The Tan-Lu Fault was once a transform fault in the Paleotethys, west of which was the Qinling-Dabie Ocean separating the Yangtze Craton from the North China Craton, and east of which was the Su-Lu Ocean separating the...The Tan-Lu Fault was once a transform fault in the Paleotethys, west of which was the Qinling-Dabie Ocean separating the Yangtze Craton from the North China Craton, and east of which was the Su-Lu Ocean separating the Su-Wan Block from the Jiao-Liao Craton. The Qinling-Dabie Ocean closed in the Indosinian orogeny, which created the China-Southeast Asia Subcontinent, with the Tan-Lu Fault becoming a marginal shear zone along the newly-formed amalgamated subcontinent. The Su-Lu Ocean subducted partly in the Indosinian.orogeny, but not closed. In the Jurassic and Early Cretaceous, the Su-Wan Block drifted northwards with subduction of the Su-Lu Ocean and moved westwards to converge the subcontinent by sinistral sheafing of the ENE-striking fractures. The Su-Lu Ocean finally closed and the Su-Wan Block collided with the Jiao-Liao Craton in the Early Cretaceous, which constituted a part of the magnificent interplate Yanshanides. The interplate orogeny rejuvenated the fossil sutures and deep fractures, as well as the Indosinian orogen, and the intraplate （intracontinental） Yanshanian orogeny occurred in the subcontinent. The East Asia Yanshanides, consisting of the interplate orogens in the outer side and the intraplate orogens in the inner side, collapsed quickly in the latest Early Cretaceous and Late Cretaceous. The eastern China area entered a tensile period from the Eogene, and the tectonic differentiation between the central and eastern China areas since the Jurassic was further strengthened.展开更多
The author proves the existence and movement of a deep-seated fraetural Zone located in the eenter zone of the diwa-type faulted basin in central Hebei Province. This deep-seated fraeturai zone tending in NNE directio...The author proves the existence and movement of a deep-seated fraetural Zone located in the eenter zone of the diwa-type faulted basin in central Hebei Province. This deep-seated fraeturai zone tending in NNE direction is a structural effect of the mtodle East Asin Grustobody in the Mexozoic-Cenozoic. This paper will diseuss the formation, evolution and the meehanism of the deep-seated fraetural zone, faulted basin and the buried hills as well as their relationships. The uthor expounds that the deep geological process is the major factor of the structural effect.展开更多
Dramatic changes in land use have occurred in arid and semi-arid landsof Asia during the 20th century. Grassland conversion into croplands and ecosystem degradation is widespread due to the high growth rate of human p...Dramatic changes in land use have occurred in arid and semi-arid landsof Asia during the 20th century. Grassland conversion into croplands and ecosystem degradation is widespread due to the high growth rate of human population and political reforms of pastoral systems. Rangeland degradation made many parts of this region vulnerable to environmental and political changes. The collapse of the livestock sector in some states of central Asia, expansion of livestock inChina and intensive degradation of grasslands in China are examples of the responses of pastoral systems to these changes over the past decades. Carbon dynamics in this region is highly variable in space and time. Land use/cover changes with widespread reduction of forest and grasslands increased carbon emission from the region.展开更多
