Based on the analysis of its basic characteristics, this article investigated the disparities of Chinese service industry among the three regions (the eastern China, the western China and the middle China) and inter...Based on the analysis of its basic characteristics, this article investigated the disparities of Chinese service industry among the three regions (the eastern China, the western China and the middle China) and inter-provincial disparities of that in the three regions by Theil coefficient and cluster analysis. Then, major factors influencing its spatial disparity were explored by correlation analysis and regression analysis. The conclusions could be drawn as follows. 1) The development of Chinese service industry experienced three phases since the 1980s: rapid growth period, slow growth period, and recovery period. From the proportion of value-added and employment, its development was obviously on the low level. From the composition of industrial structure, traditional service sectors were dominant, but modem service sectors were lagged. Moreover, its spatial disparity was distinct. 2) The level of Chinese service industry was divided into five basic regional ranks: well-developed, developed, relatively-developed, underdeveloped and undeveloped regions, As a whole, the overall structure of spatial disparity was steady in 1990-2005. But there was notable gradient disparity in the interior structure of service industry among different provinces. Furthermore, the overall disparity expanded rapidly in 1990-2005. The inter-provincial disparity of service industry in the three regions, especially in the eastern China, was bigger than the disparity among the three regions. And 3) the level of economic development, the level of urban development, the scale of market capacity, the level of transportation and telecommunication, and the abundance of human resources were major factors influencing the development of Chinese service industry.展开更多
The Taoer River basin is the epitome in the west of Northeast China and it is one of the most fragile and sensitive ecoregions. Thus, protection of water quality of the Taoer River is important. Not only point source ...The Taoer River basin is the epitome in the west of Northeast China and it is one of the most fragile and sensitive ecoregions. Thus, protection of water quality of the Taoer River is important. Not only point source pollution but non-point source (NPS) pollution results in deteriorating water quality. In this study, long-term hydrologic impact assessment model was used to evaluate the impacts of land use change impacts on NPS pollution, and the replacement cost method was used to calculate the economic loss caused by NPS pollution. Through analyzing the NPS pollutant loads of different land categories and the economic loss, the article puts forward that there exists a close relationship between land-use types and NPS pollution, and agricultural pollution is the main component of the NPS pollution in this area. The results of this study can provide decision-making basis for agricultural development and land-use change.展开更多
Taking Guangzhou as a case,this paper adopted a questionnaire survey to gather first-hand data and analyzed the characteristics and influencing factors of private car travel in Chinese cities.As the research indicated...Taking Guangzhou as a case,this paper adopted a questionnaire survey to gather first-hand data and analyzed the characteristics and influencing factors of private car travel in Chinese cities.As the research indicated,trip purposes of private car travel are mainly commute and business affairs with a more flexible trip in the urban core area.And trip intensities are concentrated in a certain extent,with trip frequency being lower in the urban core area than the peripheral area.In addition,the trip time has two significant peaks occurring in the morning and afternoon,and one trough in the midday.And trip spatial distribution is mainly within commute with both residence and employment in urban area and inward commute with residence in suburban area while employment in urban area.Both kinds of commutes direct to the urban area.The study also shows that the characteristics of private car travel are principally influenced by two aspects:travelers' attributes and urban characteristics.The main travelers' social and economic attributes influenced it include the gender,education attainment,age,driving experience and per capita monthly household income.The urban characteristics influenced it mainly cover the land use pattern,public traffic facilities and spatial attributes of residential environment.展开更多
Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential su...Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century. Based on modem weather data, 1 km-resolution land cover data, historical climatic time series, and estimation by using similar historical climatic scenes, the following was concluded: 1) The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃ or ≥ 0℃ accumulated temperature above 2500℃-2700℃, and annual precipitation above 350 mm. 2) The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890-1910 was approximately located at the position of the 1961-2000 area. The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century, whereas during the modem warm period of the 1990s, the area shifted north by 100 km on average. 3) The western and eastern boundaries of the suitable agricul^re area during the heaviest drought periods between 1920s and 1930s had shifted northeast by 250 km and 125 km, respectively, contrasting to the boundaries of 1951-2008. For the wettest period, that is, the 1890s to the 1910s, the shift of western and eastern boundaries was to the southwest by 125 km and 200 km, respectively, compared with that in the 1951-2008 period. This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area.展开更多
