## 7 Conclusions  
In the retrospective analysis of the 2022 Luding \(M_{5}\) 6.8 earthquake, the event appeared inevitable based on the recurrence interval of strong earthquakes in the region. However, conventional surface \(b\)-value scanning prior to the earthquake did not detect any low-\(b\)-value anomalies at the epicenter. This lack of detection resulted in a prediction failure.  
To gain a deeper understanding of the \(b\)-value response before the earthquake and to assess the potential risk of strong earthquakes in the study area, we divided the earthquake catalog into two stages, from 2009 to 2014 and from 2015 to May 2022, and conducted segmented analysis. The AIC-constrained \(\Delta\)b (change in \(b\)-value) effectively revealed significant areas of \(b\)-value change, pointing out potential locations for future strong earthquakes. The \(\Delta\)b and \(\Delta\)AIC maps calculated for these two periods show that, under the condition of \(\Delta\)AIC \(\geq\) 2, there is a clear abnormal \(\Delta\)b area with a radius of about 50 km (\(\Delta\)b \(<\) \(-\)0.3) where the Luding \(M_{5}\) 6.8 earthquake occurred. This low-\(\Delta\)\(b\)-value anomaly area provides a spatial reference for the spatiotemporal evolution analysis of \(b\)-values.  
Furthermore, the \(b\)-value profiles derived from precise relocation show that the abnormal low-\(b\)-value area corresponds to the position, size, and shape of the mainshock's large-slip co-seismic zone, confirming that \(b\)-values can reveal areas of stress concentration on faults and that the aftershocks triggered by the mainshock filled the seismic gaps that existed before the earthquake. The continuous decline in \(b\)-values over the past decade reveals that the Luding \(M_{5}\) 6.8 earthquake source area has undergone a long-term stress-loading process, a pattern that is consistent with the \(b\)-value evolution before other major earthquakes and the fault-locking results inverted from GNSS data. Given that \(b\)-values are dynamic functions of time and space, one-dimensional analysis may lose multidimensional information; therefore, comprehensive analysis from multiple dimensions such as surface, cross-section, and time is crucial for accurately identifying \(b\)-value anomalies.  
Finally, the Coulomb failure stress change analysis shows that 10 historical significant earthquakes, including the Luding \(M_{5}\) 6.8 earthquake, have increased the stress along the Dadukou (DF) to Kangding (KD) section of the Xianshuie fault zone south of Ya'an (SM) and the northern section of the Anning River fault zone, with the stress magnitude exceeding the threshold of 0.01 MPa, indicating that these areas still have the potential for strong earthquakes.  
Conceptualization, F.L. and L.P.; methodology, F.L., L.P., X.R. and R.W.; software, F.L. and L.P.; validation, L.P., M.Z., X.R., D.W., R.W., W.W. and C.H.; formal analysis, L.P.; investigation, L.P., M.Z. and F.L.; resources, F.L.; data curation, M.Z., X.R., D.W., R.W., W.W. and C.H.; writing--original draft preparation, L.P.; writing--review and editing, M.Z. and F.L.; visualization, L.P.; supervision, F.L. All authors have read and agreed to the published version of the manuscript.  
This study was supported by the National Key R&D Program of China (No. 2021 YFC3000702-05) and the Spark Program of Earthquake Sciences (No. XH23033A).  
Not applicable.  
The data used in the article is currently unavailable online.  
We express our gratitude to Professor [PERSON] for his insightful discussions on \(b\)-value analysis, and to [PERSON] for providing the inversion results of co-seismic slip. Most of the figures in this paper have been produced using the GMT software (version 4.5) [86].  
The authors declare no conflicts of interest.