约50—60 Ma 前,欧亚板块与印度次大陆板块发生碰撞,导致了青藏高原的崛起,成为新生代以来地球上最为醒目的构造事件,对东亚的构造和气候格局产生了非常深远的影响。在青藏高原的周缘及内部块体之间存在着一系列的大型走滑断裂带,其长...约50—60 Ma 前,欧亚板块与印度次大陆板块发生碰撞,导致了青藏高原的崛起,成为新生代以来地球上最为醒目的构造事件,对东亚的构造和气候格局产生了非常深远的影响。在青藏高原的周缘及内部块体之间存在着一系列的大型走滑断裂带,其长度往往达数百至数千km,深切下地壳乃至岩石圈地幔,且构造活动强烈(强震多发),研究这些大型走滑断裂带的形成演化历史对揭示青藏高原的生成扩展模式、陆内变形机制及强震机理研究等具有重要的意义。展开更多
The Tarim River Basin, located in the typical arid region, is one of the key regions of LUCC research in China and plays an important role in maintaining the sustainable development of the western China. In recent yea...The Tarim River Basin, located in the typical arid region, is one of the key regions of LUCC research in China and plays an important role in maintaining the sustainable development of the western China. In recent years,the ecological environment of the Tarim River Basin has degraded greatly. In the lower reaches, in particular, the riverbed has been dried up for more than 20 years, which accelerated the desertification and has been a great threat to people′s lives. Taking the section of the Tarim River between Qiala Lake and Taitema Lake as a typical region, an investigation on land cover changes was carried out with the support of remote sensing information of 1988 and 2000 respectively. The changes of land cover in this region were obtained: 1) Cropland tended to increase. 2) Urban or Built-up Area in 2000 was 324.4ha more than that in 1988. 3) Waters expanded by 3476.51ha. 4) Woodland and Grassland decreased, while Barren Land increased by 3824.9ha. The total amount of land use/land cover change between 1988 and 2000 is small,which is only 0.355% of the total area. It shows that the developmental pace of the lower reaches of the Tarim River is relative slow. Based on these results, the authors assessed the landscape dynamics of this region and pointed out that the degree of desertification was strengthened and the landscape dominated by sand land was further characterized by salt desert.展开更多
Climate change will lead to a significant alteration in the temporal and spatial pattern variation in the regional hydrological cycle, and the subsequent lack of water, environmental deterioration, floods and droughts...Climate change will lead to a significant alteration in the temporal and spatial pattern variation in the regional hydrological cycle, and the subsequent lack of water, environmental deterioration, floods and droughts etc. And it is especially remarkable in semi-humid and semi-arid region. In this paper, the impacts of climate change on the hydrological cycle were analyzed for the Hai River Basin, a semi-humid and semi-arid basin and also the water receiving area of the middle route of South-to-North Water Diversion project. Meanwhile it is the most vulnerable to climate change. Firstly, the linear regression and Mann-Kendall non-parametric test methods were used to analyze the change characteristics of the hydrological and meteorological elements for the period from 1960 to 2009. The results show a significant increase in temperature, while precipitation decreases slightly, and runoff decreases drastically over the past 50 years. Secondly, the applicability of SWAT （Soil and Water Assessment Tool） model based on the DEM （Digital Elevation Model）, land use and soil type was verified in the basin. Results show the model performs well in this basin. Furthermore, the water balance model, Fu＇s theory and Koichiro＇s theory were used to calculate the actual evaporation, comparing to the simulated actual evaporation by SWAT model to validate the result for the lack of large-scale observed evaporation datasets. Possible reasons were also analyzed to explore the reasonable factor for the decline of the runoff. Finally the precipitation, temperature, runoff and evaporation response processes based on the IPCC AR4 multi-mode climate models and the verified SWAT model under different GHG emission scenarios （SRES-A2, AIB and B1） in the 21st century were discussed in three time periods： 2020s （2011-2040）, 20S0s （2041-2070）, 2080s （2071-2099）. Results show that there are systematic positive trends for precipitation and temperature while the trends for runoff and evaporation will differ among sub-areas. The results will offer some references for adaptive water management in a changing environment, also including adaptation of a cross-basin water transfer project.展开更多