The arid and semi-arid(ASA) region of Asia occupies a large area in the middle latitudes of the Northern Hemisphere, of which the main body is the ASA region of Central and East Asia(CEA). In this region, the climate ...The arid and semi-arid(ASA) region of Asia occupies a large area in the middle latitudes of the Northern Hemisphere, of which the main body is the ASA region of Central and East Asia(CEA). In this region, the climate is fragile and the environment is sensitive. The eastern part of the ASA region of CEA is located in the marginal zone of the East Asian monsoon and is jointly influenced by westerly circulation and the monsoon system, while in the western part of the ASA of CEA,the climate is mainly controlled by westerly circulation. To understand and predict the climate over this region, it is necessary to investigate the influence of general circulation on the climate system over the ASA region of CEA. In this paper, recent progress in understanding the relationship between the general circulation and climate change over the ASA region is systematically reviewed. Previous studies have demonstrated that atmospheric circulation represents a significant factor in climate change over the ASA region of CEA. In the years with a strong East Asian summer monsoon, the water vapor flux increases and precipitation is abundant in the southeastern part of Northwest China. The opposite situation occurs in years when the East Asian summer monsoon is weak. With the weakening of the East Asian summer monsoon, the climate tends to dry over the semi-arid region located in the monsoon marginal zone. Recently, owing to the strengthening of the South Asian monsoon, more water vapor has been transported to the ASA region of Asia. The Plateau summer monsoon intensity and the precipitation in summer exhibit a significant positive correlation in Central Asia but a negative correlation in North China and Mongolia. A significant positive correlation also exists between the westerly index and the temperature over the arid region of CEA. The change in the westerly circulation may be the main factor affecting precipitation over the arid region of Central Asia.展开更多
研究中东亚干旱区2001-2013年期间土地覆盖变化特征和人类活动对潜在自然植被的影响程度,对保护生态环境和合理利用土地资源具有重要意义。本研究首先基于气象数据和综合顺序分类法(comprehensive and sequential classification system...研究中东亚干旱区2001-2013年期间土地覆盖变化特征和人类活动对潜在自然植被的影响程度,对保护生态环境和合理利用土地资源具有重要意义。本研究首先基于气象数据和综合顺序分类法(comprehensive and sequential classification system,CSCS)模型模拟了中东亚干旱区的潜在自然植被分布状况,其次基于2001-2013年的MODIS土地覆盖数据集分析了土地覆盖变化情况,最后在前两者的基础上研究了潜在自然植被的人类占用强度及其变化特征。结果表明,1)潜在自然植被以林地、草地、冻原、荒漠四大类为主;2)中东亚干旱区土地覆盖变化较大,其中中亚灌丛面积波动增加,中国华北干旱区农田面积扩张明显,蒙古国中西部灌丛和草地覆盖面积明显减少;3)研究区人类占用强度增强。其中,2010-2013年增长较为明显,4年间人类占用面积占研究区面积的比例增长了1.45%。潜在草地人类占用比例在2009-2013年间增幅最大,为2.88%;潜在林地人类占用比例在2001-2005年间增幅最大,为6.99%。4)在北哈萨克斯坦三州(北哈萨克斯坦州、阿克莫拉州、库斯塔奈州),人口迁移是潜在自然植被人类占用强度变化的主要因素,2006-2013年间人类占用强度比例增长了11.38%;中国的呼伦贝尔和山西干旱区,农业开发是人类占用强度增大的主要因素,2001-2013年间人类占用强度比例分别增长了6.62%和17.64%。展开更多
基金supported by the National Natural Science Foundation of China[grant numbers 41991280 and 42025502]the Guangdong Major Project of Basic and Applied Basic Research[grant number 2020B0301030004]the State Scholarship Fund by China Scholarship Council[grant number 202109045003].
文摘The Tan-Lu Fault was once a transform fault in the Paleotethys, west of which was the Qinling-Dabie Ocean separating the Yangtze Craton from the North China Craton, and east of which was the Su-Lu Ocean separating the Su-Wan Block from the Jiao-Liao Craton. The Qinling-Dabie Ocean closed in the Indosinian orogeny, which created the China-Southeast Asia Subcontinent, with the Tan-Lu Fault becoming a marginal shear zone along the newly-formed amalgamated subcontinent. The Su-Lu Ocean subducted partly in the Indosinian.orogeny, but not closed. In the Jurassic and Early Cretaceous, the Su-Wan Block drifted northwards with subduction of the Su-Lu Ocean and moved westwards to converge the subcontinent by sinistral sheafing of the ENE-striking fractures. The Su-Lu Ocean finally closed and the Su-Wan Block collided with the Jiao-Liao Craton in the Early Cretaceous, which constituted a part of the magnificent interplate Yanshanides. The interplate orogeny rejuvenated the fossil sutures and deep fractures, as well as the Indosinian orogen, and the intraplate （intracontinental） Yanshanian orogeny occurred in the subcontinent. The East Asia Yanshanides, consisting of the interplate orogens in the outer side and the intraplate orogens in the inner side, collapsed quickly in the latest Early Cretaceous and Late Cretaceous. The eastern China area entered a tensile period from the Eogene, and the tectonic differentiation between the central and eastern China areas since the Jurassic was further strengthened.
