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1.
大小兴安岭多年冻土的主导成因及分布模式 总被引：6，自引：0，他引：6
大小兴安岭海拔高度由北向南增高对纬度偏低带来的温升具有相对补偿功能,从而使冻土分区界线大大南凸。大兴安岭山地为一个连续的整体,不宜仅将南部视为山地多年冻土,而将中、北部划为高纬多年冻土。多年冻土南界应在黄岗梁山南麓通过。小兴安岭的多年冻土南界应在呼兰河源中山的南麓通过。大兴安岭北端断续多年冻土区应将伊勒呼里山平均海拔1000 m的中山部分包括在内;岛状融区多年冻土区南伸至阿尔山附近终结;小兴安岭南端汤旺河与呼兰河的河源区存在岛状融区多年冻土闭合圈。 相似文献
2.
青康公司（国道214线）沿线的多年冻土 总被引：6，自引：0，他引：6
青康公路沿线多年冻土主要分布于河卡南山,鄂拉山,巴颜喀拉山地及花石峡至至多间的低山区丘陵区,呈断续分布,总长共３３０ｋｍ。其分布特征主要受海拔高度控制,但又具有纬度地带性,局地因素同时也起作用。公路沿线冻土退化和冻土环境变化的迹象明显。 相似文献
3.
新藏公路新疆段多年冻土特征及其灾害初探 总被引：2，自引：1，他引：2
新藏公路新疆段沿线海拔高，气候干冷，第四纪松散堆积层厚，在高山区和山原河谷盆地区发育了多年冻土。勘查研究表明：多年冻土分布于K306 000～K310 000和K515 000～K705 00间191．6km路段上，属高原片状连续多年冻土。沿线个别路段含冰量较高，为多冰-富冰冻土，中冻胀中融沉；绝大部分路段以少冰多年冻土为主，弱冻胀弱融沉。现有公路主要冻土灾害有涎流冰、路基融沉、路面翻浆、冻胀破坏、冻融滑塌和冻融泥流等。随着整治改建工程的实施，多年冻土原有的水热平衡的破坏，冻土灾害将趋于严重。根据沿线多年冻土的特征，提出施工和运营中应采取保护冻土的设计原则，通过改线避绕、抬高路基、提高路基强度及完善截排水系统等5条措施以减少公路工程对多年冻土的扰动和破坏。 相似文献
4.
青藏高原西部区域多年冻土分布模拟及其下限估算 总被引：3，自引：0，他引：3
准确评估青藏高原西部多年冻土的空间分布及多年冻土下限深度情况对该区地下水资源利用、生态环境保护有重要意义.本文依托科技基础性工作专项“青藏高原多年冻土本底调查”在该区及周边取得的冻土调查资料,利用遥感数据和扩展地面冻结数模型模拟了该区多年冻土的空间分布,调查区的模拟验证表明该方法有较高的精度.在此基础上,根据有限的地温实测资料建立了地温与位置、高程、坡向和太阳辐射的关系,并根据地温-下限关系估算了该区多年冻土下限深度的分布情况.研究表明,该区有多年冻土约占36.9%,季节冻土占57.5%,多年冻土主要分布在34°N~36.5°N范围的喀喇昆仑、西昆仑一带,季节冻土主要分布在塔里木盆地和34°N以南地区.阿里高原及以南是岛状多年冻土分布区域,其多年冻土分布面积少于此前出版的冻土图所绘制的.青藏高原西部区域的多年冻土下限深度整体表现为由东南-西北逐渐加深. 相似文献
5.
In high mountainous areas, the development and distribution of alpine permafrost is greatly affected by macro- and micro-topographic factors. The effects of latitude, altitude, slope, and aspect on the distribution of permafrost were studied to understand the distribution patterns of permafrost in Wenquan on the Qinghai-Tibet Plateau. Cluster and correlation analysis were performed based on 30 m Global Digital Elevation Model (GDEM) data and field data obtained using geophysical exploration and borehole drilling methods. A Multivariate Adaptive Regression Spline model (MARS) was developed to simulate permafrost spatial distribution over the studied area. A validation was followed by comparing to 201 geophysical exploration sites, as well as by comparing to two other models, i.e., a binary logistic regression model and the Mean Annual Ground Temperature model (MAGT). The MARS model provides a better simulation than the other two models. Besides the control effect of elevation on permafrost distribution, the MARS model also takes into account the impact of direct solar radiation on permafrost distribution. 相似文献
6.
