双峰寺水库对承德台VP宽频带倾斜仪观测数据的影响

打开文本图片集

关键词双峰寺水库；倾斜观测；蓄水载荷；地壳形变

中图分类号：P315.63 文献标识码：A 文章编号：2096-7780（2025）08-0463-09

doi：10.19987/j.dzkxjz.2024-134

Impact of the Shuangfengsi reservoir on VP broadband tiltmeter observations at Chengde station

Guo Yaya1）， Zhang Keliang2，Zhang Yulin1，Ren Junfeng1，Yang Donghui1）

1） Chengde Earthquake Monitoring Center Station，Hebei Chengde O670oo， China

2） Institute of Geology， China Earthquake Administration，Beijing looo29， China

AbstractSinceits installation，theVPbroadband tiltmeter at Chengde stationhas exhibited along-term trend of northward tilt along the north-south （NS）axis and westward ilt along the east-west （EW）axis. However，during July to August 2021，both components showedamarked acceleration in tilting，withrates approximatelyfour times higherthan the long-term average. During the same period， the nearby Shuangfengsi reservoir， located about 10km northeast of the station，wasbeing filedandreached itsmaximumwaterlevelonAugust 24，2O21.Thisstudyanalyzes thecorrelation betweenthe inclinometer dataand changes in reservoir capacityand further quantifies theresulting crustal deformation using a non-uniform surface load model. Correlation analysis revealed a strong relationship between variation in the VP broadband tiltmeterdata andchanges inreservoir capacity.Model calculations indicated that thereservoir filingresulted in a maximum crustal subsidence of 0.4421mm ，with corresponding northward tilt of 0.1179mm and eastward tilt of （20 0.0882mm . These values are consistent with the observations recorded by the VP broadband tiltmeter.A similarly strong corelation was alsoobserved between thetiltmeterdataandreservoircapacitychanges in 2O22.The findingssuggest that recent annual variation trends observed by the VP broadband tiltmeter at Chengde station are primarily atributable to loading efects from the Shuangfengsi reservoir.By quantitatively comparing modeled ground tilt induced by reservoir impoundmentwith thetiltmeter observations，this studyeffectivelyrulesout tectonic originssuch asearthquake precursors.These results help prevent potential misinterpretationofthe dataand provide a valuable exampleof how nontectonic influences should be considered in the anomaly analysis used for earthquake forecasting.

KeywordsShuangfengsi reservoir; tilt observation; water storage load; crustal deformation

0 引言

地倾斜观测通过测量地表或近地表某处垂向位移的水平梯度或水平位移的垂向梯度获取地壳形变信息，其连续观测能够反映观测点附近区域的地壳应力变化1，常作为地震前兆的重要观测手段之一。（剩余11536字）