冰内及冰下水系演化的示踪试验及其应用研究  

Tracer Tests of Englacial and Subglacial Drainage System Evolution and a Case Study at the Hailuogou Glacier

作　　者：刘巧[1] 刘时银[2] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所山地表生过程与生态调控重点实验室,四川成都610041 [2]中国科学院寒区旱区环境与工程研究所冰冻圈科学国家重点实验室,甘肃兰州730000

出　　处：《冰川冻土》2012年第5期1206-1219,共14页Journal of Glaciology and Geocryology

基　　金：国家科技支撑计划项目(2012BAC19B07);中国科学院知识创新工程重要方向项目(KZCX2-YW-GJ04);国家自然科学基金项目(40801030);冰冻圈科学国家重点实验室项目(SKL2011-10);中国科学院西部之光西部博士项目资助

摘　　要：简要回顾和介绍了示踪试验方法在冰内及冰下水系演化研究中的应用,并以ADM模型为例,对示踪剂扩散模型进行了敏感性试验分析,分析了不同参数组合条件对示踪剂浓度变化过程的影响.在海螺沟冰川消融区下游冰舌段开展了示踪试验,通过对一个固定入水口消融期整个过程的重复投放试验,获取了每次独立示踪试验示踪剂的浓度变化过程,并用ADM扩散模型反演了示踪剂传播速度、水力扩散系数以及平均排水通道面积等相关指标,揭示了海螺沟冰川此冰舌段冰下排水系统的季节变化过程.Dye tracer test was widely used m study of englacial and subglacial drainage system. Tracer test provides information about hydraulic condi- tions of a drainage system if the tracer transport is identical to the flow of individual water particle, In this study, formation and seasonal evolution of subglacial drainage system in the lower ablation ar- ea of Hailuogou Glacier were revealed by repeated dye tracer tests during the 2009 ablation season. Between 10 April and 28 October in 2009, 18 dye tracer tests were carried out in the lower ablation area of Hailuogou Glacier. Using a simple advee tion-dispersion model, the transit velocity, the hy- drodynamic dispersion coefficient and the degree of tracer spreading were deduced. Transit velocity va- ries from 0. 148 to 0. 555 m. s 1, which is typical of those found at other glaciers. Derived dispersivi- ty shows a relatively high value than thoset found in other glaciers ranging from 27.05 to 287.49 m2. s-1. Seasonal changes of those indexes indicate that hydraulic efficiency of the subglacial drainage system in the lower ablation area of the glacier ex- periences low-high-low during the ablation period. Based on the well relationships between calculated channel cross-section area （A） and air tempera- ture, precipitation and discharge, a simple regres- sion model is obtained to deduce continuous sea- sonal change of A. The results show that A, which is also the index of the size of subglacial channel, is larger in middle summer than that in the earlier and later ablation seasons.

关 键 词：冰内及冰下水系 示踪试验 模拟 海螺沟冰川 

分 类 号：P343.6[天文地球—水文科学]