This paper utilizes the Theil and decoupling indices to analyze variation in carbon productivity as well as the factors that influence regional carbon productivity in China and proposes carbon emission reduction count...This paper utilizes the Theil and decoupling indices to analyze variation in carbon productivity as well as the factors that influence regional carbon productivity in China and proposes carbon emission reduction countermeasures. The authors conclude that most provinces exhibit year-on-year rising carbon productivity, a trend which decreases moving from east to western China. When applied to carbon productivity, the Theil index presents distinct regional differences. Moreover, the regional variance in carbon productivity is consistently reduced in eastern China and becomes smaller in central China. The difference, however, grows in western China. Carbon productivity grows with the highest speed in central China and the lowest speed in western China. Overall variation in carbon productivity mainly arises from intra-regional difference, whereas inter-regional difference mainly contributed by eastern China. In recent years; both the decoupling index, a dynamic value equal to the rate of change rate in carbon emissions divided by the rate of change in GDP during a given period of time, and carbon productivity vary in different economic development stages. Even if under the same decoupling state, carbon productivity remains different in three regions, i.e., that of the eastern region is higher than the other two regions .展开更多
Using an improved FVCOM numerical model, combined with the momentum-sinking scheme based on the structural characteristics of specific turbines, this study analyzed the temporal and spatial distributions of tidal ener...Using an improved FVCOM numerical model, combined with the momentum-sinking scheme based on the structural characteristics of specific turbines, this study analyzed the temporal and spatial distributions of tidal energy resources before and after the deployment of tidal turbines near Pingtan Island, China. Considering factors such as the distribution of tidal stream energy, bathymetry, topography, and the design parameters of the turbines, an appropriate location for a demonstration tidal turbine was selected and the corresponding energy resource was evaluated. Several sites with strong tidal streams were considered: south of the northern cape, east of the southem cape, and the southern end of Haitan Bay. The former was thought most suitable for the deployment of a tidal energy turbine, with projected power generation for approximately 470 h per month. The average power of this demonstration was about 2.4 kW, and the annual electricity output was approximately 17.47 MWh. The intervention of the turbine device had little influence on the near-field tidal stream or water level. The tidal stream was reduced slightly in the area south of the northern cape, although the effect weakened further from the turbine. Conversely, the velocity increased slightly on both sides of the demonstration site. The difference in current speed with and without the turbine was greater at slack tide than still tide. The influence of turbine operation on water level was minor. The method adopted in this study can be considered a reference for the selection of sites for the demonstration of tidal stream energy. However, the method is unable describe the dynamic characteristics of the turbulent flow surrounding the deployed turbines, which has an important role regarding the optimal designs of the turbine blade and pile foundations. Therefore, we will continue to work to improve this model in future research.展开更多
This paper provides evidence that the variation of boreal winter sea level pressure (SLP) over the North Pacific is out-of-phase with SLP fluctuation over the tropical Indian Ocean on both the interdecadal and interan...This paper provides evidence that the variation of boreal winter sea level pressure (SLP) over the North Pacific is out-of-phase with SLP fluctuation over the tropical Indian Ocean on both the interdecadal and interannual time scales.Subsequently,a SLP between tropical Indian Ocean and North Pacific (TIO-NP) oscillation index is defined to indicate the variation of such out-of-phase fluctuation.Moreover,the simultaneous surface air temperature and precipitation anomalies in China are closely related to TIO-NP oscillations.Below-normal surface air temperature anomalies in the northern and the eastern part of China,and less rainfall in southern China,correspond to positive TIO-NP oscillation phase with negative SLP anomalies in tropical Indian Ocean and positive anomalies in North Pacific.The TIO-NP oscillation affects China's winter climate anomalies,possibly through modulating the northeast East Asia winter monsoon.展开更多
