唐古拉山冬克玛底冰川流域河水总溶解固体和悬移质的变化特征

通过2013年6-9月对唐古拉山冬克玛底冰川流域河水的逐日定时样品采集，并结合流域水文与气象资料，对径流的总溶解固体（TDS）和悬移质的变化特征进行分析。结果表明：2013年消融期的平均气温为3.7℃，消融期降水量为546 mm，7月和8月两个月径流量占消融期总径流量的63%。消融期逐日的TDS变化范围为31~140 mg·L^-1，平均值为60 mg·L^-1，TDS随径流变化显著，表现为消融强烈时（7-8月） TDS浓度较低，消融初期（6月）和末期（9月）时TDS浓度较高；径流中TDS与悬移质浓度（SSC）变化表现出相反变化趋势，即消融强烈时悬移质浓度较高，而消融初期与末期悬移质浓度较低，消融期平均悬移质浓度为122.8 mg·L^-1，流量-SSC时序关系表现为以顺时针滞后事件为主。2013年冬克玛底冰川流域消融期的化学侵蚀总量和物理侵蚀总量分别为2.214×10³ t和6.722×10³ t，化学侵蚀与物理侵蚀率的比值为0.33。

The changing features of total dissolved solids and suspended sediment in the Dongkemadi Glacier catchment,Tanggula Mountains

The delivery of total dissolved solids (TDS) and suspended sediment by river water to downstream ecosystem represents an important pathway in the geochemical cycle, a key component of the exfoliation system and an important index of land degradation. In order to understand the TDS and suspended sediment transport variation with air temperature and precipitation in the Dongkemadi Glacier catchment of the Tibetan Plateau and determine its relationship with discharge, daily discharge, total dissolved solids and suspended sediment samples were collected and analyzed from June to September in 2013. It was discovered that the mean air temperature was 3.7℃ and precipitation was 546 mm during the ablation season in 2013. The total runoff during July and August accounted for 63% of that in the ablation season of 2013. Daily mean TDS in the stream ranged from 31 to 140 mg·L^-1, with a mean value of 60 mg·L^-1. The mean daily suspended sediment concentrations (SSC) for the entire sampling period was computed to be 122.8 mg·L^-1. The change of discharge and SSC in runoff showed an opposite trend. While there was a significant negative correlation between TDS and suspended sediment. At the beginning and the end of the ablation period TDS was higher, while it was lower at the middle of the ablation period. The total TDS load for the observing season was computed to be 2.214×10³ tones. The total suspended sediment load for the observing season was computed to be 6.722×10³ tones. The ratio of chemical to physical loads for gauging sites in the Dongkemadi Glacier catchment was 0.33. This study will be useful for understanding the relation between TDS and SSC and discharge with daily data in summer in the high elevation cold regions of the Tibetan Plateau.