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In recent years, the impact of land-use systems on global climate change has become increasingly significant, and land-use change has become a hot issue of concern to academics, both within China and abroad. Urbanization, as an important socioeconomic factor, plays a vital role in promoting land-use transition, which also shows a significant spatial dependence on urbanization. This paper constructs a theoretical framework for the interaction relationship between urbanization and land-use transition, taking the Yangtze River Delta as an example, and measures the level of urbanization from the perspective of population urbanization, economic urbanization and social urbanization, while also evaluating the level of land-use morphologies from the perspective of dominant and recessive morphologies of land-use. We construct a PVAR model and coupled coordination model based on the calculated indexes for empirical analysis. The results show that the relationship between urbanization and land-use transition is not a simple linear relationship, but tends to be complex with the process of urbanization, and reasonable urbanization and land-use morphologies will promote further benign coupling in the system. By analyzing the interaction relationship between urbanization and land-use transition, this study enriches the study of land-use change and provides new pathways for thinking about how to promote high-quality urbanization. [ABSTRACT FROM AUTHOR]

Mapping water quality change is helpful in the study of the water environment of a region. Using visual methods, interpretation of water condition and pollution issues can be intuitive and easy to understand. In this paper, we present a map to represent the spatial and temporal variation of water quality change in the Yangtze River during the period from 2006 to 2015. The calendar view was developed to explore the water quality condition and water pollutants for sections of the Yangtze River. A "W" construction was proposed to arrange the weekly water quality data in a continuous logic, and qualitative colors were designed to identify the change in major pollutants throughout the period. This map provides a promising visual analytical approach to investigate the water quality status and reveal the spatial and temporal patterns of water quality change in the Yangtze River. [ABSTRACT FROM AUTHOR]

The middle reaches of the Yangtze River region (MRYRR) are China’s first trans-regional urban agglomeration, located in the center of the Yangtze River Economic Belt. The MRYRR is an important ecological reserve, and its land cover changes are affected by both socio-economic development and geographical environment. In this paper, Landsat ETM/TM/OLI remote sensing images were used to monitor land use and landscape patterns from 1990 to 2015. Through supervised classification, land use transfer matrix, landscape pattern metrics and correlation analysis, the spatialtemporal patterns of land use change and its relationship with socio-economic in the study area were revealed. The results showed that: (1) the main land use types in the study area were cropland (CL) and forestland (FL), accounting for more than three-quarters of the study area. During the study period, built-up land (BL) increased, CL decreased, FL increased first and then decreased; (2) the BL expanded mainly by occupying CL and FL, and regional landscape pattern was gradually fragmented, with complex patch shape and increasing diversity and heterogeneity. Among them, the BL is gradually gathered, and the FL and CL are gradually fragmented; (3) in the past 25 years, the urbanization process in this region has been obvious, and the Gross Domestic Product (GDP) has increased by 36 times. The socioeconomic variables were positively correlated with BL, orchard (OL) and Shannon diversity index (SHID), and negatively correlated with CL, Wasteland (WL), mean patch size (MPS) and contagion size (CONTAG). The results showed that the urbanization development has a great impact on the region, and the ecological protection task is still challenging. It is necessary to protect high-quality cropland and draw a red line for ecological protection. We should strengthen the construction of ecological corridors and ecological nodes to adapt to regional sustainable development. [ABSTRACT FROM AUTHOR]

The net anthropogenic nitrogen input (NANI) is an important nutrient source that causes eutrophication in water bodies. Understanding the spatio-temporal variation of NANI is important for regional environment assessment and management. This paper calculated NANI in the upper Yangtze River basin (YRB), upstream of the Three Gorges Dam (TGD), from 1990 to 2012, and analyzed its spatio-temporal characteristics. Over the past 23 years of the study, the average annual NANI increased from 3200 kg N km to 4931 kg N km. The major components were fertilizer N application, atmospheric N deposition, and net food and feed N import. In the northwest high mountainous region with a sparse population, the main component was atmospheric N deposition. Fertilizer N application and net food and feed N import were concentrated in the Chengdu Plain because of the high population density and large areas of farmland. This research found that NANI increased with rapid urbanization and increasing population. The Pearson correlation results illustrated that the spatial distributions of NANI and its major components were affected by land cover/use, agricultural GDP and total population. Increasing NANI has been the major cause of the degrading stream water quality over the past 20 years and is becoming a major threat to the water quality of the TGD reservoir. [ABSTRACT FROM AUTHOR]

