Research progress on the evolution and environmental effects of thermokarst lakes in permafrost regions
In recent decades,with the global warming and the enhancement of human activities,the trend of per-mafrost degradation is significant. This process changes the hydrogeological conditions of the cold region,thus causing a series of ecological environment changes. Thermokarst lakes are the product of permafrost degradation and active thermokarst lakes indicate the decrease of permafrost stability. Thermokarst lakes are also a major source of greenhouse gases,which are important in the carbon cycle in cold regions. The formation and develop-ment of thermokarst lakes will cause the change of frozen soil environment,which will affect the global climate change. Therefore,in view of the increasingly serious thermokarst phenomenon in the process of permafrost deg-radation,and the resulting problems such as permafrost thawing penetration,groundwater level change,thermo-karst lake expansion and so on,the current research status of the hydrology change of thermokarst lake in perma-frost area is analyzed and sorted out. This paper mainly discusses from the following five aspects:(1) Analysis of the main factors of the formation and evolution of the thermokarst lake;(2) Analysis of temporal and spatial variation of thermokarst lake hydrological process and its influencing factors;(3) Thermokarst lake water bal-ance process and influencing factors;(4) Influence of thermokarst lake changes on regional water quality;(5) Influence of thermokarst lake on carbon cycle. Finally,the main problems in the field of thermokarst lakes are discussed:there are some defects in the identification of thermokarst lakes;the factors related to the area change of thermokarst lake are single. There is still a gap in understanding the broader relationship between permafrost gradient,permafrost degradation,and the corresponding hydrological response of thermokarst lakes. Knowl-edge of the effects of permafrost degradation on lake water chemistry is limited. Based on the existing problems,it is proposed that isotope technology should be used to fully consider the surrounding environment of the pond in the later research,and multi-factor analysis should be carried out in combination with climate change and perma-frost degradation,in order to provide reference for further research on the frozen soil hydrological process,re-gional water resources evolution and the impact on the ecological environment under the background of perma-frost degradation.
NETL
NSTL
万方数据
