The Promotion Mechanism of Frozen Stagnant Water on the Sliding in the Loess Landslide Zone of Heifangtai

Freeze-thaw cycles can significantly change the hydrologic and thermal state of slopes in cold regions and affect their stability. Landslides occur continuously in the slip area of seasonally frozen soil area during the freezing period. The freeze-thaw action and the difference in the characteristics of the underlying surface of the slope are important factors inducing landslides. Taking Heifangtai slope in Gansu Province as an example, the freezing-thawing characteristics of the slope surfaces under different underlying surface conditions were analyzed by field monitoring. A thermohydromechanical coupling model was established to reconstruct the frozen stagnant water process of the Heifangtai landslide zone, and the impact of freeze-thaw action on the loess landslide zone was studied. The results show that differences in the underlying surface led to different freezing-thawing characteristics between the unsaturated area and the groundwater overflow zone. During the freezing period, the soil freezing depth was greater, and the freezing duration was longer in the unsaturated area. The frozen stagnant water effect of the Heifangtai loess landslide zone is obvious. The maximum difference in the groundwater level between February and August could reach nearly 1 m. Meanwhile, the frozen stagnant water process of the Heifangtai landslide zone has a slip-promoting action on the slope. The factor of safety declined during the freezing period and increased during the thawing period. It reached a minimum of 1.42 in February.

Download Full-text

USING SMOS PASSIVE MICROWAVE DATA TO DEVELOP SMAP FREEZE/THAW ALGORITHMS ADAPTED FOR THE CANADIAN SUBARCTIC

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xl-1-w5-365-2015 ◽

2015 ◽

Vol XL-1-W5 ◽

pp. 365-368 ◽

Cited By ~ 1

Author(s):

P. Kalantari ◽

M. Bernier ◽

K. C. McDonal ◽

J. Poulin

Keyword(s):

Land Cover ◽

Time Series Data ◽

Passive Microwave ◽

Soil Freezing ◽

Series Data ◽

Freezing And Thawing ◽

Freeze Thaw ◽

Thaw Cycle ◽

Freeze Thaw Cycle ◽

The Impact

Seasonal terrestrial Freeze/Thaw cycle in Northern Quebec Tundra (Nunavik) was determined and evaluated with passive microwave observations. SMOS time series data were analyzed to examine seasonal variations of soil freezing, and to assess the impact of land cover on the Freeze/Thaw cycle. Furthermore, the soil freezing maps derived from SMOS observations were compared to field survey data in the region near Umiujaq. The objective is to develop algorithms to follow the seasonal cycle of freezing and thawing of the soil adapted to Canadian subarctic, a territory with a high complexity of land cover (vegetation, soil, and water bodies). Field data shows that soil freezing and thawing dates vary much spatially at the local scale in the Boreal Forest and the Tundra. The results showed a satisfactory pixel by pixel mapping for the daily soil state monitoring with a > 80% success rate with in situ data for the HH and VV polarizations, and for different land cover. The average accuracies are 80% and 84% for the soil freeze period, and soil thaw period respectively. The comparison is limited because of the small number of validation pixels.

Download Full-text

Soil infiltration characteristics and pore distribution under freezing-thawing conditions

10.5194/tc-2020-280 ◽

2020 ◽

Author(s):

Ruiqi Jiang ◽

Tianxiao Li ◽

Dong Liu ◽

Qiang Fu ◽

Renjie Hou ◽

...

Keyword(s):