Frequently occurring flood disasters caused by extreme climate and urbanization processes have become the most common natural hazard and pose a great threat to human society. Therefore, urban flood risk assessment is of great significance for disaster mitigation and prevention. In this paper, the analytic hierarchy process (AHP) was applied to quantify the spatiotemporal variations in flood risk in Wuhan during 2000-2018. A comprehensive flood risk assessment index system was constructed from the hazard, sensitivity, and vulnerability components with seven indices. The results showed that the central urban area, especially the area in the west bank of the Yangtze river, had high risk due to its high flood sensitivity that was determined by land use type and high vulnerability with dense population and per unit GDP. Specifically, the Jianghan, Qiaokou, Jiangan, andWuchang districts had the highest flood risk, more than 60% of whose area was in medium or above-medium risk regions. During 2000--2018, the flood risk overall showed an increasing trend, with Hongshan district increasing the most, and the year of 2010 was identified as a turning point for rapid risk increase. In addition, the comparison between the risk maps and actual historical inundation point records showed good agreement, indicating that the assessment framework and method proposed in this study can be useful to assist flood mitigation and management, and relevant policy recommendations were proposed based on the assessment results. [ABSTRACT FROM AUTHOR]

Runoffs in the Yellow River and Yangtze River basins, China, have been changing constantly during the last half century. In this paper, data from eight river gauging stations and 529 meteorological stations, inside and adjacent to the study basins, were analyzed and compared to quantify the hydrological processes involved, and to evaluate the role of human activities in changing river discharges. The Inverse Distance Weighted (IDW) interpolation method was used to obtain climatic data coverage from station observations. According to the runoff coefficient equation, the effect of human activities and climate can be expressed by changes in runoff coefficients and changes in precipitation, respectively. Annual runoff coefficients were calculated for the period 1950-2008, according to the correlation between respective hydrological series and regional precipitation. Annual precipitation showed no obvious trend in the upper reaches of the Yellow River but a marked downward trend in the middle and downstream reaches, with declines of 8.8 and 9.8 mm/10 a, respectively. All annual runoff series for the Yellow River basin showed a significant downward trend. Runoff declined by about 7.8 mm/10 a at Sanmenxia and 10.8 mm/10 a at Lijin. The series results indicated that an abrupt change occurred in the late 1980s to early 1990s. The trend of correlations between annual runoff and precipitation decreased significantly at the Yellow River stations, with rates ranging from 0.013/10 a to 0.019/10 a. For the hydrologic series, all precipitation series showed a downward trend in the Yangtze River basin with declines ranging from about 24.7 mm/10 a at Cuntan to 18.2 mm/10 a at Datong. Annual runoff series for the upper reaches of the Yangtze River decreased significantly, at rates ranging from 9.9 to 7.2 mm/10 a. In the middle and lower reaches, the runoff series showed no significant trend, with rates of change ranging from 2.1 to 2.9 mm/10 a. Human activities had the greatest influence on changes in the hydrological series of runoff, regardless of whether the effect was negative or positive. During 1970-2008, human activities contributed to 83% of the reduction in runoff in the Yellow River basin, and to 71% of the increase in runoff in the Yangtze River basin. Moreover, the impacts of human activities across the entire basin increased over time. In the 2000s, the impact of human activities exceeded that of climate change and was responsible for 84% of the decrease and 73% of the increase in runoff in the Yellow River and Yangtze River basins, respectively. The average annual runoff from 1980 to 2008 fell by about 97%, 83%, 83%, and 91%, compared with 1951-1969, at the Yellow River stations Lanzhou, Sanmenxia, Huayuankou and Lijin, respectively. Most of the reduction in runoff was caused by human activities. Changes in precipitation also caused reductions in runoff of about 3%, 17%, 17%, and 9% at these four stations, respectively. Falling precipitation rates were the main explanation for runoff changes at the Yangtze River stations Cuntan, Yichang, Hankou, and Datong, causing reductions in runoff of 89%, 74%, 43%, and 35%, respectively. Underlying surface changes caused decreases in runoff in the Yellow River basin and increases in runoff in the Yangtze River basin. Runoff decreased in arid areas as a result of increased water usage, but increased in humid and sub-humid areas as a result of land reclamation and mass urbanization leading to decreases in evaporation and infiltration. [ABSTRACT FROM AUTHOR]

