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The Huayuankou flood event (1938–1947) refers to the prolonged flooding caused by the artificial bursting of the Yellow River embankment at Huayuankou during the Sino-Japanese War (1937–1945). It recreated the historical scenes of frequent floods in the lower Yellow River region of China since the Ming and Qing Dynasties (1368–1911), with the counties along the Jialu River in the eastern plains of Henan especially becoming the disaster-stricken areas. The flood lasted for nearly nine years until the completion of embankment restoration work in 1947, causing long-term and extensive environmental impacts. This paper discusses this catastrophic historical flood event caused by human factors, the warfare strategies and hydraulic technology that acted as drives, and the location factors and historical context leading to the start of flooding in flood-prone areas of Henan. Based on spatial perspectives and the historical GIS approach, the paper compiles and integrates historical documents and maps with archival material and topographic maps from the 1930s and 1940s to present the extent of the flood, the associated disasters, and the persistent effects of official relief strategies and political situation in the wider context, examining how the Huayuankou flood was used as a military tactic, but with unpredictable disastrous consequences. [ABSTRACT FROM AUTHOR]

Dissolved organic matter (DOM) and microbes are key in the planetary carbon cycle, and research on them can lead to a better understanding of the global carbon cycle and an improved ability to cope with environmental challenges. Several papers have reviewed one or several aspects of the interaction of DOM and microbes, but no overall review has been performed. Here, we bibliometrically analyzed all publications from the Web of Science on DOM and microbes (1991–2020). The results showed that studies on DOM and microbes grew exponentially during this period; the USA contributed the most to the total publications, and China has had the fastest increasing rate since 2010. Moreover, we used the Latent Dirichlet Allocation model to identify topics and determine their (cold or hot) trends by analyzing the abstracts of 9851 publications related to DOM and microbes. A total of 96 topics were extracted, and these topics that are related to the source, composition, and removal path of DOM and the temporal-spatial patterns of DOM and microbes consistently rose from 1991 to 2020. Most studies have used accurate and rapid methods combined with microbiological genetic approaches to study the interaction of DOM and microbes in terrestrial and aquatic ecosystems. The results also showed that the impacts of climate change and land use on the interaction of DOM and microbes, and topics related to human health have received considerable attention. In the future, the interaction mechanism of DOM and microbes and its response to environmental change should be further elucidated. [ABSTRACT FROM AUTHOR]

Figuring out the impacts of future urbanization on hydrological response is significant in a rapidly changing environment. As an important urbanization element, the various impacts of land use/land cover change have been studied a lot with the methods of combining different land use scenarios and hydrological models. However, it needs to be improved because of only simplified land use scenarios being considered, which cannot reflect the real urbanization process of the future. Taking into account the roles of social and economic development, in this paper, a hybrid FLUS-SWAT method is proposed for the first time for accurately evaluating the hydrological responses to urbanization. First, instead of subjective assumption, future land use patterns are predicted by developing improved cellular automata model on driving forces involving regional population, gross domestic product, location, transportation network, etc. Then, spatial hydrological responses were individually analyzed by coupling projected future land use scenarios and distributed hydrological model. The results clearly forecasted a burst of urban expansion in future 100 years in Zhexi river basin, China. Loss of forest and agriculture land will lead to a 64.86% increase in surface runoff and 9.05% decrease in groundwater flow. This study is significant for ecological environment planning because it provides a direct understanding of future urbanization level as well as its impacts on hydrological processes. [ABSTRACT FROM AUTHOR]

In order to reveal the changes of vegetation in southern China since the Last Glacial Maximum, we have established high-resolution time scales and palynological sequences of borehole profiles by drilling cores in some weak areas of the research to restore vegetation changes over the past 20,000 years on the basis of previous work. This paper gives the vegetation zoning maps of 18, 9 and 6 ka BP respectively in southern China, and describes the distribution characteristics of plants in different zones/subzones. The results show that the vegetation zonations around 18 ka BP were significantly different from that at present. It appeared in turn with Cold-temperate coniferous forest and alpine meadow steppe zone, and Temperate mixed coniferous and broad-leaved forest zone/warm temperate deciduous broad-leaved forest zone from northwest to southeast in the west, and Temperate mixed coniferous and broad-leaved forest zone, Warm temperate deciduous broad-leaved forest zone, and Northern subtropical mixed evergreen and deciduous broad-leaved forest zone from north to south in the central and east. The vegetation distribution around 9 ka BP changed distinctively. Except that the northwest part was located in Mountain temperate mixed coniferous and broad-leaved forest zone, the vegetation in other areas occurred in turn with North subtropical mixed evergreen and deciduous broad-leaved forest subzone, Mid-subtropical typical evergreen broad-leaved forest subzone, and South sub-tropical monsoon evergreen broad-leaved forest subzone/Tropical seasonal rainforest and rainforest zone from north to south. There was little change in the appearance of vegetation zonations between 6 and 9 ka BP, but the northern edge of each vegetation belt moved a little northward, reflecting that the overall climate became warmer around 6 ka BP. The vegetation changes in southern China over the past 20,000 years were largely driven by environmental changes. Climate change was the main factor affecting the vegetation distribution. The impact of human activities became more and more remarkable in the later period. In the lower reaches of the Yangtze River and the delta region, sea level changes also influenced the vegetation distribution. [ABSTRACT FROM AUTHOR]

