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 Glac展开更多
Simulated rainfall is a valid tool to examine the runoff generation on the slope.13 simulated rainfall experiments with different rainfall intensities and durations are completed in a 5 m ×10 m experimental plot ...Simulated rainfall is a valid tool to examine the runoff generation on the slope.13 simulated rainfall experiments with different rainfall intensities and durations are completed in a 5 m ×10 m experimental plot in mountainous area of North China.Simultaneously,rainfall,surface runoff,soil-layer flow,mantel-layer flow and soil moisture are monitored respectively.From the results,it is found that the hydrographs in all layers have the characteristics of rapid rise and fall.The recessions of surface flow and soil-layer flow are much faster than that of mantel-layer flow.Surface flow,the main contributor,makes up more than 60% of the total runoff in the study area.It even exceeds 90% in the cases of high intensity rainfall events.Runoff coefficient(ratio of total runoff to rainfall amount) is mainly influenced by rainfall amount,rainfall intensity and antecedent soil moisture,and the relationship can be well expressed by a multiple linear regression function α = 0.002P + 0.182i + 4.88Wa-0.821.The relation between the rainfall intensity and the lag time of three flows(surface runoff,soil-layer flow and mantel-layer flow) is shown to be exponential.Then,the result also shows that the recession constant is 0.75 for surface runoff,is 0.94 for soil-layer and mantel-layer flow in this area.In this study area,the dominant infiltration excess runoff is simulated by Horton model.About 0.10 mm/min percolation is observed under the condition of different rainfall intensities,therefore the value is regarded as the steady infiltration rate of the study area.展开更多
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 Glac
基金National Natural Science Foundation of China,No.40371025
文摘Simulated rainfall is a valid tool to examine the runoff generation on the slope.13 simulated rainfall experiments with different rainfall intensities and durations are completed in a 5 m ×10 m experimental plot in mountainous area of North China.Simultaneously,rainfall,surface runoff,soil-layer flow,mantel-layer flow and soil moisture are monitored respectively.From the results,it is found that the hydrographs in all layers have the characteristics of rapid rise and fall.The recessions of surface flow and soil-layer flow are much faster than that of mantel-layer flow.Surface flow,the main contributor,makes up more than 60% of the total runoff in the study area.It even exceeds 90% in the cases of high intensity rainfall events.Runoff coefficient(ratio of total runoff to rainfall amount) is mainly influenced by rainfall amount,rainfall intensity and antecedent soil moisture,and the relationship can be well expressed by a multiple linear regression function α = 0.002P + 0.182i + 4.88Wa-0.821.The relation between the rainfall intensity and the lag time of three flows(surface runoff,soil-layer flow and mantel-layer flow) is shown to be exponential.Then,the result also shows that the recession constant is 0.75 for surface runoff,is 0.94 for soil-layer and mantel-layer flow in this area.In this study area,the dominant infiltration excess runoff is simulated by Horton model.About 0.10 mm/min percolation is observed under the condition of different rainfall intensities,therefore the value is regarded as the steady infiltration rate of the study area.
