摘要
川藏铁路波密段穿越冰川覆盖区,分布多条与断裂复合发育的大型河流,水量丰富,可与断裂共同构成构造高压涌水突泥灾害风险源。本文通过多期测流和对大气降水、冰川、河流和地下水水化学、同位素特征分析,研究了大型河流的流量变化特征和地表水与断裂带裂隙水的转化关系。结果表明:西藏波密冰川覆盖区河水主要接受冰川融水和大气降水补给。雨季河水的δ^(18)O和δD值小于旱季,说明河水雨季和旱季的补给源结构不同。旱季气温低,以大气降水补给为主;雨季冰川融水量陡增,为主要补给源。断裂影响范围内的古乡沟、比通曲和龙冲曲河水流量较大,均超过4×10^(4) m^(3)/d,但年内流量波动幅度小于非断裂带影响范围的河流。河流可渗漏补给断裂带水。浅层循环断裂带水年龄5~10 a,中深层断裂带水年龄超过4000 a,水岩作用较充分。非断裂带影响范围的河流与基岩风化裂隙水存在较密切的水力联系和较频繁的相互转化。研究成果可为青藏高原东部冰川覆盖区铁路隧道高压涌水突泥灾害的早期识别和灾害防范措施制定提供参考。
The Bomi section of the Sichuan-Tibet Railway passes through the glacier-covered area where multiple large-scale river compounded with faults occur.The river water is abundant,leading to a tectonic high-pressure water inrush and mud outburst disaster risk source.This paper studies the flow characteristics of large-scale river and the transformation relationship between surface water and tectonic fissure water through flow measurement and analysis of precipitation,glacier melting water,river water and groundwater hydrochemistry,isotopic characteristics,and hydrogeochemical processes.The results show that the river water in Bomi glacier covered area in Tibet is mainly supplied by glacier melting water and precipitation.In rainy season,the values of δ^(18)O and δD are less than those in dry season,indicating that the structure of water-supply source is different.During the dry season,the main source of replenishment is precipitation due to the low temperature,and in the rainy season the amount of glacier melting increases sharply,which becomes the main source of recharge.The discharge of rivers Guxianggou,Bitongqu and Longchongqu,which are compounded with the fault,is larger than 4×10^(4) m^(3)/d.However,the annual flow fluctuation is less than that of the rivers in the non-fault zone.The river water could supply the fault zone water,forming shallow circulation groundwater of 5−10 a and medium and deep circulation groundwater of more than 4000 a.There is a close hydraulic connection and frequent mutual transformation between the river and bedrock weathering fissure water in the non-fault zone.The research results can provide references for the early identification of high-pressure water and mud inrush disasters in tunnels and the formulation of disaster prevention measures in the glacier-covered area of the eastern Qinghai-Tibet Plateau.
作者
马剑飞
李向全
张春潮
付昌昌
白占学
王振兴
MA Jianfei;LI Xiangquan;ZHANG Chunchao;FU Changchang;BAI Zhanxue;WANG Zhenxing(Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang,Hebei 050061,China;Key Laboratory of Groundwater Science and Engineering,Ministry of Natural Resources,Shijiazhuang,Hebei 050061,China)
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2021年第5期23-33,共11页
Hydrogeology & Engineering Geology
基金
中国地质调查局地质调查项目(DD20211374,20190505)。
关键词
冰川覆盖区
地表水
构造裂隙水
转化关系
水化学
川藏铁路
glacier-covered area
surface water
tectonic fissure water
transformation relationship
hydrochemistry
Sichuan-Tibet Railway