Influences of the Three Gorges Project on seismic activities in the reservoir area

Yao, Yunsheng; Wang, Qiuliang; Liao, Wulin; Zhang, Lifen; Junhua, Chen; Li, Jinggang; Li, Yuan; Zhao, Youjian

doi:10.1016/j.scib.2017.07.014

Cited by 32 publications

(13 citation statements)

References 11 publications

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“…Referring to the rock acoustic emission experiment results 30 , 31 , we explored the possible reasons. In the early stage of reservoir impoundment, with the increasing of the water level, some karst caves or abandoned mine caverns were flooded with water, resulting in frequent occurrences of collapse-related micro-earthquakes and small earthquakes 32 . These earthquakes could be categorized as instantaneous response of reservoir water impoundment and mainly clustered in the Badong area.…”

Section: Discussionmentioning

confidence: 99%

Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area

Zhang

Liao

Chen

et al. 2022

Sci Rep

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As the largest water conservancy and hydropower project in China, the Three Gorges Reservoir is a weak seismic activity area before impoundment, but the frequency of earthquakes increases significantly after impoundment. The spatial density scanning method was used to obtain the characteristics of spatio-temporal earthquake distribution in the reservoir area during loading and unloading processes. The results show that the frequencies of earthquakes during the loading and unloading processes were higher than that during the low-water-level operation period, which is well explained by the acoustic emission test results. The seismic b-value, fractal dimension D, and spatial correlation length SCL can be used together to indicate stress criticality. To analyze the impacts of reservoir water loading and unloading on seismicity in the reservoir area, time-scan analyses were performed on the b-value, D-value, and SCL of earthquakes near the Zigui segment and the Badong segment. Previous studies argued that the time-varying characteristics of b-values do not hold predictive significance for earthquakes in the M4.0–6.2 range. However, our study found that the time-varying characteristics of b-values are of predictive significance for earthquakes around M4.0. These seismic parameters decrease significantly before moderate earthquakes but at different rates in different regions.

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Section: Discussionmentioning

confidence: 99%

Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area

Zhang

Liao

Chen

et al. 2022

Sci Rep

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“…Since the Three Gorges reservoir area began to store water in 2003, the number of earthquakes in the Badong Reservoir of the Three Gorges Reservoir area has increased significantly. The occurrence of earthquakes is closely related to the water level, the water storage period [27], and the special geological structure of the Gaoqiao fault. This article generalized the Gaoqiao fault and strata into limestone samples with variable dip angle joints and soaked them for different lengths of time in advance to simulate the immersion effect of reservoir water on the strata in the reservoir area.…”

Section: Experiments Methodsmentioning

confidence: 99%

Analysis of Reservoir Seismic Law Based on Three-Dimensional Morphological Characteristics of Joint Surface Related to Listric Fault

et al. 2022

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Since water storage, earthquakes occurred in Badong County, Hubei Province, accounted for as much as one-third of the strong earthquakes in the Three Gorges Reservoir area. For example, the MS5.1 earthquake occurred in December 2013 near the Gaoqiao fault in Badong County. The earthquake time, magnitude, and location analysis showed that reservoir earthquakes in this area exhibited some characteristics, such as periodicity, migration, and deep extension. Based on the regional stratum lithology and structural characteristics, this paper designed a curved joint on a small scale to simulate the structural morphology of the Gaoqiao fault and carried out triaxial compression tests under different immersion times to analyze the morphological parameters of the joint surface. The results showed that topological parameters such as root mean square height (Sq), arithmetic average height (Sa), reverse load area ratio (Smc), and minimum autocorrelation length (Sal) could effectively characterize the degree of damage and deterioration of curved joints. The test privides a reference for analyzing the evolution law of the seismic characteristics of the reservoir.

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“…In fact, A10 absolute gravity observations reflect all gravity effects including TGR water impoundment and other surface processes around the site, after performed preprocessing (e.g., removal of effects such as solid earth tides, ocean tides, pole motion, normal field, and elevation correction at each site). For example, several unknown environmental gravity changes such as groundwater changes [5], seasonal changes in rainfall [4], and tectonic movements [13] are reflected in A10 results, and they can cause gravity changes of about 10 µGal [28]. Wang et al [5] showed that the interannual change of the equivalent groundwater height in the TGR area is about 1.6 m, which leads to the observed gravitational changes of up to tens of µGal.…”

Section: Other Influencesmentioning

confidence: 99%

“…Models established previously [9][10][11][12] were relatively simple, and the variation of river boundaries caused by the impoundment was not considered. Since the change of reservoir water level has great influence on the nearshore area, where numerous landslides and earthquakes occurred during the impoundment process of the TGR [13,14], developing more accurate models is helpful to further understand the water storage of the TGR in different impoundment periods and dynamically analyze its impacts in time.…”

Section: Introductionmentioning

confidence: 99%

Simulation of the Dynamic Water Storage and Its Gravitational Effect in the Head Region of Three Gorges Reservoir Using Imageries of Gaofen-1

Wang

Chen

et al. 2020

Remote Sensing

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The construction of a high-resolution dynamic water storage model, driven by the mass load of the huge water storage of the Three Gorges Reservoir (TGR), is the necessary basic data for accurately simulating changes in the geophysical field, e.g., gravity, crustal deformation, and stress. However, previously established models cannot meet the needs of accurately simulating the impoundment effects of TGR, because these models were simplified and approximated and did not consider the variation of river boundaries caused by water level changes. In this study, we combined high-resolution Gaofen-1 (GF-1) satellite imageries and real-time water level in front of the dam and extracted 31 river boundaries of the head region of TGR between the lowest (145 m) and the highest (175 m) impoundment stages based on the Normalized Differential Water Index (NDWI) and threshold segmentation from Otsu method. Developed dynamic water storage model based on higher-resolution GF-1 data can show the true river boundary changes more exactly, especially in local areas. Compared to the previous approximate models, the model that we constructed accurately depicts the boundary distribution information of the different impoundment stages. Moreover, we simulated TGR-induced gravitational effects based on the high-precision forward modeling of the dynamic water storage model (i.e., considering changes of dynamic water area and water level). The theoretical modelled results are consistent with in situ gravity measurements with the difference mainly within 10 μGal. Our results indicate that water storage variations of TGR mainly affect the gravity field response within 1000 m of the reservoir bank with its maximum amplitude up to several hundred μGal. The dynamic water storage and its simulation results of gravitational effects can effectively eliminate the impact of surface water load driven by the TGR under human control and greatly improve the signal-to-noise ratio of regional gravity observational data. Thus, this work will be beneficial in the application of geophysical and geodetic monitoring aimed to comprehensively track the local and regional geological structural stability, e.g., artificial reservoir induced earthquake and landslide.

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Influences of the Three Gorges Project on seismic activities in the reservoir area

Cited by 32 publications

References 11 publications

Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area

Variations in seismic parameters for the earthquakes during loading and unloading periods in the Three Gorges Reservoir area

Analysis of Reservoir Seismic Law Based on Three-Dimensional Morphological Characteristics of Joint Surface Related to Listric Fault

Simulation of the Dynamic Water Storage and Its Gravitational Effect in the Head Region of Three Gorges Reservoir Using Imageries of Gaofen-1

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