| The topographical features and protection methods of the 500kV submarine cable in Qiongzhou Strait are briefly introduced, so as the basic principles of cable routing survey with side-scanning sonar and multi-beam, in which the principle of side-scanning sonar in the submarine cable bareness and suspending detection is highlighted. It is analyzed in detail about the recent survey data about 500kV submarine cable of Hainan Interconnection Project. For the side-scanning sonar geomorphology survey results, the key analysis is focusing on the bareness of the submarine cable, the protection status of the rock-dumping, the cast iron, and the anomalies around. Obviously, abnormalities such as bareness, collapse of the rock-dumping, as well as foreign body around, could be detected correctly. For multi-beam terrain detection results, the overall topographical condition of the submarine cable routing area and the status of the whole rock-dumping are analyzed. The different DEM (Digital Elevation Model) is produced by Kriging interpolation method, then the terrain erosion and deposition changes in the routing area are discussed from he macroscopic and microscopic. The stability of the sand wave is also analyzed. And It is proved that it is scoured extremely seriously for the terrain in some areas of the cable routing, which could easily cause the submarine cable to be exposed and suspended. So it is quite necessary to pay attention early and take anti-scouring measures. |
