冰川冰内及冰下水系研究综述

冰内及冰下水系的形成与演化具有时空变化性,对冰川汇水储水及径流过程产生影响,与之紧密联系的冰下水文过程(水力状况)与冰川运动、冰川侵蚀及冰川洪水形成等过程息息相关。冰内及冰下水系空间结构和形态复杂,且不同于一般喀斯特水文系统,具有明显的季节变化性,其空间分布和水力状况会因外界水体输入(降水和冰雪融水)的变化而改变。冰内及冰下水系的变化通过影响汇流对冰川融水的径流过程产生影响,冰川区一些溃决洪水事件的发生与冰内及冰下蓄水的突然释放有很大关系。冰川蓄排水还通过改变冰下水力条件来影响冰川运动,反之冰川运动不仅影响蓄排水过程的转换效率,且通过改变冰川消融强度(冰体向下游消融区输送速率的变化)影响冰川排水系统的空间分布范围。在气候变暖及冰川变化的背景下,研究冰内冰下水系演化的时空特征及其影响具有重要科学意义。综述了目前国内外针对冰川冰内及冰下水系相关研究的进展及主要成果,并对该领域的研究前景进行了展望。

Progress in the Study of Englacial and Subglacial Drainage System of Glaciers

This paper reviewed the recent progress in the study of englacial and subglacial drainage system of glaciers.Englacial and subglacial drainage system of glaciers play an important role in glacier runoff process,ice motion anomalies,glacier erosion rate and sedimentation processes.Efficiency of englacial and subglacial drainage system controls the runoff response from glacial catchments by modifying the input and storage rate of liquid water from ice/snow melting and rainfall.It also has important implications for glacial dynamics,through its influence on basal stress distributions or subglacial lubricating by changing the englacial and subglacial hydraulic conditions.The status of subglacial drainage system also affects physical and chemical processes at the ice-bed interface,controlling sediment and solute dynamics in proglacial streams.Furthermore,climate conditions influence glacier ablation processes by the change of the ice melting intensity,glacier melting area and glacier ablation period,which then induce the variation of subglacial water storage and drainage processes.Coupled processes between subglacial hydrology and glacier dynamics therefore should be concerned in the future related research.