文摘The author proves the existence and movement of a deep-seated fraetural Zone located in the eenter zone of the diwa-type faulted basin in central Hebei Province. This deep-seated fraeturai zone tending in NNE direction is a structural effect of the mtodle East Asin Grustobody in the Mexozoic-Cenozoic. This paper will diseuss the formation, evolution and the meehanism of the deep-seated fraetural zone, faulted basin and the buried hills as well as their relationships. The uthor expounds that the deep geological process is the major factor of the structural effect.
基金the NASA-EOS Program and the National Science Foundation-Long-Term Studies Program.
文摘Dramatic changes in land use have occurred in arid and semi-arid landsof Asia during the 20th century. Grassland conversion into croplands and ecosystem degradation is widespread due to the high growth rate of human population and political reforms of pastoral systems. Rangeland degradation made many parts of this region vulnerable to environmental and political changes. The collapse of the livestock sector in some states of central Asia, expansion of livestock inChina and intensive degradation of grasslands in China are examples of the responses of pastoral systems to these changes over the past decades. Carbon dynamics in this region is highly variable in space and time. Land use/cover changes with widespread reduction of forest and grasslands increased carbon emission from the region.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41475095, 91737101 & 91744311)
文摘The arid and semi-arid(ASA) region of Asia occupies a large area in the middle latitudes of the Northern Hemisphere, of which the main body is the ASA region of Central and East Asia(CEA). In this region, the climate is fragile and the environment is sensitive. The eastern part of the ASA region of CEA is located in the marginal zone of the East Asian monsoon and is jointly influenced by westerly circulation and the monsoon system, while in the western part of the ASA of CEA,the climate is mainly controlled by westerly circulation. To understand and predict the climate over this region, it is necessary to investigate the influence of general circulation on the climate system over the ASA region of CEA. In this paper, recent progress in understanding the relationship between the general circulation and climate change over the ASA region is systematically reviewed. Previous studies have demonstrated that atmospheric circulation represents a significant factor in climate change over the ASA region of CEA. In the years with a strong East Asian summer monsoon, the water vapor flux increases and precipitation is abundant in the southeastern part of Northwest China. The opposite situation occurs in years when the East Asian summer monsoon is weak. With the weakening of the East Asian summer monsoon, the climate tends to dry over the semi-arid region located in the monsoon marginal zone. Recently, owing to the strengthening of the South Asian monsoon, more water vapor has been transported to the ASA region of Asia. The Plateau summer monsoon intensity and the precipitation in summer exhibit a significant positive correlation in Central Asia but a negative correlation in North China and Mongolia. A significant positive correlation also exists between the westerly index and the temperature over the arid region of CEA. The change in the westerly circulation may be the main factor affecting precipitation over the arid region of Central Asia.
文摘研究中东亚干旱区2001-2013年期间土地覆盖变化特征和人类活动对潜在自然植被的影响程度,对保护生态环境和合理利用土地资源具有重要意义。本研究首先基于气象数据和综合顺序分类法(comprehensive and sequential classification system,CSCS)模型模拟了中东亚干旱区的潜在自然植被分布状况,其次基于2001-2013年的MODIS土地覆盖数据集分析了土地覆盖变化情况,最后在前两者的基础上研究了潜在自然植被的人类占用强度及其变化特征。结果表明,1)潜在自然植被以林地、草地、冻原、荒漠四大类为主;2)中东亚干旱区土地覆盖变化较大,其中中亚灌丛面积波动增加,中国华北干旱区农田面积扩张明显,蒙古国中西部灌丛和草地覆盖面积明显减少;3)研究区人类占用强度增强。其中,2010-2013年增长较为明显,4年间人类占用面积占研究区面积的比例增长了1.45%。潜在草地人类占用比例在2009-2013年间增幅最大,为2.88%;潜在林地人类占用比例在2001-2005年间增幅最大,为6.99%。4)在北哈萨克斯坦三州(北哈萨克斯坦州、阿克莫拉州、库斯塔奈州),人口迁移是潜在自然植被人类占用强度变化的主要因素,2006-2013年间人类占用强度比例增长了11.38%;中国的呼伦贝尔和山西干旱区,农业开发是人类占用强度增大的主要因素,2001-2013年间人类占用强度比例分别增长了6.62%和17.64%。
