This study investigates the dominant modes of interannual variability of snowfall frequency over the Eurasian continent during autumn and winter,and explores the underlying physical mechanisms.The first EOF mode(EOF1)...This study investigates the dominant modes of interannual variability of snowfall frequency over the Eurasian continent during autumn and winter,and explores the underlying physical mechanisms.The first EOF mode(EOF1)of snowfall frequency during autumn is mainly characterized by positive anomalies over the Central Siberian Plateau(CSP)and Europe,with opposite anomalies over Central Asia(CA).EOF1 during winter is characterized by positive anomalies in Siberia and negative anomalies in Europe and East Asia(EA).During autumn,EOF1 is associated with the anomalous sea ice in the Kara–Laptev seas(KLS)and sea surface temperature(SST)over the North Atlantic.Increased sea ice in the KLS may cause an increase in the meridional air temperature gradient,resulting in increased synoptic-scale wave activity,thereby inducing increased snowfall frequency over Europe and the CSP.Anomalous increases of both sea ice in the KLS and SST in the North Atlantic may stimulate downstream propagation of Rossby waves and induce an anomalous high in CA corresponding to decreased snowfall frequency.In contrast,EOF1 is mainly affected by the anomalous atmospheric circulation during winter.In the positive phase of the North Atlantic Oscillation(NAO),an anomalous deep cold low(warm high)occurs over Siberia(Europe)leading to increased(decreased)snowfall frequency over Siberia(Europe).The synoptic-scale wave activity excited by the positive NAO can induce downstream Rossby wave propagation and contribute to an anomalous high and descending motion over EA,which may inhibit snowfall.The NAO in winter may be modulated by the Indian Ocean dipole and sea ice in the Barents-Kara-Laptev Seas in autumn.展开更多
The opening of the new Eusasian Continental Bridge not only brings about great opportunities for development of Xinjjang, but the plays a major role in reducing the gap between the western and eastern parts of China. ...The opening of the new Eusasian Continental Bridge not only brings about great opportunities for development of Xinjjang, but the plays a major role in reducing the gap between the western and eastern parts of China. In general, Xinjiang section of the new Eusasian Continental Bridge goes ahead along the oasis belt of northern slope of the Tianshan Mountains with advanced economy and concentrated populattion. The main factor to determine the fate of oasis is water. There are relativdy more rivers in Xinjiang section Of the Eurasia Continental Bridge. But as far as the region is concerned, if we take Ururmqi as the boundary, river runoff of the western section accounts for 90%,the eastern section just occupies 10%, so surface runoff is highly concentrated in the west. In this paper, river water envirotnment and ground water environment are evaluated emphatical . On the whole,the status of water environment of seven rivers being evaluated is gradually improved and ground water quality of main cities along the bridge is good. In the future, carrying out sustainable development strategy and doing well in compositive prevention and cure should be long-term guidelines so as to ensure the normal running of the new Eurasia Continental Bridge and economic development along the continental bridge.展开更多
Land cover change has presented clear spatial differences in the New Eurasian Continental Bridge Economic Corridor(NECBEC)region in the 21 st century.A spatiotemporal dynamic probability model and a driving force anal...Land cover change has presented clear spatial differences in the New Eurasian Continental Bridge Economic Corridor(NECBEC)region in the 21 st century.A spatiotemporal dynamic probability model and a driving force analysis model of land cover change were developed to analyze explicitly the dynamics and driving forces of land cover change in the NECBEC region.The results show that the areas of grassland,cropland and built-up land increased by 114.57 million ha,8.41 million ha and 3.96 million ha,and the areas of woodland,other land,and water bodies and wetlands decreased by 74.09 million ha,6.26 million ha,and 46.59 million ha in the NECBEC region between 2001 and 2017,respectively.Woodland and other land were mainly transformed to grassland,and grassland was mainly transformed to woodland and cropland.Built-up land had the largest annual rate of increase and 50%of this originated from cropland.Moreover,since the Belt and Road Initiative(BRI)commenced in 2013,there has been a greater change in the dynamics of land cover change,and the gaps in the socio-economic development level have gradually decreased.The index of socio-economic development was the highest in western Europe,and the lowest in northern Central Asia.The impacts of socio-economic development on cropland and built-up land were greater than those for other land cover types.In general,in the context of rapid socio-economic development,the rate of land cover change in the NECBEC has clearly shown an accelerating trend since 2001,especially after the launch of the BRI in 2013.展开更多