This paper addresses the impact of climate change on the water cycle and resource changes in the Eastern Monsoon Region of China (EMRC). It also represents a summary of the achievements made by the National Key Basi...This paper addresses the impact of climate change on the water cycle and resource changes in the Eastern Monsoon Region of China (EMRC). It also represents a summary of the achievements made by the National Key Basic Research and Development Program (2010CB428400), where the major research focuses are detection and attribution, extreme floods and droughts, and adaptation of water resources management. Preliminary conclusions can be summarized into four points: 1) Water cycling and water resource changes in the EMRC are rather complicated as the region is impacted by natural changes relating to the strong monsoon influence and also by climate change impacts caused by CO2 emissions due to anthropogenic forcing; 2) the rate of natural variability contributing to the influence on precipitation accounts for about 70%, and the rate from anthropogenic forcing accounts for 30% on average in the EMRC. However, with future scenarios of increasing CO2 emissions, the contribution rate from anthropogenic forcing will increase and water resources management will experience greater issues related to the climate change impact; 3) Extreme floods and droughts in the EMRC will be an increasing trend, based on IPCC-AR5 scenarios; 4) Along with rising temperatures of 1 ~C in North China, the agricultural water consumption will increase to about 4% of total water consumption. Therefore, climate change is making a significant impact and will be a risk to the EMRC, which covers almost all of the eight major river basins, such as the Yangtze River, Yellow River, Huaihe River, Haihe River, and Pearl River, and to the South-to-North Water Diversion Project (middle line). To ensure water security, it is urgently necessary to take adaptive countermeasures and reduce the vulnerability of water resources and associated risks.展开更多
Since the end of the Cold War, the power comparison between the United States and Russia in the Middle East has been"strong US, weak Russia". But since sending troops into Syria on September 30 of 2015,Russi...Since the end of the Cold War, the power comparison between the United States and Russia in the Middle East has been"strong US, weak Russia". But since sending troops into Syria on September 30 of 2015,Russia has taken a forceful position of involvement in the Middle East and achieved fruitful results, not only boosting its military presence in the Middle East, but also greatly increasing its political influence. Russia is now an important external force influencing political changes in the Middle East.Since taking office as US president, Donald Trump has changed the policy of strategic contraction pursued by his predecessor Barack Obama in the Middle East, taking a proactive rather than a stiff approach to further intensify contention with Russia in a bid to reshape and consolidate its position as a top dog in the Middle East. US-Russia contention has led to new geopolitical divisions and realignment as well as profound and complicated changes in geopolitical structure in the Middle East, thus perpetuating US-Russia contention, as the two countries will lock themselves in fierce contention over regional dominance on both military and political battlegrounds.展开更多
This paper proposes to use DEA models with undesirable outputs to construct the Malmquist index that can be use to investigate the dynamic changes of CO 2 emission performance.With the index,the authors have measured ...This paper proposes to use DEA models with undesirable outputs to construct the Malmquist index that can be use to investigate the dynamic changes of CO 2 emission performance.With the index,the authors have measured the CO 2 emission performance of 28 provinces and autonomous regions in China from 1996 to 2007;with the convergence theory and panel data regression model,the authors analyze the regional differences and the influencing factors.It is found that the performance of CO 2 emissions in China has been continuously improved mainly due to the technological progress,and the average improvement rate is 3.25%,with a cumulative improvement rate of 40.86%.In addition,the CO 2 emission performance varies across four regions.As a whole,the performance score of eastern China is the highest.The northeastern and central China has relatively lower performance scores,and the western China is relatively backward.The regional differences are decreasing,and the performance of CO 2 emissions is convergent.The influence of some factors on the performance of CO 2 emissions is significant,such as the level of economic development,the level of industrial structure,energy intensity,and ownership structure.The influence of some factors,such as opening-up to the outside world,on the performance of CO 2 emissions is not significant..展开更多
Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and ass...Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and associated response mechanisms,thus,require further investigation.To shed light on the transmission of climate change impacts within historical Chinese society,we selected 30-year resolution sequences of temperature anomalies in eastern China and 10-year resolution sequences of grain harvest grades,famine indices,and frequencies of peasant uprisings in China over the past 2000 years.Using a food security perspective,we analyzed the impacts of temperature changes historically transmitted through Chinese production,population,and social subsystems,and differences in transmission characteristics between cold and warm units.Our results were as follows.(1)From 210 BC to 1910 AD,temperature changes in China were significantly positively correlated with grain harvest grades(correlation coefficient,0.338),and significantly negatively correlated with famine indices,and frequencies of peasant uprisings(correlation coefficients,-0.301 and-0.277,respectively).The correlation coefficients between famine indices and grain harvest grades or frequencies of peasant uprisings were very low.(2)There was a higher proportion of bumper or normal harvests(86.5%of the total decades),more moderate and mild famines(76%),and a lower proportion of peasant uprisings(33.3%)in the 30-year warm units.Conversely,there was a higher proportion of poor or normal harvests(70.7%),a greater proportion of moderate and severe famines(77.6%),and more peasant uprisings(51.7%)in the 30-year cold units.(3)Of the 23 main transmission pathways extending from temperature change to the social subsystem,13 occurred in cold units,of which 7 had an endpoint of peasant uprisings,and 10 occurred in warm units of which 3 had an endpoint of peasant uprisings.The main transmission pathways that were more likely to be associated with the impacts of temperature change were:Cold→poor harvests→severe famines→more uprisings;cold→poor harvests→moderate famines→more uprisings;warm→bumper harvests→mild famines→no uprisings;warm→bumper harvests→moderate harvests→no uprisings;warm→normal harvests→mild famines→no uprisings;and warm→normal harvests→moderate famines→no uprisings.(4)The transmission of the impacts of temperature change was a complex process.Within this process,famine was most prone to being modulated by human society.In the transmission pathways from the production to the social subsystem,there was a stepwise decrease in the occurrence rate of decades that were probably affected by climate change.In all cold units,10.4%of decades ending in more uprisings were most likely to be associated with the impacts of temperature change.In all warm units,47.9%of decades ending in no uprisings were most likely to be associated with the impacts of temperature change.This research can contribute a better understanding on the past interaction mechanisms and processes within the human-climate-ecosystem complex,as well as a better response to the impacts of the ongoing climate change.展开更多
The occurrence of bumper or poor grain harvests in ancient China plays an important role in explaining how past climate changes affected the economy.Because of the lack of long-term continuous and high-resolution quan...The occurrence of bumper or poor grain harvests in ancient China plays an important role in explaining how past climate changes affected the economy.Because of the lack of long-term continuous and high-resolution quantitative data for reconstructing the series of grain harvests in ancient China,understanding of the impacts and mechanisms involved in climate change is limited.This study presents a method designed for reconstructing grain harvest series by quantifying grain output levels based on the descriptions in historical documents.The method involves setting the grain output level for each year based on very specific meanings of different words,calculating a yield index based on the structure of each level and assessing grain yields(bumper or poor harvests)every 10 years.First,1636 records related to grain yields(including crop yields,food security,agricultural disasters,grain prices,grain storage and people's livelihoods)for each year were retrieved from history books called the Twenty-Four Histories.Second,using this method,a 10-year resolution graded grain harvest series from the Western Han Dynasty to the Five Dynasties(206 BC–960 AD)is reconstructed.Finally,the relationship between the variations in temperature and precipitation and the fluctuation of grain yields is examined.The results show that from the Western Han Dynasty to the Five Dynasties,bumper,average and poor harvest decades accounted for 33.3%,39.3%and 27.4%of the 1,166-year period,respectively.The grain yields during 206 BC–960 AD can be divided into three stages:a period of bumper harvests during 206–51 BC,poor harvests during 50 BC–590 AD and bumper harvests during 591–960 AD.Bumper harvest decades typically experienced a warm climate with normal or high levels of precipitation,while poor harvest decades had a cold and dry climate.A positive correlation was found between temperature and grain yield because a warm climate allows a full use of resources.The observed relationship between precipitation and grain yield indicated that both flooding and droughts cause poor harvests,which confirms that agricultural production in the monsoon climate of eastern China is greatly impacted by conditions of limited heat and extreme precipitation.展开更多
基金Under the auspices of National Natural Science Foundation of China (No 40871069)Megaproject of Science and Technology Research for the 11th Five-Year Plan of China (No 2006BAJ05A06)Natural Science Foundation of Beijing City (No 9072002)
