Thermal dynamics of the permafrost active layer under increased precipitation at the Qingh

Thermal dynamics of the permafrost active layer under increased precipitation at the Qinghai-Tibet

Plateau

LI De-sheng;WEN Zhi;CHENG Qian-gong;XING Ai-guo;ZHANG Ming-li;LI An-yuan 【期刊名称】《山地科学学报（英文版）》

【年(卷),期】2019(016)002

【摘要】Precipitation has a significant influence on the hydro-thermal state of the active layer in permafrost regions,which disturbs the surface energy balance,carbon flux,ecosystem,hydrological cycles and landscape processes.To better understand the hydro-thermal dynamics of active layer and the interactions between rainfall and permafrost,we applied the coupled heat and mass transfer model for soil-plant-atmosphere system into high-altitude permafrost regions in this study.Meteorological data,soil temperature,heat flux and moisture content from different depths within the active layer were used to calibrate and validate this model.Thereafter,the precipitation was increased to explore the effect of recent climatic wetting on the thermal state of the active layer.The primary results demonstrate that the variation of active layer thickness under the effect of short-term increased precipitation is not obvious,while soil surface heat flux can show the changingtrends of thermal state in active layer,which should not be negligible.An increment in year-round precipitation leads to a