地震前后井-含水层系统潮汐参数变化特征分析——以云南弥勒井为例

Analysis of Tidal Parameters Variation in the Well-aquifer System before and after the Earthquake—A Case Study of the Mile well in Yunnan Province

摘要:

本文对弥勒井2004~2016年井水位同震响应形态及地震前后井水位潮汐参数变化关系特征进行分析。结果表明，在弥勒井水流运动方向总体是以垂向流为主、径向流为辅的前提下，天然因素（地震）和人工因素（洗井、装置改造）均可改变含水层水流运动方向。当震前潮汐因子和相位差反向变化时，能量较大的地震可以改变其水流运动方向，使震后潮汐因子和相位差呈同向变化，水流运动方向由以垂向为主变为以径向为主；能量较小的地震只是改变其含水层渗透系数，没有改变其水流运动方向，震后仍以垂向流为主。当震前潮汐因子和相位差呈同向变化时，能量较大的地震发生可以使径向含水层渗透系数增大，水流运动方向不变，震后仍以径向为主。通过分析潮汐参数变化，可以进一步得知井-含水层径、垂向流渗透系数的变化，为进一步精确计算含水层参数提供了参考。

Abstract:

In this paper, the characteristics of the co-seismic response of the well water level from 2004 to 2016 and the relationship between the tidal parameters before and after the earthquake are analyzed. The results show that under the premise that the main flow direction of the Mile well is the vertical flow, natural(earthquake) and artificial(washing, plant modification) factors can change the direction of the aquifer flow. When the tidal factor and the phase difference change in the opposite direction before the earthquake, the earthquake with larger energy can change the direction of the water flow, so that the tidal factor and the phase difference change in the same direction after the earthquake, and the direction of the water flow changes from vertical to radial dominance. The earthquake with less energy only changed the permeability coefficient of the aquifer, but does not change the direction of its water flow, and still dominates the vertical flow after the earthquake. When the tidal factor and phase difference before the earthquake change in the same direction, the earthquake with larger energy can increase the permeability coefficient of the radial aquifer, the direction of the water flow is unchanged, and the radial direction is still dominant. By analyzing the changes of tidal parameters, we can further know the change of the well-aquifer radial and vertical permeability coefficient, which lays a foundation for the accurate calculation of aquifer parameters.