Alpine glaciers are the natural solid reservoirs that releases amount of meltwater to supply streams every year. Glacier meltwater, adjuSting the yearly variation of stream runoff and making it trend to wards stablen...Alpine glaciers are the natural solid reservoirs that releases amount of meltwater to supply streams every year. Glacier meltwater, adjuSting the yearly variation of stream runoff and making it trend to wards stableness, becomes the relible water resourc展开更多
Hydrology of the high glacierized region in the Tianshan Mountains is an important water resource for arid and semiarid areas of China,even Central Asia.The hydrological process is complex to understand,due to the hig...Hydrology of the high glacierized region in the Tianshan Mountains is an important water resource for arid and semiarid areas of China,even Central Asia.The hydrological process is complex to understand,due to the high variability in cli mate and the lack of hydrometeorological data.Based on field observations,the present study analyzes the meteorological and hydrological characteristics of the Koxkar Glacier River Basin during 20082011;and the factors influencing climate impact on glacier hydrology are discussed.The results show that precipitation at the terminus of the glacier was 426.2 mm,471.8 mm,624.9 mm,and 532 mm in 2008,2009,2010,and 2011,respectively.Discharge increases starting in May,reaches its highest value in July and August,and then starts to decrease.The mean annual discharge was 118.23×106 m3 during the four years observed,with 87.0%occurring in the ablation season(May September).During the study period,the runoff in August accounted for 29%of total streamflow,followed by July(22%)and June(14%).The runoff exhibited obviously high interannual variability from April to September,induced by drastic changes in climate factors.Discharge autocorrelations are very high for all the years.The climate factors show different influences on discharge.The highest correlation R between daily temperature and discharge was for a time lag of 23 days 2on the Koxkar Glacier(0.660.76).The daily depth of runoff to daily temperature and daily water vapor pressure had an R value of 0.56 and 0.69,respective ly,which could be described by an exponential function.A closer relationship is found between runoff and either tempera ture or water vapor pressure on a monthly scale;the R2 values are 0.65 and 0.78,respectively.The study helps us to under stand the mechanisms of the hydrological meteorological system of typical regional glaciers and to provide a reference for glacier-runoff simulations and water-resource management.展开更多
Hydrological processes were compared, with and without the influence of precipita- tion on discharge, to identify the differences between glacierized and non-glacierized catchments in the Urumqi River source region, o...Hydrological processes were compared, with and without the influence of precipita- tion on discharge, to identify the differences between glacierized and non-glacierized catchments in the Urumqi River source region, on the northern slope of the eastern Tianshan Mountains, during the melting season （May-September） in 2011. The study was based on hydrological data observed at 10-min intervals, meteorological data observed at 15-min intervals, and glacier melting and snow observations from the Empty Cirque, Zongkong, and Urumqi Glacier No.1 gauging stations. The results indicated that the discharge differed markedly among the three gauging stations. The daily discharge was more than the nightly discharge at the Glacier No.1 gauging station, which contrasted with the patterns observed at the Zongkong and Empty Cirque gauging stations. There was a clear daily variation in the discharge at the three gauging stations, with differences in the magnitude and duration of the peak discharge. When precipitation was not considered, the time-lags between the maximum discharge and the highest temperature were 1-3 h, 10-16 h, and 5-11 h at the Glacier No.l, Empty Cirque, and Zongkong gauging stations, respectively. When precipitation was taken into consideration, the corresponding time-lags were 0-1 h, 13 h, and 6-7 h, respectively. Therefore, the duration from the generation of discharge to confluence was the shortest in the glacierized catchment and the longest in the catchment where was mainly covered by snow. It was also shown that the hydrological process from the generation of discharge to confluence shortened when precipitation was considered. The factors influencing changes in the discharge among the three gauging stations were different. For Glacier No.1 station, the discharge was mainly controlled by heat conditions in the glacierized region, and the discharge displayed an accelerated growth when the temperature exceeded 5℃ in the melt season. It was found that the englacial and subglacial drainage channel of Glacier No.1 had become simpler during the past 20 years. Its weaker retardance and storage of glacier melting water resulted in rapid discharge confluence. It was also shown that the discharge curve and the time-lag between the maximum discharge and the highest temperature could be used to reveal the evolution of the drainage system and the process of glacier and snow melting at different levels of glacier coverage.展开更多
