Eastern Siberia permafrost transect(ESPT).A first stage:The Verkhoyansk Range part

Environmental and geomorphological processes in the mountainous areas of Eastern Siberia is strongly conditioned by the thermal state of permafrost(permanently frozen ground).However,the scarce data about climate and weak of permafrost study have led to the unclarity of mountain permafrost condition in this region.The increase in the mean annual air temperature over the past 50 years in the northeastern Siberia by various estimates is from 1.1℃to 3.3℃.So far,almost no information is available on the permafrost response to climatic changes in the region.The Kolyma Route(around 2000 km length),connecting Yakutsk and Magadan that crosses 5 climatic types and more than 10 permafrost landscapes,so it seems a suitable path for establishing basic(reference)monitoring sites.From 12 target boreholes,on the first stage 5 boreholes up to 30 m in depth were drilled and instrumented for measuring temperature at sites adjacent to weather stations in the Verkhoyansk Range from 283 to 1288 m a.s.l.Here we present conception,purpose,and methods for permafrost study project with first preliminary results from the highest weather station of the East Siberia Mountain.The following research about geophysical investigations,permafrost landscape description,mapping and spatial modelling,numerical computing,physical modelling of permafrost thickness might be initiated by the Eastern Siberia Permafrost Transect(ESPT)-project.

Assessment of the thermal effect of large industrial buildings on permafrost foundation soils in Yakutsk

The results of monitoring studies of the ground thermal state beneath the Yakutsk Combined Heat and Power Plant buildings are presented in order to determine their structural stability and the possibility of further troublefree operation of the entire complex of the structures.The main causes for the formation of water-bearing taliks under and adjacent to the buildings are presented,and the factors influencing the existing geocryological situation are discussed.The continuing stable state of the buildings demonstrates the possibility of using two construction principles on permafrost at one site,including preserving permafrost and accommodating permafrost thawing.

Temperature regime of mountain permafrost in the Russian Altai Mountains

This study presents the long-term temperature monitoring in the Russian Altai Mountains. In contrast to the Mongolian and Chinese parts, the modern temperature regime of the Russian Altai remains unclear. The complexity of a comprehensive understanding of permafrost conditions in the Russian Altai is related to the high dissection of the terrain, the paucity of the latest observational data, and the sparse population of permafrost areas. The general objective of this study is to determine the temperature regime on the surface,in the active layer, and in the zero annual amplitude(ZAA) layer, based on the known patterns of permafrost distribution in the region. Using automatic measuring equipment(loggers), we obtained information on the temperature of frozen and thawed ground within the altitudes from 1484 to 2879 m a. s. l. during the period from 2014 to 2020.An array of 15 loggers determined the temperature regime of bare and vegetated areas within watersheds,slopes, and valleys. N-factor parameters and surface temperature are similar to those in the Mongolian Altai, but the mean annual ground temperature at the depth of 1 m has a wide range of fluctuations(more than 32℃) based on research results, and we allocated it into three groups based on altitudinal zonality. Snow cover has a strong influence on the temperature regime, but the determination of the fine-scale variability requires additional study.Ground temperature regime during the observation period remained stable, but continued monitoring allows a more detailed assessment of the response to climatic changes.

Permafrost response to climate change in the Northern Tien Shan

This paper presents the results of long-term studies on the response of mountain permafrost in the Northern Tien Shan to changes in climate. Significant warming has been observed in the region over the past 70 years. Records from the high-elevation weather stations Tuyuksu-1(3,450 m a.s.l.) and Mynzhylki(3,017 m a.s.l.) indicate a warming trend of 0.02 °C/a in the mean annual air temperature during this period. Permafrost temperatures have increased at a rate of about 0.01 °C/a over the 40-year observation period. The effects of local factors, including slope aspect, tectonic faulting, snow cover, and human activities, on the distribution of temperature and thickness of permafrost are discussed in the paper.

Permafrost distribution and temperature in the Elkon Horst, Russia

The Elkon Horst is a geological structure that consists of heterogeneous strata with highly variable geocryological and temperature conditions. Gaining accurate knowledge of permafrost distribution patterns within this structure is of both scientific and practical importance. In mountainous terrain, the ground thermal regime is controlled by both surface and subsurface conditions. Surface conditions include snow cover characteristics, the presence or absence of vegetation, vegetation density, etc.. In contrast, subsurface conditions involve rock lithology or petrography, density, quantity and depth of fissures, groundwater, etc.. This article examines ground thermal regimes in various geomorphological settings based on temperature measurement data from geotechnical boreholes. The occurrence and extent of permafrost were evaluated for the entire horst area using direct and indirect methods. The maximum permafrost thickness measured in the Elkon Horst is 330 m, and the estimated maximum is 450 m at higher elevations. Thermophysical properties were determined for the major rock types, and the geothermal heat flux was estimated for the study area. The thermal conductivities were found to vary from 1.47 to 4.20 W/(m·K), and the dry bulk densities to range between 2,236 kg/m~3 and 3,235 kg/m~3. The average geothermal heat flux was estimated to be 44 mW/m~2.

