To study effects of variations in climate-marine environment in the Arctic Ocean on ecology,based on the actual and reestablished data by biomarkers of algae in sediment in 1997,1999,2003,2008,and 2010,the interannual...To study effects of variations in climate-marine environment in the Arctic Ocean on ecology,based on the actual and reestablished data by biomarkers of algae in sediment in 1997,1999,2003,2008,and 2010,the interannual and spatial variations of phytoplankton,zooplankton and chlorophyll a concentration in the Chukchi Sea and the Bering Sea as well as their relations to El Nino-Southern Oscillation( ENSO) and Arctic Oscillation( AO) were analyzed. The results show that there were spatial and temporal anomalies in the phytoplankton community structure reestablished by biomarkers of algae in the Chukchi Sea and the Bering Sea in 1999 and 2010. The total content of biomarkers( brassicasterol,dinosterol,C37 alkenones and chlesterol) in sediment collected in 2010 was far lower than that in 1999,but brassicasterol was dominant in the two years,that is,diatom was dominant,which was consistent with the actual structure and distribution of phytoplankton community in 1999 and 2010; there were great changes in the dominant species of plankton in the two seas in 1999 and 2010,which could be regarded as the ecological response of the North Pole under the background of global warming. Chlorophyll a concentration in the water of the Bering Sea was 0. 720 μg/dm^3 at 0 m and 0. 765μg/dm^3 at 10 m in 1997 and 0. 723 μg/dm^3 at 0 m and 0. 731 μg/dm^3 at 10 m in 2003,and the concentration was very close to each other,which was affected by El Ni1 o and the negative phase of AO. It was 0. 395 μg/dm^3 at 0 m in 1999 and 0. 399 μg/dm^3 at 0 m and 0. 357 μg/dm^3 at 10 m in 2008,which was influenced by La Ni1 a and the positive phase of AO. The phases and intensity of AO and ENSO had various effects on the quantity and dominant species of phytoplankton and zooplankton in the Chukchi Sea and the Bering Sea. During the period of AO with positive or negative phase and El Ni1o( in 1997 and 2003),their combination was favorable to the growth of phytoplankton and zooplankton,while the combination of negative phase of AO and La Nina( in 2010) had adverse effects on the growth of phytoplankton. The combination of AO with positive phase and strong La Nina( in 1999 and 2008) had small effects on phytoplankton community.展开更多
Coal mining subsidence is a universal environmental-geological problem in mining areas. By selecting the Shen-Dong coal mining subsidence area as the research field, this paper studies the changes in precipitation inf...Coal mining subsidence is a universal environmental-geological problem in mining areas. By selecting the Shen-Dong coal mining subsidence area as the research field, this paper studies the changes in precipitation infiltration recharge in the circumstances of coal mining subsidence by means of field geological investigation and laboratory simulation experiments, which is expected to provide a scientific basis for eco-environmental restoration in the mining area. The results indicate that at the unstable stage of subsidence, three types of subsidence in the Shen-Dong mining area have positive effects on the precipitation infiltration recharge, and the type of full-thickness bedrock subsidence has the greatest influence. In the stable stage of subsidence, the precipitation infiltration process after long- term drought and the moisture migration in the aeration zone undergo three different stages： evaporation-infiltration before precipitation, infiltration-upward infiltration-infiltration during precipitation and evaporation-infiltration after precipitation. During a heavy rainfall infiltration process, the wetting front movement in fine sand, coarse sand and dualistic structure of fine-coarse sand consists of two stages： the stage of wetting front movement during precipitation, in which the wetting front movement distance has linear relationship with the depth, and the stage of wetting front movement after precipitation, in which the wetting front movement distance has the power function relationship with the depth. The wetting front movement velocity is influenced by the rainfall amount and the lithology in the aeration zone. However, as the depth increases, the movement velocity will decay exponentially.展开更多
基金Supported by National Natural Science Foundation of China ( 41276199)Chinese Projects for Investigations and Assessments of the Arctic and Antarctic ( CHINARE 2012 - 2016 for 03-04 and 04-03)
文摘To study effects of variations in climate-marine environment in the Arctic Ocean on ecology,based on the actual and reestablished data by biomarkers of algae in sediment in 1997,1999,2003,2008,and 2010,the interannual and spatial variations of phytoplankton,zooplankton and chlorophyll a concentration in the Chukchi Sea and the Bering Sea as well as their relations to El Nino-Southern Oscillation( ENSO) and Arctic Oscillation( AO) were analyzed. The results show that there were spatial and temporal anomalies in the phytoplankton community structure reestablished by biomarkers of algae in the Chukchi Sea and the Bering Sea in 1999 and 2010. The total content of biomarkers( brassicasterol,dinosterol,C37 alkenones and chlesterol) in sediment collected in 2010 was far lower than that in 1999,but brassicasterol was dominant in the two years,that is,diatom was dominant,which was consistent with the actual structure and distribution of phytoplankton community in 1999 and 2010; there were great changes in the dominant species of plankton in the two seas in 1999 and 2010,which could be regarded as the ecological response of the North Pole under the background of global warming. Chlorophyll a concentration in the water of the Bering Sea was 0. 720 μg/dm^3 at 0 m and 0. 765μg/dm^3 at 10 m in 1997 and 0. 723 μg/dm^3 at 0 m and 0. 731 μg/dm^3 at 10 m in 2003,and the concentration was very close to each other,which was affected by El Ni1 o and the negative phase of AO. It was 0. 395 μg/dm^3 at 0 m in 1999 and 0. 399 μg/dm^3 at 0 m and 0. 357 μg/dm^3 at 10 m in 2008,which was influenced by La Ni1 a and the positive phase of AO. The phases and intensity of AO and ENSO had various effects on the quantity and dominant species of phytoplankton and zooplankton in the Chukchi Sea and the Bering Sea. During the period of AO with positive or negative phase and El Ni1o( in 1997 and 2003),their combination was favorable to the growth of phytoplankton and zooplankton,while the combination of negative phase of AO and La Nina( in 2010) had adverse effects on the growth of phytoplankton. The combination of AO with positive phase and strong La Nina( in 1999 and 2008) had small effects on phytoplankton community.
基金supported by the National Natural Science Foundation of China(No.41130637, No.40472124)International Cooperation Projects of Ministry of Science and Technology(2005DFA90200)
文摘Coal mining subsidence is a universal environmental-geological problem in mining areas. By selecting the Shen-Dong coal mining subsidence area as the research field, this paper studies the changes in precipitation infiltration recharge in the circumstances of coal mining subsidence by means of field geological investigation and laboratory simulation experiments, which is expected to provide a scientific basis for eco-environmental restoration in the mining area. The results indicate that at the unstable stage of subsidence, three types of subsidence in the Shen-Dong mining area have positive effects on the precipitation infiltration recharge, and the type of full-thickness bedrock subsidence has the greatest influence. In the stable stage of subsidence, the precipitation infiltration process after long- term drought and the moisture migration in the aeration zone undergo three different stages： evaporation-infiltration before precipitation, infiltration-upward infiltration-infiltration during precipitation and evaporation-infiltration after precipitation. During a heavy rainfall infiltration process, the wetting front movement in fine sand, coarse sand and dualistic structure of fine-coarse sand consists of two stages： the stage of wetting front movement during precipitation, in which the wetting front movement distance has linear relationship with the depth, and the stage of wetting front movement after precipitation, in which the wetting front movement distance has the power function relationship with the depth. The wetting front movement velocity is influenced by the rainfall amount and the lithology in the aeration zone. However, as the depth increases, the movement velocity will decay exponentially.