China is entering a critical and accelerating phase of urbanization. As one of the most urbanized regions in China, the Changjiang (Yangtze) River Delta has experienced dramatic urbanization and urban transformation. However, in the recent years, many changes have taken place in this region and there is limited attention to the regional urbanization path evolution, its problems and the way to solve these problems. Therefore, we should revisit the urbanization process in the Changjiang River Delta again. In this paper, we revisited urbanization paths of the Changjiang River Delta by data analysis, influence factors of urbanization by the Gray Relational Analysis, and major challenges to urbanization of the Changjiang River Delta by theoretical considerations. We found that the urbanization of the Changjiang River Delta had experienced several stages of large-scale spatial and urban system restructuring. Within the Changjiang River Delta, Shanghai, Zhejiang and Jiangshu had experienced different urbanization path with local characteristics. But with their development model gradually converging, their urbanization model is also converging. We also found that the major influence factors affecting the Changjiang River Delta urbanization were dynamic change and urbanization was driven by different key factors in different socio-economic development stages. Meanwhile, the Changjiang River Delta urbanization is facing many problems such as existing institutional arrangements, including the hukou (household registration) system and others which can not meet the needs of current socio-economic development and urbanization. Therefore, it is imperative to promote institutional innovation and adopt a new urbanization development strategy for the sake of the orderly and sustainable urbanization development in the Changjiang River Delta. [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]

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]

Detailed studies on the spatiotemporal patterns of urban agglomeration in the Middle Yangtze River Basin (MYRB) are rare. This paper analyzed the spatiotemporal patterns of urbanization in the MYRB using multi-temporal remote sensing data circa 2000, 2008 and 2016 integrated with geographic information system (GIS) techniques and landscape analysis approaches. A multi-level analysis of the rate and intensity, type as well as the landscape changes of urban expansion at regional, prefectural and inner-city levels was performed. Results show that the MYRB experienced rapid urban expansion with an annual expansion rate of 3.199%, especially in the Chang-Zhu-Tan and Poyang Lake metropolitan areas. The small and medium cities presented faster urban expansion than the larger cities with annual growth rates three times the average level. Urban expansion within the three capital cities was further analyzed in detail. It is found that outlying expansion and edge-expansion were the dominant growth patterns at all the three levels. Although urbanization in the MYRB has a remarkable increase in the past sixteen years, its annual growth rate of urban land expansion has fallen behind the three other large urban agglomerations in China as a result. Finally, the spatial evolution of the socioeconomic structure of the MYRB was further explored. It indicated that urban land was distributed mainly along the "northwest-southeast" direction and that the economic spatial interactions among cities showed a pattern of "multi-polarization and fragmentation", which illustrates the weak radiative driving forces of the central cities. The MYRB urban agglomeration faces a great challenge to manage trades-offs between narrowing the intra-regional disparity and maintaining synergetic development among cities. [ABSTRACT FROM AUTHOR]