文摘Based on the analysis of its basic characteristics, this article investigated the disparities of Chinese service industry among the three regions (the eastern China, the western China and the middle China) and inter-provincial disparities of that in the three regions by Theil coefficient and cluster analysis. Then, major factors influencing its spatial disparity were explored by correlation analysis and regression analysis. The conclusions could be drawn as follows. 1) The development of Chinese service industry experienced three phases since the 1980s: rapid growth period, slow growth period, and recovery period. From the proportion of value-added and employment, its development was obviously on the low level. From the composition of industrial structure, traditional service sectors were dominant, but modem service sectors were lagged. Moreover, its spatial disparity was distinct. 2) The level of Chinese service industry was divided into five basic regional ranks: well-developed, developed, relatively-developed, underdeveloped and undeveloped regions, As a whole, the overall structure of spatial disparity was steady in 1990-2005. But there was notable gradient disparity in the interior structure of service industry among different provinces. Furthermore, the overall disparity expanded rapidly in 1990-2005. The inter-provincial disparity of service industry in the three regions, especially in the eastern China, was bigger than the disparity among the three regions. And 3) the level of economic development, the level of urban development, the scale of market capacity, the level of transportation and telecommunication, and the abundance of human resources were major factors influencing the development of Chinese service industry.
基金supported by the Key Project of Knowledge Innovation Program of CAS(Grant No.KZCX2-YW-Q06-1)
文摘The Taoer River basin is the epitome in the west of Northeast China and it is one of the most fragile and sensitive ecoregions. Thus, protection of water quality of the Taoer River is important. Not only point source pollution but non-point source (NPS) pollution results in deteriorating water quality. In this study, long-term hydrologic impact assessment model was used to evaluate the impacts of land use change impacts on NPS pollution, and the replacement cost method was used to calculate the economic loss caused by NPS pollution. Through analyzing the NPS pollutant loads of different land categories and the economic loss, the article puts forward that there exists a close relationship between land-use types and NPS pollution, and agricultural pollution is the main component of the NPS pollution in this area. The results of this study can provide decision-making basis for agricultural development and land-use change.
基金Under the auspices of National Natural Science Foundation of China (No 40571052,40301014)
文摘Taking Guangzhou as a case,this paper adopted a questionnaire survey to gather first-hand data and analyzed the characteristics and influencing factors of private car travel in Chinese cities.As the research indicated,trip purposes of private car travel are mainly commute and business affairs with a more flexible trip in the urban core area.And trip intensities are concentrated in a certain extent,with trip frequency being lower in the urban core area than the peripheral area.In addition,the trip time has two significant peaks occurring in the morning and afternoon,and one trough in the midday.And trip spatial distribution is mainly within commute with both residence and employment in urban area and inward commute with residence in suburban area while employment in urban area.Both kinds of commutes direct to the urban area.The study also shows that the characteristics of private car travel are principally influenced by two aspects:travelers' attributes and urban characteristics.The main travelers' social and economic attributes influenced it include the gender,education attainment,age,driving experience and per capita monthly household income.The urban characteristics influenced it mainly cover the land use pattern,public traffic facilities and spatial attributes of residential environment.
基金Under the auspices of China Global Change Research Program(No.2010CB950103)National Natural Science Foundation of China(No.40901099)
文摘Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century. Based on modem weather data, 1 km-resolution land cover data, historical climatic time series, and estimation by using similar historical climatic scenes, the following was concluded: 1) The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃ or ≥ 0℃ accumulated temperature above 2500℃-2700℃, and annual precipitation above 350 mm. 2) The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890-1910 was approximately located at the position of the 1961-2000 area. The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century, whereas during the modem warm period of the 1990s, the area shifted north by 100 km on average. 3) The western and eastern boundaries of the suitable agricul^re area during the heaviest drought periods between 1920s and 1930s had shifted northeast by 250 km and 125 km, respectively, contrasting to the boundaries of 1951-2008. For the wettest period, that is, the 1890s to the 1910s, the shift of western and eastern boundaries was to the southwest by 125 km and 200 km, respectively, compared with that in the 1951-2008 period. This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area.