Using thermal remote sensing in the classification of mountain permafrost landscapes

Thermal infrared satellite imagery is increasingly utilized in permafrost studies.One useful application of the land surface temperature(LST)products is classification and mapping of landscapes in permafrost regions,as LST values can help differentiate between frozen and unfrozen ground.This article describes a new approach to the use of LST.The essence of the new approach lies in the fact that in the territory where it is impossible to determine(indicate)the state of the underlying ground according to the same morphological characteristics(relief,vegetation,soil composition,etc.),the LST parameter,which reflects the thermal state of the landscape,allows as an additional criterion(indicator)identify frozen/un-frozen landscapes.In this work,using the above approach,a map has been compiled,which shows the permafrost natural-territorial complexes of the Elkon Massif,Eastern Siberia,including topography,slope aspect,slope angle,vegetation,snow cover and LST.The map provides a more detailed and updated description of permafrost distribution in the study area.

Utilizing natural cryogenic resources to improve the stability of natural-technical systems in the permafrost zone

Siberia and the Russian Far East contain about 75% of the country's hydrocarbon and mineral resources. These regions pose many engineering and environmental problems for economic development due to the cold climate and difficult geologic conditions, including the occurrence of permafrost. One of the major challenges in permafrost areas is to maintain the stability of both individual structures and large-scale engineering projects. The use of natural cryogenic resources of the Earth is proposed here as one possible solution.

Safety of small and medium dams in permafrost regions

Safe operation and performance of dams is one of the key issues in permafrost regions. At present, the existing dams are 40–45 years old and they are reaching their design life limit. Intensive geocryological processes（thermokarst, thermal erosion, frost heaving, suffosion, concentrated seepage along the voids left by melt ice and others） begin to develop at the early stages of construction. These processes are even more intensive under severe climatic conditions of the permafrost zone due to the large thermal and moisture gradients and the resulting complex thermal stress-strain state in the structures. Determining safety criteria is a critical and difficult task in dam safety management. The existing procedures need to be continuously refined and improved depending on dam importance class. Some researchers recommend introducing process development criteria（stability, destabilization, and extremality） for more objective assessment of dam safety, in addition to the existing two condition criteria. In other words, they call for a multi-factor dam – environment interaction system. A case study of safety declaration for an existing dam is presented.

Monitoring of small and medium embankment dams on permafrost in a changing climate

Global climate warming which began in the second half of the twentieth century is continuing. It is associated with increased risks for ecological management, especially in permafrost areas comprising over 65% of Russia. Of special concern are dams constructed on permafrost. They are subject not only to climatic impacts, but also to additional hydrothermal loads from water reservoirs. This paper presents the concept of geocryological monitoring of dams and other water resource projects and substantiates its necessity in view of climatic change. It also presents methods, scope and implementation of geocryological monitoring at medium and small dams, considering the specific nature of Far Northern areas, as well as the complicated geotechnical, hydrogeological and permafrost conditions.

The convection cooling system of the Yakutsk permafrost seed repository

Temperature is critical to maintaining seed viability under long-term storage conditions. It has been common practice to use refrigeration systems to maintain required storage temperatures. A seed repository constructed in permafrost in Yakutsk, Russia is the first seed storage facility that relies solely on natural cold. This paper describes the design and performance of the cooling system of the repository. An innovative aspect of the cooling system is that it utilizes the patterns of temperature wave propagation in permafrost. Predicted and measured ground temperatures for the first year of operation are presented and analyzed. Results indicate that convection air cooling systems can be used to control the temperature regime in underground facilities in permafrost.

Medium and small embankment dams on permafrost: A discussion of current concepts

This article discusses the current concepts of dam design and construction in permafrost regions. It is demonstrated that embankment dams often change their state from frozen to thawed and back during the operation period. It is shown that these transitions are not always attributable to observed climate warming. Where geotechnical, hydrogeological, and permafrost conditions are complicated, proper performance of embankment dams can only be provided by adhering to a selected thermal design for, as an example, a frozen state.