In recent years, climate and environment changes since the Little Ice Age have become a focus in modern research. The paper selected the sediment (77 cm) of Sihu Lake, which was located in Guilin, southern China, as the research object and analyzed the karst wetland environmental changes within nearly 450 years. According to the vertical profile of indicators and geochemical elements in sediment core, the regional environmental evolution was divided into four stages. The former two stages were mainly influenced by Little Ice Age (1562–1895). The third stage climate has changed slowly. The fourth stage was mainly affected by human activities and global warming. The factor analysis of geochemical elements indicated that karst wetland regional environmental change was affected by four major factors. In the 53–77 cm stage (1562–1703), F1 (erosion factor), F2 (watershed runoff and diagenesis factor) and F3 (regional background factor) were reduced, indicating that it was in cold and dry stage of Little Ice Age. In the 20–53 cm stage (1703–1895), F1 and F2 increased, indicating that it was in cold and wet stage of Little Ice Age. In the 4–20 cm stage (1895–1987), F1, F2 and F4 (human activity factor) increased slowly, indicating that the climate was affected by global warming and more precipitation. In the 0–4 cm stage (1987–2007), F1 and F2 reduced and F4 increased, indicating the reduced precipitation, rising temperature and more impact of human activities. In addition, it was proposed that the Little Ice Age in Guilin District in southern China started in the 1560s and lasted until the 1895s or so. [ABSTRACT FROM AUTHOR]

The Carnian Pluvial Event (CPE) induced an intense carbon-cycle disturbance and biological crisis at a global scale. The eruption of the Wrangellia Large Igneous Province (W-LIP) is considered a possible triggering mechanism; however, this cannot fully explain the significant differences in environmental perturbations across different regions. In this paper, we present detailed records of petrography, mercury geochemistry, carbon and sulfur isotopes, trace elements, and provenance data for the Triassic lacustrine facies of the Ordos Basin in the North China Plate, which provide insights into the important effects of volcanic activities, other than the W-LIP, on palaeoenvironment during the CPE interval. Massive emissions of SO 2 , CO 2 , and pyroclastic deposits resulting from these volcanic activities triggered four humid episodes, each characterized by lake-level rise, negative δ13C org excursion, a transition from mudstones to organic-rich shales facies, as well as algal bloom within a time span of 180 kyrs. The establishment of an age framework in the Ordos Basin enables comparative analyses of environmental evolution during the Carnian age across the North China Plate, the western Tethys domain, and the South China Plate. During the period of global climate perturbation driven by the W-LIP eruption, we conclude that short-term localized volcanic activities may have further induced high frequentcy environmental perturbations, which influenced biological shifts and increase organic carbon burial. These short-term volcanic activities with different occurrence times and frequencies complicate local-scale palaeoenvironmental evolutions, which may be an important reason contributing to significant differences in environmental perturbations during the CPE interval across different regions of the globe. • Four humid episodes and sedimentary changes occurred within 0.18Ma in the Ordos Basin during Carnian age. • Environmental changes in the Ordos Basin was related to the local volcanisms in its nearby Qinling orogenic belts. • Short-term local volcanisms can complicate the environmental evolutions in different parts of globe during the CPE interval. • Local volcanic processes may cause inconsistent environment perturbation in different parts of globe during the CPE interval. [ABSTRACT FROM AUTHOR]

There is increasing interest in the application of digital soil mapping (DSM) projections to infer changes in soil carbon across both space and time. This approach relies on the assumption that the spatially modeled soil carbon-environment relationship can be transferred over time. However, this assumption is rarely tested due to a lack of temporally independent validation data. This paper assesses this assumption by developing models of topsoil organic carbon stocks (SOCS) with a deep learning algorithm and data covering mainland China pertaining to the 1980s and 2010s. The temporal prediction performance of models capturing a specific period was assessed by evaluating their performance in the prediction of data during another period. The results revealed that the prediction accuracy of temporal modeling decreased, as indicated by the coefficient of determination, and was lower than that of spatial modeling. The lower prediction accuracy obtained with the DSM-projection approach may result from differences in the magnitudes of influential variables across periods. We found that different levels of environmental similarity and model projection sensitivity to dynamic variables may cause discrepancies in forecast and hindcast accuracy. Our results demonstrate that the prediction error in temporal modeling is related to the degree of environmental similarity between periods. Our findings generally support the implementation of the DSM-projection approach in soil carbon change modeling. However, caution should be exercised, as there exists much uncertainty regarding the projection of spatial models over time. • DSM projection may facilitate a more precise estimation of large-scale soil carbon changes. • Discrepancies in the environment between periods reduce the temporal predictive skill. • The variability in the model performance is related to the magnitude of environmental influences. [ABSTRACT FROM AUTHOR]

