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This paper presents an empirical analysis of regional disparities from 2000 to 2012 based on a time series of data involving 74 cities within three mega-urban regions along Yangtze River in China. Differing from previous researches on inter-provincial and coastal/interior data, this paper provides a new perspective of mega-urban regions and their cities in China. By Coefficient of Variation and Analysis of Variance the selection of three mega-urban regions along Yangtze River reveals how the mega-urban regional disparities evolve among the east, middle and west up to date in China. In terms of general trend the mega-urban regional inequalities have been decreasing ever since the year around 2005. By traditional regression modeling this paper relates the mega-urban regional inequality and the alleviation to the urbanization and its focus on mega-urban regional development. The regression shows that the evolution of intra mega-urban regions disparities is negatively influenced by the urbanization with meaningful statistical significance from 2000 to 2012. The multilevel regression is further applied based on the nested hierarchical data structure. The results indicate a complicated relationship of the urban population density of the city level, the urbanization ratio of the mega-urban region level and the urban disparities in 2012. Finally limitations and further research advice are provided. [ABSTRACT FROM AUTHOR]

In the late 1990s, China’s Yangtze and Yellow River Basins suffered devastating natural disasters widely attributed to the degradation of soil and water resources. The Government of China responded with a number of major environmental programs, the most expensive and influential of which, the Grain for Green (GfG) Program, was implemented widely from 1999. Under the GfG Program—also known as the Sloping Land Conversion or Conversion of Cropland to Forest Program—the central government compensates farmers to convert cropland on steep slopes or otherwise ecologically sensitive areas to forest or grassland. Its long-term success depends on households’ ability to make sustainable changes to their household income streams and income diversification strategies. In this paper, we use a difference-in-difference estimation approach to examine the role of migration as a household-level response to the GfG Program, testing the extent to which individuals migrate following a reduction in land available for farming. Importantly, we exploit 15 years of data on migration decisions and establish that participating and non-participating households were on parallel migration paths before the program, thus refuting a key threat to causality in a difference-in-difference model. We find that participating families do, in fact, choose migration as an income diversification strategy more frequently than non-participants. The program effects varied over time but peaked post-Great Recession in 2011 when migration rates in GfG households exceeded those of non-GfG households by 5.9% points (p = 0.003) or about 26%. Our findings should encourage policymakers that families are making long-term adjustments to their livelihood strategies to avoid poverty in anticipation of the eventual withdrawal of government supports. [ABSTRACT FROM AUTHOR]

Hedgerow intercropping systems were introduced in China in early 1990s. Achievements in research and extension of contour hedgerow intercropping in China during the past 15 years are reviewed here. Results reported in over 70 published papers have shown that hedgerow intercropping contributes to soil and water conservation, soil fertility amelioration, land productivity improvement, bioterrace formation, and gives more options for income generation based on local resources in mountain areas. Research and demonstration works on contour hedgerow systems have achieved success by integrating local resources and needs into the system, especially in the dry valleys of the upper reaches of the Yangtze River, and the Three Gorges region. Contour hedgerow intercropping has attracted the attention of researchers, policy-makers, and farmers, and has been taken as an alternative to implementation of the Grain for Green policy, and ecological reconstruction and restoration today. To date, hedgerow intercropping has been demonstrated and applied practically on sloping land in more than six provinces of China, particularly Sichuan, Guizhou, Shanxi, Shaanxi, as well as in the Three Gorges region of Chongqing and Hubei Province. The intercropping system has also been practiced as an optimized technology for conserving farming on sloping lands, improving cash income, and reducing agricultural risks in depressed mountainous regions in southwest and northern China over recent years. Some misunderstandings and problems in studies and extension of the system in China are summarized and clarified, and some recommendations for further research and expansion of the system are also presented in this paper. [ABSTRACT FROM AUTHOR]

By Hirschman-Herfindahl Index, the paper measures the spatial structure transformation of the Chinese container port system from the perspective of cargo flow in recent 13 years. It indicates that the spatial structure of container port system enters into 'the challenge of the periphery' phase as a whole, the decentralization of container flow become the mainstream tendency of the spatial variation of China's container port system; on the other hand, the spatial structure of container port system shows different characteristic in seven port regions, such as low-level equilibrium, single-gateway, multi-gateway and so on. It is a fact that multi-gateway port region of container port system has formed in Yangtze River Delta and Pearl River Delta region. Economic and foreign trade development, government macro-control and policy guidance, challenge of the periphery, network expansion of the terminal operators and shipping liners are the main driving forces for these new phenomena. [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]