《自然地理学》2013,34(4):249-263
Permafrost occupies 25% of the terrestrial surface of the Northern Hemisphere, but approximately 70% of Russia. Thus, it is not surprising that Russian researchers pioneered its scientific investigation. The first written accounts of perennially frozen ground in Russia appeared in the 17th century during a time of exploration and settlement of remote areas of Siberia. Nineteenth century investigations emphasized mapping, measuring, and describing permafrost and its thermal regime, primarily for reasons of scientific interest. About the turn of the 20th century, construction of the Trans-Siberian Railroad and other issues related to the large migration of people to Siberia instigated a trend toward more applied investigations. In his 1927 book on permafrost research, Sumgin subdivided the history of Russian permafrost studies into three periods, designated the initial accumulation of facts, the academic period, and the utilitarian period. Although these periods are not separated by precise temporal bounds, it remains a useful scheme for presenting this overview of the history of Russian permafrost studies emphasizing the 19th and early 20th centuries. Developments in geothermal observations, permafrost modeling and mapping, ground-ice investigations, and the organization of observational networks remain important research topics because of their relationships to climate change in the Arctic. 相似文献
7.
This paper summarizes an analysis of consequences of railway subgrade construction and maintenance solutions in northern areas of the Russian Far East. An idea of the natural long-term stabilization of the subgrade-base geotechnical system is presented. Proposals to improve the decision-making of construction and engineering solutions are formulated. 相似文献
8.
《自然地理学》2013,34(4):264-278
Permafrost studies first developed as part of the science of geocryology in Russia in the early part of the 20th century. Periglacial geomorphology emerged in the 1950s as a branch of a European-dominated climatic geomorphology. Since then, periglacial geomorphology in North America has become increasingly concerned with permafrost-related process studies and is now viewed by some as a branch of geocryology. The recent development of North American cryostratigraphy allows inferences to be made regarding paleoenvironmental conditions while traditional Pleistocene-oriented periglacial geomorphology has been largely replaced by Quaternary science. The danger exists that North American periglacial geomorphology will cease to be a recognizable sub-branch of geomorphology. 相似文献
9.
Permafrost in China includes high latitude permafrost in northeastern China, alpine permafrost in northwestern China and high plateau permafrost on the Tibetan Plateau. The high altitude permafrost is about 92% of the total permafrost area in China. The south boundary or lower limit of the seasonally frozen ground is defined in accordance with the 0 oC isothermal line of mean air temperature in January, which is roughly corresponding to the line extending from the Qinling Mountains to the Huaihe River in the east and to the southeast boundary of the Tibetan Plateau in the west. Seasonal frozen ground occurs in large parts of the territory in northern China, including Northeast, North, Northwest China and the Tibetan Plateau except for permafrost regions, and accounting for about 55% of the land area of China. The southern limit of short-term frozen ground generally swings south and north along the 25o northern latitude line, occurring in the wet and warm subtropic monsoon climatic zone. Its area is less than 20% of the land area of China. 相似文献
10.
中国冻土研究进展 总被引：6，自引：0，他引：6
Permafrost in China includes high latitude permafrost in northeastern China, alpine permafrost in northwestern China and high plateau permafrost on the Tibetan Plateau. The high altitude permafrost is about 92% of the total permafrost area in China. The south boundary or lower limit of the seasonally frozen ground is defined in accordance with the 0 ℃ isothermal line of mean air temperature in January, which is roughly corresponding to the line extending from the Qinling Mountains to the Huaihe River in the east and to the southeast boundary of the Tibetan Plateau in the west. Seasonal frozen ground occurs in large parts of the territory in northern China, including Northeast, North, Northwest China and the Tibetan Plateau except for permafrost regions, and accounting for about 55% of the land area of China. The southern limit of short-term frozen ground generally swings south and north along the 25° northern latitude line, occurring in the wet and warm subtropic monsoon climatic zone. Its area is less than 20% of the land area of China. 相似文献
11.
The acquisition of a freezing remanent magnetization (FRM) has been studied in controlled magnetic and thermal environments by successive freezing and thawing (−18 to +20°C) of samples of natural sediments from a frost polygon near Ny Ålesund, Spitsbergen. Successive freeze-thaw cycles cause a significant decrease in the intensity of the initially induced shock remanent magnetization (SRM), associated with directional trends towards the ambient magnetic field direction during the freezing phase. A slow increase in intensity commences after seven to 10 freeze-thaw cycles. The acquisition of a FRM in samples carrying an isothermal remanent magnetization shows a significantly smaller reduction in intensity and only minor directional variations. This result indicates that only a fraction of the magnetic grains in a natural sediment contributes to the natural remanent magnetization. Insignificant changes in lengths and directions of the principal susceptibility ellipsoid axes also indicate that magnetic fabric and remanent magnetization are carried by partly different populations of magnetic grains.
