地电场对青藏高原东北部季节冻土的响应特性

地电场的变化与台址环境的水文、气象及地质背景等相关，在青藏高原东北部季节冻土区，11个地电场台站处于较高的海拔，据台址下覆场地属性分为A类（黄土型）和B类（高原草场型）台站。通过对青藏高原季节冻土区域的地电场和大地电流场的计算和分析，联系区域构造活动和地质环境得出以下认识：青藏高原东北部季节冻土区地电场变化对水热环境响应明显，冬、夏两季测值可能发生跃变；长周期的地电场变化曲线可能与台址附近气温变化相关；台站大地电流矢量在冻土部分冻融交替过程中发生方向和幅度值的改变。A类和B类台址显示出不同的季节变化规律，地电场曲线上升和下降的时间节点各异，这种现象可应用于监测该区域冻土冻融情况和冻土的时空演变。

Geoelectricity response to seasonally frost soil change on the northeast Tibetan Plateau

In seasonally frost soil area,geoelectric field monitoring data have an obvious respond to the flowing and freezing water,which can cause dramatic change in resistivity.It also relates to hydrological,meteorological,geological background and other factors surrounding the monitoring site.On the seasonally frost soil area of northeast Tibetan Plateau,there are 12 geoelectric monitoring stations all located in relatively high altitude,which can be divided into Type A (loess stations) and Type B (alpine meadows stations) according to soil type.Through calculation and analysis of geoelectric field and telluric current field in the study area,combined with considering the geological environment,the following conclusions can be drawn:the geoelectdc field monitoring values have a sensitive response to environment,which may jump on winter and summer;long period geoelectric field curve may relate to temperature changes surrounding the station;the direction and amplitude of the telluric current vector changes in the process of the soil partly freezing and thawing alternation.The geoelectric field curve in Type A and Type B stations shows seasonal variation,that is their time points of curve raising or downing is different.This phenomenon may be used in monitoring the soil state as well as the spatial and temporal evolution of the seasonally frost soil.