Xinjiang Line of New Eurasian Continental Bridge is the important lifeline project inwestern China. Various disasters, such as flood, strong wind, sandstorm, and roadbed disasters,have been seriously affecting the rai...Xinjiang Line of New Eurasian Continental Bridge is the important lifeline project inwestern China. Various disasters, such as flood, strong wind, sandstorm, and roadbed disasters,have been seriously affecting the railway transportation. The field investigation and analysis on thedata collected since 1959 show that: serious floods often occurred when the rain intensity reached25 mm/h or 30 mm/d; the critical wind speed for turning over a train is between 35 m/s and 67 m/s,and such cases happened in draught places of mountain opening and trunk valley; the angle be-tween wind direction and railway is closely related to the thickness of accumulative sand along thelines; roadbed disasters taking the form of side-slope sliding, roadbed sinking and silt turning uptook place in spring when the temperature rapidly rose to 10-15℃ from zero and precipitationcame forth or when the thickness of snow cover on shade slope reached above 20 cm in winter;the disasters taking place in the 1990s were far stronger than those of the 1980s and the order ofhazard intensity along the Xinjiang Line is Urumqi＞Shihezi＞Kuitun＞Liuyuan＞Shanhan＞Hami.展开更多
This article has discussed the effects on the eastern coastal areas of China brought by the new Eurasian Continental Bridge when it was joined up from Chinese coastal harbour Lianyungang to Rotterdam Harbour in Hollan...This article has discussed the effects on the eastern coastal areas of China brought by the new Eurasian Continental Bridge when it was joined up from Chinese coastal harbour Lianyungang to Rotterdam Harbour in Holland.The effects will be discussed from f展开更多
Ample observational evidence shows that there is a northward crustal subduction zone underneath the Yarlung Zangbo suture between India and Eurasia. It penetrates Moho to a depth of about 100 km. There are probably mu...Ample observational evidence shows that there is a northward crustal subduction zone underneath the Yarlung Zangbo suture between India and Eurasia. It penetrates Moho to a depth of about 100 km. There are probably multiple such crustal subductions under the Himalayas. They are different from lithosphere subduction during oceanic collisions. The detected slabs in the upper mantle north of the Yarlung Zangbo suture can be interpreted as remains of the Indian Plate＇s mantle lithosphere. In contrary to ocean-continent subduction, the mantle lithosphere is de- laminated from the crust as the Indian Plate subducts underneath Eurasia. Existing structural images of the crust and upper mantle of the Tibetan Plateau reveal that there were both northward and southward subductions over different geological period, causing some seismic velocity annmalies around those subduction zones.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41991283).
文摘This study investigates the dominant modes of interannual variability of snowfall frequency over the Eurasian continent during autumn and winter,and explores the underlying physical mechanisms.The first EOF mode(EOF1)of snowfall frequency during autumn is mainly characterized by positive anomalies over the Central Siberian Plateau(CSP)and Europe,with opposite anomalies over Central Asia(CA).EOF1 during winter is characterized by positive anomalies in Siberia and negative anomalies in Europe and East Asia(EA).During autumn,EOF1 is associated with the anomalous sea ice in the Kara–Laptev seas(KLS)and sea surface temperature(SST)over the North Atlantic.Increased sea ice in the KLS may cause an increase in the meridional air temperature gradient,resulting in increased synoptic-scale wave activity,thereby inducing increased snowfall frequency over Europe and the CSP.Anomalous increases of both sea ice in the KLS and SST in the North Atlantic may stimulate downstream propagation of Rossby waves and induce an anomalous high in CA corresponding to decreased snowfall frequency.In contrast,EOF1 is mainly affected by the anomalous atmospheric circulation during winter.In the positive phase of the North Atlantic Oscillation(NAO),an anomalous deep cold low(warm high)occurs over Siberia(Europe)leading to increased(decreased)snowfall frequency over Siberia(Europe).The synoptic-scale wave activity excited by the positive NAO can induce downstream Rossby wave propagation and contribute to an anomalous high and descending motion over EA,which may inhibit snowfall.The NAO in winter may be modulated by the Indian Ocean dipole and sea ice in the Barents-Kara-Laptev Seas in autumn.