With rapid development of big data technologies urbanization, the railway networks have also developed rapidly. The optimization of various aspects of railway networks has become more and more important with the shift of main contradictions in our society. With more than one hundred years of development of China railway network expansion, especially under the driving of "one belt and one road", China railway network is gradually mature. Up to now, the total length of China railways ranks second in the world, with a mileage of 127,000 km. The spatial service scope of railway network has been further expanded and the structure has become more and more perfect, which has brought positive impacts on the development of all aspects of China. This paper analyzes the railways (lines) and stations (points) in five different development stages in China in the past 100 years, by means of spatial statistical and nuclear density analysis, based on which the spatial accessibility in different periods is calculated using cost distance analysis. The results show that the distribution of spatial pattern in Middle East region is higher than that in west region. The accessibility shows a significant difference between east and west, that the eastern region is superior to the western region. The difference of spatial pattern between the north and the south of Yangtze river is obvious. The overall spatial pattern presents a concentric structure, radiating from the North China region to the surrounding areas, and the reachable time from the North China region to the East China and Central South regions is gradually increasing. The conclusions of the study are as follows: (1) The coverage region of China railways has been expanded. Since the completion of the first self-built railway (Beijing-Zhangjiakou Railway), the total length of China railways, has expanded from 5006.5 km in 1911 to 127,000 km in the end of 2017, which means it has increased by 253.6 times over 100 years, with an average annual growth rate of 1,1933.9km. The coverage of China Railways has expanded from 21 provinces in 1911 to all the provinces. (2)The development of the time accessibility of the China railway network takes a favorable trend. The railway network has gradually improved, after more than 100 years' development. In 1911, the number of prefecture-level stations connected by the China railway network was only 62. By 2000, 83.6% of prefecture-level stations in China had been connected, and the number of connected ground-level stations reached 276. In 2018, more than 3066 ground-level stations have been connected, reaching time reduced from 1030 hours in 1911 to 64 hours in 2018. For example, the time from Beijing to Shanghai was shortened from more than 30 hours to 4 hours, saving about 8 times than before. It provides an important guarantee for the exchange of information between various regions in China. (3)The overall expansion of China railway network presents an expansion from the coastal areas to inland areas. A detailed analysis of the seven major economic zones shows the expansion is from Bohai Economic Zone to other economic zones. After five stages of development, the sites in the eastern, central and western regions accounted for 28%, 33% and 38% respectively of the total. The spatial distribution of the sites in the eastern, central and western regions gradually became balanced, but the degree of perfection still differed. [ABSTRACT FROM AUTHOR]

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

How to balance ecosystem health and economic development is essential to study sustainability of urban ecosystems. Many methods for assessing urban sustainability have been developed, among which ecological footprint analysis (EFA) has been widely applied as a promising policy and planning tool. This paper proposed a modified EFA with the local ecological footprint being justified by adapting equivalence and yield factors in context of net primary productivity (NPP) from the Miami model. Biodiversity reserves were also incorporated using GIS technology and synthetic assessment of attributes to reflect various ecological functions. In addition, ecological footprint deficit (EFD), implying that the productive land cannot sustain current levels of consumption for a given population, was used to reveal the extent of ecological debt, while the ecological footprint variation index (EFVI) was proposed to describe the tradeoffs between real consumption and the carrying capacity of a specific region. A case study of urban areas in the middle stream of the Yangtze River Basin showed that the per capita EFD of the Wanjiang urban belt, central Poyang Lake urban agglomeration, suburban Poyang Lake urban agglomeration, Wuhan megalopolis, Jingmen–Jingzhou–Yichang urban agglomeration, central Changsha–Zhuzou–Xiangtan urban agglomeration, and suburban Changsha–Zhuzou–Xiangtan urban agglomeration increased by 64.83%, 178.05%, 214.82%, 59.08%, 71.68%, 100.62%, and 91.06% between 2000 and 2010, respectively. The local ecological footprint pressure index (EFPI) was classified into five levels. The Poyang lake urban agglomeration was found to be in a slight deficit, while all others were in a severe deficit in 2010. Calculations of EFVI also revealed that the booming urbanization occurred at great cost to the deteriorating ecosystems between 2000 and 2010. Accordingly, relevant influence factors were investigated using a forward stepwise regression method, which indicated that ecological deficit was positively correlated with GDP, population density, and emission of industrial waste, but negatively correlated with the tertiary industry. [ABSTRACT FROM AUTHOR]

