Hydrochemical characteristics and solute dynamics of bulk meltwater draining from Urumqi Glacier No.1 were investigated in years 2006 and 2007. The glacial meltwater was slightly alkaline with the mean pH of 7.64 and ...Hydrochemical characteristics and solute dynamics of bulk meltwater draining from Urumqi Glacier No.1 were investigated in years 2006 and 2007. The glacial meltwater was slightly alkaline with the mean pH of 7.64 and 7.61 in 2006 and 2007, respectively. In the meltwater, the dominant anions were the bicarbonate and sulphate, and the dominant cation was calcium. The concentration of major cations were varied as c（Ca2＋） 〉 c（Mg2＋） 〉 c（K＋） 〉 c（Na＋）, while the order for the cations was c（HCO3-） 〉 c（SO42-） 〉 c（NQ-） 〉 c（C1-）. The total dissolved solids （TDS） in meltwater had inverse relationships with the diurnal discharge. The major ion composition of meltwater was mainly controlled by rock weathering as inferred from the Gibbs model. Furthermore, the ion ratios and Piper diagram indicated that the main processes controlling the meltwater chemistry were carbonate weathering, pyrite weathering and feldspar weathering in rocks, and Ca2＋ and HCQ- were the dominant ions during the carbonate weathering process. Solute flux calculation at Glacier No.1 station suggested that chemical denudation rates were 11.46 and 13.90 tonkm-2.yr-1 in 2006 and 2007, respectively.展开更多
Based on the flood affected area （FA） data of the provinces in China from 1950 to 2005, the article discusses the change of the flood patterns in China, and investigates its relationship with climate change and huma...Based on the flood affected area （FA） data of the provinces in China from 1950 to 2005, the article discusses the change of the flood patterns in China, and investigates its relationship with climate change and human activities. The flood center shifted from North China and the Yangtze-Huaihe basin in the 1950s towards the south, north and west of China, and located in the south of the Yangtze River and South China after the 1990s. The FA in the western provinces was continuously on the rise since the 1950s. There are two characteristics for the future flood pattem in China. The pattern of ＂flood in the south and drought in the north＂ depends on the north-south shift of the maximum rainfall region in eastern China. The flood intensification to the west of Hu Huanyong＇s line mainly results from the increase of rainfall, extreme precipitation and the melting of glaciers under the background of human activity magnification.展开更多
基金supported by the Knowledge Innovation Project of the Chinese Academy of Sciences(KZCX2-EW-311)the National Natural Science Foundation of China(Nos. 91025012,40701034,J0630966/J0109, 40701035)+1 种基金the SKLCS founding(SKLCS-ZZ-201004,SKLCS-ZZ-2012-01-01)the Foundation for Excellent Youth Scholars of CAREERI,Chinese Academy of Sciences(Y184C81001)
文摘Hydrochemical characteristics and solute dynamics of bulk meltwater draining from Urumqi Glacier No.1 were investigated in years 2006 and 2007. The glacial meltwater was slightly alkaline with the mean pH of 7.64 and 7.61 in 2006 and 2007, respectively. In the meltwater, the dominant anions were the bicarbonate and sulphate, and the dominant cation was calcium. The concentration of major cations were varied as c（Ca2＋） 〉 c（Mg2＋） 〉 c（K＋） 〉 c（Na＋）, while the order for the cations was c（HCO3-） 〉 c（SO42-） 〉 c（NQ-） 〉 c（C1-）. The total dissolved solids （TDS） in meltwater had inverse relationships with the diurnal discharge. The major ion composition of meltwater was mainly controlled by rock weathering as inferred from the Gibbs model. Furthermore, the ion ratios and Piper diagram indicated that the main processes controlling the meltwater chemistry were carbonate weathering, pyrite weathering and feldspar weathering in rocks, and Ca2＋ and HCQ- were the dominant ions during the carbonate weathering process. Solute flux calculation at Glacier No.1 station suggested that chemical denudation rates were 11.46 and 13.90 tonkm-2.yr-1 in 2006 and 2007, respectively.
基金funded by the key program of National Natural Science Foundation of China (Grant No.40730635)Commonweal and Specialized Program for Scientific Research,Ministry of Water Resources of China (Grant No.2007011024)
文摘Based on the flood affected area （FA） data of the provinces in China from 1950 to 2005, the article discusses the change of the flood patterns in China, and investigates its relationship with climate change and human activities. The flood center shifted from North China and the Yangtze-Huaihe basin in the 1950s towards the south, north and west of China, and located in the south of the Yangtze River and South China after the 1990s. The FA in the western provinces was continuously on the rise since the 1950s. There are two characteristics for the future flood pattem in China. The pattern of ＂flood in the south and drought in the north＂ depends on the north-south shift of the maximum rainfall region in eastern China. The flood intensification to the west of Hu Huanyong＇s line mainly results from the increase of rainfall, extreme precipitation and the melting of glaciers under the background of human activity magnification.
