Dazu Well is located in Shiwan Town of Dazu County .Chongqing City,the well is 108. 7m deep. The observed aquifer layer is weather-fractured phreatic aquifer,of which the rock stratum is mudstone of Middle Jurassic Shaximiao Formation ( J2S) interbedded by sand. Years of observations show that whenever the nearby well, which is 14. 6m away, was pumped, the water level of Dazu well rose instead of drop. This kind of anomalous response has been rarely reported both at home and abroad. By analyzing the observation data, investigating the local geological and hydrogeological conditions, field observation and theoretic analysis, etc., we conclude that the anomalous response of Dazu well water level to the pumping of nearby well is attributed to the special water level regime of the observation well caused by hydrodynamic pressure due to the larger flow velocity in the outer boundary of pum-ping-depression cone,under a specific hydrogeological condition.%大足井位于重庆市大足县拾万镇,井深108.7m,观测含水层为J2s泥岩夹砂层的风化裂隙潜水层.多年的观测结果表明,每当相距仅14.6m的邻井抽水时,该井水位不仅不降,反而上升,是国内外罕见的奇异现象.通过对这一现象进行的观测资料分析、井区地质-水文地质条件调查、现场试验观测及理论分析等得出,大足井水位对邻井抽水的奇异响应是在特定的水文地质条件下,抽水降落漏斗外边界带上因水流速度较大引起的动水压力使该处的观测井产生的特殊井水位动态.
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