川滇地区数字化水位孔隙度和渗透系数时序特征分析

Time Series Analysis of Porosity and Permeability Coefficients Based on Digital Water Level in Sichuan and Yunnan Region

利用川滇地区12口水井的气压系数和M2波潮汐因子等,滑动拟合得到不排水状态下,各井的孔隙度和渗透系数等含水层参数,并定量分析了这些参数的时序变化特征。结果表明:各井的孔隙度和渗透系数在大部分历史强震前有明显异常特征,孔隙度和渗透系数同步性较好,反应了区域构造应力场的变化。在含水层受力状态变化引起的孔隙率(度)和孔隙压力动态变化过程中,当含水层介质受压力变形时,孔隙压力随之增大,则孔隙率(度)和渗透系数同步减小;反之亦然。

Using the pressure coefficient and the wave tide factor of the 12 wells of the Sichuan and Yunnan area, the permeability coefficient and porosity of each well are obtained under undrained condition. Quantitative analysis of the time series variation characteristics of these parameters is achieved. The results show that the porosity and per- meability coefficient of each well have obvious anomalies before strong earthquakes, and the porosity and per- meability coefficient have better synchronization, showing the regional tectonic stress changes. During the porosi- ty and pore pressure change caused by the aquifer stress state change process, when the aquifer medium pressure deforms and pore pressure increase, the porosity and permeability coefficients reduceequally, and vice versa.