Water Scarcity and drought are recurrent phenomena in China. In the context of environmental change, an increasing tendency in drought frequency and severity is observed in China in recent years. Therefore, it is imperative to take necessary initiatives to reduce the impacts of drought. In this paper, an attempt is made to identify the best water management strategies to cope with droughts. For this objective the records of historical droughts and their impacts in China over the period of 1950-2009 are analyzed. It is observed that the drought affected area has increased nearly by 12 folds and the drought damaged area has increased by about 22 times in China in last 60 years. Over 87,000 reservoirs were built with a total water storage capacity of about 7,064 billion m to cope with droughts. However, this structural supply-based management strategy was not enough to meet the increasing water demand caused by rapid economic development and population growth. A typical relationship between socio-economic development and water resources management strategy to attain sustainability in water management is developed in this study. The relationship shows that the demand-side water management strategies can be the best option to meet the challenges posed by increased severity of drought, population growth, economic development and possible climate change. The concept is later verified through the analysis of changing pattern of water consumptions by different sectors in last 60 years. [ABSTRACT FROM AUTHOR]

China is a large country by area. In situ monitoring of the environment cannot meet the demand of the society. For large areas, remote sensing is the only viable technology for environmental monitoring of the entire area. Although satellite observation capabilities as well as remotely sensed data acquired on board of satellites from both within and outside China are widely available, research is rare that targets the entire territory of China for environmental monitoring. In this paper, the process of environmental change has been categorized into changes in driving forces, environmental change, materials transport and transformation, concentration and abundance change, exposure and infection change of human and ecosystems, and impacts. The potential in monitoring changes in these various aspects is assessed. The progress of environmental change monitoring over the entire territory of China is reviewed. It is suggested that at the methodological level, remote sensing should not only be applied to observation and experiments as well as understanding the change mechanism, but also be coupled with environmental simulation and forecasting so as to support environmental policy making. At the application level, remote sensing should be used beyond its traditional application fields to include species diversity, biological invasion, public health, air and water quality monitoring. Finally, at the technical level, systematic research should be devoted to the improvement of operational and automatic use of remotely sensed data. [ABSTRACT FROM AUTHOR]

In this paper, we summarize the Holocene environmental history of the lower Yangtze region, east China, based on the sedimentary records and microfossil diatom, pollen, fungal and charcoal data that were published in the past two decades. We then examine the linkage between changes in the coastal environment and the development of rice agriculture in the region, with reference to the available archaeological evidence and historical archives. Based on the sedimentary and archaeological evidence, we conclude that during the early Holocene sea-level movements and sedimentary processes significantly changed the region’s landscape from an open, brackish water environment to a largely enclosed, wetland system. This newly established freshwater marsh environment provided a habitat favourable to rice agriculture. The early Neolithic farmers took the opportunity presented to them and started rice cultivation in locations where freshwater wetland systems were established. During the middle Holocene, environmental conditions were largely stable, and the coastal wetlands evolved slowly. Environmental change was only a supportive player in the Neolithic cultural processes, because the Neolithic people were able to adapt to these changes and took advantages of the newly emerging marsh land for food collection and production. Around 4200 years ago, the prosperous Liangzhu society fell, but there is no evidence to suggest the fall was related to a significant environmental change. The coastal environment continued to evolve slowly during the late Holocene. But this period saw rapid technological development in irrigation and flood protection, and the environmental factor was reduced to background noise. Throughout the Holocene, the main strategy taken by the Neolithic people to cope with environmental change was migration to find better food sources. Along with this strategy was the development of technology in landscape management to ensure a more reliable food production in addition to food collection through hunting, gathering and fishing. [ABSTRACT FROM AUTHOR]

The last glacial period was vital for the distribution and evolution of early modern humans in Asia. The Shuidonggou Late Paleolithic site, dated at 30-20 ka BP, accumulated cultural remains during the important late stage of MIS 3 period in the last glacial. These remains represent characteristics of typical Late Paleolithic conditions in North China: high degree of standardization and morphological variability of tool types, exploitation of bone materials, systematic use of body decorations, extensive use of earth-pit hearths, distinct functional spatial organization within habitations, and conversion of subsistence patterns. These characteristics illustrate early modern human behaviors during the late MIS3 period, and provide clues and perspectives for the analysis of early modern human origins in China. At the same time, the conversion of subsistence patterns is considered to be a combination of multiple early modern human behaviors, as well as the result of the Broad Spectrum Revolution. In this paper, we argue for the dynamic mechanism of Broad Spectrum Revolution from a human behavioral and ecological perspective. [ABSTRACT FROM AUTHOR]

