Active layer is a key component for permafrost environment studies as many subsurface biological,biogeochemical,ecological,and pedogenic activities prevail in this layer.This study focuses on active layer temperature ...Active layer is a key component for permafrost environment studies as many subsurface biological,biogeochemical,ecological,and pedogenic activities prevail in this layer.This study focuses on active layer temperature monitoring in an area with sporadic permafrost at two adjacent sites along China-Russia Crude Oil Pipeline(CRCOP),NorthEast China.Site T1 is located in disturbed ground on the right-of-way(on-ROW)2 m away from the center of the oil pipeline.T2 is located in a natural and undisturbed site,around 16.6 m off-ROW.Our objective was to study seasonal variability of the active layer depth and thermal regime from October 2017 to September 2018.The monitoring sites consist of soil temperature probes arranged in a vertical array at different depths at both sites.The following parameters were computed:number of isothermal days(ID),freezing days(FD),thawing days(TD),freezing degree days(FDD),thawing degree days(TDD),number of freeze-thaw days(FTD).The mean air temperature in the monitoring period reached-3.2℃.The temperature profile indicates that the maximum active layer thickness observed during the study period was 10 m at T1 and 2 m at T2.The majority of the soil temperatures were above or close to 0℃,resulting in great values of TDD,especially in the first 4 m depth.TDD for T1 were predominant and ranged between 600-1160℃·days(0-4 m depth)reflecting the influence of oil temperature from the pipeline.In T2 borehole FDD were predominant for all the soil layer depths resulting in less permafrost degradation.This comparison emphasizes the significant influence of vegetation removal and the dispersed heat from the pipeline on the active layer thickness.展开更多
The cold-region eco-environments along the China-Russia Crude Oil Pipeline (CRCOP) in northern Northeast China are in disequilibrium due to the combined influences of pronounced climate warming and intensive anthropog...The cold-region eco-environments along the China-Russia Crude Oil Pipeline (CRCOP) in northern Northeast China are in disequilibrium due to the combined influences of pronounced climate warming and intensive anthropogenic activities.This is evidenced by the sharp areal reduction and northward shifting of the boreal forests,shrinking of wetlands,enhancing of soil erosion,accelerating degradation of permafrost and deteriorating of cold-region eco-environments.The degradation of permafrost plays an important role as an internal drive in the eco-environmental changes.Many components of the cold-region eco-environments,including frozen ground,forests,wetlands and peatlands,forest fires and 'heating island effect' of rapid urbanization,are interdependent,interactive,and integrated in the boreal ecosystems.The construction and long-term operation of the CRCOP system will inevitably disturb the cold-region environments along the pipeline.Therefore,a mandatory and carefully-elaborated environ-mental impact statement is indispensable for the proper mitigation of the ensued adverse impacts.Proper management,effective protection and practical rehabilitation of the damaged cold-region environments are a daunting,costly and long-term commitment.The recommended measures for protection and restoration of permafrost eco-environments along the pipeline route include adequate investigation,assessment and monitoring of permafrost and cold-region environments,compliance of pipeline construction and operation codes for environmental management,proper and timely re-vegetation,returning the cultivated lands to forests and grasslands,and effective mitigation of forest fire hazards.展开更多
The permafrost along the China-Russia Crude Oil Pipeline(CRCOP) is degrading since the pipeline operation in 2011. Heat dissipated from the pipeline, climate warming and anthropogenic activities leads to permafrost wa...The permafrost along the China-Russia Crude Oil Pipeline(CRCOP) is degrading since the pipeline operation in 2011. Heat dissipated from the pipeline, climate warming and anthropogenic activities leads to permafrost warming. The processes of permafrost warming along the CRCOP were studied based on the monitoring of air and soil temperatures, and electrical resistivity tomography(ERT) surveys. Results show that:(1) the mean annual air temperature(MAAT) in permafrost regions along the CRCOP increased with a rate of 0.21°C/10a–0.40°C/10 a during the past five decades;(2) the mean annual ground temperature(MAGT, at-15 m depth) of undisturbed permafrost increased by 0.2°C and the natural permafrost table remained unchanged due to the zero-curtain effect;(3) permafrost surrounding the uninsulated pipeline right-of-way warmed significantly compared with that in a natural site. During 2012–2017, the MAGT and the artificial permafrost table, 2 m away from the pipeline centerline, increased at rates of 0.063°C/a and 1.0 m/a. The thaw bulb developed around the pipe and exhibits a faster lateral expansion;(4) 80-mm-thick insulation could reduce the heat exchange between the pipeline and underlying permafrost and then keep the permafrost and pipe stable. The MAGT and the artificial permafrost table, 4.8 m away from the center line of the pipeline, increased by 0.3°C/a and 0.43 m/a, respectively. Due to the heat disturbance caused by warm oil, the degradation of wetland, controlled burn each autumn and climate warming, the permafrost extent reduced and warmed significantly along the CRCOP route. Field observations provide basic data to clarify the interactions between CRCOP and permafrost degradation and environmental effects in the context of climate change.展开更多
