## 5 Conclusions  
Under the condition of complex reservoir water level at the initial stage of operation, the deformation of an ultra-high arch dam varies greatly between different parts. Because the traditional deformation analysis method is difficult to apply to the deformation law analysis of an ultra-high arch dam, the clustering and zoning model based on the panel data theory improved by the CRITIC method and CSP index is constructed in this paper. Additionally, the temporal and spatial characteristics of the deformation measurement points of an ultra-high arch dam are comprehensively considered in this model. It not only reflects the spatial correlation characteristics of different measuring points but also characterizes the dynamic change characteristics of deformation measuring points. The distance indexes of the three-panel data defined can represent the space-time matrix of dam body deformation of the ultra-high arch dam. The dam deformation-sensitive area is in the middle and lower part of the dam at the initial stage and gradually moves to the middle with the increase of operation time. Therefore, the middle area is an important object of dam displacement monitoring. Meanwhile, the monitoring points with more changes in dam deformation zoning are also concentrated in the middle of the dam. The analysis of the deformation characteristics of the dam body conforms to the deformation law of the ultra-high arch dam. The clustering results can make the temporal and spatial characteristics and water level characteristics of dam deformation more efficiently analyzed. The case study shows that good dynamic clustering and zoning results under different water level conditions of an ultra-high arch dam are obtained by this model and it has strong adaptability and reliability. On this basis, the interference and biased judgment caused by different measuring points can be eliminated when monitoring, predicting, and analyzing the representative measuring points of the same type. Moreover, the workload of analysis is greatly reduced, and it could make the management personnel more efficient at mastering the operation behavior of the dam in time. The model can solve the problem of analyzing the deformation field of a statically indeterminate arch dam and can also be extended to the study of temperature field, stress field, and gravity of a dam. With the increase of dam operation time, the law of dam deformation under normal operating conditions will also change. Because only the normal water level operation condition of the ultra-high arch dam in the early service stage is considered in this paper, the research of the long operation time can be carried out according to the operation characteristics in the actual project. It would be also advisable that comparative analyses such as observational methods, numerical back-analyses, and centrifuge modeling techniques be used and discussed to demonstrate reliability and facilitate cross-verification of the work [45; 46]. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Coefficient** & **PL11-4** & **PL11-5** & **PL13-4** & **PL13-5** & **PL16-4** & **PL16-5** \\ \hline Multi-correlation & 0.998 & 0.982 & 0.983 & 0.978 & 0.971 & 0.969 \\ coefficient \(R\) & 0.655 & 1.509 & 2.323 & 1.908 & 2.697 & 2.122 \\ Mean relative error (predication) & 1.86\% & 5.81\% & 2.98\% & 3.96\% & 3.79\% & 3.66\% \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Model accuracy of representative key monitoring positions. **Author Contributions:** Formal analysis, Y.L. and D.Z. ; Methodology, D.Z. and Y.L. ; Writing-original draft, Y.L. and X.W. ; Writing-review & editing, Y.L., C.G. and T.K. ; Supervision, D.Z. and C.G., Data curation, E.C. and J.M. All authors have read and agreed to the published version of the manuscript. This research was funded by the National Key R&D Program of China (2018 YFC1508603, 2018 YFC0407104, 2018 YFC0407101, 2016 YFC0401601), National Natural Science Foundation of China (Grant Nos.