武都水库是高坝大型水库（设防烈度Ⅶ度），库区地处龙门山断裂带的主中央断裂与主边界断裂之间，并位于2008年汶川MS 8.0地震的破裂带内。本文选取2014年2月1日—2018年12月31日武都水库监测区记录的4 142次地震进行时空分析，厘清地震的空间分布特征、大坝周围分布特征和时间进程分布特征，并对库区及周边14次ML≥3.0地震对水库大坝的影响进行分析，得出以下结论：①武都水库监测区地震分布特征：2014—2018年，监测区共发生ML≥3.0地震7次；地震活动集中分布在水库库尾和坝前，形成2个明显的丛集区；地震主要沿SW—NE和NW—SE两个垂直剖面分布，震源深度均小于20 km；在大坝NW偏N方向约3—40 km处，地震活动频次较高；监测区内地震活动水平整体较低，地震日频次仅2.89；②在研究时段内，监测区及周边ML≥3.0地震对水库大坝的影响有限，但仍需密切关注地震活动，以保障人民的生产、生活和生命安全。
The Wudu reservoir is a large reservoir with a high dam (located in the earthquake intensity VII area). The whole reservoir is located between the main central fault and the main boundary fault of the Longmen mountain fault zone, also located in the rupture zone of the 2008 Wenchuan MS 8.0 earthquake. This paper selected 4 142 earthquakes recorded in the Wudu reservoir monitoring area from Feb. 1, 2014, to Dec. 31, 2018, to carry out a spatial-temporal analysis to clarify the spatial distribution characteristics of the earthquakes, the distribution characteristics around the dam, and the distribution characteristics along time. The impacts of 14 ML ≥ 3.0 earthquakes in and around the reservoir on the reservoir dam were also analyzed. It is concluded that①A total of 4 142 earthquakes were recorded within the monitoring area, including 7 ML ≥ 3.0 and earthquakes. The seismic activities of the Wudu reservoir are concentrated at the end of the reservoir and in front of the reservoir dam, forming two obvious cluster areas. The earthquakes are mainly distributed on two perpendicular profiles in the SW-NE and NW-SE directions, with depths of less than 20 km. High seismic activity is observed 3-40 km away from the dam in the north-northwest direction. The seismic activity level in the monitoring area is relatively low with a daily seismic frequency of only 2.89. This paper also describes the impacts of 14 typical ML ≥ 3.0 earthquakes on the reservoir and the dam. ② During the study period, the impacts of ML ≥ 3.0 earthquakes on the reservoir dam were limited; however, seismic activity still needs to be closely watched to ensure the safety of the people's production and life.
2022,43（5）: 33-39 收稿日期：2020-08-07
DOI：10.3969/j.issn.1003-3246.2022.05.005
基金项目：中国地震局监测、预报、科研三结合课题（课题编号：3JH-202002020）
作者简介：王翠芳(1969-),女,高级工程师,主要从事水库地震观测及地震仪器开发工作
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