As China experienced rapid economic growth, non-agricultural land, particularly industrial land, expanded significantly within its peri-urban areas. This paper takes two typical peri-urban areas: Jiangyin in the Yangtze River Delta and Shunde in the Pearl River Delta, as cases, and applies landscape ecology indices to analyze land use dynamics through overlay of their land use maps from 2001 to 2010. This research reveals that local cadres such as township governments and village collectives utilize land finance as a strategy to contest the reshuffling of central-local power brought about by the 1994 tax-sharing scheme. Meanwhile, under the stringent land quota system, local cadres allocated most quotas to the industrial sector in order to encourage economic growth. However, the fragmented governance regime, including county/city, township to administrative village and natural village, led to land fragmentation, which had adverse impacts on sustainable development. In general, the research on land use of peri-urban areas requires a comprehensive perspective of social, economic and institutional aspects. [ABSTRACT FROM AUTHOR]

Accelerating urbanization all over the world has renewed interdisciplinary interest and public concerns over sustainable urban forms. Despite abundant literature on the concentric model and its application to urban land-use patterns, a rigorous and straightforward methodology to characterize the model quantitatively in space is especially needed. In this paper we present a diagramatic method and refine five indicators to measure and clarify the circular pattern of urban expansion. With remote sensing data, the approach has been examined for the sample set of fifty-one cities in the Yangtze River Delta (YRD) region of China. The five indicators adopted illustrated that most of YRD cities display a compact centralized form with a relatively small matured core area and are undergoing fast expansion. Furthermore, we have found distinctive local models of density gradient in built-up areas, shaped by urban population size and local institutional structures. The preliminary results related to the methodology are inspiring, which should be useful for elucidating urban growth trends and for decision making. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the variability of daily temperature in the Yangtze River Delta (YRD) for the period 1958–2007 was investigated by selecting three typical temperature variables (daily minimum, mean and maximum temperatures) and the diurnal temperature range (DTR). Three variability patterns of daily mean temperature and two variability patterns of daily minimum and maximum temperatures were first classed, and then statistical properties of three temperature variables in 1958–1985 and 1986–2007 were analyzed. After that, temporal trends of three temperature variables and DTR were detected. Finally, the impacts of urbanization on the variability of daily temperature were investigated. Results indicate that: (1) daily mean temperature shows more complex variability than daily minimum and maximum temperatures; (2) in 1986–2007 three temperature variables have bigger mean values but smaller C v (coefficient of variance) values, and are more close to normal probability distribution; (3) three temperature variables show positive trends in 1986–2007, and the increase of daily mean temperature is more due to the increase of daily minimum temperature in the northern YRD but due to daily maximum temperature in the mid and southern YRD; (4) in the mid and southern YRD, daily maximum temperature has bigger increasing magnitude than daily minimum temperature in 1986–2007, causing positive trend of DTR; and (5) rapid urbanization causes normal distribution of three temperature variables, and notably increasing magnitude of daily temperature and DTR in 1986–2007 at the lower reaches of the Yangtze River and the Hangzhou Bay. [Copyright &y& Elsevier]

A dataset from 763 national Reference Climate and Basic Meteorological Stations (RCBMS) was used to analyze surface air temperature (SAT) change in mainland China. The monthly historical observational records had been adjusted for urbanization bias existing in the data series of size-varied urban stations, after they were corrected for data inhomogeneities mainly caused by relocation and instrumentation. The standard procedures for creating area-averaged temperature time series and for calculating linear trend were used. Analyses were made for annual and seasonal mean temperature. Annual mean SAT in mainland China as a whole rose by 1.24°C for the last 55 years, with a warming rate of 0.23°C decade−1. This was close to the warming of 1.09°C observed in global mean land SAT over the period 1951–2010. Compared to the SAT before correction, after-corrected data showed that the urbanization bias had caused an overestimate of the annual warming rate of more than 19.6% during 1961–2015. The winter, autumn, spring, and summer mean warming rates were 0.28°, 0.23°, 0.23°, and 0.15°C decade−1, respectively. The spatial patterns of the annual and seasonal mean SAT trends also exhibited an obvious difference from those of the previous analyses. The largest contrast was a weak warming area appearing in central parts of mainland China, which included a small part of southwestern North China, the northwestern Yangtze River, and the eastern part of Southwest China. The annual mean warming trends in Northeast and North China obviously decreased compared to the previous analyses, which caused a relatively more significant cooling in Northeast China after 1998 under the background of global warming slowdown. [ABSTRACT FROM AUTHOR]