文摘The opening of the new Eusasian Continental Bridge not only brings about great opportunities for development of Xinjjang, but the plays a major role in reducing the gap between the western and eastern parts of China. In general, Xinjiang section of the new Eusasian Continental Bridge goes ahead along the oasis belt of northern slope of the Tianshan Mountains with advanced economy and concentrated populattion. The main factor to determine the fate of oasis is water. There are relativdy more rivers in Xinjiang section Of the Eurasia Continental Bridge. But as far as the region is concerned, if we take Ururmqi as the boundary, river runoff of the western section accounts for 90%,the eastern section just occupies 10%, so surface runoff is highly concentrated in the west. In this paper, river water envirotnment and ground water environment are evaluated emphatical . On the whole,the status of water environment of seven rivers being evaluated is gradually improved and ground water quality of main cities along the bridge is good. In the future, carrying out sustainable development strategy and doing well in compositive prevention and cure should be long-term guidelines so as to ensure the normal running of the new Eurasia Continental Bridge and economic development along the continental bridge.
基金National Key R&D Program of China,No.2017YFA0603702,No.2018YFC0507202National Natural Science Foundation of China,No.41971358,No.41930647,No.41977066+1 种基金Strategic Priority Research Program(A)of the Chinese Academy of Sciences,No.XDA20030203Innovation Project of LREIS,No.O88RA600YA。
文摘Land cover change has presented clear spatial differences in the New Eurasian Continental Bridge Economic Corridor(NECBEC)region in the 21 st century.A spatiotemporal dynamic probability model and a driving force analysis model of land cover change were developed to analyze explicitly the dynamics and driving forces of land cover change in the NECBEC region.The results show that the areas of grassland,cropland and built-up land increased by 114.57 million ha,8.41 million ha and 3.96 million ha,and the areas of woodland,other land,and water bodies and wetlands decreased by 74.09 million ha,6.26 million ha,and 46.59 million ha in the NECBEC region between 2001 and 2017,respectively.Woodland and other land were mainly transformed to grassland,and grassland was mainly transformed to woodland and cropland.Built-up land had the largest annual rate of increase and 50%of this originated from cropland.Moreover,since the Belt and Road Initiative(BRI)commenced in 2013,there has been a greater change in the dynamics of land cover change,and the gaps in the socio-economic development level have gradually decreased.The index of socio-economic development was the highest in western Europe,and the lowest in northern Central Asia.The impacts of socio-economic development on cropland and built-up land were greater than those for other land cover types.In general,in the context of rapid socio-economic development,the rate of land cover change in the NECBEC has clearly shown an accelerating trend since 2001,especially after the launch of the BRI in 2013.
基金supported by the National Natural Science Foundation of China.
文摘Xinjiang Line of New Eurasian Continental Bridge is the important lifeline project inwestern China. Various disasters, such as flood, strong wind, sandstorm, and roadbed disasters,have been seriously affecting the railway transportation. The field investigation and analysis on thedata collected since 1959 show that: serious floods often occurred when the rain intensity reached25 mm/h or 30 mm/d; the critical wind speed for turning over a train is between 35 m/s and 67 m/s,and such cases happened in draught places of mountain opening and trunk valley; the angle be-tween wind direction and railway is closely related to the thickness of accumulative sand along thelines; roadbed disasters taking the form of side-slope sliding, roadbed sinking and silt turning uptook place in spring when the temperature rapidly rose to 10-15℃ from zero and precipitationcame forth or when the thickness of snow cover on shade slope reached above 20 cm in winter;the disasters taking place in the 1990s were far stronger than those of the 1980s and the order ofhazard intensity along the Xinjiang Line is Urumqi＞Shihezi＞Kuitun＞Liuyuan＞Shanhan＞Hami.
文摘This article has discussed the effects on the eastern coastal areas of China brought by the new Eurasian Continental Bridge when it was joined up from Chinese coastal harbour Lianyungang to Rotterdam Harbour in Holland.The effects will be discussed from f
基金National Natural Science Foundation of China (49374207 and 49974021).
文摘Ample observational evidence shows that there is a northward crustal subduction zone underneath the Yarlung Zangbo suture between India and Eurasia. It penetrates Moho to a depth of about 100 km. There are probably multiple such crustal subductions under the Himalayas. They are different from lithosphere subduction during oceanic collisions. The detected slabs in the upper mantle north of the Yarlung Zangbo suture can be interpreted as remains of the Indian Plate＇s mantle lithosphere. In contrary to ocean-continent subduction, the mantle lithosphere is de- laminated from the crust as the Indian Plate subducts underneath Eurasia. Existing structural images of the crust and upper mantle of the Tibetan Plateau reveal that there were both northward and southward subductions over different geological period, causing some seismic velocity annmalies around those subduction zones.