The acquisition of a FRM in nature has yet to be explored. If such a process is confirmed, however, it has the potential for obtaining age estimates of ancient thaw depths and for providing insights into material transport processes in frost polygons. 相似文献
The acquisition of a FRM in nature has yet to be explored. If such a process is confirmed, however, it has the potential for obtaining age estimates of ancient thaw depths and for providing insights into material transport processes in frost polygons. 相似文献
12.
This paper lists difficult railway construction conditions that are typical for the northern areas of the Russian Far East. Permafrost-bound issues of railway and highway construction and operation are described. Some of the authors'' developments for subgrade stabilization in the foregoing conditions are given as examples. 相似文献
13.
黄河源区多年冻土温度及厚度研究新进展 总被引：5，自引：0，他引：5
利用新布设的冻土孔及原有冻土资料,分析黄河源区冻土温度和厚度的空间分布。源区实测多年冻土年均地温最低为-1.81℃,冻土最厚74 m,均位于巴颜喀拉山北坡的查拉坪。214国道(K445-K604段)沿线多为高温多年冻土(年均地温>-1℃),但巴山北坡海拔4 520 m、布青山海拔4 300 m以上,年均地温低于-0.5℃。巴山北坡海拔4 610 m、布青山海拔4 420 m以上,年均地温低于-1℃。巴山北坡海拔每升高100 m,年均地温减少0.47~0.75℃,冻土厚度增加16~25 m;纬度向北增加1°,年均地温减少0.85℃,冻土厚度增加20~30 m。 相似文献
14.
CHRISTOF KNEISEL Þ. SÆMUNDSSON A.A. BEYLICH 《Geografiska Annaler: Series A, Physical Geography》2007,89(1):41-50
Four different sites in the highlands of central Iceland have been investigated for permafrost occurrence using two‐dimensional resistivity imaging. The results of the surveys indicate the presence of shallow permafrost of low to medium resistivity. The distribution pattern is spatially heterogeneous which is consistent with permafrost at the fringe of seasonal frost. These sites are likely to react rapidly to changes of the environmental boundary conditions, therefore future research should include monitoring for detecting the early impact of climate change on permafrost degradation. The extent to which periglacial morphodynamics and sediment fluxes are influenced by permafrost and/or seasonal frost and potential permafrost degradation is hard to determine. Hence, long‐term monitoring approaches for both permafrost and sediment dynamics are essential. 相似文献
15.
OLIVER SASS 《Geografiska Annaler: Series A, Physical Geography》2010,92(3):375-391
Lichenometric measurements using Rhizocarpon ssp. were carried out on 20 talus slopes in the cirques of the Finstertal valley (Austria) at an elevation of 2300–3000 m a.s.l. The aim was to assess activity patterns on selected slopes and between the slopes of the study area, to find evidence of rockfall pulses in the last centuries and to calculate rockwall retreat rates. A calibration curve was derived from five sites of known age and adapted to the prevailing size of talus boulders. We measured the five largest lichens on more than 300 boulders and the percentage coverage of Rhizocarpon‐free clasts on more than 1000 test fields. Most of the investigated talus cones are characterized by moderate rockfall supply, with the apex being more active than the talus foot and moderate redistribution by avalanche and debris flows. Considerably enhanced activity was found under rockwalls influenced by permafrost, particularly on the north faces at an elevation of >2600 m a.s.l. At currently moderately active sites, boulder falls seem to have been slightly more frequent in the late nineteenth and first half of the twentieth century. In positions where permafrost is expected in the rockwalls, a weak maximum in the late nineteenth century and highly active present‐day conditions were found, the latter being assigned to current permafrost melt. Rockwall retreat rates derived from lichen coverage are between 400 and 1500 mm/ka which is in good concurrence with talus volume assessments, but higher than the rates derived from direct rockfall measurements. The rates derived from lichen coverage have to be taken with caution as the effects of debris redistribution are hard to quantify. 相似文献
16.
This paper puts forward the coupling model of the heat-moisture-stress field based on the governing equation of
non-stationary heat transfer, moisture movement and the basic differential equations of deformation problem by displacement
under axisymmetric conditions. Using a detailed calculation example for the section of the Xiang Pi Mountain
in 109th National Highway, a mechanical model of the cylinder made by typical silty clay soil is simulated. Results show
that in the coupling process, dynamic stress pays little contribution to the distribution of temperature field along different
depths, and the amount of thawing deformation increased with dynamic loading time under the same frequency and
amplitude. 相似文献
17.
