TY - JOUR

T1 - 天然状态下多年冻土区活动层厚度研究进展与展望

AU - Макарьева, Ольга Михайловна

AU - 罗栋梁,

AU - 金会军,

AU - 吴青柏,

AU - 田世民,

AU - 康建芳,

AU - 王金牛,

AU - 彭小清,

AU - 陈方方,

AU - DOBIŃSKI, Wojciech

PY - 2023/4/1

Y1 - 2023/4/1

N2 - The active layer is the most thermodynamically active near-surface soil layer in the permafrost regions. It is vital to the permafrost eco-environments as it serves as the critical zone for the supply of water and nutrients for the growth of alpine/northern plants，as well as the habitats for most frequent microbial activities and critical biogeochemical cycles. It also plays an indispensable role in the exchanges of water and energy between the atmosphere and the near-surface ground. Recently，the active layer thickness（ALT）under natural and undisturbed conditions had been prevalently increased under the dual influences of climate warming and increasing anthropogenic activities，which poses significant adverse influences on the cold environment and frozen ground engineering. In this paper，we reviewed the influencing factors of the ALT under natural and undisturbed conditions in the aspects of macro-scale geology and geography and micro-scale local factors，the measurements and simulations of ALT，as well as the response characteristics of ALT to climate change. Moreover，we also discussed the impact of ALT change on the alpine ecological environment. The past modeling and observations demonstrated that the spatial heterogeneity of ALT was primarily attributed to the redistribution of solar radiation and its complex interactions with the underlying conditions. Presuming no differentiation in climate and local factors，the thicker ALT is always found in the vicinity of the lower limits of elevational permafrost or of the southern/northern limits of latitudinal permafrost. In the past three decades，ALT has increased sensitively to climate warming，which is characteristic of increasing with the rise of air temperature. The increase of ALT shows an obvious regional differentiation，among which the ALT at most of the mid-latitude alpine and mountainous permafrost regions，such as in the Tibetan Plateau and the Alps，has shown significant increasing trends，while the deepening of ALT to a certain extent was offset by the melting of ground ice and ensued thaw settlement or ground surface subsidence at high-latitude ice-rich permafrost areas. Therefore，not all sites at high latitudes have experienced significant increasing trends as revealed by the observations. However，when analyzing the sensitivity of ALT by the ratio of its changing rate to its average value，we have found that the sites in the Alps （1. 46）and the Nordic regions（1. 27）were the most sensitive，followed by the sites in Alaska（0. 93）and on the Tibetan Plateau（0. 91），while those in Canada（0. 25）had relatively low sensitivity. We conclude that the future research directions of ALT should focus on the precise simulation and mapping of ALT，the adaptive mechanisms of ALT to climate changes，the impact of changing ALT on the biogeochemical cycles，hydrological processes，and water resources and structures in cold regions，among many others.

AB - The active layer is the most thermodynamically active near-surface soil layer in the permafrost regions. It is vital to the permafrost eco-environments as it serves as the critical zone for the supply of water and nutrients for the growth of alpine/northern plants，as well as the habitats for most frequent microbial activities and critical biogeochemical cycles. It also plays an indispensable role in the exchanges of water and energy between the atmosphere and the near-surface ground. Recently，the active layer thickness（ALT）under natural and undisturbed conditions had been prevalently increased under the dual influences of climate warming and increasing anthropogenic activities，which poses significant adverse influences on the cold environment and frozen ground engineering. In this paper，we reviewed the influencing factors of the ALT under natural and undisturbed conditions in the aspects of macro-scale geology and geography and micro-scale local factors，the measurements and simulations of ALT，as well as the response characteristics of ALT to climate change. Moreover，we also discussed the impact of ALT change on the alpine ecological environment. The past modeling and observations demonstrated that the spatial heterogeneity of ALT was primarily attributed to the redistribution of solar radiation and its complex interactions with the underlying conditions. Presuming no differentiation in climate and local factors，the thicker ALT is always found in the vicinity of the lower limits of elevational permafrost or of the southern/northern limits of latitudinal permafrost. In the past three decades，ALT has increased sensitively to climate warming，which is characteristic of increasing with the rise of air temperature. The increase of ALT shows an obvious regional differentiation，among which the ALT at most of the mid-latitude alpine and mountainous permafrost regions，such as in the Tibetan Plateau and the Alps，has shown significant increasing trends，while the deepening of ALT to a certain extent was offset by the melting of ground ice and ensued thaw settlement or ground surface subsidence at high-latitude ice-rich permafrost areas. Therefore，not all sites at high latitudes have experienced significant increasing trends as revealed by the observations. However，when analyzing the sensitivity of ALT by the ratio of its changing rate to its average value，we have found that the sites in the Alps （1. 46）and the Nordic regions（1. 27）were the most sensitive，followed by the sites in Alaska（0. 93）and on the Tibetan Plateau（0. 91），while those in Canada（0. 25）had relatively low sensitivity. We conclude that the future research directions of ALT should focus on the precise simulation and mapping of ALT，the adaptive mechanisms of ALT to climate changes，the impact of changing ALT on the biogeochemical cycles，hydrological processes，and water resources and structures in cold regions，among many others.

KW - active layer thickness（ALT）

KW - climate change

KW - eco-hydrological effects

KW - permafrost

KW - spatial differentiation

UR - http://www.bcdt.ac.cn/EN/10.7522/j.issn.1000-0240.2023.0043

UR - https://www.mendeley.com/catalogue/7b69175e-9c4e-3e8b-b734-1454ecdf21bc/

U2 - 10.7522/j.issn.1000-0240.2023.0043

DO - 10.7522/j.issn.1000-0240.2023.0043

M3 - статья

VL - 45

SP - 558

EP - 574

JO - Journal of Glaciology and Geocryology

JF - Journal of Glaciology and Geocryology

SN - 1000-0240

IS - 2

ER -