The urban clusters in the Middle Reaches of the Yangtze River (MRYR) in China include the Chang-Zhu-Tan urban agglomeration, the Wuhan metropolitan area, and the Poyang Lake urban agglomeration. While previous studies of urban expansion in China focused mainly on the coastal regions, this study aimed to investigate urban expansion patterns and factors in the MRYR, which are crucial for urban development in Central China. A neighborhood statistics analysis (NSA) method and a local-optimized threshold method were used to detect urban changes during 1992–2011 from the time-series Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS) nighttime light (NTL) images. The evolution of urban expansion intensity and landscape metrics were analyzed at multiple spatial scales, including the whole region, urban agglomeration, and city scales. Finally, the expanded STochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model was built to explore the factors that controlled NTL intensity. The results revealed that urban areas extracted from the NTL data were consistent with those extracted from the Landsat Thematic Mapper data, with an overall accuracy of 81.74% and a Kappa of 0.40. A relatively slow urbanization pace was observed from 1992 to 2002 in the MRYR region, which then accelerated in the period of 2002 to 2007 and then slowed down between 2007 and 2011. Additionally, urban expansion exhibited a radial pattern. The results further indicated that major factors controlling NTL intensity were gross domestic product, followed by total investment in fixed assets, tertiary industry, urban construction area, non-agricultural population, and industrial output in the city clusters. The study provides important insights for further studies on the urbanization processes in the MRYR region. [ABSTRACT FROM AUTHOR]

Significantly increased sedimentation rates (SRs) in lakes worldwide in recent decades due to higher inputs of silt and eutrophication have led to significant environmental problems such as lake size diminishment and degraded water quality. Many lakes in the middle and lower reaches of the Yangtze River basin (MLYB) have followed this pattern. For effective lake management, it is essential to understand the pattern and drivers of SRs in these lakes. Fourteen typical lakes in the MLYB were chosen to examine the spatiotemporal patterns of SRs and identify the drivers over different time periods. Since 1900, SRs increased from <0.2 to 0.3-0.6 g·cm-2·year-1, particularly notable during 1930-1990. Combined with climatic factors, SR correlated negatively with lake (catchment) size and abundance of aquatic vegetation, whereas other lake features including nutrient status did not contribute significantly to the variation in SRs, due to the fast decomposition processes of organic matter in shallow lakes. Detrimental land use practices especially reclamation for croplands and rapid urbanization was revealed to elevate SRs pronouncedly. We propose various management strategies aiming to maintain SR reference condition at ~0.16 ± 0.08 g·cm-2·year-1, which is analogous to the SR value between 1850 and 1900. [ABSTRACT FROM AUTHOR]

Construction of numerous water conservancy and hydropower engineering and migration projects, increased regional population, and accelerated urbanization have seriously polluted the ecological environment of the Yangtze River Basin and upset coordinated development economy, society, and ecological environments. This study comprehensively analyses the ecological environment status of the Yangtze River Basin, explores causes of the regional environmental pollution, and provides countermeasures to improve the regional ecological environment through ecological compensation. Results suggest that construction of a large number of water conservancy projects, large-scale project-caused migration, extensive economic growth mode, and adoption of imbalanced development policies are the most important causes of environmental pollution in China's Yangtze River Basin. The ecological environment of the Yangtze River Basin can be improved in the following aspects: improving the government's transfer payment from the exchequer system and expanding the ecological compensation fund-raising channels; improving the environmental resource ownership system and actively developing the emission trading market; improving the legal system and strengthening government supervision; and vigorously developing environmentally-friendly industries and techniques, and sharpening the public's awareness of ecological compensation. All these findings can provide referential experiences for promoting coordinated ecological and economic development, and improving the ecological compensation mechanism in the Yangtze River Basin. [ABSTRACT FROM AUTHOR]

