## 3 Integrated Geophysical Exploration Techniques for Earth and Rock Dams
### Data Fusion Analysis System for GIS-Based Integrated Geophysical Exploration
Figure 11 shows the functional modules of the generalized GIS system. Integrated Geophysical Exploration Information Fusion Technology Based on Data Fusion and Joint Interpretation  
Integrated geophysical exploration techniques have been widely used in the detection of leakage hazards in earth and rock dams, and many research results have been achieved. However, the following deficiencies still exist. * There are limitations in the application process of the technology, and the combination form is relatively single. The commonly used combinations of techniques include the electrical resistivity tomography method and sonar method, land sonar method and electric method, electromagnetic method, and pseudo-random flow field method, shallow seismic reflection method and sonar method, surface wave method and electric method, and other combinations. These are mostly based on the extension of the electrical-based geophysical exploration technology. * The integrated geophysical exploration techniques optimizes the problem of interpreting geophysical exploration data, and to some extent reduces the multi-interpretation situation in the application of a single geophysical exploration method. However, there is no real integration of geophysical exploration techniques. The current integrated geophysical exploration techniques applied to the detection of leakage potentials in earth and rock dams are mainly at the level of combining different methods, which is in essence an optimization of experience. The data source of  
Figure 11: Generalized GIS system functional modules. integrated geophysical exploration techniques is still a single physical field, which cannot meet the requirements of data information richness, accuracy, and reliability. * In the existing technological framework, leakage hazards in earth and rock dams are detected and dealt with late. By the time leakage hazards are detected, the leakage risk has been developing inside the dam for a long time. The detection and risk control of leakage hazards are in a reactive state. With the passage of time, the location of hidden hazards may change, and the exploration data can only reflect the state at the time of exploration. In the long run, the key to ensuring the long-term stable operation of earth and rock dams is to establish a time series of physical field data inside the dam and to develop the hidden hazard monitoring technology based on integrated geophysical exploration techniques. The integrated geophysical exploration techniques cannot be limited to the combination of methods but require conducting a comprehensive analysis of geophysical exploration data, engineering geological conditions, and hydrogeological conditions. Moreover, fusion and inversion methods for multiple physical prospecting data should be studied, and a unified inversion expression for multiple geophysical parameters should be established so that integrated geophysical exploration can be extended to the study of the internal laws of multiple data. Multisource heterogeneous data fusion technology [104] provides ideas in this direction, which has developed from sensor fusion to data fusion and then to image fusion. It has now become a relatively mature technology. Based on the data fusion method, multiple geophysical exploration data are integrated into the same coordinate system, a mathematical physical algorithm is used to fuse and reconstruct them, and a unified inversion expression for multiple geophysical parameters is established for joint inversion. The inversion results are analyzed and compared, and if the predicted results are consistent with the actual geological conditions, they have a greater practical application value.