Variability of Soil Water Heat and Energy Transfer Under Different Cover Conditions in a Seasonally Frozen Soil Area

Abstract

In a seasonally frozen soil area, there is frequent energy exchange between soil and environment, which changes the hydrological cycle process, and then has a certain impact on the prediction and management of agricultural soil moisture. To reveal the effects of different modes of regulation on the energy budget of soil in a region with seasonally frozen soil, four treatments, including the regulation of bare land (BL), biochar (CS), and straw (JS), and the combined regulation of biochar and straw (CJS), were used in field experiments. The variations in the soil temperature, liquid water content, and total water content were analyzed, the energy budget of the soil was calculated, the response functions of the soil energy were determined, and the mechanism of soil energy transfer was elucidated. The results showed that, during the freezing period, the JS treatment reduced the amplitudes of the variations in the soil temperature and liquid water content and increased the water content at the soil surface. During the thawing period, the CJS treatment effectively improved the soil hydrothermal conditions. During the freezing period, the heat absorbed by the CS and JS treatments reduced the fluctuation of the soil energy budget. At a soil depth of 10 cm, the spectral entropy of a time series of the soil net energy was 0.837 under BL treatment, and the CS, JS, and CJS treatments decreased by 0.015, 0.059, and 0.045, respectively, compared to the BL treatment. During the thawing period, the CS treatment promoted energy exchange between the soil and the external environment, and the spectral entropy of a time series of the soil net energy was increased; the JS treatment had the opposite effect. The CJS treatment weakened the impact of environmental factors on the soil energy budget during the freezing period, while it enhanced the energy exchange between the soil and the environment during the thawing period. This study can provide important theoretical and technical support for the efficient utilization of soil hydrothermal resources on farmland in cold regions.

Characteristics of Soil Moisture and Heat Change during Freeze–Thaw Process in the Alpine Grassland of Duogerong Basin in the Source of the Yellow River

“…The vicinity of Gongyu pressway K430 is located in the central and southern part of Duogerong Basin, close to exit of the basin, which is the place where the surface and groundwater of the basin gath The loose sediments in this section mainly consist of three layers: the surface layer is ab 1 m-thick Holocene loessial silty soil, the middle is about a few meters-thick late Plei cene aeolian fine sand or silty sand, and below 7~8 m are river-lake fine sand-silty c interbedded sediments. Sufficient moisture and light conditions provide a suitable en ronment for soil freeze-thaw cycle and water migration [20,[30][31][32].…”

“…The loose sediments in this section mainly consist of three layers: the surface layer is about 1 m-thick Holocene loessial silty soil, the middle is about a few meters-thick late Pleistocene aeolian fine sand or silty sand, and below 7~8 m are river-lake fine sand-silty clay interbedded sediments. Sufficient moisture and light conditions provide a suitable environment for soil freeze-thaw cycle and water migration [20,[30][31][32].…”

An Enhanced Saline Soil Dielectric Constant Model Used for Remote Sensing Soil Moisture and Salinity Retrieval

“…At the same time, soil moisture is critical as a sink of precipitation and groundwater recharge [6,7]. The amount of soil moisture influences the exchanges of energy and matter between the surface environment and the soil [8][9][10]. Moreover, salinity is an essential soil parameter influencing land surface processes, such as the freezing and thawing cycle [11,12] and cultivated land salinization [3,13].…”

Research on Spatial Scale of Fluctuation for the Uncertain Thermal Parameters of Artificially Frozen Soil

“…Many studies had focused on the thermal properties of artificial frozen soils, and the analytic solutions and numerical solutions of the temperature field for artificially frozen soil around the freezing pipe had been developed [4][5][6][7][8][9][10]. However, the complex geological environment and physicochemical processes make the frozen soil show strong spatial variability and correlation characteristics [11][12][13]. On the macroscopic aspect, the distribution of soil particles and ice particles is stochastic; the transformation of unfrozen water and ice crystals is dynamic, and the air content in the pores is variable.…”