Based on the National Land Use/Cover Database of China (NLUD-C) in the end of the 1980s (the 1980s, hereafter), 1995, 2000, 2005, and 2010, 665 cities were selected to study the size distribution and its changes of urban lands in China. In this study, the spatiotemporal evolutions of urban land size distribution as well as the influence of administrative-level on these cities were explored by combining urban spatial positions and administrative-levels. Results indicate that: 1) City size distribution using urban lands was more practical and reasonable than using non-agricultural population. 2) In the 1980s, cities with ascending urban land rank were centralized in Eastern China, specially the Changjiang (Yangtze) River Delta, the Zhujiang (Pearl) River Delta, and Beijing-Tianjin-Hebei region. Cities in Central, Western, and Northeast China mainly indicated descending urban land rank. 3) The transfer of national development focus resulted in cities with ascending urban land rank becoming evenly distributed nationwide; however, this trend was slightly centralized around Chengdu, Chongqing, and Wuhan in different periods. 4) During the 1980s to 2010, the proportion of cities with ascending urban land rank in provincial capitals, municipalities, and special administrative regions (high-level cities, hereafter) was consistently higher than those in prefecture- and county-level cities except for 2005-2010. The ranks of the majority of the prefecture- and county-level cities were mainly descending, supported by ascending; the proportion of cities with unchanged rank is small. This study breaks through the bottleneck of traditional research in the area of city size distribution by examining urban land replacing the non-agricultural population. The current study also provides scientific explanation for the healthy and reasonable development of urban land as well as the coordinated development of population urbanization and land urbanization. [ABSTRACT FROM AUTHOR]

The impact of urbanization for a summertime rainstorm process in the Yangtze River Delta was investigated based on two 96 member ensembles using the Weather Research and Forecasting (WRF) model. Results show that the increase of precipitation mainly occurs downwind of the city belt in this region. The increase and decrease of precipitation forms two zigzag belts in the precipitation area. The t-test illustrates that the discrepancies of near-surface environment around the city belt, the precipitation downwind of the city belt as well as the atmospheric variables in the lower troposphere over the rain belt, caused by urbanization, is significant in such a short-term rainstorm process. Copyright © 2012 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

Urbanization transforms landscape structure and profoundly affects biodiversity and ecological processes. To understand and solve these ecological problems, at least three aspects of spatiotemporal patterns of urbanization need to be quantified: the speed, urban growth modes, and resultant changes in landscape pattern. In this study, we quantified these spatiotemporal patterns of urbanization in the central Yangtze River Delta region, China from 1979 to 2008, based on a hierarchical patch dynamics framework that guided the research design and the analysis with landscape metrics. Our results show that the urbanized area in the study region increased exponentially during the 30 years at the county, prefectural, and regional levels, with increasing speed down the urban hierarchy. Three growth modes—infilling, edge-expanding, and leapfrogging—operated concurrently and their relative dominance shifted over time. As urbanization progressed, patch density and edge density generally increased, and the connectivity of urban patches in terms of the average nearest neighbor distance also increased. While landscape-level structural complexity also tended to increase, the shape of individual patches became increasingly regular. Our results suggest that whether urban landscapes are becoming more homogenous or heterogeneous may be dependent on scale in time and space as well as landscape metrics used. The speed, growth modes, and landscape pattern are related to each other in complicated fashions. This complex relationship can be better understood by conceptualizing urbanization not simply as a dichotomous diffusion-coalescence switching process, but as a spiraling process of shifting dominance among multiple growth modes: the wax and wane of infilling, edge-expansion, and leapfrog across the landscape. [ABSTRACT FROM AUTHOR]

