Improved characterization of frozen soil processes in the Versatile Soil Moisture Budget model

2013 ◽  
Vol 93 (4) ◽  
pp. 511-531 ◽  
Author(s):  
Getachew A. Mohammed ◽  
Masaki Hayashi ◽  
Christopher R. Farrow ◽  
Yasuhide Takano

Mohammed, G. A., Hayashi, M., Farrow, C. R. and Takano, Y. 2013. Improved characterization of frozen soil processes in the Versatile Soil Moisture Budget model. Can. J. Soil Sci. 93: 511–531. Soil freezing and thawing influence the infiltration of rain and snow melt water and subsequent redistribution, runoff generation, and a host of other processes. Accurate characterization of frozen soil processes in hydrological models is important for their use in managing agricultural activities and water resources. The Versatile Soil Moisture Budget (VSMB) is a relatively simple soil water balance model, which has been widely used in Canada for several decades, but its application has primarily been for crop-growing seasons. We have modified the VSMB to include new algorithms for snow accumulation and melt, soil freezing and thawing, and snowmelt infiltration and runoff; and evaluated its performance using field data from a grassland site in Alberta. The new VSMB model simulates snow processes with reasonable accuracy and predicts the day of thawing within several days of observation. It also estimates the amount of runoff and its inter-annual variability reasonably well, although the model still has limitations in accurately predicting the vertical distribution of water content. Despite these limitations, the model will be useful for estimating the amount of snowmelt runoff that provides the critical water inputs to wetlands and dugouts, and for understanding the effects of landuse variability on these processes.

1993 ◽  
Vol 73 (4) ◽  
pp. 489-501 ◽  
Author(s):  
H. N. Hayhoe ◽  
R. G. Pelletier ◽  
L. J. P. van Vliet

Rainfall and snowmelt runoff on soil frozen below the surface are recognized as important factors contributing to soil loss in Canada. The risk of rain on frozen soil has been quantified, and the amount of snowmelt on frozen soil has been estimated. This study extends such research to derive a climate-based model to estimate winter and spring runoff. This could result in a more accurate erosion prediction for areas where snowmelt is a major source for runoff. Selected components of the Water Erosion Prediction Project (WEPP) model and the versatile soil moisture budget (VB) were tested on observed data for two study sites in the Peace River region. The version of the WEPP model available to us estimated snow depth, soil frost depth and frequency of freeze–thaw cycles. However, the results did not adequately match observed data. The VB was modified in this study to improve the estimate of potential winter and spring runoff, and it was shown that incorporating observations of snow depth improved the estimate of the time and amount of snowmelt runoff. The modified runoff model was validated with data collected in the Peace River area of northern Alberta and British Columbia and with published data from the Prairies. Key words: Snowmelt, runoff, soil moisture budget


2016 ◽  
Vol 7 (3) ◽  
pp. 611-625 ◽  
Author(s):  
Stefan Hagemann ◽  
Tanja Blome ◽  
Altug Ekici ◽  
Christian Beer

Abstract. Permafrost or perennially frozen ground is an important part of the terrestrial cryosphere; roughly one quarter of Earth's land surface is underlain by permafrost. The currently observed global warming is most pronounced in the Arctic region and is projected to persist during the coming decades due to anthropogenic CO2 input. This warming will certainly have effects on the ecosystems of the vast permafrost areas of the high northern latitudes. The quantification of such effects, however, is still an open question. This is partly due to the complexity of the system, including several feedback mechanisms between land and atmosphere. In this study we contribute to increasing our understanding of such land–atmosphere interactions using an Earth system model (ESM) which includes a representation of cold-region physical soil processes, especially the effects of freezing and thawing of soil water on thermal and hydrological states and processes. The coupled atmosphere–land models of the ESM of the Max Planck Institute for Meteorology, MPI-ESM, have been driven by prescribed observed SST and sea ice in an AMIP2-type setup with and without newly implemented cold-region soil processes. Results show a large improvement in the simulated discharge. On the one hand this is related to an improved snowmelt peak of runoff due to frozen soil in spring. On the other hand a subsequent reduction in soil moisture enables a positive feedback to precipitation over the high latitudes, which reduces the model's wet biases in precipitation and evapotranspiration during the summer. This is noteworthy as soil-moisture–atmosphere feedbacks have previously not been the focus of research on the high latitudes. These results point out the importance of high-latitude physical processes at the land surface for regional climate.


1961 ◽  
Vol 33 (1) ◽  
pp. 233-239
Author(s):  
Mikko Sillanpää

A laboratory study was conducted to evaluate the effects of soil moisture and air temperature on soil freezing and thawing. The time required to freeze or thaw a soil sample was a linear function of soil moisture content and a linear log-log function of the temperature of the surrounding air. The differences in the freezing-thawing properties between the three mineral soils under study were small when compared with the effect of soil moisture content. In field conditions the indirect effects of those soil properties that determine the moisture-holding properties of various soils seem to be of prime importance in influencing the course of the freezing and thawing processes.


Author(s):  
S.E. Rudov ◽  
◽  
V.Ya. Shapiro ◽  
O.I. Grigoreva ◽  
I.V. Grigorev ◽  
...  

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.


1968 ◽  
Vol 48 (5) ◽  
pp. 535-544 ◽  
Author(s):  
A. R. Mack ◽  
W. S. Ferguson

Actual evapotranspiration (AE), soil moisture distribution, and moisture stress for a wheat crop (PE-AE) were estimated by the modulated soil moisture budget of Holmes and Robertson. The estimated soil moisture was reasonably well correlated with soil moisture measured weekly by means of gypsum blocks. Wheat yields from experimental plots in the corresponding area were related more closely to the moisture stress function (PE-AE: r = − 0.83), than to the seasonal precipitation (r = 0.62), the potential evapotranspiration (PE) or the evapotranspiration ratio (AE/PE). Regression analyses showed that the grain yields were reduced by an average of 156 (±sb = 40) kg/ha per cm of moisture stress from emergence to harvest, or by 311 and 69 kg/ha per cm of stress, from the fifth-leaf to the soft-dough stage and from the soft-dough stage to maturity, respectively. The moisture stress function may be used to characterize the soil–plant–atmosphere environment for the growing season of a crop. Precipitation and evapotranspiration data are presented annually for three standardized growing periods at Brandon from 1921 to 1963.


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