Modern hydrobiology,mainly,is based on conception,which may be named Conception of unicity of ecosystem stable state(CUESS):Mature ecosystems are stable and in dynamic equilibrium.Ecosystem state fluctuates around
This article recounts the current state of the research, developmemt and exploitation of the salt-lake resources in China’s hinterland with emphasis placed on those in Qinghai Province. It suggests that R&D input...This article recounts the current state of the research, developmemt and exploitation of the salt-lake resources in China’s hinterland with emphasis placed on those in Qinghai Province. It suggests that R&D input in and exploitation of the resources be stepped up, as this is of vital significance in boosting the regional economy of northwest China.展开更多
Nam Co is the largest (1920 km2 in area) and highest (4718 m above sea level) lake in Tibet. According to the discovery of lake terraces and highstand lacustrine deposits at several places in Nam Co and its adjacent a...Nam Co is the largest (1920 km2 in area) and highest (4718 m above sea level) lake in Tibet. According to the discovery of lake terraces and highstand lacustrine deposits at several places in Nam Co and its adjacent areas, the authors confirm the existence of an ancient large lake in the southeastern part of the northern Tibetan Plateau. On the basis of the U-series, 14C and ESR dating, coupled with the levelling survey of lake deposits and geomorphology, the evolutionary process of the ancient large lake in the southeastern part of the northern Tibetan Plateau may fall into three stages: (1) the ancient large lake stage at 115-40 ka BP, when the ancient lake level was 140-26 m above the level of present Nam Co; (2) the outflow lake stage at 40-30 ka BP, when the ancient level was 26-19 m above the present lake level; and (3) the Nam Co stage since 30 ka BP, when the ancient lake level was < 19 m above the present lake level. During the ancient large lake stage, a large number of modern large, medium-sized and small lakes, including Nam Co, Siling Co and Zhari Namco, in the southeastern part of the northern Tibetan Plateau, were connected into a single large ancient lake, rather than several separate lakes connected by river channels. Its areal extent may have gone beyond the watersheds of the modern endorheic and exorheic drainage systems; so it may be called the 'ancient east lake', 'ancient south lake' and 'ancient west lake'. It might also be connected with other ancient lakes in the southern and western parts of the northern Tibetan Plateau to form a unified 'ancient large lake' on the northern Tibetan Plateau.展开更多
The Himalayas are prone to glacial lake outburst floods,which can pose a severe threat to downstream villages and infrastructure.The Zhangmu and Gyirong land treaty ports are located on the China-Nepal border in the c...The Himalayas are prone to glacial lake outburst floods,which can pose a severe threat to downstream villages and infrastructure.The Zhangmu and Gyirong land treaty ports are located on the China-Nepal border in the central Himalayas.In recent years,the expansion of glacial lakes has increased the threat of these two port regions.This article describes the results of mapping the glacial lakes larger than 0.01 km^2 in the Zhangmu and Gyirong port regions and analyzes their change.It provides a comprehensive assessment of potentially dangerous glacial lakes and predicts the development of future glacial lakes.From 1988 to 2019,the glacial lakes in these port regions underwent"expansion",and moraine-dammed lakes show the most significant expansion trend.A total of eleven potentially dangerous glacial lakes are identified based on the assessment criteria and historical outburst events;most expanded by more than 150%from 1988 to 2019,with some by over 500%.The Cirenmaco,a moraine-dammed lake,is extremely prone to overtopping due to ice avalanches or the melting of dead ice in the dam.For other large lakes,such as the Jialongco,Gangxico and Galongco,ice avalanches may likely cause the lakes to burst besides self-destructive failure.The potential dangers of the Youmojianco glacial lakes,including lakes Nos.9,10 and 11,will increase in the future.In addition,the glacier-bed topography model predicts that 113 glacial lakes with a size larger than 0.01 km^2,a total area of 11.88 km2 and a total volume of 6.37×10^9 m^3 will form in the study area by the end of the 21 century.Due to global warming,the glacial lakes in the Zhangmu and Gyirong port regions will continue to grow in the short term,and hence the risk of glacial lake outburst floods will increase.展开更多