Arable Land ◽

Frozen Soil ◽

Pore Distribution ◽

Ice Crystals ◽

Soil Freezing ◽

Freezing And Thawing ◽

Soil Infiltration ◽

Infiltration Capacity ◽

Saturated Flow ◽

Freeze Thaw

Abstract. Frozen soil infiltration widely occurs in hydrological processes such as seasonal soil freezing and thawing, snowmelt infiltration, and runoff. Accurate measurement and simulation of parameters related to frozen soil infiltration processes are highly important for agricultural water management, environmental issues and engineering problems in cold regions. Temperature changes cause soil pore size distribution variations and consequently dynamic infiltration capacity changes during different freeze-thaw periods. To better understand these complex processes and to reveal the freeze-thaw action effects on soil pore distribution and infiltration capacity, selected black and meadow soils and chernozem, which account for the largest arable land area in Heilongjiang Province, China. Laboratory tests of soils at different temperatures were conducted using a tension infiltrometer and ethylene glycol aqueous solution. The stable infiltration rate, hydraulic conductivity were measured, and the soil pore distribution was calculated. The results indicated that for the different soil types, macropores, which constituted approximately 0.1 % to 0.2 % of the soil volume under unfrozen conditions, contributed approximately 50 % of the saturated flow, and after soil freezing, the soil macropore proportion decreased to 0.05 % to 0.1 %, while their saturated flow proportion decreased to approximately 30 %. Soil moisture froze into ice crystals inside relatively large pores, resulting in numerous smaller-sized pores, which reduced the number of macropores while increasing the number of smaller-sized mesopores, so that the frozen soil infiltration capacity was no longer solely dependent on the macropores. After the ice crystals had melted, more pores were formed within the soil, enhancing the soil permeability.

Download Full-text

Soil infiltration characteristics and pore distribution under freezing–thawing conditions

The Cryosphere ◽

10.5194/tc-15-2133-2021 ◽

2021 ◽

Vol 15 (4) ◽

pp. 2133-2146

Author(s):

Ruiqi Jiang ◽

Tianxiao Li ◽

Dong Liu ◽

Qiang Fu ◽

Renjie Hou ◽

...

Keyword(s):

Arable Land ◽

Frozen Soil ◽

Pore Distribution ◽

Ice Crystals ◽

Soil Freezing ◽

Soil Types ◽

Soil Infiltration ◽

Infiltration Capacity ◽

Saturated Flow ◽

Freeze Thaw

Abstract. Frozen soil infiltration widely occurs in hydrological processes such as seasonal soil freezing and thawing, snowmelt infiltration, and runoff. Accurate measurement and simulation of parameters related to frozen soil infiltration processes are highly important for agricultural water management, environmental issues, and engineering problems in cold regions. Temperature changes cause soil pore size distribution variations and consequently dynamic infiltration capacity changes during different freeze–thaw periods. To better understand these complex processes and to reveal the freeze–thaw action effects on soil pore distribution and infiltration capacity, black soils, meadow soils, and chernozem were selected as test subjects. These soil types account for the largest arable land area in Heilongjiang Province, China. Laboratory tests of soils at different temperatures were conducted using a tension infiltrometer and ethylene glycol aqueous solution. The stable infiltration rate and hydraulic conductivity were measured, and the soil pore distribution was calculated. The results indicated that for the different soil types, macropores, which constituted approximately 0.1 % to 0.2 % of the soil volume under unfrozen conditions, contributed approximately 50 % of the saturated flow, and after soil freezing, the soil macropore proportion decreased to 0.05 % to 0.1 %, while the saturated flow proportion decreased to approximately 30 %. Soil moisture froze into ice crystals inside relatively large pores, resulting in numerous smaller-sized pores, which reduced the number of macropores but increased the number of smaller-sized mesopores, so that the frozen soil infiltration capacity was no longer solely dependent on the macropores. After the ice crystals had melted, more pores were formed within the soil, enhancing the soil permeability.

Download Full-text

Modeling soil freeze-thaw and ice effect on canal bank

Canadian Geotechnical Journal ◽

10.1139/t98-032 ◽

1998 ◽

Vol 35 (4) ◽

pp. 655-665 ◽

Cited By ~ 6

Author(s):

Z X Zhang ◽

R L Kushwaha

Keyword(s):

Frozen Soil ◽

Soil Freezing ◽

Frost Heave ◽

Energy Status ◽

Abrupt Increase ◽

Water Ice ◽

Freeze Thaw ◽

Thaw Cycle ◽

Initial Soil ◽

Freeze Thaw Cycle

The experiments for modeling soil freeze-thaw and ice action on canal banks were conducted in a laboratory. In addition to the frost heave that was observed during the period of soil freezing, there was an abrupt increase in frost heave that occurred at the beginning of soil thawing. This phenomenon lasted for over approximately 100 hours, and the frost heave induced during this period reached as much as 22.62 mm. At the same time, peak ice pressures also occurred as the soil was thawing. It has been suggested that the frost heave during initial soil thawing may be associated with the change in energy status at the water-ice interface resulting from the buildup of internal stress in the soil during the formation of ice lenses.Key words: frozen soil, freeze-thaw cycle, frost heave, thawing settlement, canal protection.

