## 6 Conclusions  
To investigate the activity of the Weihe Fault, three-dimensional ground deformation rates were estimated by the integration of GNSS and InSAR observations, and the vertical component was evaluated by using the dependently observed leveling data. Then, the tectonic vertical deformation was decomposed from the integrated vertical deformation field by wavelet analysis. Finally, the improved dip-slip model was adopted to inverse the slip rate, locking depth, and dip changes along the Weihe fault. Based on this study, the following conclusions are made:  
1. The high-spatial-resolution vertical deformation rate of the Weihe Fault was successfully estimated through integrating InSAR and GNSS observations. The GNSS was sensitive to the horizontal deformation, while InSAR was sensitive to the vertical deformation. Based on this fact, the three-dimensional deformation rates were produced by integrating GNSS and InSAR datasets. The standard deviation between the leveling and integrated vertical deformation rate was 1.69 mm/yr, and the mean value was 0.6 mm/yr, demonstrating the reliability of the proposed method.
2. The earthquake risk of the eastern section of the Weihe Fault should attract attention. The long-wavelength tectonic movement and small-scale human-activities-induced deformation were decomposed by wavelet analyses. The expected tectonic velocity gradient was found along the Weihe Fault, implying stress accumulation and posing a risk of moderate to strong earthquakes in the Weihe Fault. Taking into account the higher locking depth and historical earthquake record, attention should be paid to the earthquake risk of the eastern section of the Weihe Fault.  
Although the activity of the Weihe Fault was investigated in this study, there are still two limitations. The first concerns the limited SAR images. A total of 26 ascending Sentinel-1A images spanning from 2015 to 2019 were utilized in this case. These datasets may be enough for estimating the LOS deformation rate. However, they are not enough to obtain the two- or three-dimensional time series deformation. The second limitation concerns the time series deformation. Besides spatial deformation variation, temporal deformation variation is also an important aspect of fault investigation. However, the time series deformation in the Weihe Fault was not estimated in this study due to the limited datasets. Thus, these two limitations should be addressed in the future.  
Conceptualization, Q.-H.T. and W.-T.Z.; methodology, Q.-H.T., W.-T.Z. and W.Z.; software, Q.-H.T., W.-T.Z. and W.Z.; validation, Q.-H.T. and W.-T.Z.; formal analysis, Q.-H.T., W.-T.Z. and W.Z.; investigation, W.-T.Z. and W.Z.; resources, Q.-H.T. and W.-T.Z.; data curation, Q.-H.T., W.-T.Z. and W.Z.; writing--original draft preparation, Q.-H.T.; writing--review and editing, W.-T.Z. and W.Z.; visualization, Q.-H.T., W.-T.Z. and W.Z.; supervision, W.Z.; project administration, W.-T.Z.; funding acquisition, Q.-H.T. and W.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Natural Science Foundation of China (NSFC) (Nos. 42074040, 42004048), Natural Science Basic Research Plan in Shaanxi Province of China (2023-JC-JQ-24), Key Research and Development Program of Shaanxi (No. 2021 ZDLSF06-02), Innovative Talents Promotion Plan of Shaanxi Province (Grant No. 2022 KJOX-22), and Fundamental Research Funds for the Central Universities of CHD (Nos: 300102262902, 300102263401, 300102262512).  
Not applicable.  
Several figures were prepared using Generic Mapping Tools software. We are grateful to the anonymous reviewers for their constructive comments that improved this manuscript.  
The authors declare no conflict of interest.