Abstract: In this study, the hydrological processes were used to analyze the differences between the glacierized catchment and the non-glacierized catchment of the eastern Tianshan Mountains in the melting season (May-September) in 2011, from two perspectives in regard to and regardless of the influence of precipitation on discharge. The data included the observed hydrological data (10 minutes interval), meteorological data (15 minutes interval), glacier melting and snow observation materials from Urumqi Glacier No.1, Empty Cirque and Zongkong gauging sites in the Urumqi River source region. The results showed that there was difference in the discharge among three gauging sites. The daily discharge was more than the night value at Glacier No.1 gauging site, but it was on the contrary at Zongkong and Empty Cirque gauging sites. Moreover, the discharge at three gauging sites presented an obvious daily variation process, and their peak time points were different. With no consideration of precipitation, the delay time between the maximum discharge and the highest temperature was 1-3 h, 10-16 h and 5-11 h at Glacier No.1, Empty Cirque and Zongkong gauging sites, respectively. If the precipitation was taken into account, the corresponding delay time at three gauging sites was 0-1 h, 13 h and 6-7 h, respectively. The comparison proved that the duration from the discharge generation to confluence was the shortest in the glacierized catchment and the hydrological process became shorter along with the increase of precipitation. Factors influencing discharge change of three gauging sites were different. For Glacier No.1 station, the discharge change was mainly influenced by heat conditions in the glacierized region and the discharge showed an accelerated growth, when the temperature in the melting season was more than 5oC. In comparison, it was found that the englacial and subglacial drainage channel of Glacier No.1 became simpler during the past 20 years. Its weaker retardant and storage on the glacier melting water resulted in the quick discharge confluence. The result also demonstrated the discharge curve and the lag time between the maximum discharge and the highest temperature could reveal the drainage system evolution and the process of glacier and snow melting in different glacier coverage to some extent.

Key words: runoff generation and confluence, Urumqi River, glacier and snow melting, hydrological process, Tianshan Mountains