white-fronted geese has important ecological implications for habitat protection and management. In this study, scan sampling and focal animal sampling were used to record the foraging behaviors of greater white-fronted geese wintering at Shengjin Lake, and the plant height and water content of Carex were surveyed simultaneously. The relationship between plant characteristics and foraging behaviors was tested using a linear regression equation. The results showed that Carex had two growth periods at Shengjin Lake, and the pecking rate and foraging time budget of greater white-fronted geese were higher during these two periods. Plant characteristics were positively correlated with goose foraging behaviors. The strategic adjustment of the foraging behaviors adopted by wintering greater white-fronted geese was consistent with the growth stage of Carex, which is the optimal foraging window for greater white-fronted geese. During the foraging windows, geese changed their foraging strategies to obtain more energy in order to guarantee successful wintering and migration.