Download Full-text

An Improved Algorithm for Discriminating Soil Freezing and Thawing Using AMSR-E and AMSR2 Soil Moisture Products

Remote Sensing ◽

10.3390/rs10111697 ◽

2018 ◽

Vol 10 (11) ◽

pp. 1697 ◽

Cited By ~ 2

Author(s):

Huiran Gao ◽

Wanchang Zhang ◽

Hao Chen

Keyword(s):

Soil Moisture ◽

Brightness Temperature ◽

Surface Soil ◽

Microwave Remote Sensing ◽

Passive Microwave ◽

Soil Freezing ◽

Classification Rate ◽

Freeze Thaw ◽

The Impact ◽

Improved Algorithm

Discriminating between surface soil freeze/thaw states with the use of passive microwave brightness temperature has been an effective approach so far. However, soil moisture has a direct impact on the brightness temperature of passive microwave remote sensing, which may result in uncertainties in the widely used dual-index algorithm (DIA). In this study, an improved algorithm is proposed to identify the surface soil freeze/thaw states based on the original DIA in association with the AMSR-E and AMSR2 soil moisture products to avoid the impact of soil moisture on the brightness temperature derived from passive microwave remotely-sensed soil moisture products. The local variance of soil moisture (LVSM) with a 25-day interval was introduced into this algorithm as an effective indicator for selecting a threshold to update and modify the original DIA to identify surface soil freeze/thaw states. The improved algorithm was validated against in-situ observations of the Soil Moisture/Temperature Monitoring Network (SMTMN). The results suggest that the temporal and spatial variation characteristics of LVSM can significantly discriminate between surface soil freeze/thaw states. The overall discrimination accuracy of the improved algorithm was approximately 89% over a remote area near the town of Naqu on the East-Central Tibetan Plateau, which demonstrated an obvious improvement compared with the accuracy of 82% derived with the original DIA. More importantly, the correct classification rate for the modified pixels was over 96%.

Download Full-text

A Predictive Model of the Impact of the Skidding System on Forest Soil in Severe Climatic Conditions

Lesnoy Zhurnal (Forestry Journal) ◽

10.37482/0536-1036-2020-5-131-144 ◽

2020 ◽

pp. 131-144

Author(s):

S.E. Rudov ◽

◽

V.Ya. Shapiro ◽

O.I. Grigoreva ◽

I.V. Grigorev ◽

...

Keyword(s):

Forest Soil ◽

Warm Season ◽

Climatic Conditions ◽

Soil Freezing ◽

Class Iii ◽

Freezing And Thawing ◽

Metal Structures ◽

Rapid Adjustment ◽

Soil Freezing And Thawing ◽

The Impact

In the Russian Federation logging operations are traditionally carried out in winter. This is due to the predominance of areas with swamped and water-logged (class III and IV) soils in the forest fund, where work of forestry equipment is difficult, and sometimes impossible in the warm season. The work of logging companies in the forests of the cryolithozone, characterized by a sharply continental climate, with severe frosts in winter, is hampered by the fact that forest machines are not recommended to operate at temperatures below –40 °C due to the high probability of breaking of metal structures and hydraulic system. At the same time, in the warm season, most of the cutting areas on cryosolic soils become difficult to pass for heavy forest machines. It turns out that the convenient period for logging in the forests of the cryolithozone is quite small. This results in the need of work in the so-called off-season period, when the air temperature becomes positive, and the thawing processes of the soil top layer begin. The same applies to the logging companies not operating in the conditions of cryosolic soils, for instance, in the Leningrad, Novgorod, Pskov, Vologda regions, etc. The observed climate warming has led to a significant reduction in the sustained period of winter logging. Frequent temperature transitions around 0 °C in winter, autumn and spring necessitate to work during the off-season too, while cutting areas thaw. In bad seasonal and climatic conditions, which primarily include off-season periods in general and permafrost in particular, it is very difficult to take into account in mathematical models features of soil freezing and thawing and their effect on the destruction nature. The article shows that the development of long-term predictive models of indicators of cyclic interaction between the skidding system and forest soil in adverse climatic conditions of off-season logging operations in order to improve their reliability requires rapid adjustment of the calculated parameters based on the actual experimental data at a given step of the cycles.