冻土水分迁移机理研究:评述与展望

土冻结过程中的水分迁移、积聚是冻害形成的关键环节,至今仍是冻土物理学研究的前沿和重要课题。二十世纪七八十年代冻土水分迁移研究黄金时代以后,长期未有经典理论和科学认知的重大突破,冻土水分迁移中涉及的许多机理性问题和关键瓶颈难题至今仍不能准确回答,尚存在很多争议和认识上的不足,现有研究成果在实际工程中的应用并不令人完全满意。因其性质的易变性、微观性和突变性,冻结相变区(冻结缘)仍是冻土水热输运研究中的一个“黑箱”。研究评述了冻土水分迁移驱动力与迁移过程相关研究的发展历程、主要研究进展与现状;分析了孔隙水压力、土水势驱动冻土水分迁移的物理原理和基本规律,综述了孔隙水压力、土水势的理论表征与试验测试等方面的最新进展、认知现状与主要科学问题;分析了三种流行的冻土水分迁移理论,即毛细水迁移理论、薄膜水迁移理论和水汽迁移理论;总结了制约冻土水分迁移科学认知突破的关键瓶颈难题,展望了未来研究的重点和方向。认为未来的研究应加强仪器设备的改进、研发与新技术引入,重点关注冻土水分迁移驱动力的物理本质和精准监测,强化冻土水分迁移的微观过程及机制认识,需从非平衡态热力学的视角关注热质输运与冰-水相变过程,注重工程化冻土多物理场模型的开发与自主开源计算平台的构建。本文旨在系统梳理冻土水分迁移机理的研究历史与现状,总结概述冻土水分迁移研究在新思想、新理论、新方法和新技术等方面的最新研究动态,凝练指出亟待解决的前沿科学问题和未来研究的重点,促进冻土热质输运基础理论的发展与完善,更好地服务于寒区工程冻融灾害和环境问题的解决。

Evaluating the thermal environment of urban land surfaces in Yakutsk,a city located in a region of continuous permafrost

Rapid urbanization has led to changes in the urban land surface thermal environment.However,there are still much unknown about the urban land surface thermal conditions in permafrost regions.Permafrost is a unique geological environment,changes in the urban land surface thermal environment may trigger geological disasters caused by permafrost degradation.This study utilized remote sensing data and geographic de-tectors to identify the dynamic changes in land surface temperature(LST)and land use/land cover(LU/LC)in Yakutsk,as well as the potential factors contributing to LST variations.Between 1992 and 2020,the built-up area in Yakutsk increased by 36%,and the annual average LST in Yakutsk has risen by 6.67℃,accompanied by an expansion of high-temperature areas.Despite ongoing greening efforts,rapid urbanization poses a threat to these green spaces.Changes in the normalized difference built-up index(NDBI)and land use transfer(LDT)were identified as the primary drivers of urban LST changes.By integrating geographic detector technology and artificial neural network models,we optimized the selection of input factors in the prediction model and used it to explore the future changes in LST in Yakutsk.The average LST in Yakutsk is expected to reach 23.4℃ and 25.1℃ in 2030 and 2040,respectively,with a further increase in high-temperature areas.This study provides a reference for ecological,hydrological,and geological assessments of cities in permafrost regions.

冻土区的地下水基础研究--《寒区冻结层上水》简介(英文)

由俄罗斯科学院西伯利亚分院Melnikov冻土研究所的V.V.Shepelev教授编写,R.V.Zhang教授编辑的《寒区冻结层上水》(Suprapermafrost Waters in the Cryolithozone)一书已于2011年由俄罗斯新西伯利亚的地球科学学术出版社(Novosibirsk:Academic Publishing House"Geo")出版发行.全书分为5章,共130页,包括50幅彩图,17个表格,426条主要参考文献,硬皮封面.针对地球科学界提出的一个新研究领域"寒区水文地质学(cryohydrogeology)",该书介绍了其概念、分类方案、主要影响因素、水的化学组成特性、持水系统的水动力特征以及他们对技术影响的响应等.全书包含了作者及其团队多年来对俄罗斯地区冻结层上水的形成规律、区域边界特征、相变特征等进行系统观测所得到的大量数据,并进行系统分析所得到的研究结果,具有很好的应用参考价值.该专著不但会引起水文地质学和冻土学专家的极大兴趣,而且可以作为主修地质学、地理学、土木工程、水文地质学、冻土学的大学生或研究生的教科书,也可以作为专业人员的参考书籍.

