Research on the Characteristics of Climate and Frozen Soil Changes along the Qinghai-Tibet Line under Heating Conditions
Research purposes:The permafrost on the Qinghai-Tibet Railway is gradually degraded due to the global temperature rise,which brings many technical problems to railway safety operation and related railway construction in the plateau cold region.By collecting and analyzing the changes in temperature,precipitation,ground temperature,and frozen soil upper limit of meteorological stations along the Qinghai-Tibet Railway,the characteristics of climate and frozen soil changes along the Qinghai-Tibet Railway under the condition of temperature rise of the Qinghai-Tibet Railway are analyzed.The research results aim to provide theoretical support for the engineering maintenance and engineering construction in the plateau cold area under warming conditions.Research conclusions:(1)In the past 20 years,the warming rate of the Qinghai-Tibet Plateau has reached 0.64℃/10 a,and the precipitation has increased at a rate of 16.8 mm/10 a.(2)The temperature along the Qinghai-Tibet Railway is influenced by altitude and dimensions,with an average temperature value of-5.9℃~-2.7℃.The annual average precipitation has shown an increasing trend from 1996 to 2022,an increase of 75~86 mm compared to 1976 to 1995.(3)The ground temperature in the permafrost region of the Qinghai-Tibet Railway in 2022 has increased by 0.06~0.21℃compared to 2007,and the temperature at the north and south ends of the permafrost has increased by 0.04℃~0.17℃.The freezing index along the route ranges from 1.5 to 5.6.(4)The research results can provide theoretical support and technical reference for the construction of road projects in plateau cold areas and the disposal of existing engineering diseases.