This cross-cultural study examined college students' environmental risk perception and their preference in terms of risk communication and educational strategies in China and the United States. The results indicated that the Chinese respondents were more concerned about environmental risk, and they perceived the environmental issues to be more harmful to health, to the environment, and to social economic development of the nation than did the American respondents. Both groups desired transparent communications in decision processes and would support educational strategies that foster behavior change for reduction of environmental risks. On the basis of the findings, the paper discusses the changes that would potentially improve non-formal and formal environmental education in China from the perspectives of program foci and approaches. [ABSTRACT FROM AUTHOR]

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]

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]

Abstract: Holocene environmental change and environmental archaeology are important components of an international project studying the human-earth interaction system. This paper reviews the progress of Holocene environmental change and environmental archaeology research in the Yangtze River Valley over the last three decades, that includes the evolution of large freshwater lakes, Holocene transgression and sea-level changes, Holocene climate change and East Asian monsoon variation, relationship between the rise and fall of primitive civilizations and environmental changes, cultural interruptions and palaeoflood events, as well as relationship between the origin of agriculture and climate change. These research components are underpinned by the dating of lacustrine sediments, stalagmites and peat to establish a chronology of regional environmental and cultural evolution. Interdisciplinary and other environment proxy indicators need to be used in comparative studies of archaeological site formation and natural sedimentary environment in the upper, middle and lower reaches of the Yangtze River Valley. Modern technology such as remote sensing, molecular bioarchaeology, and virtual reality, should be integrated with currently used dating, geochemical, sedimentological, and palaeobotanical methods of analysis in environmental archaeology macro- and micro-studies, so as to provide a greater comprehensive insight into Holocene environmental and cultural interaction and change in the Yangtze River Valley area. [Copyright &y& Elsevier]

Abstract: This paper reviews our current understanding of Quaternary climate and landscape changes in the desert areas of northern China, a key portion of the middle-latitude drylands on Earth. Combining earlier studies with our recent research and experience, we offer a comprehensive picture of the state of Chinese deserts during the Quaternary and, in the interest of enhancing future research, identify knowledge gaps and areas of uncertainty. Lacustrine deposits found over an area ranging from China’s western Taklamakan Desert to the eastern Hunshandake Sandy Lands suggest that extensive lakes occurred in China’s deserts during the Pleistocene. Analysis of digital elevation models from SRTM (Shuttle Radar Topography Mission) data supports this interpretation and shows the significant extent of these former lakes. New estimates of mean annual evaporation of ca. 1000 mm from lake surfaces and ca. 100 mm from land surfaces, confirms that local and regional rainfall is critical for maintenance of desert lakes in this temperate zone, especially during intervals when the mean annual rainfall is more than 100 mm. Rapid shifts between sand seas and lakes in geologically and environmentally diverse settings suggest that the drylands of China are very sensitive ephemeral systems, and not long-lasting as previously thought. Available chronologies suggest that there were large lakes in the western Taklamakan Desert and the Chadamu Basin during MIS (Marine Isotope Stage) 3, at ∼30 ka, probably related to a period of strong influence of northern hemispheric westerly winds. Channels and elevation models revealed by SRTM data and remains of lacustrine sediments also indicate that there was a large lake in the Hunshandake Sandy Lands in the eastern portion of the desert belt during the Quaternary. There is significant evidence that during the middle Holocene strong summer monsoons led to a relatively large increase in moisture availability in the entire desert belt of northern China. Lacustrine records from the Badain Jaran Desert in western Inner Mongolia suggest that it was generally dry before 10 cal ka, becoming wetter from 10 to 4 cal ka, and dry again afterwards. Study of palaeosols widely occurring in dune stratigraphy in the eastern portion of the desert belt, suggests that there was a period of wet and warm climate in this region during the mid-Holocene Optimum, at a minimum between 6 ka and 4 ka, but possibly lasting longer. Recent observations dealing with the generation and transport of dust from Central Asia indicate that the causal relationship between sand seas and loess sequences is not as close as previously assumed. These results suggest that there is an urgent need to examine whether the frequency and amplitude of climatic variation in Chinese deserts are somehow similar to that having occurred in the Sahara Desert of North Africa. Deserts in northern China were also important focal regions for Neolithic cultures during intervals when environmental conditions supported a denser vegetative cover. There is evidence that some areas of woody vegetation to the west of Badain Jaran Desert were deforested by humans by ca. 4000 yr B P, although it is still debatable whether humans have had a significant impact in other areas at that time. Opinions on the severity of desertification vary and are sometimes contradictory due to the lack of long-term, field-based, investigations. [Copyright &y& Elsevier]