In contrast to the input perspective for evaluating planning metrics, this research takes the climatic environmental output effects as the starting point for assessing ecological city construction. Based on approaches...In contrast to the input perspective for evaluating planning metrics, this research takes the climatic environmental output effects as the starting point for assessing ecological city construction. Based on approaches such as observation data analysis, meteorological model simulation, and remote sensing, a set of climatic environmental performance assessment methods is developed and established. These methods mainly focus on surface ventilation assessment and urban thermal environment assessment. With the Yanqi Lake ecological development demonstration area located in Huairou district, Beijing as an example, the assessment of the local climatic environment before and after the construction are conducted, and relevant policy suggestions for urban planning and construction are presented. The results show that after development, the ventilation capacity will decrease overall and the ventilation potential index will decrease from 0.53 to 0.44. While this is not a large reduction, and is still at a favorable level, the ventilation potential in some local areas will markedly decrease. Furthermore, the thermal environment will become poorer to some extent; the urban heat island(UHI) area and intensity will increase compared with the current situation;continuous heat islands may occur in local areas; the UHI potential index of the core area will rise from 0.0878 to 0.1217(still a favorable level).Therefore, urban surfaces should be carefully developed and arranged during planning. It is suggested that the negative impacts of large areas of urban construction on the local climatic environment in the Yanqi Lake could be mitigated by 1) strengthening the airflow by introducing fresh,cold, northwesterly air via constructed ventilation corridors, 2) increasing the number of ecological cold sources, particularly for water bodies and green belts to prevent the UHI in the southern region of Yanqi Lake from becoming linked with each other, and 3) considering a pre-program before sub-domain and building planning to obtain optimum building locations. Different construction standards should be developed for different ventilation potential and UHI intensity levels. For strong heat island areas, land areas should be reserved to serve as cold sources.展开更多
文摘Modern hydrobiology,mainly,is based on conception,which may be named Conception of unicity of ecosystem stable state(CUESS):Mature ecosystems are stable and in dynamic equilibrium.Ecosystem state fluctuates around
文摘This article recounts the current state of the research, developmemt and exploitation of the salt-lake resources in China’s hinterland with emphasis placed on those in Qinghai Province. It suggests that R&D input in and exploitation of the resources be stepped up, as this is of vital significance in boosting the regional economy of northwest China.
文摘Nam Co is the largest (1920 km2 in area) and highest (4718 m above sea level) lake in Tibet. According to the discovery of lake terraces and highstand lacustrine deposits at several places in Nam Co and its adjacent areas, the authors confirm the existence of an ancient large lake in the southeastern part of the northern Tibetan Plateau. On the basis of the U-series, 14C and ESR dating, coupled with the levelling survey of lake deposits and geomorphology, the evolutionary process of the ancient large lake in the southeastern part of the northern Tibetan Plateau may fall into three stages: (1) the ancient large lake stage at 115-40 ka BP, when the ancient lake level was 140-26 m above the level of present Nam Co; (2) the outflow lake stage at 40-30 ka BP, when the ancient level was 26-19 m above the present lake level; and (3) the Nam Co stage since 30 ka BP, when the ancient lake level was < 19 m above the present lake level. During the ancient large lake stage, a large number of modern large, medium-sized and small lakes, including Nam Co, Siling Co and Zhari Namco, in the southeastern part of the northern Tibetan Plateau, were connected into a single large ancient lake, rather than several separate lakes connected by river channels. Its areal extent may have gone beyond the watersheds of the modern endorheic and exorheic drainage systems; so it may be called the 'ancient east lake', 'ancient south lake' and 'ancient west lake'. It might also be connected with other ancient lakes in the southern and western parts of the northern Tibetan Plateau to form a unified 'ancient large lake' on the northern Tibetan Plateau.