文摘This paper utilizes the Theil and decoupling indices to analyze variation in carbon productivity as well as the factors that influence regional carbon productivity in China and proposes carbon emission reduction countermeasures. The authors conclude that most provinces exhibit year-on-year rising carbon productivity, a trend which decreases moving from east to western China. When applied to carbon productivity, the Theil index presents distinct regional differences. Moreover, the regional variance in carbon productivity is consistently reduced in eastern China and becomes smaller in central China. The difference, however, grows in western China. Carbon productivity grows with the highest speed in central China and the lowest speed in western China. Overall variation in carbon productivity mainly arises from intra-regional difference, whereas inter-regional difference mainly contributed by eastern China. In recent years; both the decoupling index, a dynamic value equal to the rate of change rate in carbon emissions divided by the rate of change in GDP during a given period of time, and carbon productivity vary in different economic development stages. Even if under the same decoupling state, carbon productivity remains different in three regions, i.e., that of the eastern region is higher than the other two regions .
基金Supported by the Chinese Marine Renewable Energy Special Fund(Nos.GHME2012ZC05,GHME2013GC03,GHME2013ZC01,GHME2014ZC01)
文摘Using an improved FVCOM numerical model, combined with the momentum-sinking scheme based on the structural characteristics of specific turbines, this study analyzed the temporal and spatial distributions of tidal energy resources before and after the deployment of tidal turbines near Pingtan Island, China. Considering factors such as the distribution of tidal stream energy, bathymetry, topography, and the design parameters of the turbines, an appropriate location for a demonstration tidal turbine was selected and the corresponding energy resource was evaluated. Several sites with strong tidal streams were considered: south of the northern cape, east of the southem cape, and the southern end of Haitan Bay. The former was thought most suitable for the deployment of a tidal energy turbine, with projected power generation for approximately 470 h per month. The average power of this demonstration was about 2.4 kW, and the annual electricity output was approximately 17.47 MWh. The intervention of the turbine device had little influence on the near-field tidal stream or water level. The tidal stream was reduced slightly in the area south of the northern cape, although the effect weakened further from the turbine. Conversely, the velocity increased slightly on both sides of the demonstration site. The difference in current speed with and without the turbine was greater at slack tide than still tide. The influence of turbine operation on water level was minor. The method adopted in this study can be considered a reference for the selection of sites for the demonstration of tidal stream energy. However, the method is unable describe the dynamic characteristics of the turbulent flow surrounding the deployed turbines, which has an important role regarding the optimal designs of the turbine blade and pile foundations. Therefore, we will continue to work to improve this model in future research.
基金supported by the National Basic Research Program of China (973 Projects) under Grant 2011CB309704the National Special Scientific Research Project for Public Interest under Grant 201006021the National Natural Science Foundation of China under Grants 40890155,U0733002,and 40810059005
文摘This paper provides evidence that the variation of boreal winter sea level pressure (SLP) over the North Pacific is out-of-phase with SLP fluctuation over the tropical Indian Ocean on both the interdecadal and interannual time scales.Subsequently,a SLP between tropical Indian Ocean and North Pacific (TIO-NP) oscillation index is defined to indicate the variation of such out-of-phase fluctuation.Moreover,the simultaneous surface air temperature and precipitation anomalies in China are closely related to TIO-NP oscillations.Below-normal surface air temperature anomalies in the northern and the eastern part of China,and less rainfall in southern China,correspond to positive TIO-NP oscillation phase with negative SLP anomalies in tropical Indian Ocean and positive anomalies in North Pacific.The TIO-NP oscillation affects China's winter climate anomalies,possibly through modulating the northeast East Asia winter monsoon.
基金Acknowledgment This study was supported by the National Key Basic Research Development Program Project (2010CB428400) and the Natural Science Foundation of China (51279140).
