Human activities in a transborder watershed are complex under the influence of domestic policies,international relations,and global events.Understanding the forces driving human activity change is important for the de...Human activities in a transborder watershed are complex under the influence of domestic policies,international relations,and global events.Understanding the forces driving human activity change is important for the development of transborder watershed.In this study,we used global historical land cover data,the hemeroby index model,and synthesized major historical events to analyze how human activity intensity changed in the Heilongjiang River(Amur River in Russia)watershed(HLRW).The results showed that there was a strong spatial heterogeneity in the variation of human activity intensity in the HLRW over the past century(1900-2016).On the Chinese side,the human activity intensity change shifted from the plain areas for agricultural reclamation to the mountainous areas for timber extraction.On the Russian side,human activity intensity changes mostly concentrated along the Trans-Siberian Railway and the Baikal-Amur Mainline.Localized variation of human activity intensity tended to respond to regional events while regionalized variation tends to reflect national policy change or broad international events.The similarities and differences between China and Russia in policies and positions in international events resulted in synchronous and asynchronous changes in human activity intensity.Meanwhile,policy shifts were often confined by the natural features of the watershed.These results reveal the historical origins and fundamental connotations of watershed development and contribute to formulating regional management policies that coordinate population,eco-nomic,social,and environmental activities.展开更多
Industrialization has been a dream for the Chinese nation since modern history and a goal of the Communist Party of China(CPC).Ever since its founding in 1921,the CPC has been exploring a path for China’s industrial ...Industrialization has been a dream for the Chinese nation since modern history and a goal of the Communist Party of China(CPC).Ever since its founding in 1921,the CPC has been exploring a path for China’s industrial development based on socialism as the political and institutional premise.Since the founding of the People’s Republic of China in 1949,the Chinese people have established a socialist system under the CPC’s leadership and carried out industrial development for over seven decades in the world’s most populous country,blazing a new trail of socialist industrialization with Chinese characteristics.Under the CPC’s leadership,China established an independent and complete industrial system in less than three decades from 1949 to 1978,and developed into the world’s largest industrial power with the most complete industrial sectors in over three decades from 1979 to 2016.In its future industrial development,China aims to complete new-type industrialization by 2035,build a modern economic system,reach the level of moderately developed countries in terms of GDP per capita,and develop into a major world industrial power by the centennial of the founding of the People’s Republic of China in 2049.展开更多
Climate data from the Climatic Research Unit (CRU) for the period 1901-2013 are used to investigate the drought response to air temperature change over China on the centennial scale. Drought is observed to have incr...Climate data from the Climatic Research Unit (CRU) for the period 1901-2013 are used to investigate the drought response to air temperature change over China on the centennial scale. Drought is observed to have increased evidently across China, except for some regions in eastern China. This increase is much stronger in northern China compared to southern China, especially in Northwest and North China. These change characteris- tics of drought are closely associated with air temperature change, with the severe droughts in the major drought episodes of the last century generally coinciding with higher temperatures. The significantly increasing trend of drought in China based on observations only appears when considering the effects of air temperature change, which can explain -49% of droughts in observations and 30%-65% of droughts in Coupled Model Intereomparison Project Phase 5 (CMIP5) model simulations. Furthermore, the response of drought to air temperature change generally increases as the drought time scale increases. Furthermore, drought shows relatively high sensitivity in spring and early summer in China on the centennial scale.展开更多
THE world audience watched as Gloria Eastephan presented her rendition of the heroic song Peak of Perfection, to close this year’s grand Centennial Olympics. The modem Olympics, which have played a major part in outs...THE world audience watched as Gloria Eastephan presented her rendition of the heroic song Peak of Perfection, to close this year’s grand Centennial Olympics. The modem Olympics, which have played a major part in outstanding human creation over the past century, have provided a platform enabling human beings to demonstrate their unremitting struggle and indefatigable creative spirit. The past 100 years of the Olympics represent an展开更多
