Climate background, fact and hydrological effect of multiphase water transformation in cold regions of the Western China: A review

2019 ◽  
Vol 190 ◽  
pp. 33-57 ◽  
Author(s):  
Li Zongxing ◽  
Feng Qi ◽  
Li Zongjie ◽  
Yuan Ruifeng ◽  
Gui Juan ◽  
...  
Keyword(s):  
Western China ◽  
Cold Regions ◽  
Climate Background

scholarly journals Research on the Pore Evolution of Sandstone in Cold Regions under Freeze-Thaw Weathering Cycles Based on NMR

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zheng Pan ◽  
Keping Zhou ◽  
Rugao Gao ◽  
Zhen Jiang ◽  
Chun Yang ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Pore Structure ◽  
Western China ◽  
Cold Regions ◽  
Abrupt Decrease ◽  
Evolution Law ◽  
Red Sandstone ◽  
Freeze Thaw ◽  
Evolution Characteristics ◽  
Pore Evolution

The evolution of the rock pore structure is an important factor influencing rock mechanical properties in cold regions. To study the mesoscopic evolution law of the rock pore structure under freeze-thaw weathering cycles, a freeze-thaw weathering cycle experiment was performed on red sandstone from the cold region of western China with temperatures ranging from -20°C to +20°C. The porosity, T2 spectral distribution, and magnetic resonance imaging (MRI) characteristics of the red sandstone after 0, 20, 40, 60, 80, 100, and 120 freeze-thaw weathering cycles were measured by the nondestructive detection technique nuclear magnetic resonance (NMR). The results show that the porosity of sandstone decreases first and then increases with the increase of the freeze-thaw weathering cycles and reaches the minimum at 60 of freeze-thaw weathering cycles. The evolution characteristics of porosity can be divided into three stages, namely, the abrupt decrease in porosity, the slow decrease in porosity, and the steady increase in porosity. The evolution characteristics of the T2 spectrum distribution, movable fluid porosity (MFP), and MRI images in response to the freeze-thaw weathering process are positively correlated with the porosity. Analysis of the experimental data reveals that the decrease in the porosity of the red sandstone is mainly governed by mesopores, which is related to the water swelling phenomenon of montmorillonite. Hence, the pore connectivity decreases. As the number of freeze-thaw cycles increases, the effect of the hydrophysical reaction on the porosity gradually disappears, and the frost heaving effect caused by the water-ice phase transition gradually dominates the pore evolution law of red sandstone.

scholarly journals Extension of the Representative Elementary Watershed approach for cold regions: constitutive relationships and an application

2008 ◽  
Vol 12 (2) ◽  
pp. 565-585 ◽  
Author(s):  
L. Mou ◽  
F. Tian ◽  
H. Hu ◽  
M. Sivapalan
Keyword(s):  
Energy Balance ◽  
Soil Freezing ◽  
Western China ◽  
Unfrozen Water ◽  
Balance Equations ◽  
Freezing And Thawing ◽  
Modeling Framework ◽  
Cold Regions ◽  
Constitutive Relationships ◽  
Unfrozen Water Content

Abstract. The Representative Elementary Watershed (REW) approach proposed by Reggiani et al. (1998, 1999) represents an attempt to develop a scale adaptable modeling framework for the hydrological research community. Tian et al. (2006) extended the original REW theory for cold regions through explicit treatment of energy balance equations to incorporate associated cold regions processes, such as snow and glacier melting/accumulation, and soil freezing/thawing. However, constitutive relationships for the cold regions processes needed to complete these new balance equations have been left unspecified in this derivation. In this paper we propose a set of closure schemes for cold regions processes within the extended framework. An energy balance method is proposed to close the balance equations of melting/accumulation processes as well as the widely-used and conceptual degree-day method, whereas the closure schemes for soil freezing and thawing are based on the maximum unfrozen-water content model. The proposed closure schemes are coupled to the previously derived balance equations and implemented within the Thermodynamic Watershed Hydrological Model (THModel, Tian, 2006) and then applied to the headwaters of the Urumqi River in Western China. The results of the 5-year calibration and 3-year validation analyses show that THModel can indeed simulate runoff processes in this glacier and snow-dominated catchment reasonably well, which shows the prospects of the REW approach and the developed closure schemes for cold regions processes.

scholarly journals Extension of the Representative Elementary Watershed approach for cold regions: constitutive relationships and an application

2007 ◽  
Vol 4 (5) ◽  
pp. 3627-3686
Author(s):  
L. Mou ◽  
F. Tian ◽  
H. Hu ◽  
M. Sivapalan
Keyword(s):  
Energy Balance ◽  
Soil Freezing ◽  
Western China ◽  
Unfrozen Water ◽  
Balance Equations ◽  
Freezing And Thawing ◽  
Modeling Framework ◽  
Cold Regions ◽  
Constitutive Relationships ◽  
Unfrozen Water Content

Abstract. The representative elementary watershed (REW) approach proposed by Reggiani et al. (1998, 1999) represents an attempt to develop a scale adaptable modeling framework for the hydrological research community. Tian et al. (2006a) extended the original REW theory for cold regions through explicit treatment of energy balance equations to incorporate associated cold regions processes, such as melting and accumulation of glacier and snow, and freezing and thawing of soil ice. However, constitutive relationships for the cold regions processes needed to complete these new balance equations have been left unspecified in this derivation. In this paper we propose a set of closure scheme for cold regions processes within the extended framework provided by Tian et al. (2006a). A rigorous energy balance method is proposed to close the balance equations of melting/accumulation processes as well as the widely-used and conceptual degree-day method, whereas the closure schemes for soil freezing and thawing are based on the "maximum unfrozen-water content" model. The proposed closure schemes are coupled to the previously derived balance equations and implemented within Thermodynamic Watershed Hydrological Model (THModel, Tian, 2006b) and then applied to the headwaters of the Urumqi River in Western China. The results of the 4-year calibration and 1-year validation analyses show that THModel can indeed simulate runoff processes in this snow and glacier-dominated catchment very well, which confirms the applicability of the modeling based on the REW approach and the validity of the developed closure schemes for cold regions processes.

TBE in China

2020 ◽  
Keyword(s):  
Western China ◽  
Ixodes Persulcatus ◽  
West China ◽  
North West ◽  
Haemaphysalis Concinna ◽  
Viral Subtype ◽  
Japanese Military ◽  
Natural Foci ◽  
Far Eastern ◽  
The Brain

The first TBE patients in China were reported in 1943, and the TBEV was isolated from the brain tissues of 2 patients in 1944 by Japanese military scientists,1 and from patients and ticks (Ixodes persulcatus and Haemaphysalis concinna) in 1952 by Chinese researchers.2 The Far Eastern viral subtype (TBEV-FE) is the endemic subtype that has been isolated from all 3 known natural foci (northeastern China, western China, and southwestern China).14 Recently a new “Himalayan subtype” of the TBEV (TBEV-HIM) was isolated from wild rodent Marmoata himalayana in the Qinghai-Tibet Plateau15. The main vector of the TBEV in China is I. persulcatus.3 One recent report suggests that the TBEV-SIB is prevalent in the Uygur region (North West China)13 but epidemiological modelling indicates that the TBEV may occur even widely all over China (Figure 3).4 Likely, the disease is often missed by clinicians due to a lack of the availability of specific diagnostic assays16.

Solar Heating in Cold Regions

1996 ◽  
Author(s):  
Jean-François Rozis ◽  
Alain Guinebault
Keyword(s):  
Solar Heating ◽  
Cold Regions
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