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
Arriving to the east African coast in the 16th century, Portuguese faced an important and well-structured commercial network dominated by Muslim merchants. Operating throughout the Indian Ocean and in articulation wit...Arriving to the east African coast in the 16th century, Portuguese faced an important and well-structured commercial network dominated by Muslim merchants. Operating throughout the Indian Ocean and in articulation with the inland African trade routes by way of the coastal settlements from Bazaruto up to the north of Mozambique, this network bustled luxury goods and basic goods benefiting either from a network of inter-personal relationships and kinship that supported the whole business, or from an ancestral knowledge on the techniques and particular procedures indispensable to navigating in the Indian Ocean. This trade made the prosperity of small southern ports, like Sofala or Mozambique long before the Portuguese arrival. However, this trade was so much dependent on the network＇s capacity of organisation and the supply demand relation of the goods involved, as well as on other factors such as the political stability of the African kingdoms, the environmental changes that shaped flows and trade routes or the actual knowledge of the region and of the different forms of organization of local communities. By focusing in the ports of Sofala and Mozambique and the information provided by the Portuguese documents we intend to analyse its evolution during the 16th century in order to understand its role in the Indian Ocean commercial network under Portuguese rule.展开更多
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.
文摘Arriving to the east African coast in the 16th century, Portuguese faced an important and well-structured commercial network dominated by Muslim merchants. Operating throughout the Indian Ocean and in articulation with the inland African trade routes by way of the coastal settlements from Bazaruto up to the north of Mozambique, this network bustled luxury goods and basic goods benefiting either from a network of inter-personal relationships and kinship that supported the whole business, or from an ancestral knowledge on the techniques and particular procedures indispensable to navigating in the Indian Ocean. This trade made the prosperity of small southern ports, like Sofala or Mozambique long before the Portuguese arrival. However, this trade was so much dependent on the network＇s capacity of organisation and the supply demand relation of the goods involved, as well as on other factors such as the political stability of the African kingdoms, the environmental changes that shaped flows and trade routes or the actual knowledge of the region and of the different forms of organization of local communities. By focusing in the ports of Sofala and Mozambique and the information provided by the Portuguese documents we intend to analyse its evolution during the 16th century in order to understand its role in the Indian Ocean commercial network under Portuguese rule.