Globally, climate change impacts on marine ecosystems are evident in physical, chemical, and biological processes, and are generally more extensive in faster warming regions. China makes the largest contribution of any country to global fisheries production and has experienced severe declines in marine health and biodiversity, and so the current and potential impacts of marine climate change are a large concern for both fisheries and biodiversity. China also has marine regions warming in the top 10% globally, necessitating a thorough understanding of how marine systems are changing so that appropriate corresponding countermeasures can be identified and prioritized. Here, we review and collate what is currently understood about documented and projected responses of marine systems to climate change in Chinese coasts and oceans, from physical, biological, and ecological perspectives, through to impacts on key ecosystems. Our results show extensive change attributed to climate change throughout Chinese marine systems, including red tide bloom events that have been recorded an order of magnitude more frequently in recent decades. Ocean acidification has led to the increased mortality of marine calcifying organisms through effects on the biomineralization process and physiological functions. Moreover, many species have been documented undergoing extensive changes in geographic distribution, with potential implications for species interactions and trophic food webs, as well as important habitats like coral reefs, seagrass, and mangroves. Some constructive laws and actions have been introduced in response to these climate-driven changes, such as actions to reduce pollution and increase artificial propagation and replanting of habitat species, however, addressing the impacts of marine climate change remains a considerable and escalating challenge. [ABSTRACT FROM AUTHOR]

The middle–late Cambrian is a key interval between the Cambrian Explosion and the Great Ordovician Biodiversification Event (GOBE) that marks a major biologic evolutionary transition in the geologic record. Diversity (i.e. richness) patterns in this interval show that macro-biota experienced evolutionary setbacks for the first time. However, relatively little attention has been paid to this interval in previous macroevolutionary studies and very different conclusions about the diversity patterns in coarse time-resolution have been documented. As a dominate group of marine benthic organisms in the Cambrian, trilobites provide insightful information to understand the history of biodiversity in the Cambrian marine ecosystem from the Cambrian Explosion to the GOBE. South China is a region with relatively good preservation of Cambrian fossil materials and sections, and 4 out of 6 Cambrian GSSPs were established in South China. In this paper, we use constrained optimization (CONOP) to correlate 19 sections from South China to reduce the Signor-Lipps effect and integrate the results with high-resolution chronostratigraphic data to evaluate the middle–late Cambrian trilobite diversity pattern in South China. This study, for the first time, constructs a high time-resolution (about 60 kyr) trilobite species-level richness curve with estimated time from Age 4 to the Paibian. A double-peaked species diversification is separated by a minor extinction in Stage 4; this is followed by a gradual decline of species diversity over the entire Wuliuan Age. A radiation of three times increase of species diversity in the Drumian and Guzhangian is exhibited and the diversity remains high for most of the Guzhangian Stage; this is followed by a great extinction at the end of the Guzhangian with around 50% species lost. Detailed comparison with previous composite studies and fossil material from single sections revealed that the Signor-Lipps effect could produce large biases in diversity pattern. In addition, a precise analysis of species evolution features compared with environmental indices provides a perspective about trilobite evolutionary mechanisms associated with environmental changes related to the carbon cycle and biotic competition. • Middle-late Cambrian trilobite diversity trajectory of South China is established. • High temporal resolution of diversity pattern is produced with CONOP method. • The results reveal two major diversity losses and a biodiversification event in Guzhuangian. • Signor-Lipps effect may affect diversity pattern significantly. • Major extinctions of trilobites are correlative with carbon isotope excursions. [ABSTRACT FROM AUTHOR]

Dramatic environmental changes and species invasions are increasingly threatening the diverse fish fauna of the Yellow River, China. This study examines temporal changes in the alpha and beta components of fish taxonomic, functional and phylogenetic diversity in relation to anthropogenic environmental changes over the past 50 years. We hypothesized that temporal trends in multifaceted components of diversity would be highly congruent, but that the relative importance of anthropogenic disturbances would differ in shaping spatial patterns of fish diversity. We found that all three components of alpha diversity increased over time but at different rates (19.1%, 21.3% and 15.3% for taxonomic, functional and phylogenetic diversity, respectively). Fish faunas of the Yellow River have also become homogenized over time, but this was much greater for functional and phylogenetic components of beta diversity than for taxonomic diversity (change in beta diversity = − 0.11, − 0.24 and − 0.02, respectively). Temporal changes in alpha and beta diversity were strongly related to invasion of non-native fish species and changes in temperature, sediment load, reservoir capacity and aquaculture area. Our results underscore the ongoing need for threat mitigation (particularly relating to dams and aquaculture) to conserve the unique biodiversity of one of the world's largest rivers. [ABSTRACT FROM AUTHOR]