大通河源区多年冻土的地温特征及其影响因素分析 总被引：1，自引：0，他引：1
多年冻土是一种热现象,地温是判断多年冻土特征的有效指标。通过对祁连山区东北部大通河源区多年冻土分布状况的野外考察与钻探等工作,借助于实测地温数据和地温曲线分析工具,对大通河源区39个钻孔点的多年冻土地温特征进行了对比分析,对影响多年冻土地温的主要因素进行了概括和总结。结果表明,在大通河源区,高程、植被类型、地表覆盖特征、土壤水分条件等是影响多年冻土地温的主要因素。根据尺度性划分的结果,高程是影响区域多年冻土地温变化的一级因素;随着空间尺度的下降,植被类型和地表覆盖特征成为二级影响因素;在沼泽化草甸植被覆盖区,土壤水分条件又成为影响多年冻土地温的三级影响因素。对多年冻土地温特征及影响因素的分析不仅有助于了解区域多年冻土的稳定性、预测全球气候变暖背景下的多年冻土演变和退化,还可以为寒区气候变化、生态、水文等相关领域的发展提供基础,为各项工程设施的实施和维护提供建议和指导。 相似文献
18.
考虑局地因素坡向影响的青藏高原工程走廊冻土分布与制图研究 总被引：2，自引：0，他引：2
通过Pearson相关性分析,选取对青藏高原工程走廊多年冻土分布影响较大、在GIS技术支持下较容易量化的坡向因子,结合走廊内2000—2010年29个钻孔点的地温监测数据,建立了年均地温与坡向、纬度和高程的关系模型。根据高原冻土工程地温分带指标,制作了工程走廊内符合实际的冻土分布图,由面积统计结果知:多年冻土区占整个区域的94.06%,其中,低温稳定带占多年冻土区面积的15.94%,主要分布在风火山和可可西里的高山基岩区;低温基本稳定带占16.97%,主要分布在风火山及可可西里丘陵地带;高温不稳定带占48%,主要分布于可可西里和北麓河盆地东缘;高温极不稳地带占19.09%,主要分布于北麓河盆地和楚玛尔河高平原。 相似文献
19.
Studies on frozen ground of China 总被引：5，自引：0，他引：5
1ThestatusoffrozengroundinChinaBased on previous studies, Zhou and Guo (1982) summarized the distribution characteristics of permafrost in China and indicated that the permafrost area in China is about 215×104 km2, in which about 163.4×104 km2 is on the Tibetan Plateau. After mapping and zonation of frozen ground in 1983, Xu and Wang suggested that the areas of permafrost, seasonally frozen ground and temporal frozen ground in China were 206.8×104 km2, 513.7×104 km2 and 229.1×104 km2 … 相似文献
20.
Morten Rasch Birger Hansen Ole Humlum Niels Nielsen Peter Funch Stephen D. Gurney 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):143-159
188 new and previously published radiocarbon dates on Holocene material from Disko Bugt, central West Greenland, are presented together with relevant informations (laboratory number, place name, dated material, geografic coordinates, altitude and δ13C-value) about the dates. In October 1990 an automatic weather station was established at the Arctic station (65 °15′N,53 °31′W), Qeqertarsuaq (Godhavn), Central West Greenland. The Station register parameters each 20 min., and the parameters have been described in an earlier paper in this journal by Nielsen et al. (1995). The present paper summarises main points of the climate during 1996. Open system, or more correctly, hydraulic pingos, are genetically poorly understood. A continuing problem concerns their need for a perennial groundwater supply (intra- or sub-permafrost). This has to be maintained despite the existence of continuous permafrost in many areas where they are located. Recent work on Disko Island has suggested a new type of hydraulic pingo developing only in a “marsh environment”. It is argued that the marsh setting is not relevant to the formation of these features and that they are simply hydraulic pingos. Abstract A group of marsh initiated open system pingo remnants from the Iterdlagssûp kûgssua valley mouth, in Mellemfjord, Disko Island, Central West Greenland was described in Christiansen (1995). Gurney and Worsley (1997) state that the location of this group of pingo remnants in the Iterdlagssûp kûgssua valley mouth is of no relevance to their genesis, and that they presumably were the result of an assumed late Holocene sea level regression, causing permafrost to be established in the valley bottom. In this reply the arguments by Gurney and Worsley (1997) on the Iterdlagssûp kûgssua valley pingos are commented, and it is argued by way of sea level information, frost penetration and water supply that the special setting must indeed have caused pingo initiation and growth. Furthermore, the area has experienced a relative sea level rise during the late Holocene. 相似文献