## 5 Conclusions and Outlook  
As important water conservancy projects, earth and rock dams play an important role in the development of the national economy of China. Dams in long-term operation exhibit local leakage and other hidden dangers after a long service period, making it necessary to detect the leakage import and export as well as the location of the channel for removal and reinforcement work to ensure dam safety. Geophysical exploration technology has been developed for leakage detection in earth and rock dams, and there is a preliminary framework for integrated geophysical exploration techniques. However, the research focus has been on the use of a combination of methods. A future direction should be the study of the internal laws of geophysical exploration data and a data fusion technology for integrated geophysical exploration. The theoretical model of integrated geophysical exploration information fusion technology was proposed based on data fusion and joint inversion methods. The main research contents and conclusions are as follows. (1) The main problem in geophysical detection technology is that the use of a single geophysical exploration method produces multiple solutions. Despite the wide variety of physical exploration techniques, each technique has its own limitations and different adaptability depending on the detection environment. For example, geophysical exploration techniques based on apparent resistivity mostly require drilling holes to embed electrodes and have boundary effects. A single technique alone cannot quickly and accurately detect leakage channels in earth and rock dams. 2. Most of the commonly used integrated geophysical exploration techniques are based on electrical detection, supplemented by seismic and pseudo-random flow field methods for integrated detection, with a high resolution and accuracy. However, each geophysical exploration method has strict application conditions. Electrical-based detection may be difficult to apply under some geological conditions involving complex dikes, and there is a need to explore a combination of methods to adapt to various detection conditions. 3. The integrated geophysical exploration techniques should complement each technology, and different detection methods must be chosen based on the specific conditions of dike hazards. By constructing a quantitative evaluation model for dike hazards, multiple geological information can be provided to alleviate the phenomenon of multiple solutions, improve the data interpretation accuracy, and better integrate the detection and analysis of hazards encountered in earth and rock dams. However, the current integrated geophysical exploration techniques still stay at the level of multi-method combination, which cannot meet the requirements of information richness and data reliability. Research on the joint inversion of multi-source physical fields and data fusion is the development trend in the future. 4. Data fusion and joint inversion presuppose the existence of certain interrelationships between different geophysical parameters and some complementarity at different scales. The connection between different physical parameters of the soil body is crucial. The theoretical model of integrated geophysical exploration information fusion technology based on data fusion and joint inversion was proposed, and its basic principle and processing flow were described. Although it is still immature, the integrated geophysical exploration information fusion technology based on joint interpretation of multi-physical fields is an important research direction in the future. 5. By constructing the theoretical model for data fusion and joint inversion of multiple physical fields, different aspects of the same geophysical model can be combined to form a geologic model that is closer to the real one. The main process of the theoretical model is to derive the expression of multi-physical fields joint inversion, and then carry out spatial alignment and standardization of the data information obtained from the inversion.