In light of the rapid urbanization of the world's population over the past decades, there is a growing concern about the environmental impacts of urban population growth. Rural-urban migration is a particularly important component of the urbanization process in developing countries and is often considered to be detrimental to urban environmental conditions. However, few studies have explicitly examined the presumed negative impacts of in-migration on the natural environment of cities. The continuously increasing volume of rural-urban labor migration in China since the early 1980s has formed the largest population flow in world history. This study links the existing literature on population-environment and urbanization-environment interactions by empirically assessing the relationship between rural-urban migration and urban air conditions in China. A two-period (2004 and 2010) longitudinal dataset for the 113 key environmental protection cities of China was constructed based on multiple data sources. We applied the STIRPAT equation using conventional and spatial panel regression models to examine whether rural-urban migration flows were associated with air pollution in cities. Results show a strong negative association of in-migration with urban air quality even after controlling for the effects of other population, affluence, and technology factors. Findings from this research can contribute to a better understanding of the environmental consequences of rural-urban migration in China, with broader implications for sustainable development research and policies. [ABSTRACT FROM AUTHOR]

Lake Chenpu is located in the western part of Hetao Basin approaching the Ulan Buh Desert in the upper reaches of the Yellow River in northern China. An 84 cm sediment core was collected from the center of the lake. Geochronology radiometric method using Pb was subsequently used to date the short sediment core in the hope that it would reflect environmental changes over the past 150 years. Principal component analysis and the variation of the grain-size standard deviation were used to identify latent factors and extract environmentally sensitive grain-size components in sediment. Then a combination of sensitive grain-size parameters, magnetic susceptibility, total organic matter (TOC), and total nitrogen (TN) was used to reconstruct the recent lake environmental sequence. The result showed that the lake has seen increasing salinization and swampiness over the past 150 years. Further, sensitive grain-size parameters displayed several abrupt environment changes, i.e. 1850 AD, 1920 AD, and 1980 AD, which are supported by written records. In the 1850s, the yellow clay content increased dramatically, and that of silt declined. Magnetic susceptibility and C/N values increased significantly, as indicated by flood action. In the 1920s and the 1980s, dust-sand activity was recorded twice in the lake sediments with a markedly higher value of 16-32 μm and average grain size (C2). Grain size and other environmental proxies showed the period after the mid-1990s to be mainly dominated by wind-sand activity and anthropogenic impacts, which marked by obviously increasing grain-size coarse, carbonate content, TOC, and TN values. The results show that the lake sediments provide a dependable archive for studying the environmental history of the lake. [ABSTRACT FROM AUTHOR]

To address the growing need for developable land, many coastal cities are draining and filling wetlands, transforming them into urban built-up areas, and thereby substantially altering the structure and function of coastal ecosystems. We demonstrate an integrative approach for investigating the dynamics and impacts of coastal development in China's Jiangsu Province, where urban expansion has resulted in extensive wetland losses and sea reclamation (the process of creating new land from ocean or coastal waters). Remotely sensed data reveal that landscape change in the study area has been accompanied by an increase in total impervious surface area and an increase in mean surface 'heat island effect.' These indicators of change can be detected with remote sensing data and used to support a strategic environmental assessment (SEA) for urban coastal planning. Changes detected in Lianyungang during 2000-2006 suggest that reclaimed areas are environmentally sensitive and should be a focus of concern in future development planning, which has historically targeted coastal salt pond wetlands for conversion to land for the development. Given the current and projected rate of coastal development in China and elsewhere in the developing world, our findings and assessment approach have implications for coastal management decisions in the developing coastal zones of China and other regions of the world that are experiencing rapid urban growth. [ABSTRACT FROM AUTHOR]

New pollen, phytolith, charcoal and diatom data from 14C AMS-dated sediments from three clusters of former occupation sites on the southern Yangtze Delta – Liangzhu, Majiabang and Chuodun – reveal that hydrological conditions were a key factor influencing early food production on the southern Yangtze Delta. At least two episodes of inundation are recognized, the first occurring at c. 7200–5700 cal. yr BP and a second from c. 4700 cal. yr BP. The first involved increasing salinity of surface waters, likely associated with marine intrusion linked to post-glacial sea-level change (meltwater pulse (MWP) 2). The second appears to have been freshwater in nature and driven at least in part by extreme meteorological events of high levels of precipitation in combination with impeded drainage. These two episodes had profound impacts on Neolithic settlement and farming. Further hydrological changes, presumably linked to changes in sedimentary regime, geomorphology and drainage of the Taihu depression, recorded at the Chuodun site after c. 3000 cal. yr BP, appear to have had a major effect on technologically relatively advanced food production systems. While environmental pressures appear to have played an important role in shaping human activities and settlement on the southern Yangtze Delta, people responded by adopting strategies that included an increased reliance on food production, migration to more clement locations and implementation of new technologies, which possibly included the construction of flood defence works. [ABSTRACT FROM AUTHOR]