In this study, the Glacier Lake Outburst Flood(GLOF) that occurred over Kedarnath in June 2013 was modeled using integrated observations from the field and Remote Sensing(RS). The lake breach parameters such as area, ...In this study, the Glacier Lake Outburst Flood(GLOF) that occurred over Kedarnath in June 2013 was modeled using integrated observations from the field and Remote Sensing(RS). The lake breach parameters such as area, depth, breach, and height have been estimated from the field observations and Remote Sensing(RS) data. A number of modelling approaches, including Snow Melt Runoff Model(SRM), Modified Single Flow model(MSF), Watershed Management System(WMS), Simplified Dam Breach Model(SMPDBK) and BREACH were used to model the GLOF. Estimations from SRM produced a runoff of about 22.7 m3 during 16–17, June 2013 over Chorabari Lake. Bathymetry data reported that the lake got filled to its maximum capacity(3822.7 m3) due to excess discharge. Hydrograph obtained from the BREACH model revealed a peak discharge of about 1699 m3/s during an intense water flow episode that lasted for 10–15 minutes on 17 th June 2013. Excess discharge from heavy rainfall and snowmelt into the lake increased its hydrostatic pressure and the lake breached cataclysmically.展开更多
The covered-ice breakup in subarctic to arctic rivers in the early snowmelt season often gives any damage to instruments monitoring physical and chemical factors of water. The serious condition has brought few time se...The covered-ice breakup in subarctic to arctic rivers in the early snowmelt season often gives any damage to instruments monitoring physical and chemical factors of water. The serious condition has brought few time series data during the snowmelt runoff except the river stage or discharge. In this study, the contribution of snowmelt runoff to the discharge and sediment load is quantified by monitoring water turbidity and temperature at the lowest gauging station of U. S. Geological Survey in the Yukon River, Alaska, for more than 3 years (June 2006 to September 2009). The turbidity was recorded by a self-recording turbidimeter with a sensor of infrared-ray back-scattering type, of which the window is cleaned by a wiper just before a measurement. The turbidity time series, coupled with frequent river water sampling at mid-channel, produce time series of suspended sediment (SS) concentration, particulate organic carbon (POC) concentration and particulate organic nitrogen (PON) concentration (mg?L–1) by using the high correlation (R2 = 0.747 to 0.790;P 11 to 2.01 × 1011 m3), 8.7% - 22.5% of the annual sediment load (3.94 × 107 to 5.08 × 107 ton), 11.6% - 23.7% of the annual POC flux (4.05 × 105 to 4.77 × 105 ton), and 10.3% - 24.5% of the annual PON flux (2.80 × 104 to 3.44 × 104 ton). In the snowmelt season, the peak suspended sediment concentration preceded the peak discharge by a few days. This probably results from the fluvial sediment erosion in the river channels.展开更多
文摘Alpine glaciers are the natural solid reservoirs that releases amount of meltwater to supply streams every year. Glacier meltwater, adjuSting the yearly variation of stream runoff and making it trend to wards stableness, becomes the relible water resourc
基金supported by the National Natural Science Foundation of China(41971094,41871055,41871059)a project of the State Key Laboratory of Cryospheric Science(SKLCS-ZZ-2019)+1 种基金the Youth Innovation Promotion Association CAS(2019414)the CAS Pioneer Hundred Talents Program(Xiaoming Wang)
文摘Hydrology of the high glacierized region in the Tianshan Mountains is an important water resource for arid and semiarid areas of China,even Central Asia.The hydrological process is complex to understand,due to the high variability in cli mate and the lack of hydrometeorological data.Based on field observations,the present study analyzes the meteorological and hydrological characteristics of the Koxkar Glacier River Basin during 20082011;and the factors influencing climate impact on glacier hydrology are discussed.The results show that precipitation at the terminus of the glacier was 426.2 mm,471.8 mm,624.9 mm,and 532 mm in 2008,2009,2010,and 2011,respectively.Discharge increases starting in May,reaches its highest value in July and August,and then starts to decrease.The mean annual discharge was 118.23×106 m3 during the four years observed,with 87.0%occurring in the ablation season(May September).During the study period,the runoff in August accounted for 29%of total streamflow,followed by July(22%)and June(14%).The runoff exhibited obviously high interannual variability from April to September,induced by drastic changes in climate factors.Discharge autocorrelations are very high for all the years.The climate factors show different influences on discharge.The highest correlation R between daily temperature and discharge was for a time lag of 23 days 2on the Koxkar Glacier(0.660.76).The daily depth of runoff to daily temperature and daily water vapor pressure had an R value of 0.56 and 0.69,respective ly,which could be described by an exponential function.A closer relationship is found between runoff and either tempera ture or water vapor pressure on a monthly scale;the R2 values are 0.65 and 0.78,respectively.The study helps us to under stand the mechanisms of the hydrological meteorological system of typical regional glaciers and to provide a reference for glacier-runoff simulations and water-resource management.
