# Optimization Method for Improving Efficiency of Thermal Field Reconstruction in Concrete Dam
## 5 Conclusions  
This study presented an optimization method for improving the efficiency of thermal field reconstruction in concrete dams, comprising three key components: evaluation and selection of interpolation algorithms, optimization of monitoring point numbers, and analysis of monitoring position impacts. While ensuring accuracy, this method significantly reduced the computational load and enabled real-time, precise thermal field reconstruction based on the construction schedule. The thermal field obtained was used to guide the strategy of the intelligent cooling control system and verified at the WDD dam. The conclusions are as follows:  
1. An optimization method for improving the efficiency of thermal field reconstruction was proposed. The applicability of Kriging, Natural Neighbor, and Inverse Distance Weighting interpolation algorithms is evaluated quantitatively based on the actual optical fiber layout scheme. The Kriging is the optimal one when the optical fiber is embedded in a \"Z shape\". The reconstructed thermal field was in accordance with the point measurements by digital thermometers, and the mean absolute error and root mean squared error were 0.75 and 0.96, respectively.
2. The impact of the number and position of monitoring points on thermal field reconstruction was analyzed. Sensitivity analysis indicated that with a \"Z-shaped\" optical fiber and the Kriging interpolation algorithm, reducing the number of temperature-monitoring points lowers calculation complexity and improves response speed while maintaining accuracy (error < 1 \({}^{\circ}\)C). Monitoring points near the transverse joint had a greater effect on reconstruction accuracy than those at the center of the concrete block.
3. The method was combined with the intelligent cooling control system, and the effectiveness was verified in the 7# dam monolith of the WDD dam. The maximum temperature of the concrete block is 25.4 \({}^{\circ}\)C (meeting the requirement of not exceeding 27 \({}^{\circ}\)C). Compared with the dam monolith without this method, the 7# dam monolith has a smoother temperature curve and a cooling rate of 0.4 \({}^{\circ}\)C/day (meeting the requirement of 0.3-0.5 \({}^{\circ}\)C/day).  
Figure 17: Effectiveness evaluation of engineering application.  
**Author Contributions:** Y.X.: investigation, writing--original draft preparation, and validation; P.L.: investigation, writing--review and editing, and supervision; H.P.: visualization and data curation; Z.L.: writing--review and editing and visualization; Y.L.: supervision; Y.Q.: data curation; Z.Y.: validation. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by the China Three Gorges Corporation Research Program (WDD/0578); the Snohydroo Bureau 11 Co., Ltd.'s Management Department of the Julius Nyerere Hydropower Station Project in the United Republic of Tanzania (No. SHC-JNHPP-JSFW-01-18012022); and China Huaneng Group Co., Ltd.'s Research Program (HNKJ23-H4 HY2023/D14).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The data presented in this study are available on request from the corresponding author. The data are not publicly available due to privacy.  
**Conflicts of Interest:** Author [PERSON] was employed by the company Yalong River Hydropower Development Company, Ltd., author [PERSON] was employed by the company Sinohydro Bureau 11 Co., Ltd., author [PERSON] was employed by the company China Three Gorges Corporation, and author [PERSON] was employed by the company Huaneng Lancang River Hydropower Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The funder had no role in the design of the study in the collection, analysis, or interpretation of data, in the writing of the manuscript, or in the decision to publish the results.