It is very common to design water supply system to adjust runoff. Thus it will not meet the practical needs if only the hydrologic drought in natural basin is studied. In practice the natural water balance and water d...It is very common to design water supply system to adjust runoff. Thus it will not meet the practical needs if only the hydrologic drought in natural basin is studied. In practice the natural water balance and water deficits must be researched, i. e. . the adjusting effects of the water supply sys- tem such as a reservoir should be considered, and the drought event be distinguished according to the special system. The problem of drought identification under adjusted runoff was investigated in this study. By considering water transfer during different periods, a method to distinguish hydrologic drought for the water supply system was developed, and a standard drought severity index SWDSI was proposed. The method has been applied in Pan Jiakou water supply system in China. From 1953 to 1997,a total of 14 hydrologic droughts were identified in the water supply system, among which there were 3 severe droughts, 6 moderate droughts and 5 light droughts. The results are in good agreement with the historic drought records.展开更多
From the outcrops in the Yaomoshan and Hongyanchi sections, oil shales, deep dark mudstones or black mudstones with better organic richness were found. Through the analysis of the samples in the organic petrology meth...From the outcrops in the Yaomoshan and Hongyanchi sections, oil shales, deep dark mudstones or black mudstones with better organic richness were found. Through the analysis of the samples in the organic petrology method, the microscope features of the sedimentary organic matter were studied. The results indicate that three types of kerogens present in the measured samples. Kerogen type I consists of the laminate algainite, abundant sporinite and only little content of cutinite, which can mainly generate oil. The generation hydrocarbon components of the type II kerogen are dominated by the sporinite, cutinite and little the exinite debris. The type III kerogen is comprised of the sporinite and debris of the exinite with some components of gas generation. Through the analysis of the experiments, the organic kerogen of the Lucaogou formation is mostly comprised of the type I, partially type II, and particularly type III. In Hongyanchi formation, the organic type is mixed by the types II and III. The plot of the （$1＋$2） or TOC value and the content of exinite show two trends. From the evolution of burial and the Permian source rocks in Changji Depression, the Permian formation source rock has ended the generation of hydrocarbon. A significant difference in constituents of the organic macerals among three kerogens in these samples leads to the distinction of the potential hydrocarbon generation. The Lucaogou formation for kerogen type I has better potential hydrocarbon generation. It can reach the oil peak with Ro ratio Of 0.9%. For the kerogen II, the oil peak of the source rocks comes late with the Ro ratio of 1.0% with less quantity of the generation hydrocarbon than the kerogen I. For type III, it can mainly generate gas and reach the gas peak with the Ro ratio of 1.3%. In a word, the Lucaogou formation and Hongyanchi formation source rocks with high organic richness in Permian source rocks have well exploration prospects.展开更多
On the basis of the shape and inner structure of volcanic edifice,the dip angle and coherence were selected to recognize the buried volcanic edifices in Songliao Basin.Five volcanic edifices were recognized in both tw...On the basis of the shape and inner structure of volcanic edifice,the dip angle and coherence were selected to recognize the buried volcanic edifices in Songliao Basin.Five volcanic edifices were recognized in both two methods in the first volcanic cycle of Yingcheng Formation and the prediction perfectly corresponds to the drilling results in well XS8 area.The results are satisfying when the prediction method were employed in the exploration and development of Qingshen gas field.展开更多
The tempo-spatial development of the Cenozoic Asian aridification across the Eocene-Oligocene and its controlling factors are important scientific topics in Earth Sciences, which are pertinent to regional and global t...The tempo-spatial development of the Cenozoic Asian aridification across the Eocene-Oligocene and its controlling factors are important scientific topics in Earth Sciences, which are pertinent to regional and global tectonic and climatic events. However, sedimentary rocks preserving the record of aridification during this time from central Asia(ACA) are rare. Here we present a preliminary analysis of sedimentary facies of the lower Paleogene in the northeastern Tajik Basin, which reveals that: the lower part of the studied section is dominated by shallow marine deposits of the Paratethys, the middle part is typical of alternations of eolian dune and fluvial deposits, the upper part is represented by eolian loess-sandy loess(L&SL) like facies, and the top exhibits alternations of fluvial-lacustrine and loess like facies. Based on a chronological framework derived from preliminary magnetostratigraphy, published U-Pb dating of a volcanic ash, and regional litho-stratigraphic correlations, we determine that eolian and L&SL facies accumulated in the northeastern Tajik Basin during the Late Eocene and through most of the Oligocene. These sedimentary units indicate that semi-arid to arid environments of ACA had developed at least since the late Eocene. This initial aridification is closely linked to the westward retreat of the Paratethys that was likely driven by a combination of tectonic activity and sea level changes.展开更多