基金National Science and Technology Support Plan Projects,No.2012BAC19B07Scientific Research Project of Higher Learning Institution in Gansu Province,No.2013A-018Project of Scientific Ability Promoting of Young Teachers of Northwest Normal University,No.NWNU-LKQN-12-20
文摘Hydrological processes were compared, with and without the influence of precipita- tion on discharge, to identify the differences between glacierized and non-glacierized catchments in the Urumqi River source region, on the northern slope of the eastern Tianshan Mountains, during the melting season （May-September） in 2011. The study was based on hydrological data observed at 10-min intervals, meteorological data observed at 15-min intervals, and glacier melting and snow observations from the Empty Cirque, Zongkong, and Urumqi Glacier No.1 gauging stations. The results indicated that the discharge differed markedly among the three gauging stations. The daily discharge was more than the nightly discharge at the Glacier No.1 gauging station, which contrasted with the patterns observed at the Zongkong and Empty Cirque gauging stations. There was a clear daily variation in the discharge at the three gauging stations, with differences in the magnitude and duration of the peak discharge. When precipitation was not considered, the time-lags between the maximum discharge and the highest temperature were 1-3 h, 10-16 h, and 5-11 h at the Glacier No.l, Empty Cirque, and Zongkong gauging stations, respectively. When precipitation was taken into consideration, the corresponding time-lags were 0-1 h, 13 h, and 6-7 h, respectively. Therefore, the duration from the generation of discharge to confluence was the shortest in the glacierized catchment and the longest in the catchment where was mainly covered by snow. It was also shown that the hydrological process from the generation of discharge to confluence shortened when precipitation was considered. The factors influencing changes in the discharge among the three gauging stations were different. For Glacier No.1 station, the discharge was mainly controlled by heat conditions in the glacierized region, and the discharge displayed an accelerated growth when the temperature exceeded 5℃ in the melt season. It was found that the englacial and subglacial drainage channel of Glacier No.1 had become simpler during the past 20 years. Its weaker retardance and storage of glacier melting water resulted in rapid discharge confluence. It was also shown that the discharge curve and the time-lag between the maximum discharge and the highest temperature could be used to reveal the evolution of the drainage system and the process of glacier and snow melting at different levels of glacier coverage.
基金conducted as part of the DST, Govt. of India, New Delhi sponsored research project titled "Risk Assessment for Kedarnath Glacial Lake Outburst Floods" under the national project "Mapping Your Neighborhood in Uttarakhand (MANU)"the financial assistance received under the project to accomplish this research
文摘In this study, the Glacier Lake Outburst Flood(GLOF) that occurred over Kedarnath in June 2013 was modeled using integrated observations from the field and Remote Sensing(RS). The lake breach parameters such as area, depth, breach, and height have been estimated from the field observations and Remote Sensing(RS) data. A number of modelling approaches, including Snow Melt Runoff Model(SRM), Modified Single Flow model(MSF), Watershed Management System(WMS), Simplified Dam Breach Model(SMPDBK) and BREACH were used to model the GLOF. Estimations from SRM produced a runoff of about 22.7 m3 during 16–17, June 2013 over Chorabari Lake. Bathymetry data reported that the lake got filled to its maximum capacity(3822.7 m3) due to excess discharge. Hydrograph obtained from the BREACH model revealed a peak discharge of about 1699 m3/s during an intense water flow episode that lasted for 10–15 minutes on 17 th June 2013. Excess discharge from heavy rainfall and snowmelt into the lake increased its hydrostatic pressure and the lake breached cataclysmically.
文摘The covered-ice breakup in subarctic to arctic rivers in the early snowmelt season often gives any damage to instruments monitoring physical and chemical factors of water. The serious condition has brought few time series data during the snowmelt runoff except the river stage or discharge. In this study, the contribution of snowmelt runoff to the discharge and sediment load is quantified by monitoring water turbidity and temperature at the lowest gauging station of U. S. Geological Survey in the Yukon River, Alaska, for more than 3 years (June 2006 to September 2009). The turbidity was recorded by a self-recording turbidimeter with a sensor of infrared-ray back-scattering type, of which the window is cleaned by a wiper just before a measurement. The turbidity time series, coupled with frequent river water sampling at mid-channel, produce time series of suspended sediment (SS) concentration, particulate organic carbon (POC) concentration and particulate organic nitrogen (PON) concentration (mg?L–1) by using the high correlation (R2 = 0.747 to 0.790;P 11 to 2.01 × 1011 m3), 8.7% - 22.5% of the annual sediment load (3.94 × 107 to 5.08 × 107 ton), 11.6% - 23.7% of the annual POC flux (4.05 × 105 to 4.77 × 105 ton), and 10.3% - 24.5% of the annual PON flux (2.80 × 104 to 3.44 × 104 ton). In the snowmelt season, the peak suspended sediment concentration preceded the peak discharge by a few days. This probably results from the fluvial sediment erosion in the river channels.
