云南姚安井2009年10月后水位下降的成因分析

Causation of groundwater level descending since October 2009 in Yunnan Yaoan well

地下水动态的异常变化既有可能是地震前兆异常信息,也有可能是某种环境干扰所引起,如降雨和地下水开采等.如何及时识别并排除环境干扰,对于成功判定地震前兆异常至关重要.云南姚安井水位于2009年10月后出现了下降趋势的异常变化,截止2011年底,最大下降幅度达3m.为分析该井水位异常变化的形成原因,依据姚安井水文地质环境特征,建立了相关的数学物理模型,定量分析了降水量和地下水开采量对该井水位的影响.分析结果表明,姚安井2009年后出现的水位大幅下降可能与区域降水量减小导致的地下水开采活动增强有一定的相关性.文中所采取的异常识别与分析方法,对今后地下水动态异常识别及前兆信息判定工作具有一定的借鉴意义.

Abnormal dynamic change of groundwater could be the precursors of earthquake, but sometimes it was induced by other environmental disturbances, such as rainfall and groundwater exploitation. For distinguishing earthquake precursor, it is important to identify environmental disturbance in time. Water level in Yaoan well consistently declined since October 2009, and the max am- plitude was about 3 meters. The influence of rainfall and groundwater pumping was analyzed by using a mathematical physics model in consideration of the characteristics of hydrological geology environment. The result shows that thedecline of groundwater level may be related to the increased groundwater pum- ping owing to the reduced precipitation around Yaoan well since October 2009. The approach of this study may be helpful for future disturbance identification and precursor confirmation.