文摘This paper addresses the impact of climate change on the water cycle and resource changes in the Eastern Monsoon Region of China (EMRC). It also represents a summary of the achievements made by the National Key Basic Research and Development Program (2010CB428400), where the major research focuses are detection and attribution, extreme floods and droughts, and adaptation of water resources management. Preliminary conclusions can be summarized into four points: 1) Water cycling and water resource changes in the EMRC are rather complicated as the region is impacted by natural changes relating to the strong monsoon influence and also by climate change impacts caused by CO2 emissions due to anthropogenic forcing; 2) the rate of natural variability contributing to the influence on precipitation accounts for about 70%, and the rate from anthropogenic forcing accounts for 30% on average in the EMRC. However, with future scenarios of increasing CO2 emissions, the contribution rate from anthropogenic forcing will increase and water resources management will experience greater issues related to the climate change impact; 3) Extreme floods and droughts in the EMRC will be an increasing trend, based on IPCC-AR5 scenarios; 4) Along with rising temperatures of 1 ~C in North China, the agricultural water consumption will increase to about 4% of total water consumption. Therefore, climate change is making a significant impact and will be a risk to the EMRC, which covers almost all of the eight major river basins, such as the Yangtze River, Yellow River, Huaihe River, Haihe River, and Pearl River, and to the South-to-North Water Diversion Project (middle line). To ensure water security, it is urgently necessary to take adaptive countermeasures and reduce the vulnerability of water resources and associated risks.
文摘Since the end of the Cold War, the power comparison between the United States and Russia in the Middle East has been"strong US, weak Russia". But since sending troops into Syria on September 30 of 2015,Russia has taken a forceful position of involvement in the Middle East and achieved fruitful results, not only boosting its military presence in the Middle East, but also greatly increasing its political influence. Russia is now an important external force influencing political changes in the Middle East.Since taking office as US president, Donald Trump has changed the policy of strategic contraction pursued by his predecessor Barack Obama in the Middle East, taking a proactive rather than a stiff approach to further intensify contention with Russia in a bid to reshape and consolidate its position as a top dog in the Middle East. US-Russia contention has led to new geopolitical divisions and realignment as well as profound and complicated changes in geopolitical structure in the Middle East, thus perpetuating US-Russia contention, as the two countries will lock themselves in fierce contention over regional dominance on both military and political battlegrounds.
基金financial support provided by the National Social Science Foundation of China (Grant No. 08 &ZD046)National Natural Science Foundation of China (Grant No.70903031 and 41071348)
文摘This paper proposes to use DEA models with undesirable outputs to construct the Malmquist index that can be use to investigate the dynamic changes of CO 2 emission performance.With the index,the authors have measured the CO 2 emission performance of 28 provinces and autonomous regions in China from 1996 to 2007;with the convergence theory and panel data regression model,the authors analyze the regional differences and the influencing factors.It is found that the performance of CO 2 emissions in China has been continuously improved mainly due to the technological progress,and the average improvement rate is 3.25%,with a cumulative improvement rate of 40.86%.In addition,the CO 2 emission performance varies across four regions.As a whole,the performance score of eastern China is the highest.The northeastern and central China has relatively lower performance scores,and the western China is relatively backward.The regional differences are decreasing,and the performance of CO 2 emissions is convergent.The influence of some factors on the performance of CO 2 emissions is significant,such as the level of economic development,the level of industrial structure,energy intensity,and ownership structure.The influence of some factors,such as opening-up to the outside world,on the performance of CO 2 emissions is not significant..