Water resources and soil erosion are the most important environmental concerns in the Yangtze River basin, where soil erosion and sediment yield are closely related to rainfall erosivity. The present study explores the spatial and temporal changing patterns of the rainfall erosivity in the Yangtze River basin of China during 1960-2005 at annual, seasonal and monthly scales. The Mann-Kendall test is employed to detect the trends during 1960-2005, and the T test is applied to investigate possible changes between 1991-2005 and 1960-1990. Meanwhile the Rescaled Range Analysis is used for exploring future trend of rainfall erosivity. Moreover the continuous wavelet transform technique is using studying the periodicity of the rainfall erosivity. The results show that: (1) The Yangtze River basin is an area characterized by uneven spatial distribution of rainfall erosivity in China, with the annual average rainfall erosivity range from 131.21 to 16842 MJ mm ha h. (2) Although the directions of trends in annual rainfall erosivity at most stations are upward, only 22 stations have significant trends at the 90 % confidence level, and these stations are mainly located in the Jinshajiang River basin and Boyang Lake basin. Winter and summer are the seasons showing strong upward trends. For the monthly series, significant increasing trends are mainly found during January, June and July. (3) Generally speaking, the results detected by the T test are quite consistent with those detected by the Mann-Kendall test. (4) The rainfall erosivity of Yangtze River basin during winter and summer will maintain a detected significant increasing trend in the near future, which may bring greater risks to soil erosion. (5) The annual and seasonal erosivity of Yangtze River basin all have one significant periodicity of 2-4 years. [ABSTRACT FROM AUTHOR]

In this study, the applicability of the statistical downscaling model (SDSM) in downscaling precipitation in the Yangtze River basin, China was investigated. The investigation includes the calibration of the SDSM model by using large-scale atmospheric variables encompassing NCEP/NCAR reanalysis data, the validation of the model using independent period of the NCEP/NCAR reanalysis data and the general circulation model (GCM) outputs of scenarios A2 and B2 of the HadCM3 model, and the prediction of the future regional precipitation scenarios. Selected as climate variables for downscaling were measured daily precipitation data (1961-2000) from 136 weather stations in the Yangtze River basin. The results showed that: (1) there existed good relationship between the observed and simulated precipitation during the calibration period of 1961-1990 as well as the validation period of 1991-2000. And the results of simulated monthly and seasonal precipitation were better than that of daily. The average R values between the simulated and observed monthly and seasonal precipitation for the validation period were 0.78 and 0.91 respectively for the whole basin, which showed that the SDSM had a good applicability on simulating precipitation in the Yangtze River basin. (2) Under both scenarios A2 and B2, during the prediction period of 2010-2099, the change of annual mean precipitation in the Yangtze River basin would present a trend of deficit precipitation in 2020s; insignificant changes in the 2050s; and a surplus of precipitation in the 2080s as compared to the mean values of the base period. The annual mean precipitation would increase by about 15.29% under scenario A2 and increase by about 5.33% under scenario B2 in the 2080s. The winter and autumn might be the more distinct seasons with more predicted changes of precipitation than in other seasons. And (3) there would be distinctive spatial distribution differences for the change of annual mean precipitation in the river basin, but the most of Yangtze River basin would be dominated by the increasing trend. [ABSTRACT FROM AUTHOR]

Known as the four famous carps in China, black carp ( Mylopharyngodon piceus), grass carp ( Ctenopharyngodon idella), silver carp ( Hypophthalmichthys molitrix) and bighead carp ( Hypophthalmichthys nobilis) are commercially important fish species with a high production in China. To reveal the relationships between meteorological conditions and the natural spawning behavior of these fishes, we considered six meteorological factors (including wind, rainfall, temperature, air pressure, sunshine hours and humidity) and the weather conditions in 80 spawning events. The results showed that the spawning activities were more likely to be activated in consecutive rainy days or days when weather changed drastically, while the spawning activities showed no tendency for the weather type except consecutive rainy days. Our analyses also showed that the average rainfall in the initial spawning days is higher than that in the spawning time windows (the time from the earliest spawning activity to the latest spawning activity), while other meteorological elements remained at more or less the same values in both time periods; spawning activity tended to happen in days when the average air pressure was going down or the average temperature going up, while the other meteorological elements showed no consistent tendency. [ABSTRACT FROM AUTHOR]

In the source regions of the Yangtze and Yellow Rivers of China, glaciers, frozen ground, the hydrological system, and alpine vegetation have changed over the past decades years. Climatic causes of these variations have been analyzed using mean monthly air temperature and monthly precipitation between 1956 and 2000, and monthly evaporation from φ20 evaporation pans between 1961 and 1996. In the source region of the Yangtze River, lower temperature and plentiful precipitation during the 1960s and continuing into the early 1980s triggered a glacier advance that culminated in the early 1990s, while a robust temperature increase and precipitation decrease since 1986 has forced glaciers to retreat rapidly since 1995. Permafrost degradation is another consequence of the climatic warming. The variations in the hydrological system and alpine vegetation are controlled mainly by the climate during the warm season. Warmer and drier summer climate is the major cause of a degradation of the vegetation, desiccation of the high-cold marshland, a decrease in the areas and numbers of lakes and rivers in the middle and north source regions of the Yangtze and Yellow Rivers, and a reduction in surface runoff in the source region of the Yangtze River for the last 20 years. The causes of eco-environmental change in Dari area, near the outlet from the source area of the Yellow River, are different from those elsewhere in the study area. A noticeable reduction in runoff in the source region of the Yellow River and degradation of alpine vegetation in Dari area are closely related to the permafrost degradation resulting from climate warming. [ABSTRACT FROM AUTHOR]