A 475-cm long sediment core (QH-2005) from Lake Qinghai was used to carry out multi-proxy analysis of δO and body length of ostracod valves and redness and grain size of sediments, in order to reconstruct environmental changes during the past 13500 cal. a BP. The age model was based on 6 C dates for bulk orgnic carbon (BOC) and 2 C dates for lignin. The lignin C dates are apparently younger than the corresponding layers' BOC C dates, indicating that the reservoir age varied from 728 to 1222 a since the Late Glacial and from 2390 to 2490 a immediately before the pre-bomb era. Hence, the C age model for Core QH-2005 was corrected by the changing reservoir age. Ostracod δO values were primarily related to dilution and evaporative enrichment of the lake water. The reconstructed salinity based on ostracod body length coincides well with ostracod δO values. High redness and mean grain size (MZ) values indicate increased riverine supply to Lake Qinghai associated with increasing monsoon rainfall. Multi-proxy results show that climate during 13500-10900 cal. a BP was relatively cold and dry with frequent short-term fluctuations; a warm and wet climate began at about 10900 cal. a BP and culminated around 6500 cal. a BP as a result of monsoon strengthening; the climate became cold and dry afterwards and has remained relatively stable since 3400 cal. a BP. Our data also reveal short-term (millennial/centennial timescales) climatic fluctuations including: Younger Dryas events, ice-rafting events 8 and 1 (by ∼11000 cal. a BP and ∼1600 cal. a BP respectively), 8200 cal. a BP cold event, Little Ice Age and the Medieval Warm Period. [ABSTRACT FROM AUTHOR]

A typical lake sediment core is obtained from the Chaohu Lake in the lower reaches of the Yangtze River, Anhui Province, China. The timing scale is constrained by AMS 14C dating method. Climate proxies such as pollen and grain size in the core are analyzed to reconstruct the environment changes at this site approximately between 9870 and 2170 cal. a BR The results indicate that at the research area, the climate in the early-middle Holocene had evolved through 3 stages. From 9870 to 6040 cal. a BP, proxy records show a warm and dry climate with low water levels after the late-glacial period. During this stage, cool and dry events occurred at about 8910 and 6060-6030 cal. a BP. Then, between 6040 and 4860 cal. a BP, the climate was humid and vegetation was more flourishing in the Chaohu Lake Valley. The Holocene Optimum occurred at 5840-5500 cal. a BP in the Chaohu Lake, showing the best condition of water and heat. Elm Decline occurred at the period of 5380-4930 cal. a BP. Since 4860 cal. a BP, the climate was warm and dry through 2170 cal. a BP as shown in both pollen spectrum and grain-size histories. Two obvious dry events occurred in 3760 and 2170 cal. a BP, respectively. At 2170 cal. a BP, the water level of the Chaohu Lake reached the lowest as the lakebed possibly exposed. Such lake sediment observations are consistent with the historical records in this area. [ABSTRACT FROM AUTHOR]

An inventory of isolated tree stands surrounded by desert pastures in Southern Tibet (A.R. Xizang, China) revealed more than 50 sites with vigorous trees of Juniperus convallium Rehder & E.H. Wilson and Juniperus tibetica Kom and additional more than 10 records where juniper trees had been destroyed between 1959–1976. The tree stands are not restricted to any specific habitat, and occur within an area stretching 650 km westwards from the current forest border of Southern Tibet. The trees are religious landmarks of the Tibetan Buddhists. The highest trees were found at an elevation of 4,860 m. Vegetation records, rainfall correlations and temperature data collected by local climate stations and successful reforestation trials since 1999 indicate that forest relicts fragmented through human interference could regenerate if current cattle grazing and deforestation practices are halted. The drought line of Juniperus forests in Southern Tibet is approximately 200–250 mm/a. A first pollen diagram from Lhasa shows forest decline associated with the presence of humans since at least 4,600 yr BP. The currently degraded commons developed in the last 600 yr. To date, no findings of remains of ancient forests in the Central Tibetan Highlands of the Changtang have been reported. [ABSTRACT FROM AUTHOR]

Recent sedimentary history of natural environmental change and anthropogenic influence in an ephemeral river catchment has been reconstructed using selected major and trace elements, element ratios, and their different geochemical phases ( Tessier sequential extraction methods), pollen, and grain size combined with 210Pb- and 137Cs-dating method in marsh sedimentary cores. Attempts were made to use selected element ratios with different geochemical phases—residual phase of Ti, Al, V, Cr, Ni, Rb, K, Sr, and Ba; mobile Sr and Ba—combined with 210Pb- and 137Cs-chronology to interpret certain time information of environmental changes saved within the marsh sediments. Results indicate that there were two marked humid periods during 1850–1860 ad and 1890–1920 ad, and sand storm activities prevailed during 1920–1930 ad. After about 1900 ad, soil erosion has increased with the extensive agricultural activities in the Huolin River catchments, and further intensified after 1950s. After 1980, soil erosion has become even more intense, which is consistent with the reinforcement of human activities, the drastic loss of vegetation cover in the upstream lands, especially, the exploitation of the open cast coalmine in the upstream of Huolin River at that time. Influenced by the inundation of the Huolin River, the heavy metal pollution historical trends in Xianghai marsh wetland could be roughly divided into three periods by analysis of sediment enrichment factor (KSEF) and the index of geoaccumulation ( I geo):1760–1880 ad, 1880–1980 ad, and 1980–now. Human activities accelerate the inputs of heavy metal, which leads to degradation of the marsh. This study also investigated on source of marsh sediments (by Ti/Al), redox condition [by V/Cr and V/(V + Ni)], and salinization indicators (by Sr/Ba and Rb/K). The results demonstrate that sources of sediments and redox conditions were partly similar for both riparian and depressional marshes. Besides, some differences in degree of salinization between two types of marsh were also identified, especially after 1880. [ABSTRACT FROM AUTHOR]