基金supported by the Major State Basic Research Development Program of China (Grant No. 2010CB950103)the National Natural Science Foundation of China (Grant No. 41371201)the Strategic Project of Science and Technology of the Chinese Academy of Sciences (Grant No. XDA05080102)
文摘Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and associated response mechanisms,thus,require further investigation.To shed light on the transmission of climate change impacts within historical Chinese society,we selected 30-year resolution sequences of temperature anomalies in eastern China and 10-year resolution sequences of grain harvest grades,famine indices,and frequencies of peasant uprisings in China over the past 2000 years.Using a food security perspective,we analyzed the impacts of temperature changes historically transmitted through Chinese production,population,and social subsystems,and differences in transmission characteristics between cold and warm units.Our results were as follows.(1)From 210 BC to 1910 AD,temperature changes in China were significantly positively correlated with grain harvest grades(correlation coefficient,0.338),and significantly negatively correlated with famine indices,and frequencies of peasant uprisings(correlation coefficients,-0.301 and-0.277,respectively).The correlation coefficients between famine indices and grain harvest grades or frequencies of peasant uprisings were very low.(2)There was a higher proportion of bumper or normal harvests(86.5%of the total decades),more moderate and mild famines(76%),and a lower proportion of peasant uprisings(33.3%)in the 30-year warm units.Conversely,there was a higher proportion of poor or normal harvests(70.7%),a greater proportion of moderate and severe famines(77.6%),and more peasant uprisings(51.7%)in the 30-year cold units.(3)Of the 23 main transmission pathways extending from temperature change to the social subsystem,13 occurred in cold units,of which 7 had an endpoint of peasant uprisings,and 10 occurred in warm units of which 3 had an endpoint of peasant uprisings.The main transmission pathways that were more likely to be associated with the impacts of temperature change were:Cold→poor harvests→severe famines→more uprisings;cold→poor harvests→moderate famines→more uprisings;warm→bumper harvests→mild famines→no uprisings;warm→bumper harvests→moderate harvests→no uprisings;warm→normal harvests→mild famines→no uprisings;and warm→normal harvests→moderate famines→no uprisings.(4)The transmission of the impacts of temperature change was a complex process.Within this process,famine was most prone to being modulated by human society.In the transmission pathways from the production to the social subsystem,there was a stepwise decrease in the occurrence rate of decades that were probably affected by climate change.In all cold units,10.4%of decades ending in more uprisings were most likely to be associated with the impacts of temperature change.In all warm units,47.9%of decades ending in no uprisings were most likely to be associated with the impacts of temperature change.This research can contribute a better understanding on the past interaction mechanisms and processes within the human-climate-ecosystem complex,as well as a better response to the impacts of the ongoing climate change.
基金supported by the Major State Basic Research Development Program of China (973 Program) (Grant No. 2010CB950103)National Natural Science Foundation of China (Grant No. 41071127)Strategic Project of Science and Technology of the Chinese Academy of Sciences (Grant No. XDA05080102)
文摘The occurrence of bumper or poor grain harvests in ancient China plays an important role in explaining how past climate changes affected the economy.Because of the lack of long-term continuous and high-resolution quantitative data for reconstructing the series of grain harvests in ancient China,understanding of the impacts and mechanisms involved in climate change is limited.This study presents a method designed for reconstructing grain harvest series by quantifying grain output levels based on the descriptions in historical documents.The method involves setting the grain output level for each year based on very specific meanings of different words,calculating a yield index based on the structure of each level and assessing grain yields(bumper or poor harvests)every 10 years.First,1636 records related to grain yields(including crop yields,food security,agricultural disasters,grain prices,grain storage and people's livelihoods)for each year were retrieved from history books called the Twenty-Four Histories.Second,using this method,a 10-year resolution graded grain harvest series from the Western Han Dynasty to the Five Dynasties(206 BC–960 AD)is reconstructed.Finally,the relationship between the variations in temperature and precipitation and the fluctuation of grain yields is examined.The results show that from the Western Han Dynasty to the Five Dynasties,bumper,average and poor harvest decades accounted for 33.3%,39.3%and 27.4%of the 1,166-year period,respectively.The grain yields during 206 BC–960 AD can be divided into three stages:a period of bumper harvests during 206–51 BC,poor harvests during 50 BC–590 AD and bumper harvests during 591–960 AD.Bumper harvest decades typically experienced a warm climate with normal or high levels of precipitation,while poor harvest decades had a cold and dry climate.A positive correlation was found between temperature and grain yield because a warm climate allows a full use of resources.The observed relationship between precipitation and grain yield indicated that both flooding and droughts cause poor harvests,which confirms that agricultural production in the monsoon climate of eastern China is greatly impacted by conditions of limited heat and extreme precipitation.