热泵在多年冻土地区工程中的应用(英文)

The inclement climate and permafrost have a strong influence on human activities and life in cold regions. It is important to adjust to these conditions in such a way as to minimize adverse environmental impacts. In order to maintain the ecological equilibrium, various technologies have been developed which involve the use of the ’natural cold’ for solving difficult engineering problems. Heat pumps hold much promise in this context. They can help protect the environment from the thermal effects of human activities and, unlike the conventional refrigeration devices; the produced heat can be utilized. They also provide a solution to another problem vitally important for the northern regions - saving of fuel and energy resources. In case of global warming with an increasing need for artificial refrigeration, the use of heat pumps will be the most economical solution, preventing catastrophic loss of structural stability virtually without additional costs.

多年冻土地区金刚石矿的环境问题——以Yakutia西北部Anabar矿为例(英文)

Placer diamond mining in the Anabar area involves various operations that cause long-term (nearly a quarter of a century) environmental impacts. The long history of mining activities, the technology used to mine the placers, as well as the poor assimilative capacity of the natural systems can result in serious environmental impacts in the area. The primary geochemical processes in the diamond-bearing area are affected by the occurrence of permafrost and relict ice, the lengthy duration of ice cover in water bodies, and the widespread development of cryogenic processes. This promotes physical migration of contaminants, cryogenic metamorphization of waters, and long-term accumulation of organic contaminants in low-temperature, reduction and sedimentation barriers. In this paper, some environmental and geochemical effects of diamond mining in the Arctic area are discussed.

内蒙古鄂尔多斯高原古冰缘遗迹科学考察研究进展

冰缘遗迹(特别是冷生楔形构造及融冻褶皱)是重建古气候及第四纪晚期多年冻土环境的重要证据。内蒙古鄂尔多斯高原是我国北方地区冰缘现象最为发育的地区之一。为准确了解鄂尔多斯高原冰缘遗迹类型及其分布特征、区域冻土演化历史等,中国科学院西北生态环境资源研究院和荷兰自由大学共同组成科研小组,于2018年5—6月组织了"鄂尔多斯高原冰缘遗迹科学考察"。考察区域涉及靖边—城川—乌审旗—鄂尔多斯东胜区一带约12000km2的范围。考察内容主要包括鄂尔多斯高原冰缘遗迹类型及特征、分布区域、各类型冰缘遗迹所指示的气候条件的初步推断等。结果表明:冻融褶皱和冷生楔体构造是鄂尔多斯高原主要存在的两大类冰缘遗迹。基于本次考察中关于冰缘遗迹的分布与特征等新发现,并综合前人研究成果,初步推断:在气温极低、多年冻土非常发育的时段,有利于形成各类冷生楔状构造,如冰楔假形和大型原生砂楔等;在气候转暖、多年冻土退化,但还没有全部融化完阶段,可能形成融冻褶皱;区域性大面积分布和成群出现的融冻褶皱一般反映较暖气候环境下,多年冻土层上部已退化到一定程度。基于光释光(OSL)年代测试结果,结合冰缘遗迹的特征及其所指示的古气候环境,初步重建了鄂尔多斯5万年以来的冻土环境变化序列。区内多年冻土在多年冻土最大期(LPM,25~19ka BP)时最发育,以大面积连续多年冻土为主;之后,随气温转暖,总趋势呈退化状态,多年冻土分布逐渐变为片状→岛状→零星斑状,直至现今全部融完变为深季节冻土区。

表生风化作用下多年冻土土壤的理论粒径分布(英文)

The paper discusses the distinctive features of grain size distribution of permafrost soils formed under conditions of continental lithogenesis and cryogenic weathering of rocks. As a functional consequence of surface erosion of mineral particles, the log-normal distribution of the density function of grain size is derived confirmed for any conditions and sediment types.

基于颗粒类型的冻土分类(英文)

Based on the log-normal distribution of the grain size density function derived earlier for the entire zone of mineral disintegration, a unified granulometric taxon of perennially frozen soils is proposed which generalizes the existing soil classifications.

地下水储藏仓冻融过程的计算分析(英文)

Thawing and freezing processes are developed subsequently with filling of constructed-in-permafrost underground reservoirs with water. The paper proposes an approximate method to assess these processes with instant filling of reservoirs with water. This method is based on experimentally found mechanism of water cooling in underground reservoirs.Calculation results are given showing effects on the reservoir radius during thaw/freeze cycles, on water and soil temperature as well as on water storage duration.