On-site monitoring is very important for understanding formation mechanisms of frost hazards frequently occurring in pipeline foundation soils and for designing and deploying according mitigative measures in permafros...On-site monitoring is very important for understanding formation mechanisms of frost hazards frequently occurring in pipeline foundation soils and for designing and deploying according mitigative measures in permafrost regions.Significant thaw subsidence of ground surfaces along the ChinaRussia Crude Oil Pipeline(CRCOP) from Mo'he to Daqing,Heilongjiang Province,Northeast China have been observed at some segments underlain by ice-rich warm(>1.0°C) permafrost since the official operation in January 2011.Recent monitoring results of the thermal states of foundation soils at the kilometer post(KP) 304 site along the CRCOP are presented in this paper.The results indicate that during the period from 2012 to 2014,shallow soils(at the depths from0.8 to 4.0 m from ground surface) has warmed by approximately 1.0°C in the lateral range of 1.2 to 2.1 maway from the pipeline axis,and deeper permafrost(such as at the depth of 15 m,or the depth of zero annual amplitude of ground temperatures) by 0.08°C per year 4 m away from the pipe axis,and 0.07°C per year 5 m away from the pipeline axis.The results indicate an all-season talik has developed around and along the CRCOP.The thaw bulb,with a faster lateral expansion(compared with the vertical growth),enlarges in summer and shrinks in winter.This research will provide important references and bases for evaluating thermal influences of warm pipeline on permafrost and for design,construction,operation and maintenance of pipelines in permafrost regions.展开更多
基金supported by the National Natural Science Foundation of China(NNSFC)(No.41672310)Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA2003020102)+4 种基金China’s Second Tibetan Plateau Scientific Expedition and Research(2019QZKK0905)the NNSFC(Nos.U1703244 and 41630636)National Key Research and Development Program(2017YFC0405101)the Major Program of Bureau of International Cooperation of the Chinese Academy of Sciences(131B62KYSB20170012)Foundation of the State Key Laboratory of Frozen Soil Engineering(No.SKLFSE-ZY-20)。
文摘Active layer is a key component for permafrost environment studies as many subsurface biological,biogeochemical,ecological,and pedogenic activities prevail in this layer.This study focuses on active layer temperature monitoring in an area with sporadic permafrost at two adjacent sites along China-Russia Crude Oil Pipeline(CRCOP),NorthEast China.Site T1 is located in disturbed ground on the right-of-way(on-ROW)2 m away from the center of the oil pipeline.T2 is located in a natural and undisturbed site,around 16.6 m off-ROW.Our objective was to study seasonal variability of the active layer depth and thermal regime from October 2017 to September 2018.The monitoring sites consist of soil temperature probes arranged in a vertical array at different depths at both sites.The following parameters were computed:number of isothermal days(ID),freezing days(FD),thawing days(TD),freezing degree days(FDD),thawing degree days(TDD),number of freeze-thaw days(FTD).The mean air temperature in the monitoring period reached-3.2℃.The temperature profile indicates that the maximum active layer thickness observed during the study period was 10 m at T1 and 2 m at T2.The majority of the soil temperatures were above or close to 0℃,resulting in great values of TDD,especially in the first 4 m depth.TDD for T1 were predominant and ranged between 600-1160℃·days(0-4 m depth)reflecting the influence of oil temperature from the pipeline.In T2 borehole FDD were predominant for all the soil layer depths resulting in less permafrost degradation.This comparison emphasizes the significant influence of vegetation removal and the dispersed heat from the pipeline on the active layer thickness.
基金funding from the Chinese Academy of Sciences Knowledge Innovation Program (Grant No. KZCX2-YW-311)the Chinese Academy of Sciences 100-Talents Program (HuiJun Jin)
文摘The cold-region eco-environments along the China-Russia Crude Oil Pipeline (CRCOP) in northern Northeast China are in disequilibrium due to the combined influences of pronounced climate warming and intensive anthropogenic activities.This is evidenced by the sharp areal reduction and northward shifting of the boreal forests,shrinking of wetlands,enhancing of soil erosion,accelerating degradation of permafrost and deteriorating of cold-region eco-environments.The degradation of permafrost plays an important role as an internal drive in the eco-environmental changes.Many components of the cold-region eco-environments,including frozen ground,forests,wetlands and peatlands,forest fires and 'heating island effect' of rapid urbanization,are interdependent,interactive,and integrated in the boreal ecosystems.The construction and long-term operation of the CRCOP system will inevitably disturb the cold-region environments along the pipeline.Therefore,a mandatory and carefully-elaborated environ-mental impact statement is indispensable for the proper mitigation of the ensued adverse impacts.Proper management,effective protection and practical rehabilitation of the damaged cold-region environments are a daunting,costly and long-term commitment.The recommended measures for protection and restoration of permafrost eco-environments along the pipeline route include adequate investigation,assessment and monitoring of permafrost and cold-region environments,compliance of pipeline construction and operation codes for environmental management,proper and timely re-vegetation,returning the cultivated lands to forests and grasslands,and effective mitigation of forest fire hazards.