基金This work is supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP,Grant No.2019QZKK0208)the Innovation Fund Designated to Graduate Students of Yunnan University(Grant No.2020Z47)+1 种基金the National Natural Science Foundation of China(Grant No.41761144075)the Research Seed Fund for Talents of Yunnan University(No.YJRC3201702).
文摘The Himalayas are prone to glacial lake outburst floods,which can pose a severe threat to downstream villages and infrastructure.The Zhangmu and Gyirong land treaty ports are located on the China-Nepal border in the central Himalayas.In recent years,the expansion of glacial lakes has increased the threat of these two port regions.This article describes the results of mapping the glacial lakes larger than 0.01 km^2 in the Zhangmu and Gyirong port regions and analyzes their change.It provides a comprehensive assessment of potentially dangerous glacial lakes and predicts the development of future glacial lakes.From 1988 to 2019,the glacial lakes in these port regions underwent"expansion",and moraine-dammed lakes show the most significant expansion trend.A total of eleven potentially dangerous glacial lakes are identified based on the assessment criteria and historical outburst events;most expanded by more than 150%from 1988 to 2019,with some by over 500%.The Cirenmaco,a moraine-dammed lake,is extremely prone to overtopping due to ice avalanches or the melting of dead ice in the dam.For other large lakes,such as the Jialongco,Gangxico and Galongco,ice avalanches may likely cause the lakes to burst besides self-destructive failure.The potential dangers of the Youmojianco glacial lakes,including lakes Nos.9,10 and 11,will increase in the future.In addition,the glacier-bed topography model predicts that 113 glacial lakes with a size larger than 0.01 km^2,a total area of 11.88 km2 and a total volume of 6.37×10^9 m^3 will form in the study area by the end of the 21 century.Due to global warming,the glacial lakes in the Zhangmu and Gyirong port regions will continue to grow in the short term,and hence the risk of glacial lake outburst floods will increase.
基金sponsored by Beijing Municipal Science and Technology Project(Z131100001113026)the Program of the Research and Innovation Team on Urban Climate Assessment of Beijing Meteorological Bureau,Climate Change Special Foundation of China Meteorology Administration(CCSF201506)+1 种基金Science and technology project of Beijing Meteorological Bureau(BMBKJ201402002)National Natural Science Foundation of China(71473146)
文摘In contrast to the input perspective for evaluating planning metrics, this research takes the climatic environmental output effects as the starting point for assessing ecological city construction. Based on approaches such as observation data analysis, meteorological model simulation, and remote sensing, a set of climatic environmental performance assessment methods is developed and established. These methods mainly focus on surface ventilation assessment and urban thermal environment assessment. With the Yanqi Lake ecological development demonstration area located in Huairou district, Beijing as an example, the assessment of the local climatic environment before and after the construction are conducted, and relevant policy suggestions for urban planning and construction are presented. The results show that after development, the ventilation capacity will decrease overall and the ventilation potential index will decrease from 0.53 to 0.44. While this is not a large reduction, and is still at a favorable level, the ventilation potential in some local areas will markedly decrease. Furthermore, the thermal environment will become poorer to some extent; the urban heat island(UHI) area and intensity will increase compared with the current situation;continuous heat islands may occur in local areas; the UHI potential index of the core area will rise from 0.0878 to 0.1217(still a favorable level).Therefore, urban surfaces should be carefully developed and arranged during planning. It is suggested that the negative impacts of large areas of urban construction on the local climatic environment in the Yanqi Lake could be mitigated by 1) strengthening the airflow by introducing fresh,cold, northwesterly air via constructed ventilation corridors, 2) increasing the number of ecological cold sources, particularly for water bodies and green belts to prevent the UHI in the southern region of Yanqi Lake from becoming linked with each other, and 3) considering a pre-program before sub-domain and building planning to obtain optimum building locations. Different construction standards should be developed for different ventilation potential and UHI intensity levels. For strong heat island areas, land areas should be reserved to serve as cold sources.