Using the southern limit of snowfall recorded in Chinese documents, chronologies of tree-ring width, and tree-ring stable oxygen isotope(δ^(18)O), the annual temperature anomaly in southern China during 1850–200...Using the southern limit of snowfall recorded in Chinese documents, chronologies of tree-ring width, and tree-ring stable oxygen isotope(δ^(18)O), the annual temperature anomaly in southern China during 1850–2009 is reconstructed using the method of signal decomposition and synthesis. The results show that the linear trend was 0.47℃(100 yr)^(-1)over 1871–2009,and the two most rapid warming intervals occurred in 1877–1938 and 1968–2007, at rates of 0.125℃(10 yr)^(-1)and 0.258℃(10 yr)^(-1), respectively. The decadal variation shows that the temperature in the moderate warm interval of the 1910s–1930s was notably lower than that of the 1980s–2000s, which suggests that the warming since the 1980s was unprecedented for the past 160 years, though a warming hiatus existed in the 2000s. Additionally, there was a rapid cooling starting from the 1860s,followed by a cold interval until the early 1890s, with the coldest years in 1892 and 1893. A slight temperature decline was also found from the 1940s to the late 1960s. This study provides an independent case to validate the global warming for the past 160 years and its hiatus recently, because the proxy data are not affected by urbanization.展开更多
The regional mean surface air temperature(SAT)in China has risen with a rate of 1.3–1.7℃(100 yr)^-1 since 1900,based on the recently developed homogenized observations.This estimate is larger than those[0.5–0.8℃(1...The regional mean surface air temperature(SAT)in China has risen with a rate of 1.3–1.7℃(100 yr)^-1 since 1900,based on the recently developed homogenized observations.This estimate is larger than those[0.5–0.8℃(100 yr)^-1]adopted in the early National Reports of Climate Change in China.The present paper reviews the studies of the longterm SAT series of China,highlighting the homogenization of station observations as the key progress.The SAT series of China in early studies showed a prominent warm peak in the 1940s,mainly due to inhomogeneous records associated with site-moves of a number of stations from urban to outskirts in the early 1950s,thus leading to underestimates of the centennial warming trend.Parts of China were relatively warm around the 1940s but with differentphase interdecadal variations,while some parts were even relatively cool.This fact is supported by proxy data and could partly be explained by interdecadal changes in large-scale circulation.The effect of urbanization should have a minor contribution to the observed warming in China,although the estimates of such contributions for individual urban stations remain controversial.Further studies relevant to the present topic are discussed.展开更多
We present a230Th-dated stalagmite oxygen isotope(δ^18O)record from Loushanguan Cave in the Yangtze River valley,China.The^δ18O record,if viewed as a proxy of the Asian summer monsoon(ASM)intensity,provides an ASM h...We present a230Th-dated stalagmite oxygen isotope(δ^18O)record from Loushanguan Cave in the Yangtze River valley,China.The^δ18O record,if viewed as a proxy of the Asian summer monsoon(ASM)intensity,provides an ASM history for the early Holocene with clear centennial-scale variability.A significant approximately 200-yr cycle between 10.2 and 9.1 ka BP(before present,where"present"is defined as the year AD 1950),as revealed by spectral power analyses,is of global significance and is probably forced by the Suess or de Vries cycle of solar activity.Here,we explore a physical mechanism to explain the relationship between the solar activity and the ASM.A strong coherence between the ASM and El Ni?o–Southern Oscillation(ENSO)has been observed by performing crosswavelet analyses on this cycle.Our study suggests that a strong(weak)ASM state corresponds to a warm(cold)ENSO,which is consistent with modern meteorological observations but contrasts with previous studies on regions far from the Meiyu rainbelt.We argue that the centennial fluctuations of the ASM are a fundamental characteristic forced by the solar activity,with the ENSO variability as a mediator.The relationship between ENSO and the ASM displayed spatial heterogeneity on the centennial scale during the early Holocene,which is a more direct analogue to the observed modern interannual variability of the ASM.展开更多