Download Full-text

THE EFFECT OF ANTECEDENT FREEZE-THAW FREQUENCY ON RUNOFF AND SOIL LOSS FROM FROZEN SOIL WITH AND WITHOUT SUBSOIL COMPACTION AND GROUND COVER

Canadian Journal of Soil Science ◽

10.4141/cjss89-080 ◽

1989 ◽

Vol 69 (4) ◽

pp. 799-811 ◽

Cited By ~ 14

Author(s):

LINNELL M. EDWARDS ◽

J. R. BURNEY

Keyword(s):

Prince Edward Island ◽

Sandy Loam ◽

Bare Soil ◽

Winter Rye ◽

Rainfall Simulator ◽

Fine Sandy Loam ◽

Freeze Thaw ◽

Sediment Loss ◽

Freezing Period ◽

Subsoil Compaction

Three soils from Prince Edward Island (a loam, a fine sandy loam, and a sandy loam) were tested under a laboratory rainfall simulator to examine the effects of frequency of freezing and thawing, winter rye cover, incorporated cereal residue, and subsoil compaction on runoff volume and sediment loss. Wooden soil boxes were subjected to simulated rain (i) at the end of a 10-d freezing period, and (ii) at the end of the 5th 24-h freezing period of a 10-d alternating freeze-thaw cycle (freeze/thaw). Where the soil was continuously frozen for 10 d, there was 178% greater sediment loss and 160% greater runoff than with daily freeze/thaw over the same period, but there was no difference in sediment concentration. Incorporated cereal residue decreased sediment loss to 50% and runoff to 77% of that from bare soil. Winter rye cover decreased sediment loss to 73% of that from bare soil. Simulated soil compaction caused a 45% increase in sediment loss. The loam soil showed 16.5% greater loss of fine sediment fractions <0.075 mm than the fine sandy loam which showed 23.4% greater loss than the sandy loam. Key words: Freeze-thaw, erosion, compaction, winter rye, cereal residue, rainfall simulator, Prince Edward Island soils

Download Full-text

Volume change behaviour and microstructure of stabilized loess under cyclic freeze–thaw conditions

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2016-0052 ◽

2016 ◽

Vol 43 (10) ◽

pp. 865-874 ◽

Cited By ~ 18

Author(s):

Sheng-lin Wang ◽

Qing-feng Lv ◽

Hassan Baaj ◽

Xiao-yuan Li ◽

Yan-xu Zhao

Keyword(s):

Fly Ash ◽

Volume Change ◽

Cement Content ◽

Frost Heave ◽

Equivalent Diameter ◽

Surface Porosity ◽

Change Rate ◽

Freeze Thaw ◽

Significant Damage ◽

The Impact

Freeze–thaw action is considered to be one of the most destructive actions that can induce significant damage in stabilized subgrades in seasonally frozen loess areas. Laboratory tests including frost heave – thaw shrinkage and microstructure change during freeze–thaw cycles were conducted to evaluate the volume change rate of loess stabilized with cement, lime, and fly ash under the impact of cyclic freeze–thaw conditions. The loess specimens collapsed after eight freeze–thaw cycles (192 h), but most stabilized loess specimens had no visible damage after all freeze–thaw cycles were completed. All of the stabilized loess samples underwent a much smaller volume change than the loess alone after the freeze–thaw cycles. Although surface porosity and equivalent diameter of stabilized loess samples increased, the stabilized loess can retain its microstructure during freeze–thaw cycles when the cement content was less than 6%. To ensure freeze–thaw resistance of stabilized loess subgrades, the mix proportions of the three additives was recommended to be 4 to 5% cement, 6% lime, and 10% fly ash.

Download Full-text