The article presents abstracts of several studies on environmental geochemistry. Some of the abstracts presented include "Biogeochemical Cycling of Nutrients in Karstic Catchments, Southwestern China: Linkages to Changes of Eco-Environments," by Congqiang Liu and "Emerging Organic Contamination in China," by Guibin Jiang and colleagues.

Rapid land-use change has taken place in many arid and semi-arid regions of China over the last decade as the result of demand for food for its growing population. The Heihe River Basin, a typical inland river basin of temperate arid zone in northwestern China, was investigated to assess land-use change dynamics by the combined use of satellite remote sensing and geographical information systems (GIS), and to explore the interaction between these changes and the environment. Images were classified into six land-use types: cropland, forestland, grassland, water, urban or built-up land, and barren land. The objectives were to assess and analyze landscape change of land use/cover in Heihe River Basin over 15 years from 1987 to 2002. The results show that (1) grassland and barren land increase greatly by 22.3, and 268.2 km2, respectively, but water area decreased rapidly by 247.2 km2 in the upper reaches of Heihe River Basin; (2) cropland and urban or built-up land increased greatly by 174.9, and 64.6 km2, respectively, but grassland decreased rapidly by 210.3 km2 in the middle reaches of Heihe River Basin; and (3) barren land increased largely by 397.4 km2, but grassland degraded seriously and water area decreased obviously by 313.3, and 21.7 km2, respectively in the lower reaches of Heihe River Basin. These results show that significant changes in land-use occur within the whole basin over the study period and cause severe environmental degradation, such as water environmental changes (including surface water runoff change, decline of groundwater table and degeneration of surface water and groundwater quality), land desertification and salinization, and vegetation degeneracy. [ABSTRACT FROM AUTHOR]

Xinjiang Autonomous Region is located in the arid area of westerly of China and there are many arguments about the changes of past temperature and moisture. Most of the lakes on the plain in northern Xinjiang are sealed lakes and terminal lakes. They can evidently reflect the changes in palaeoclimate. The palaeoenvironmental changes of some plain lakes in northern Xinjiang during the late Holocene will be analysed mainly based on the data of pollen, sedimentary facies, loss on ignition (LOl), susceptibility and grain size from the Sichang Lake, Dongdaohaizi Lake and Aibi Lake. Results reveal an assembled pattern of temperature and moisture dominated by cold-wet and warm-dry. In addition, the impact factor will be discussed. [ABSTRACT FROM AUTHOR]

Land use/cover in Northeast China went through extensive changes during the 1990s. This report explores the interaction between these changes and the environment, and the implication of these changes for rational allocation of water resources. Two maps of land use/cover produced from 1990 and 2000 Landsat TM satellite images were overlaid in ArcInfo to reveal changes in land cover. Results indicate that farmland and grassland decreased by 386,195 and 140,075 ha, respectively, while water, built-up areas, and woodland increased by 238,596, 194,231, and 192,682 ha, respectively. These changes bore a mutual relationship with the environmental change. On the one hand, climate warming made some of these changes (e.g., conversion of woodland and grassland to farmland) possible. On the other hand, the changed surface cover modified the local climate. These changes, in turn, caused severe environmental degradation and increased flooding. The change between dry field and rice paddy, in particular, raised severe implications for the proper allocation of limited water resources in the Northeast. Efforts are needed to coordinate their rational allocation to reap maximum and sustainable return over the entire area, not just in some localities. Results obtained in this study should be of interest to the international audience of Environmental Management in that they highlight the interactive nature of human activities and the environment and the off-site impact of these activities on the environment. [ABSTRACT FROM AUTHOR]

Linguists studying the Austronesian languages claim to demonstrate a human migration out of southern China, Taiwan or the northern Philippines that transformed the peoples and cultures of the Pacific. However, while local conditions favored divergence in customs, ways of speech and physical appearance during the Pleistocene, by 6,000 years ago New Guineans and their neighbors east and west were in the throes of major environmental changes. These changes may have profoundly affected how intimately people were in touch with one another near and far in the ancient voyaging corridor between Asia and the Pacific that flows just off New Guinea's northern coastline. [ABSTRACT FROM AUTHOR]