基金funded by the National Key Research and Development Program(2016YFC0802103)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA2003020102)+3 种基金National Natural Science Foundation of China(Grants Nos.U1703244,41672310,41630636 and 41702333)the Research Project of the State Key Laboratory of Frozen Soils Engineering(Grant No.SKLFSE-ZY-16)the Major Program of Bureau of International Cooperation of CAS(131B62KYSB20170012)the STS research project of CAS(HHS-TSS-STS-1502)
文摘The permafrost along the China-Russia Crude Oil Pipeline(CRCOP) is degrading since the pipeline operation in 2011. Heat dissipated from the pipeline, climate warming and anthropogenic activities leads to permafrost warming. The processes of permafrost warming along the CRCOP were studied based on the monitoring of air and soil temperatures, and electrical resistivity tomography(ERT) surveys. Results show that:(1) the mean annual air temperature(MAAT) in permafrost regions along the CRCOP increased with a rate of 0.21°C/10a–0.40°C/10 a during the past five decades;(2) the mean annual ground temperature(MAGT, at-15 m depth) of undisturbed permafrost increased by 0.2°C and the natural permafrost table remained unchanged due to the zero-curtain effect;(3) permafrost surrounding the uninsulated pipeline right-of-way warmed significantly compared with that in a natural site. During 2012–2017, the MAGT and the artificial permafrost table, 2 m away from the pipeline centerline, increased at rates of 0.063°C/a and 1.0 m/a. The thaw bulb developed around the pipe and exhibits a faster lateral expansion;(4) 80-mm-thick insulation could reduce the heat exchange between the pipeline and underlying permafrost and then keep the permafrost and pipe stable. The MAGT and the artificial permafrost table, 4.8 m away from the center line of the pipeline, increased by 0.3°C/a and 0.43 m/a, respectively. Due to the heat disturbance caused by warm oil, the degradation of wetland, controlled burn each autumn and climate warming, the permafrost extent reduced and warmed significantly along the CRCOP route. Field observations provide basic data to clarify the interactions between CRCOP and permafrost degradation and environmental effects in the context of climate change.
基金supported by the National Natural Science Foundation Program of China on"Formation mechanisms and mitigative measures for thaw settlement of foundation soils of the China-Russia Crude Oil Pipeline"(Grant No.41171055)the State Key Laboratory of Frozen Soils Engineering Research Projects of China on"Monitoring on thaw settlement of permafrost around the China-Russia Crude Oil Pipeline"(Grant No.SKLFSE-ZY-11)and"Research on isotope tracing and radar detection of permafrost along the China-Russia Crude Oil Pipeline route"(Grant No.SKLFSE-201302)
文摘On-site monitoring is very important for understanding formation mechanisms of frost hazards frequently occurring in pipeline foundation soils and for designing and deploying according mitigative measures in permafrost regions.Significant thaw subsidence of ground surfaces along the ChinaRussia Crude Oil Pipeline(CRCOP) from Mo'he to Daqing,Heilongjiang Province,Northeast China have been observed at some segments underlain by ice-rich warm(>1.0°C) permafrost since the official operation in January 2011.Recent monitoring results of the thermal states of foundation soils at the kilometer post(KP) 304 site along the CRCOP are presented in this paper.The results indicate that during the period from 2012 to 2014,shallow soils(at the depths from0.8 to 4.0 m from ground surface) has warmed by approximately 1.0°C in the lateral range of 1.2 to 2.1 maway from the pipeline axis,and deeper permafrost(such as at the depth of 15 m,or the depth of zero annual amplitude of ground temperatures) by 0.08°C per year 4 m away from the pipe axis,and 0.07°C per year 5 m away from the pipeline axis.The results indicate an all-season talik has developed around and along the CRCOP.The thaw bulb,with a faster lateral expansion(compared with the vertical growth),enlarges in summer and shrinks in winter.This research will provide important references and bases for evaluating thermal influences of warm pipeline on permafrost and for design,construction,operation and maintenance of pipelines in permafrost regions.