文摘约50—60 Ma 前,欧亚板块与印度次大陆板块发生碰撞,导致了青藏高原的崛起,成为新生代以来地球上最为醒目的构造事件,对东亚的构造和气候格局产生了非常深远的影响。在青藏高原的周缘及内部块体之间存在着一系列的大型走滑断裂带,其长度往往达数百至数千km,深切下地壳乃至岩石圈地幔,且构造活动强烈(强震多发),研究这些大型走滑断裂带的形成演化历史对揭示青藏高原的生成扩展模式、陆内变形机制及强震机理研究等具有重要的意义。
基金Under the auspices of Special Science Foundation for Doctoral Subject of Universities,Ministry of Education(No.20020001019)
文摘The Tarim River Basin, located in the typical arid region, is one of the key regions of LUCC research in China and plays an important role in maintaining the sustainable development of the western China. In recent years,the ecological environment of the Tarim River Basin has degraded greatly. In the lower reaches, in particular, the riverbed has been dried up for more than 20 years, which accelerated the desertification and has been a great threat to people′s lives. Taking the section of the Tarim River between Qiala Lake and Taitema Lake as a typical region, an investigation on land cover changes was carried out with the support of remote sensing information of 1988 and 2000 respectively. The changes of land cover in this region were obtained: 1) Cropland tended to increase. 2) Urban or Built-up Area in 2000 was 324.4ha more than that in 1988. 3) Waters expanded by 3476.51ha. 4) Woodland and Grassland decreased, while Barren Land increased by 3824.9ha. The total amount of land use/land cover change between 1988 and 2000 is small,which is only 0.355% of the total area. It shows that the developmental pace of the lower reaches of the Tarim River is relative slow. Based on these results, the authors assessed the landscape dynamics of this region and pointed out that the degree of desertification was strengthened and the landscape dominated by sand land was further characterized by salt desert.
基金supported by National Basic Research Program of China(2010CB428406)the National Natural Science Foundation of China (No. 41071025/40730632)MWR Commonweal Project (200801001)
文摘Climate change will lead to a significant alteration in the temporal and spatial pattern variation in the regional hydrological cycle, and the subsequent lack of water, environmental deterioration, floods and droughts etc. And it is especially remarkable in semi-humid and semi-arid region. In this paper, the impacts of climate change on the hydrological cycle were analyzed for the Hai River Basin, a semi-humid and semi-arid basin and also the water receiving area of the middle route of South-to-North Water Diversion project. Meanwhile it is the most vulnerable to climate change. Firstly, the linear regression and Mann-Kendall non-parametric test methods were used to analyze the change characteristics of the hydrological and meteorological elements for the period from 1960 to 2009. The results show a significant increase in temperature, while precipitation decreases slightly, and runoff decreases drastically over the past 50 years. Secondly, the applicability of SWAT （Soil and Water Assessment Tool） model based on the DEM （Digital Elevation Model）, land use and soil type was verified in the basin. Results show the model performs well in this basin. Furthermore, the water balance model, Fu＇s theory and Koichiro＇s theory were used to calculate the actual evaporation, comparing to the simulated actual evaporation by SWAT model to validate the result for the lack of large-scale observed evaporation datasets. Possible reasons were also analyzed to explore the reasonable factor for the decline of the runoff. Finally the precipitation, temperature, runoff and evaporation response processes based on the IPCC AR4 multi-mode climate models and the verified SWAT model under different GHG emission scenarios （SRES-A2, AIB and B1） in the 21st century were discussed in three time periods： 2020s （2011-2040）, 20S0s （2041-2070）, 2080s （2071-2099）. Results show that there are systematic positive trends for precipitation and temperature while the trends for runoff and evaporation will differ among sub-areas. The results will offer some references for adaptive water management in a changing environment, also including adaptation of a cross-basin water transfer project.
基金Supported by National Natural Science Foundation of China ( No. 50579049) and Doctoral Special Foundationof China (No. 20040056060).