Knowledge of the evolution of pedogenic processes in the carbonate area is important to understand the dynamics of rock desertification.A precisely-dated stalagmite δ13C record between 61.3 and 50.5 ka BP from southw...Knowledge of the evolution of pedogenic processes in the carbonate area is important to understand the dynamics of rock desertification.A precisely-dated stalagmite δ13C record between 61.3 and 50.5 ka BP from southwestern China,potentially related to soil biogenic CO2 production,shifts within a narrow range between -9‰ and -7‰,and exhibits a prominent cycle of 350-470 a,independent of the Asian monsoon changes.This indicates that a threshold effect might control the amplitude of calcite δ13C variability,likely associated with the vertical soil loss in the carbonate area.The periodic δ13C changes reflect that the loss/recovery of soil cover can operate on centennial scale.Thus,the rock desertification in southwestern China might at least initiate 60 ka ago and should be of natural origin.展开更多
基金Under the auspices of National Key Research and Development Program of China(No.2017YFA0604403)National Natural Science Foundation of China(No.41801108)。
文摘Human activities in a transborder watershed are complex under the influence of domestic policies,international relations,and global events.Understanding the forces driving human activity change is important for the development of transborder watershed.In this study,we used global historical land cover data,the hemeroby index model,and synthesized major historical events to analyze how human activity intensity changed in the Heilongjiang River(Amur River in Russia)watershed(HLRW).The results showed that there was a strong spatial heterogeneity in the variation of human activity intensity in the HLRW over the past century(1900-2016).On the Chinese side,the human activity intensity change shifted from the plain areas for agricultural reclamation to the mountainous areas for timber extraction.On the Russian side,human activity intensity changes mostly concentrated along the Trans-Siberian Railway and the Baikal-Amur Mainline.Localized variation of human activity intensity tended to respond to regional events while regionalized variation tends to reflect national policy change or broad international events.The similarities and differences between China and Russia in policies and positions in international events resulted in synchronous and asynchronous changes in human activity intensity.Meanwhile,policy shifts were often confined by the natural features of the watershed.These results reveal the historical origins and fundamental connotations of watershed development and contribute to formulating regional management policies that coordinate population,eco-nomic,social,and environmental activities.
文摘Industrialization has been a dream for the Chinese nation since modern history and a goal of the Communist Party of China(CPC).Ever since its founding in 1921,the CPC has been exploring a path for China’s industrial development based on socialism as the political and institutional premise.Since the founding of the People’s Republic of China in 1949,the Chinese people have established a socialist system under the CPC’s leadership and carried out industrial development for over seven decades in the world’s most populous country,blazing a new trail of socialist industrialization with Chinese characteristics.Under the CPC’s leadership,China established an independent and complete industrial system in less than three decades from 1949 to 1978,and developed into the world’s largest industrial power with the most complete industrial sectors in over three decades from 1979 to 2016.In its future industrial development,China aims to complete new-type industrialization by 2035,build a modern economic system,reach the level of moderately developed countries in terms of GDP per capita,and develop into a major world industrial power by the centennial of the founding of the People’s Republic of China in 2049.
基金supported by the ‘Strategic Priority Research Program-Climate Change: Carbon Budget and Relevant Issues’ of the Chinese Academy of Sciences (Grant No.XDA05090306)the National Natural Science Foundation of China (Grant No. 41305061)the National Basic Research Program of China (Grant No. 2012CB955401)
文摘Climate data from the Climatic Research Unit (CRU) for the period 1901-2013 are used to investigate the drought response to air temperature change over China on the centennial scale. Drought is observed to have increased evidently across China, except for some regions in eastern China. This increase is much stronger in northern China compared to southern China, especially in Northwest and North China. These change characteris- tics of drought are closely associated with air temperature change, with the severe droughts in the major drought episodes of the last century generally coinciding with higher temperatures. The significantly increasing trend of drought in China based on observations only appears when considering the effects of air temperature change, which can explain -49% of droughts in observations and 30%-65% of droughts in Coupled Model Intereomparison Project Phase 5 (CMIP5) model simulations. Furthermore, the response of drought to air temperature change generally increases as the drought time scale increases. Furthermore, drought shows relatively high sensitivity in spring and early summer in China on the centennial scale.
