Estimation of influence of climatic factors on condition of permafrost according to data of monitoring of their apparent resistivity

Abstract

Features of seasonal periodic changes of temperature and apparent resistivity of permafrost dispersed soil mass are shown based on results of field measurements of surface impedance in the 100–1000 kHz frequency range. It is shown a possibility of use of periodicity of changes in the apparent resistivity for an estimation of influence of surface air temperature and precipitation on a degree of freezing of permafrost soils. It is given a correspondence of characteristic changes of climatic factors and apparent resistivity of soils to certain periods of time. The apparent resistivity of the permafrost dispersed soil mass is shown to correspond to the degree of soil freezing. In addition, the seasonal changes of the apparent resistivity reflect four degrees of soil freezing: winter, spring, summer and autumn. Apart from the surface air temperature, the precipitation also has the significant influence on the condition of the soil, influencing it through climate elements such as thickness of snow cover and abundance of rainfall. The results of the analysis of the experimental data of observation of the changes of the apparent resistivity under the influence of the climatic factors in an annual cycle are given. Dependence of the degree of freezing of the permafrost soil mass in the summer period on its value during the preceding spring will allow predicting the state of the permafrost soils for rapid adoption of preventive measures to protect buildings and engineering structures in the cryolithozone under the conditions of a warming climate.