Author(s)

Hui Sun¹, Shuai Liu², Jihong Qin^3*

¹Department of Environmental Science and Engineering, Sichuan University, Chengdu, China.
²Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
³Department of Environmental Engineering, College of Urban and Rural Construction, Chengdu University, Chengdu, China.

Seasonally frozen soil in alpine and subalpine zones in the mountains of Qinghai-Tibetan Plateau is particularly sensitive to global climate change. Therefore, a better understanding of the thermal properties of frozen soil is crucial for predicting the responses of frozen soils to soil warming. In this study, thermal properties of frozen soil with different moisture contents under subzero temperature (0°C - 20°C) in an alpine forest in western Sichuan were analyzed by KD₂ Pro in its cooling and heating processes, respectively. Our results reveal that the soil apparent volumetric specific heat capacity (C_v) and apparent thermal conductivity (K) under the same water content show similar response patterns to changing temperature lower than -2°C in both heating and cooling processes. Moreover, ice content of frozen soils can be well predicted by Logistic model in cooling and heating processes. The C_v and K tend to increase along with increasing soil moisture contents. Remarkably, asymptotic characters of the value of C_v and K are at the vicinity of the initial temperature of phase transitions, indicating that both C_v and K are particularly sensitive to changing soil temperature at the range of -2°C to 0°C. Therefore, the widely distributed frozen soil layers with temperature above -2°C in alpine and subalpine zones over Qinghai-Tibetan Plateau are susceptible to the observed climate warming during cold season.

Alpine Soil, Seasonally Frozen Soil, Thermal Properties, Qinghai-Tibetan Plateau

Sun, H. , Liu, S. and Qin, J. (2016) Characterizing Subzero-Temperature Thermal Properties of Seasonally Frozen Soil in Alpine Forest in the Western Sichuan Province, China. Journal of Water Resource and Protection, 8, 583-593. doi: 10.4236/jwarp.2016.85048.