文摘THE world audience watched as Gloria Eastephan presented her rendition of the heroic song Peak of Perfection, to close this year’s grand Centennial Olympics. The modem Olympics, which have played a major part in outstanding human creation over the past century, have provided a platform enabling human beings to demonstrate their unremitting struggle and indefatigable creative spirit. The past 100 years of the Olympics represent an
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA05090104)the National Natural Science Foundation of China(Grant Nos.41430528 and 41671201)
文摘Using the southern limit of snowfall recorded in Chinese documents, chronologies of tree-ring width, and tree-ring stable oxygen isotope(δ^(18)O), the annual temperature anomaly in southern China during 1850–2009 is reconstructed using the method of signal decomposition and synthesis. The results show that the linear trend was 0.47℃(100 yr)^(-1)over 1871–2009,and the two most rapid warming intervals occurred in 1877–1938 and 1968–2007, at rates of 0.125℃(10 yr)^(-1)and 0.258℃(10 yr)^(-1), respectively. The decadal variation shows that the temperature in the moderate warm interval of the 1910s–1930s was notably lower than that of the 1980s–2000s, which suggests that the warming since the 1980s was unprecedented for the past 160 years, though a warming hiatus existed in the 2000s. Additionally, there was a rapid cooling starting from the 1860s,followed by a cold interval until the early 1890s, with the coldest years in 1892 and 1893. A slight temperature decline was also found from the 1940s to the late 1960s. This study provides an independent case to validate the global warming for the past 160 years and its hiatus recently, because the proxy data are not affected by urbanization.
基金Supported by the National Key Technologies Research and Development Program(2017YFE0133600)Chinese Academy of Sciences Pioneering Project(XDA19030402)International Cooperation Project(134111KYSB20160010)。
文摘The regional mean surface air temperature(SAT)in China has risen with a rate of 1.3–1.7℃(100 yr)^-1 since 1900,based on the recently developed homogenized observations.This estimate is larger than those[0.5–0.8℃(100 yr)^-1]adopted in the early National Reports of Climate Change in China.The present paper reviews the studies of the longterm SAT series of China,highlighting the homogenization of station observations as the key progress.The SAT series of China in early studies showed a prominent warm peak in the 1940s,mainly due to inhomogeneous records associated with site-moves of a number of stations from urban to outskirts in the early 1950s,thus leading to underestimates of the centennial warming trend.Parts of China were relatively warm around the 1940s but with differentphase interdecadal variations,while some parts were even relatively cool.This fact is supported by proxy data and could partly be explained by interdecadal changes in large-scale circulation.The effect of urbanization should have a minor contribution to the observed warming in China,although the estimates of such contributions for individual urban stations remain controversial.Further studies relevant to the present topic are discussed.
基金Supported by the National Natural Science Foundation of China(40701013,41877453,and 41572151)National Key Research and Development Program of China(2018YFA0605603)。
文摘We present a230Th-dated stalagmite oxygen isotope(δ^18O)record from Loushanguan Cave in the Yangtze River valley,China.The^δ18O record,if viewed as a proxy of the Asian summer monsoon(ASM)intensity,provides an ASM history for the early Holocene with clear centennial-scale variability.A significant approximately 200-yr cycle between 10.2 and 9.1 ka BP(before present,where"present"is defined as the year AD 1950),as revealed by spectral power analyses,is of global significance and is probably forced by the Suess or de Vries cycle of solar activity.Here,we explore a physical mechanism to explain the relationship between the solar activity and the ASM.A strong coherence between the ASM and El Ni?o–Southern Oscillation(ENSO)has been observed by performing crosswavelet analyses on this cycle.Our study suggests that a strong(weak)ASM state corresponds to a warm(cold)ENSO,which is consistent with modern meteorological observations but contrasts with previous studies on regions far from the Meiyu rainbelt.We argue that the centennial fluctuations of the ASM are a fundamental characteristic forced by the solar activity,with the ENSO variability as a mediator.The relationship between ENSO and the ASM displayed spatial heterogeneity on the centennial scale during the early Holocene,which is a more direct analogue to the observed modern interannual variability of the ASM.
基金supported by the National Natural Science Foundation of China(41172148and41130210)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Knowledge of the evolution of pedogenic processes in the carbonate area is important to understand the dynamics of rock desertification.A precisely-dated stalagmite δ13C record between 61.3 and 50.5 ka BP from southwestern China,potentially related to soil biogenic CO2 production,shifts within a narrow range between -9‰ and -7‰,and exhibits a prominent cycle of 350-470 a,independent of the Asian monsoon changes.This indicates that a threshold effect might control the amplitude of calcite δ13C variability,likely associated with the vertical soil loss in the carbonate area.The periodic δ13C changes reflect that the loss/recovery of soil cover can operate on centennial scale.Thus,the rock desertification in southwestern China might at least initiate 60 ka ago and should be of natural origin.