نتایج جستجو برای: Soil freezing

تعداد نتایج: 197785  

2016
Ying Zhao Bingcheng Si Hailong He Jinghui Xu Stephan Peth Rainer Horn Jun Xu

Accurate simulation of soil water and heat transfer is critical to understand surface hydrology under cold conditions. Using an extended freezing code in HYDRUS-1D (freezing module), this study was conducted: (1) to evaluate the freezing module using field data collected in a grazed steppe of Inner Mongolia; and (2) to further simulate grazing effects on frozen soil hydrological processes. The ...

Journal: :Environmental science & technology 2003
Ross D Fitzhugh Gene E Likens Charles T Driscoll Myron J Mitchell Peter M Groffman Timothy J Fahey Janet P Hardy

Soil freezing is a disturbance of the below ground environment, potentially resulting in increased losses of NO3- and surface water acidification. Here, we report the effects of soil freezing on interannual variation in stream chemistry at the Hubbard Brook Experimental Forest, New Hampshire. Data from 1970 to 1997 of soil frost depth, snow cover, precipitation, air temperature, and stream disc...

2012
Zilong Wang Qiuxiang Jiang Qiang Fu Tianxiao Li

The identification of freezing-thawing soil hydraulic properties is the basis and key problem of studying soil water movement. Current identifying methods of the properties have many limitations, such as big error, high uncertainty and low operability. Thus, the identifying method of freezingthawing soil hydraulic properties was researched in the research. The estimating parameters of soil free...

2016
Xiangdong Hu Shengjun Deng Hui Ren Xianchang Li

In order to solve the water sealing problem of soil between pipes of long distance curved pipe-jacked technology, Freeze-Sealing Pipe Roof (FSPR) as an innovative pre-supporting method in tunnel engineering is being applied to the Gongbei Tunnel in the Hong Kong-Zhuhai-Macau Bridge. The definition of FSPR is that large diameter steel pipes are laid out in a circle around the cross section of tu...

Journal: :Global change biology 2014
John L Campbell Anne M Socci Pamela H Templer

The depth and duration of snow pack is declining in the northeastern United States as a result of warming air temperatures. Since snow insulates soil, a decreased snow pack can increase the frequency of soil freezing, which has been shown to have important biogeochemical implications. One of the most notable effects of soil freezing is increased inorganic nitrogen losses from soil during the fo...

Journal: :Carbon Balance and Management 2007
Irina Kurganova Robert Teepe Norman Loftfield

BACKGROUND The repeated freeze-thaw events during cold season, freezing of soils in autumn and thawing in spring are typical for the tundra, boreal, and temperate soils. The thawing of soils during winter-summer transitions induces the release of decomposable organic carbon and acceleration of soil respiration. The winter-spring fluxes of CO2 from permanently and seasonally frozen soils are ess...

2016
Haohao Wu Xingkai Xu Cuntao Duan Tuansheng Li Weiguo Cheng

There is limited knowledge about how the interaction of dissolved organic carbon (DOC) and inorganic nitrogen (N) released into the soil just after freezing can affect methane (CH4) uptake in forest soils. Here, we present how freezing treatment and glucose, as a DOC source, can affect the roles of NH4(+)-N and NO3(-)-N in inhibiting soil CH4 uptake, by using soil-core incubation experiments. A...

2011
I. Gouttevin G. Krinner P. Ciais

Soil freezing is a major feature of boreal regions with substantial impact on climate. The present paper describes the implementation of the thermal and hydrological effects of soil freezing in the land surface model ORCHIDEE, which includes a physical description of continental hydrology. The new soil freezing scheme is evaluated against analytical solutions and in-situ observations at a varie...

Journal: :Remote Sensing 2014
Thomas Jagdhuber Julia Stockamp Irena Hajnsek Ralf Ludwig

The monitoring of soil freezing and thawing states over large areas is very challenging on ground. In order to investigate the potential and the limitations of space-borne SAR polarimetry at C-band for soil state survey, analyses were conducted on an entire winter time series of fully polarimetric RADARSAT-2 data from 2011/2012 to identify freezing as well as thawing states within the soil. The...

Journal: :desert 2008
a. khalili h. rahimi z. agha shariatmadari

depth of frost penetration is one of the main indices in agriculture, civil and transportation engineering. soil temperature is a function of several factors including: topography, solar radiation, air temperature, moisture content and other physical properties of soil such as thermal capacity, coefficient of heat conductivity, and specific heat. the main objective of the present paper is to de...

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