文摘It is very common to design water supply system to adjust runoff. Thus it will not meet the practical needs if only the hydrologic drought in natural basin is studied. In practice the natural water balance and water deficits must be researched, i. e. . the adjusting effects of the water supply sys- tem such as a reservoir should be considered, and the drought event be distinguished according to the special system. The problem of drought identification under adjusted runoff was investigated in this study. By considering water transfer during different periods, a method to distinguish hydrologic drought for the water supply system was developed, and a standard drought severity index SWDSI was proposed. The method has been applied in Pan Jiakou water supply system in China. From 1953 to 1997,a total of 14 hydrologic droughts were identified in the water supply system, among which there were 3 severe droughts, 6 moderate droughts and 5 light droughts. The results are in good agreement with the historic drought records.
基金Project(2011ZX05002-006)supported by the National Science and Technology Project,China
文摘From the outcrops in the Yaomoshan and Hongyanchi sections, oil shales, deep dark mudstones or black mudstones with better organic richness were found. Through the analysis of the samples in the organic petrology method, the microscope features of the sedimentary organic matter were studied. The results indicate that three types of kerogens present in the measured samples. Kerogen type I consists of the laminate algainite, abundant sporinite and only little content of cutinite, which can mainly generate oil. The generation hydrocarbon components of the type II kerogen are dominated by the sporinite, cutinite and little the exinite debris. The type III kerogen is comprised of the sporinite and debris of the exinite with some components of gas generation. Through the analysis of the experiments, the organic kerogen of the Lucaogou formation is mostly comprised of the type I, partially type II, and particularly type III. In Hongyanchi formation, the organic type is mixed by the types II and III. The plot of the （$1＋$2） or TOC value and the content of exinite show two trends. From the evolution of burial and the Permian source rocks in Changji Depression, the Permian formation source rock has ended the generation of hydrocarbon. A significant difference in constituents of the organic macerals among three kerogens in these samples leads to the distinction of the potential hydrocarbon generation. The Lucaogou formation for kerogen type I has better potential hydrocarbon generation. It can reach the oil peak with Ro ratio Of 0.9%. For the kerogen II, the oil peak of the source rocks comes late with the Ro ratio of 1.0% with less quantity of the generation hydrocarbon than the kerogen I. For type III, it can mainly generate gas and reach the gas peak with the Ro ratio of 1.3%. In a word, the Lucaogou formation and Hongyanchi formation source rocks with high organic richness in Permian source rocks have well exploration prospects.
基金Supported by NSFC Project No 40372066,and SRFDP No 20030183042
文摘On the basis of the shape and inner structure of volcanic edifice,the dip angle and coherence were selected to recognize the buried volcanic edifices in Songliao Basin.Five volcanic edifices were recognized in both two methods in the first volcanic cycle of Yingcheng Formation and the prediction perfectly corresponds to the drilling results in well XS8 area.The results are satisfying when the prediction method were employed in the exploration and development of Qingshen gas field.
基金supported by the National Natural Science Foundation of China(Grant Nos.41302144&41130102)the Programme of Introducing Talents of Discipline to Universities(111 Project)(Grant No.B06026)the Open Foundation of MOE Key Laboratory of Western China’s Environmental System,Lanzhou University(Grant No.LZUJBKY-2013-BT01)
文摘The tempo-spatial development of the Cenozoic Asian aridification across the Eocene-Oligocene and its controlling factors are important scientific topics in Earth Sciences, which are pertinent to regional and global tectonic and climatic events. However, sedimentary rocks preserving the record of aridification during this time from central Asia(ACA) are rare. Here we present a preliminary analysis of sedimentary facies of the lower Paleogene in the northeastern Tajik Basin, which reveals that: the lower part of the studied section is dominated by shallow marine deposits of the Paratethys, the middle part is typical of alternations of eolian dune and fluvial deposits, the upper part is represented by eolian loess-sandy loess(L&SL) like facies, and the top exhibits alternations of fluvial-lacustrine and loess like facies. Based on a chronological framework derived from preliminary magnetostratigraphy, published U-Pb dating of a volcanic ash, and regional litho-stratigraphic correlations, we determine that eolian and L&SL facies accumulated in the northeastern Tajik Basin during the Late Eocene and through most of the Oligocene. These sedimentary units indicate that semi-arid to arid environments of ACA had developed at least since the late Eocene. This initial aridification is closely linked to the westward retreat of the Paratethys that was likely driven by a combination of tectonic activity and sea level changes.