This work presents an overview of 1 yr measurements of ozone (O) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. Ozone and PM2.5 showed strong seasonal cycles but with contrast patterns: O reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O chemistry and a formation of secondary aerosols under conditions of high O in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O exceedance and 148 days of PM2.5 exceedance during the 1 yr period, suggesting a severe air pollution situation in this region. Case studies for typical O and PM2.5 episodes demonstrated that these episodes were generally associated with an air mass transport pathway over the mid-YRD, i.e., along the Nanjing- Shanghai axis with its city clusters, and showed that synoptic weather played an important role in air pollution, especially for O. Agricultural burning activities caused high PM2.5 and O pollution during harvest seasons, especially in June. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O precursor CO, with a majority from the mid-YRD. North-YRD and the North China Plain are the main contributors to PM2.5 pollution in this region. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions. [ABSTRACT FROM AUTHOR]

Outward expansion of urban lands in the developing nations is often associated with a substantial loss of environmental resources such as forests, wetlands, freshwater and cash crop fields. Yet, determining how different aspects of urbanisation – such as city population size and spread pattern of built-up lands – contribute to the cumulative loss of resources remains controversial. In this study, data sets were constructed describing changes to land cover across 65,200 grid cells at 1 km2 spatial resolution for China's Changjiang Delta Region over the past 60 years. The results showed that the region lost 12.2% of total resource sites. The distribution of resource degradation showed a highly dispersed pattern and was not confined to a few intense areas associated with large cities. No empirical evidence was found that city population size alone accurately predicts the distribution of resource loss. Very large cities (N = 4) contributed 35% to the total loss, demonstrating impacts similar to those of much more scattered towns (N = 230). Urban expansion of large cities may lead to extensive resource loss; however, a set of non-linear mechanisms, such as the diminishing effects of per-unit area urban spread on resources and interactions between urban patterns and the size of urban spread, can also play a significant role in downsizing the negative effects of large cities on resource sites. Thus, effective urban policies should carefully weigh the cumulative urban spread mechanisms of both large and small cities responsible for spatially dispersed degradation of environmental resources. [ABSTRACT FROM AUTHOR]

This article focuses on new features and problems in the urbanization of the economically developed region of the Yangzi Delta. Suzhou City and the six counties (cities) under its jurisdiction, namely, Shazhou, Changshu, Kunshan, Wujiang, Wuxian, and Taichang, are located in the economically developed Taihu basin of the Chang Jiang (Yangzi) Delta. The region has a total area of 8,802 square kilometers and a population of 5.28 million. In addition to the key city of Suzhou, the region has 18 towns under the jurisdiction of its counties, 138 market towns, and 77 natural villages. It is an area with a flourishing economy, high population density, and a concentration of cities and towns. The region under the jurisdiction of Suzhou City has a long history of economic development, and the strength of its rural economy is substantial. Residents in both urban and rural areas are well educated and have a high technical level. Its industrial and agricultural production departments enjoy technological superiority, and it has a developed commodity economy.

Urbanization is an engine of economic development, but this process is often constrained by increasingly scarce water resources. A model predicting the drag effect of water consumption on urbanization would be useful for future planning for sustainable water resource utilization and economic growth. Using panel data from 11 provinces in China's Yangtze River economic belt (YREB) from 2000 to 2015, we apply Romer's growth drag theory with spatial econometric models to quantitatively analyze the drag effect of water consumption on urbanization. The results show the following. (1) The drag effect of water consumption on urbanization has significant spatial correlation; the spatial Durbin model is the best model to calculate this spatial connection. (2) The spatial coefficient is 0.39 and the drag that is caused by water consumption on urbanization in the YREB is 0.574, which means that when spatial influences are considered, urbanization speed slows by 0.574% due to water consumption constraints. (3) Each region in the YREB has different water consumption patterns and structure; we further calculate each region's water consumption drag on urbanization. We find that areas with high urbanization levels, like Shanghai (average 84.7%), have a lower water consumption drag effect (0.227), and they can avoid the "resource curse" of water resource constraints. However, some low-level urbanization provinces, like Anhui (average 39.3%), have a higher water consumption drag effect (1.352). (4) Our results indicate that the water drag effect is even greater than the drag effect of coal and land. Therefore, policies to increase urbanization should carefully consider the way that water constraints may limit growth. Likewise, our spatial model indicates that policy makers should work with neighboring provinces and construct an effective regional water cooperation mechanism. [ABSTRACT FROM AUTHOR]